Search Results: Tonya McKay
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Andre Walker, who has won numerous Emmys for his work on the Oprah Winfrey Show, has worked out this hair classification system.
Many of you have seen it referenced on the discussion boards. For your convenience, we’ve excerpted it here, and added some of our own recommendations and tips.
For more information about the hair types and how to make the best of each type, check out his book, Andre Talks Hair.
2a: Joss Stone
2b: Sandra Oh
Type 2: Wavy hair
Mousses and gels work best for type 2s. Try our Type 2 Cocktail —
Curltini, or a combination of these:
- Jessicurl Rockin’ Ringlets
- AG Foam Weightless Volumizer
- Curly Hair Solutions Curl Keeper
- Curlisto Bio-Gel Mousse
- AG HairCosmetics Mousse Gel
- John Masters Organics Sweet Orange & Silk Protein Styling Gel
- Batia & Aleeza Bio-Herbal Mineral Styling Gel
- Curlisto Structura Lotion
- Curlisto Control I Gel
- DevaCurl Angell
- Curl Junkie Curl Fuel
- MOP Glisten High Shine Pomade
- MOP C-Curl Defining Cream
- Innersense Quiet Calm Curl Control
Click here for photos of 2A and 2B hair.
Type 2 hair falls into the great divide between Type 1, straight hair, and Type 3, curly hair. A relatively unusual type, wavy hair tends to be coarse, with a definite "S" pattern to it. By that I mean the wave forms throughout the hair in the shape of the letter "S". Your hair is wavy, or Type 2, if it curves in the "S" shape while laying flat against the scalp, instead of standing away from the head the way curly hair does. Supermodel Yasmeen Ghauri, actress/model Isabella Rosellini and actress Jennifer Aniston of Friends (the one who sparked a craze for the ubiquitous "Friends haircut" of the mid-1990s”> are all Type 2s. Type 2s are often confused with Type 3s because it is easy to get curly hair to lay flat and look wavy. But don’t be fooled: you can’t get Type 2 hair to look like Type 3 without a lot of work. Why? The hallmark of wavy hair is that it sticks close to the head: even if you cut it in layers, it won’t bounce up. There are three Type 2 subtypes: A, fine and thin; B, medium-textured; and C, thick and coarse. Type 2A is very easy to handle, pliantly blowing out into a straighter style or taking on curlier looks with relative ease. Types 2B and 2C are a little more resistant to styling and have a tendency to frizz
Tips: This hair type needs lighter products that enhance curls. Let hair air dry or use a diffuser. Use duckbill clips on the crown of your head to lift top curls as needed. Once your curls are dry, rub a little pomade into the palm of your hands and smooth over your hair. Please do not use a brush or comb on your dry curls. Sleeping on a satin pillowcase is recommended to reduce tangles.
3a: Nicole Kidman
3b: Juliana Margulies
3c: Rachel True
Type 3: Curly hair
For type 3a hair, try gels and styling creams. Consider our Type 3a Curly Cocktail, Cosmocurlitan, or a combination of these:
- Curlisto Control II
- AG Recoil
- Batia & Aleeza Herbal Mineral Sculpting Gel
- Innersense Inner Peace Whipped Creme Texturizer
- Innersense Quiet Calm Curl Control
Click here for photos of 3A.
For Type 3b hair, gels, styling creams work best. Curl & Tonic is our Curly Cocktail for 3b hair. Or:
- Curlisto Structura Lotion
- Curlisto Control Gel II
- AG Hair Cosmetics Re:coil
- Curly Hair Solutions Curl Keeper
- Cutler Curling Cream
- Curly Hair Solutions Tweek
- DevaCare Arc Angell
Click here for photos of 3b.
We recommend styling creams and butters for type 3C. In addition to our Type 3c Curly Cocktail, Curlarita, some of our picks are:
- HPO Curly Conditioning Styling Pudding
- Curl Junkie CoffeeCoco Curl Creme
- Miss Jessie’s Curly Meringue
- Oyin Handmade Whipped Pudding
- MYHoneyChild Type3/Type4 Combo Hair Creme
- Kinky-Curly Curling Custard
- Blended Beauty Happy Nappy Styles/a>
Click here for photos of 3c.
With curly hair, there is a definite loopy "S" pattern. Pluck out a hair, stretch it out. Notice the curvy lines. Looks like s stretched-out Slinky, doesn’t it? Most people think curly hair is coarse, but actually it is usually baby soft and very fine in texture – there’s just a lot of it. Because the cuticle layers don’t like as flat, curly hair isn’t as shiny as straight or wavy hair. The hair doesn’t have a very smooth surface, so light doesn’t reflect off of it as much. When curly hair is wet, is usually straightens out. As it dries, it absorbs the water and contracts to its curliest state. Those of you with Type 3 hair know all too well that humidity makes curly hair even curlier, or even frizzier.
If you’re a Type 3, your hair has a lot of body and is easily styled in its natural state, or it can be easily straightened with a blow-dryer into a smoother style. Healthy Type 3 hair is shiny, with soft, smooth curls and strong elasticity. The curls are well-defined and springy: pull out a strand of hair and stretch it; it won’t snap in two. Damaged Type 3 hair is usually frizzy, dull, hard and dry to the touch, with fuzzy, ill-defined curls.
There are two subtypes of curly hair. Type 3A, hair that is very loosely curled like Julia Robert’s or Susan Sarandon’s is usually very shiny with big curls. The shorter the hair, the straighter it gets. The longer the hair the more defined the curl. Type 3B, on the other hand, is hair with a medium amount of curl, ranging from bouncy ringlets – think of Shirley Temple – to tight corkscrews – think of actress Cree Summer of television’s Sweet Justice of jazz singer Cleo Laine. It’s not unusual to find both subtypes coexisting on the same head. In fact, curly hair usually consists of a combination of textures, with the crown being the curliest part.
Tips for 3a hair: This hair type needs light moisture and products that define the curls. Let hair air dry or use a diffuser. Use duckbill clips at the crown of your head to lift top curls as needed. Once curls are dry, rub a little pomade into the palm of your hands and smooth over your hair. Please do not use a brush or comb on your dry curls. Sleeping on a satin pillowcase is recommended to reduce tangles.
Tips for 3b hair : This hair type needs extra moisture and products that define curls and fight frizz. Let hair air dry or use a diffuser. Use duckbill clips at the crown of your head to lift top curls as needed. Once curls are dry, rub a little pomade into the palm of your hands and smooth over your hair. Please do not brush or comb your dry curls. Sleeping on a satin pillowcase is recommended to reduce tangles.
Addendum:
Naturallycurly.com readers have suggested a third Type 3 subtype: 3c.Type 3C, is hair with tight curls in corkscrews. The curls can be either kinky, or very tightly curled, with lots and lots of strands densely packed together. Some people refer to this as "big hair." Getting this type of hair to blowdry straight is more challenging than for 3A or 3B, but it usually can be done. This includes those with very tight curls but finer hair, as well as coarser hair. 3C has really really tight curls, like pencil or straw circumference. 3B is like sidewalk chalk or salt shaker circumference, and 4A is like coffee stirrer circumference.
Tips: This hair type needs extra moisture and tender-loving care because it can be fragile. Let the hair air dry and do not use a brush or comb. To refresh bed head or fight fuzzy hair line, use a moisturizing hairdress like Miss Jessie’s Curly Buttercreme or Jane Carter Solution Nourish & Shine.
4a: Nadia Turner
4b: Erykah Badu
Type 4: Kinky hair
- Blended Beauty Curl Styling Butter
- Jane Carter Nourish & Shine
- Mixed Chicks Leave-in Conditioner
- Long Lovely Locks Coco Light
- MYHoneyChild Honey Hair Creme
- Kinky-Curly Curling Custard
- MYHoneyChild Organic Styling Creme
- Jane Carter Solution Twist & Lock
- MYHoneyChild Twist Out Creme
- Miss Jessie’s Curly Pudding
- Oyin Handmade Whipped Pudding
Click here for photos of 4a and 4b.
If your hair falls into the Type 4 category, then it is kinky, or very tightly curled. Generally, Type 4 hair is very wiry, very tightly coiled and very, very fragile. Like Type 3 hair, Type 4 hair appears to be coarse, but it is actually quite fine, with lots and lots of this strands densely packed together. Healthy Type 4 hair won’t shine, but it will have sheen. It will be soft to the touch and will pass the strand test with ease. It will feel more silky than it will look shiny. Oprah, Whoopi Goldberg and the actress Angela Bassett are all Type 4s.
Type 4 hairs looks tough and durable, but looks can be deceiving. If you have Type 4 hair, you already know that it is the most fragile hair around. Why? Type 4 hair has fewer cuticle layers than any other hair type, which means that it has less natural protection from the damage you inflict by combing, brushing, curling, blow-drying and straightening it. The more cuticle layers in a single strand of hair, the more protection it has from damage. Each time you damage your hair — fire up the curling iron, fry it with chemicals – you break down a cuticle layer, robbing your hair of much-needed moisture. I cannot emphasize this enough. It’s like taking a wire and bending it again and again. Eventually, it’s going to snap and break.
Many women with Type 4 hair rely on chemical relaxers to make hair easier to control. In its natural states, sometimes Type 4 hair doesn’t grow very long because every time you comb it, it breaks. (Of course, if you have dreadlocks and never comb them or keep them braided, your hair can and does grow quite long.”>
There are two subtypes of Type 4 hair: Type 4A, tightly coiled hair that, when stretched, has an "S" pattern, much like curly hair; and Type 4B, which has a "Z" pattern, less of a defined curl pattern (instead of curling or coiling, the hair bends in sharp angles like the letter "Z"”>. Type 4A tends to have more moisture than Type 4B, which will have a wiry texture. But what if your hair has been chemically straightened? How can you tell which subtype you belong to if your hair is relaxed? You’ll need at least one inch of new growth to tell. Pull at the roots. If you can see a definite curl pattern, then it’s an A, if not, then it’s a B.
Addendum:
NaturallyCurly.com type 4 readers have found the above description limiting, and somewhat misleading. We offer the following addendum:Type 4 hair can range from fine/thin to wiry/coarse strand texture. Generally, this hair is densely packed to give the appearance of very thick but fragile hair. 4a hair has a clearly visible curl and wave pattern that ranges from pen size curls to pen spring size coils. 4b hair has a tighter wave pattern and kinks of various size. This texture does not exhibit the shine or silkiness of looser type curls, but instead has sheen, and a soft, almost cotton-like feel. As with other types of curly hair, showing the true length can be an extra challenge, as the hair may grow “up” or “out” before starting to hang down. In its unlocked/unbraided state, type 4 hair is known to shrink up to 75% of the actual hair length. With the proper care and technique, type 4 hair is indeed resilient, manageable, durable, growable and easy to control.
Type 1: Straight Hair
For hair with no texture or curl patterns, we suggest:
- Jessicurl Hair Cleansing Cream
- Jessicurl Aloeba
- John Masters Evening Primrose Shampoo
- John Masters Oranics Lavender & Avocado Intensive Conditioner
- Elucence Moisture Benefits Shampoo
- Elucence Moisture Balancing Conditioner
- Max Green Alchemy Scalp Rescue Shampoo
- Max Green Alchemy Scalp Rescue Conditioner
- Innersense Pure Inspiration Daily Conditioner
- nnersense Pure Inspiration Hair Bath
We get a lot of questions about whether or not castor oil is okay for curly hair. Another related question is what PEG-30 castor oil is (or any other PEG-#”>, and whether it is compatible with curly hair, especially for those on shampoo-free or shampoo-minimal routines.
What is Castor Oil?
Castor oil is a plant-derived oil obtained from the seeds (castor beans”> of the plant Ricinus communis. It is a mixture of triglycerides composed of several different fatty acids. It is a mono-unsaturated fat, with a one double carbon-carbon bond per arm of the triglyceride. The major component is ricinoleic acid, with the remainder of the oil being comprised of oleic, linoleic, stearic, and several other organic acids.
What Does it do?
Castor oil is known for its excellent emollient and lubricant properties, as well as for its film-forming capabilities that make it useful in skin creams and in some hair styling products. The chemical structure of castor oil also helps it act as a humectant, so that it attracts water to the hair and skin. It has a relatively high viscosity, enabling a formulator to use it to thicken products, which can impart a more luxurious sensation for the consumer.
One drawback of castor oil is that the film it forms has been found to sometimes feel a bit tacky or sticky to the touch. Also, if used on hair in its natural state, the film it forms on hair is not water soluble, which can be a problem for those who use low- or no-shampoo routines. This film can also have a tendency to attract other oils and dirt if not removed regularly, so it would be necessary to use a reasonably strong shampoo when you’re using a castor oil product.
The chemistry of the major component of castor oil (ricinoleic acid”> is fairly unique among triglycerides. This unusual fatty acid possesses hydroxyl (-OH”> groups on each arm of the molecule, which make it more polar than other fatty acids. The hydroxyl group also facilitates chemical modification of the triglyceride, allowing creation of derivatives with desired properties for many different applications.Molecular structure of PEG-modified castor oil surfactants. Surfactol 318 and 365 are trade names for products with different PEG amounts.
Castor Oil in Hair Care Products
One such derivative, frequently seen in hair-care products, is PEG-x castor oil (x = number of ethylene glycol units”>. Ricinoleic acid (castor oil”> reacted with ethylene oxide produces a polyethylene glycol modified castor oil, with the number of ethylene glycol units varying from as few as two to more than100. The ethylene glycol portion of the molecule is hydrophilic (water soluble”>. This hydrophilic portion, coupled with the hydrophobic oil portion of the triglyceride, creates a nonionic surfactant molecule. These surfactant molecules can be used by formulators as excellent emulsifiers of conditioning agents, stabilizers, and thickeners.
The ethylene glycol groups enhance the humectant properties of the castor oil molecule, which can be of help to curly hair in moderate climates. (Read this article for more information on humectants and curly hair.”> PEG-castor oil molecules range from dispersible in aqueous solutions to completely water soluble, depending upon the PEG-#. When the PEG-# exceeds approximately 35, the molecule becomes completely water soluble. This is great for those on no- or low-shampoo regimens because there is little fear of buildup.
Hydrogenated castor oil, also called castor wax, is the result of a reaction with hydrogen in the presence of a catalyst in order to remove the single double bond present on each arm of the triglyceride. This is done to make the molecule less susceptible to oxidation and spoilage. The result is a hard waxy substance that is highly insoluble in water. This wax can still be reacted with ethylene glycol and yields compounds with much the same properties as the non-hydrogenated varieties of PEG-x castor oil.
Benefits and Drawbacks
Results obtained by using products containing castor oil and its derivatives will really depend upon a consumer’s hair type and normal routine of hair care, as well as the overall formula of the product being used. Some have reported that it weighed their hair down or made it greasy, and others have had problems with frizziness when using PEG-modified versions of the oil. But some also love the results they get from products with this ingredient
As always, it is worth experimenting with a new product, especially if you have some knowledge about the ingredient and how it might impact your hair.
Q: What is the difference between lanolin and lanolin oil, and how might each affect my hair?
A: Lanolin is a very greasy material produced by the sebaceous glands of sheep. It acts as an excellent moisturizer for skin and hair and also functions as an effective water barrier. A byproduct of wool-gathering and refining, it is easily obtained and is a renewable resource. For this reason, lanolin has been used as an emollient in hand and body creams and hair products for many centuries. Many consider animal oils to be more compatible with human skin and hair than vegetable or mineral oils.
Lanolin is a mixture of fatty acids, wax esters, and a complex mixture of other organic compounds. It is classified as a wax (as opposed to an oil or fat”>, and is a solid at room temperature (melting point: 100-107°F”>. In its natural state, lanolin contains about 25-30% water by weight. When applied to skin or hair, it is very effective at penetrating the surface and enhancing moisture retention. Lanolin is also beneficial because it continues to absorb moisture from the air, and can thus act as a humectant for the skin or hair.
Lanolin is sometimes considered to be too thick and greasy to be used liberally on curly hair, as it can really weigh down the curls and create frizz, but this is really dependent upon the degree of curl. A person with wavy hair or only slightly curly hair may find it to be too much for them, while a person with extremely curly hair would find it very beneficial to their hair. Its unique and complex chemical composition should make it very easily removed from the hair with a gentle shampoo or conditioner wash.
Lanolin oil is a derivative of lanolin and is a liquid at room and body temperature. In this liquid state, lanolin oil is much easier to use in the manufacturing processes because it does not require temperatures to be elevated above 100°F. This saves time and money for the manufacturer as well as (presumably”> the consumer. Lanolin oil should also be a somewhat lighter moisturizer than regular lanolin wax, but with many of the same beneficial properties.
In summary, lanolin is an excellent conditioning agent for both skin and hair, but consideration of hair type should be used when selecting products for hair. As a deep conditioning agent, used infrequently, probably all curly-haired people would benefit from a product containing lanolin (in the wax form”>. People with extremely curly hair (such as those with 3c, and the 4’s“> can most likely use lanolin-containing products in their regular regime and enjoy soft, smooth hair without losing curl or gaining frizz. Those with wavy or slightly curly hair (such as 2a, 2b, 3a, and 3b type”> may find products containing lanolin oil to have excellent performance. But they may not be able to routinely use products containing significant amounts of lanolin wax because they may be too heavy.
Q: Is cetrimonium chloride a silicone? If not, what is it and what is its purpose in my hair-care product? When this ingredient appears on a label with amodimethicone and trideceth-12, does this mean the amodimethicone is now water soluble?
A: This question comes up frequently, because something about that name seems similar to some of the names seen for different silicones. The actual chemical name of this ingredient is cetyl (hexadecyl, more properly”> trimethyl-ammonium chloride (CTAC”>. It is definitely not a silicone or silicone derivative. It is a quaternized ammonium molecule (frequently abbreviated as quat”>, and it has a single positive charge at the head group. CTAC belongs to a family of molecules known as cationic surfactants, which can be used as emulsifying or conditioning agents. Some other commonly used molecules in this group are cetrimonium bromide (CTAB”>, behentrimonium chloride, and quaternium-15.
Their conditioning capabilities are due to electrostatic attraction between the positively-charged head group of the cationic surfactant and negative charges that occur along the surface of hair strands. This electrostatic attraction causes cationic surfactant molecules to deposit themselves onto the cuticle of the hair, which helps create a smoother surface and also reduces static-induced flyaway hair that can occur in cold, dry weather.
As emulsifying agents, cationic surfactants can be used to aid the formulator in getting many different types of hydrophobic (water fearing”> oils to go into solution. They are frequently used in mixtures with a nonionic surfactant. These mixtures can form large micelles, or emulsion droplets. Oil-in-water micelles are clusters of molecules with an oily center or core, made up of the non-polar tails of the surfactants, surrounded by an outer shell formed by the polar portion of the molecule. The polar portion of the shell is water soluble, and the interior of the micelle can encapsulate a water-insoluble oil, such as silicone. This complex particle can then be dispersed into an aqueous solution, such as a hair conditioner or shampoo formula. (There are also micelles known as water-in-oil micelles, where the polar groups are in the interior portion of the micelle, and the oil soluble portions are on the exterior of the micelle.”>
A common example of such a mixture is cetrimonium chloride, trideceth-12 (the nonionic surfactant”>, and amodimethicone. The two surfactants surround the amodimethicone, which is water insoluble. The resultant aggregate of all three components is dispersible in water, due to the hydrophilic nature of the micelle shell. However, it should be noted that this mixture is dispersible in water for the purposes of ease of manufacture of the shampoo or conditioner. The mixture does not remain intact during product use, and it should not be inferred that having those three components in a formula renders the amodimethicone water soluble once it is applied to the hair.
Once the actual product is applied to wet hair in the shower, the aggregate is broken up and each component does what it would ordinarily do. The nonionic surfactant is washed away when the hair is rinsed; the positively-charged amodimethicone and the cationic surfactant are each deposited (separately”> onto the surface of the hair. The amodimethicone is left alone, and is thus in its water insoluble state, and it dries to form a film, which imparts sheen and silkiness to the hair. Despite the fact that it is water insoluble, amodimethicone has been found to resist the formation of build up, and most users have reported excellent results with products containing amodimethicone, even if they use a shampoo-free regimen.
Because of the high interest in silicones, we periodically take a closer look at some of the many silicones found in hair-care products. This month we’ll be looking at Cyclomethicone.
Cyclomethicone is the INCI (International Nomenclature for Cosmetic Ingredients”> name for a category of silicones used in many personal-care products. Cyclopentsiloxane, cyclotetrasiloxane, and cyclohexasiloxane are also designations for the same class of molecules. In contrast with linear silicones such as dimethicone, these molecules have a cyclic, or ring-like architecture comprised of only four to six repeat units of the dialkyl siloxane group. These are much smaller molecules than the polymeric silicones, such as polydimethyl siloxane (dimethicone”> which may have hundreds of thousands of siloxane repeat units.
Cyclic silicones (or siloxanes”> are frequently used as solvents for fragrance and essential oils, and also as carrier fluids for higher molecular weight silicones such as dimethicone and dimethiconol. This aids the formulator in preparing her final product because she can prepare her oil phase by combining cyclomethicone and the silicone and/or fragrance oil and add her emulsifier, prior to addition of the entire oil phase to the aqueous phase.
Cyclomethicones are also favored by formulators because they spread easily on the hair and skin, and the lubrication they provide isn’t greasy or tacky. Because of their low vapor pressure, they evaporate easily from hair or skin at room temperature, and therefore aren’t prone to build-up or an oily residue. For this reason, they are sometimes used as an additive in products such as spray leave-in conditioners to help speed drying time. Another benefit of their low vapor pressure is that it provides a way for the desired ingredients to penetrate into the hair shaft or skin. The cyclic silicone is too large to penetrate the skin or hair itself, but is small enough to dissolve the beneficial ingredient, deposit it onto the hair surface, and then evaporate, leaving behind the beneficial ingredient.
Cyclic silicones may appear on labels by several different names, such as:
- Cyclomethicone (can be a single cyclic silicone or a mixture of two or more”>
- Cyclopentasiloxane
- Cyclotetrasiloxane
- Cyclohexasiloxane
- Octamethyl cyclotetrasiloxane
Several curly-haired consumers on NaturallyCurly have reported very unfavorable results with products containing cyclopentasiloxane in particular. These problems were attributed to build-up on the surface or build up due to penetration of the smaller silicone into the hair shaft. However, this seems unlikely because of the chemical and physical properties of these molecules. I believe that evaporation of the cyclic silicones creates a ruffled hair cuticle that creates a rough, unpleasant texture on the hair surface in the same manner as evaporation of ethyl alcohol or isopropyl alcohol. The mildly acidic pH of a shampoo and conditioner will help restore the sealed, flat surface of the cuticle, thereby improving the texture and gloss of the hair.
Last month we discussed how humectants work, and how the temperature and humidity can affect that process. We also discussed the effects of temperature and humidity on the hair itself, and how the use of products containing humectants can impact hair in various weather conditions.
This month, we will discuss some of the humectants found in hair-care products in more detail. While most humectants share the fact that they contain at least one hydroxyl group (-OH”>, they can be separated into several different categories, including alcohols, saccharides, provitamins, proteins, and many other types of molecules. We will discuss a few of the ones that are most commonly seen in hair-care products.
Alcohols
The most frequently used humectants are diols and triols — compounds which contain two or three hydroxyl groups (-OH”> that attract water molecules through hydrogen bonding. These include glycerin, phytantriol, erythritol, and numerous varieties of alkyl diols and triols (propylene glycol, 1,2,6-hexanetriol, triethyelene glycol, etc.”>.
One common diol, and a very effective humectant, is propylene glycol. This ingredient is used in many personal-care products, as well as a variety of other applications. There has been a lot of debate about the possible health hazards of this diol.
The non-cosmetics-related application, which is the source of alarm, is its occasional use as an “anti-freeze.” Because of this, there have been implications that this ingredient has the toxicity associated with the more usual component of anti-freeze, ethylene glycol, which is quite toxic, even lethal at relatively small doses.
The truth is that propylene glycol has been substituted for ethylene glycol in many commercially available antifreeze formulations because it is much safer than ethylene glycol. The other important thing to note is that the word “anti-freeze” — used to strike fear into the heart of the educated consumer — is actually the technical word to describe a completely innocuous process, the lowering of the freezing point of a liquid. I am sure many of you are familiar with the application of salt to the streets and sidewalks to help prevent the formation of dangerous ice, which it does by lowering the freezing point of water. This is an example of a “safe” chemical being used as an “anti-freeze.”
My point is that one need not be alarmed by the chemical propylene glycol. While few chemicals are entirely without risk, propylene glycol is considered to be safe at the low concentrations used in personal care products and even food products, and is quite effective as a humectant.
Biologically Significant Humectants
Sodium PCA (sodium-2-pyrrolidone-5- carboxylate”> is an interesting humectant that naturally occurs in human skin. It can attract and bind several times its own weight in water and is considered to be one of the primary moisturizers of skin cells. Panthenol is another very popular humectant for hair-care products. It is a provitamin of B5 (pantothenic acid”>, and is present in many living cells.
Another excellent humectant of biological origin is hyaluronic acid, a naturally occurring polysaccharide. This material is found not only in the epithelial cells of the skin, but also in connective and nervous tissue throughout the body. It is capable of binding incredible amounts of water molecules to itself, due to its polymeric sugar structure with many available hydroxyl sites along its backbone.
Other Molecules as Humectants
Simple sugars (monosaccharides”> and sugar alcohols possess 5-6 hydroxyl sites available for hydrogen bonding with water, making them excellent humectants. Sorbitol, glucose, and fructose are all commonly found in hair-care products. Many other types of molecules are used as humectants, including (but not limited to”> copolymers of silicone with polyols (usually PEG”>, PEG polymers (polyethers”> of differing lengths, proteins, amino acids, short chain ethers, and certain vitamins.
New Advances in Humectants for Hair and Skin care
In recent years, Colonial Chemical, Inc. has developed two new molecules that perform exceedingly well at both low and high humidity levels. These two materials are known by the trade names Cola Moist 200 and 300P, and by the INCI names hydroxypropyl bis-hydroxyethyldimonium chloride and polyquaternium-71, respectively. Cola Moist 200 is a highly ionized small molecule, while Cola Moist 300P is a highly ionized polymeric molecule. Both are extremely hygroscopic (readily absorbs water”>, prevent dehydration of the hair, are water soluble, and moisturize very effectively. Their high degree of ionization is responsible for the excellent performance. Testing has shown these materials to outperform several traditional humectants by 3 to 6 times at low humidity. They have also been found to enhance the performance of humectants such as glycerin.
In conclusion, there are many humectants available for use in hair- and skin-care formulations. Even some of the simplest, such as glycerin and propylene glycol, can add benefit to a formulation. Some of the more expensive ones, such as hyaluronic acid, and the newer ionized humectants may provide superior benefits, especially in drier climates.
When selecting humectant-containing products, one must keep in mind the climate in which they live, how that impacts hair, and how they might expect a humectant to contribute to the overall performance of their own hair within the constraints of that climate. Scientists are continuously researching this area, and are developing new types of molecules in order to overcome some of the limitations of existing ones.
Examples of Humectants
- Diols and TriolsPropylene glycol
- 1,2,6 hexanetriol
- Butylene Glycol
- Dipropylene glycol
- Hexylene Glycol
- Glycerin
- Triethylene glycol
- Erythritol
- Capryl glycol
- Phytantriol
- Hexanediol or -triol beeswax
Humectants of biological origin
- Panthenol
- Sodium PCA
- Hyaluronic acid
- Inositol
- Glycogen Sugars and modified sugars
- Sorbitol
- Polyglyceryl sorbitol
- Glucose
- Fructose
- Xylitol Hydrolyzed proteins
- Elastin, collagen, silk, keratin EthersIsoceteth-x, Isolaureth-x,
- Laneth-x, Laureth-x, Steareth-xPEG-x (polyethylene glycol”>
- Silicone copolyols
Email your questions to Tonya.
We hear a lot about the humectants. But many of us may not know what they are and how they work.
Humectants are used in skin and hair-care products to promote moisture retention. These hygroscopic compounds posses a chemical structure that attracts water from the atmosphere and binds it to various sites along the molecule.
There are many different types of molecules that are effective humectants, but the chemical similarity they share is having multiple alcohol (hydroxyl”> or similarly hydrophilic sites (such as ethers or ammonium groups”> available for hydrogen bonding with water molecules. The strength of the hydrogen bonding between humectants and H2O improves moisture retention by minimizing water loss due to evaporation.
These ingredients are used in many products, especially those designed for consumers with dry, damaged hair. While they can provide benefit in certain circumstances, it is important to understand how they work and under what circumstances they might provide less-than-optimal results. When considering whether to use humectants, the most important piece of the puzzle is how the weather can impact your hair and the performance of these molecules.
Effects of Relative Humidity on Hair and Humectants
The laws of thermodynamics have a daily influence on our hair. There is a driving force in nature for everything to be in a state of equilibrium. Molecules that exist in an area of higher concentration in contact with an area of lower concentration will move toward the area of lower concentration in an attempt to reach an equilibrium state where the concentration is the same for both areas. For example, dry hair exposed to a very humid environment will become gradually immersed with water molecules, as they diffuse from the air (an area of higher concentration”> into the hair (an area of lower concentration”>. Curly hair is especially susceptible to this type of diffusion because it is naturally more porous than straight hair.
Hair exposed to very dry air without protection can lose its moisture, develop an unpleasant texture and can become unruly, flyaway, and frizzy. It also can become more prone to breakage and split ends. Conversely, unprotected exposure to excessive moisture and humidity can swell the hair cortex, causing the cuticle scales on the exterior of the hair shaft to become ruffled and giving hair a coarse, unpleasant texture. Clearly, neither scenario is desirable.
Low Humidity
In extremely low-humidity conditions, such as a cold, dry winter air, there is no appreciable amount of water in the air for the humectant to attract to the surface of the hair. In this particular type of climate, the best one can hope for with most traditional humectants is for them to prevent evaporation of water from the hair into the environment. Also, under these circumstances, there is some risk of the humectant actually removing moisture from the cortex of the hair itself, creating the problem it was intended to prevent.
That’s why in dry climates it is important to use conditioning products which rely on strong moisturizers rather than traditional humectants. However, it is interesting to note that new humectants are being developed that perform well even in low humidity (such as hydroxypropyl bis-hydroxyethyldimonium chloride and dihydroxypropyltrimonium chloride”>.
High Humidity
In high-humidity conditions, such as summertime in the southeastern United States or the tropics — where the relative humidity can easily reach or exceed 90 percent during the day — there is a tremendous amount of moisture in the air. This can be disastrous for curly hair. If curly hair is dry and damaged, it is very porous, and easily absorbs water from the air. In high-humidity conditions, this can cause curly hair to swell so much that cuticles are raised, making the surface of the hair very rough. These cuticles can then become entangled with cuticles of adjacent hairs and create a huge, tangled mass, which is prone to breakage. Also, curly hair swollen by excess water can lose its curl pattern, creating the dreaded summer frizz.
Clearly, products heavy in humectants will only exacerbate problems with humidity-induced frizz. Some humectants can also develop a sticky feeling when they become saturated with water, which is certainly an undesirable characteristic for hair. Thus, in tropical and subtropical climates, it is essential to maintain well-moisturized hair that is in good condition (which will be less prone to absorbing water from the hair”>. But it is preferable to use products containing fewer humectants or humectants with less hygroscopic capacity.
Due to the limitations and pitfalls of humectants in extreme weather conditions, it is apparent that these ingredients probably function best for curly-haired consumers in moderate climates, with temperatures and humidity in the medium range.
Next month, we will discuss some of the different humectants in more detail.
Examples of Humectants
Diols and TriolsPropylene glycol 1,2,6 hexanetriol Butylene Glycol Dipropylene glycol Hexylene Glycol Glycerin Triethylene glycol Erythritol Capryl glycol Phytantriol Hexanediol or -triol beeswax Humectants of biological origin
Panthenol Sodium PCA Hyaluronic acid Inositol Glycogen Sugars and modified sugars
Sorbitol Polyglyceryl sorbitol Glucose Fructose Xylitol Hydrolyzed proteins
Elastin, Collagen Silk Keratin Ethers
Isoceteth-x, Isolaureth-x, Laneth-x, Laureth-x, Steareth-x PEG-x (polyethylene glycol”>Silicone copolyols
For people with curly hair, silicones elicit many emotions. For some, they are a holy grail ingredient, while others shy away from them for fear they will dry out their hair.
It is evident that there exists a considerable amount of confusion in the curly community in regard to whether silicones are good for curly hair and compatible with shampoo free hair care routines.
In this column, we’ll take a look at amodimethicone and other similar molecules, such as bis-aminopropyl dimethicone and trimethyl silylamodimethicone. And we’ll talk about the pros and cons of using them, especially if you shy away from sulfates.
These are being used more often by chemists as conditioning agents in hair product formulations. They are popular because of their ease of use in processing and manufacturing products as well as for their many benefits to the hair.
Amodimethicone is an abbreviation of “amine-functionalized silicone,” which is a family of silicones modified to have specific properties. The simplest, and perhaps most well-known silicone, polydimethylsiloxane (dimethicone, by INCI naming standards”>, consists of methyl groups (-CH3″> as the pendant group along the backbone of the polymer chain (Figure 1″>. Amine-functionalized silicones have been chemically modified so that some of the pendant groups along the backbone have been replaced with various alkylamine groups (-R-NH2″>. These amine groups become positively charged in aqueous solutions because of their electron-donating (basic”> tendencies, yielding an inorganic, cationic polymer.
Check here for sulfate-free shampoos.
These inorganic cationic polymers deposit onto the hair because of the electrostatic attraction between the polymer and the negatively-charged protein surface of the cuticle. In this manner, they behave much like polyquaternium materials (organic cationic polymers”>, which are excellent conditioning agents as well. The charge density of the polymer can be varied by changing the placement and quantity of the amine groups. A polymer with greater charge density will be more substantive to the hair than one with lesser charge density.
One interesting property of these polymers is that they provide selective conditioning to the areas most in need of it. The mechanism by which they accomplish this is, again, electrostatic attraction. Highly damaged areas of the hair cuticle possess higher negative charge density, which enhances the affinity of the cationic polymer to that specific area. These polymers can provide a targeted beneficial effect.
Once the amine-functional silicone is deposited onto the surface of the hair, it spreads out and forms a cross linked film when it dries. This cross linked film can last through several washings, which is considered to be advantageous in most applications. A unique property of these polymers is that once in place on the surface of the hair, they repel further deposition of amine-functional polymers on top of the existing layer, preventing buildup. This cross-linked film seals moisture inside the hair shaft, holding the cuticle flat and providing excellent wet and dry comb-ability. An additional benefit of these silicones over other cationic polymers (such as polyquats”> is their high refractive index, which gives the hair a high degree of gloss and shine.
Silicones, including amodimethicone, also protect from thermal damage resulting from styling tools, such as hot rollers, curling irons, and blow dryers. This phenomenon is due to their very low thermal conductivity — much lower than water, glycerin, or mineral oil. This reduces heat transfer through the hair surface to the cortex of the hair. Very high temperatures found when styling or processing hair (sometimes as high as 100°C to 160°C”> are capable of vaporizing water contained within the cortex. It is extremely important to maintain proper hydration of the hair because water has a very high specific heat which helps protect the hair from getting too hot. Hair that reaches too high temperatures can suffer permanent damage to the delicate keratin fibrils in the cortex. A protective layer of amodimethicone on the surface can help prevent or reduce damage done in this manner. One frequent question that arises is whether these amine-functional silicones — amodimethicone in particular — are water soluble. This question is most relevant for those on a shampoo free routine who wash with conditioners. They fear that the only way to prevent buildup of these silicones is to use a traditional surfactant such as sodium lauryl or laureth sulfate, cocamidopropyl betaine, or the ammonium lauryl or laureth sulfates.
The short answer is that these polymers are not water soluble. The silicone is provided to product manufacturers as a mixture of silicone/cationic surfactant/nonionic surfactant, which enables it to be readily dispersed into an aqueous formulation because this mixture is water soluble. However, once the product is used and the amodimethicone is deposited onto the surface of the hair and forms a film, it is not water soluble.
Conclusions
Amodimethicone and other similarly modified silicone polymers are considered to be among the best high-performance conditioning polymers currently available to the hair-care product formulator. They provide many unique benefits, including the following:
- Provide deep conditioning
- Provide targeted conditioning to areas of particularly damaged hair
- Protect from thermal damage
- Increase color retention
- Resist build up
- Impart gloss and shine
These modified silicones seem to be of particular benefit for those of us with damaged hair, permanently colored hair or those concerned about the buildup of conditioning agents. It would be necessary to use a shampoo containing one of the lauryl or laureth sulfates or cocamidopropyl betaine to completely remove this silicone from the hair, which may be of concern to those who prefer to use only conditioner-cleansing methods.
References
[i] Urrutia, Adriana, Silicone: The Basis of a Perfect Formulation for Hair Care, Dow Corning de Mexico S.A. de C.V.
[ii] Wacker-Belsil corporate literature
[iii] Heat Protection for Hair Care, Dow Corning
McKay: The ingredients listed are organic molecules used in hair-are products, cosmetics, cleaning products, candles, and perfumes as fragrance additives. They are all naturally occurring components of various essential oils found in the plant kingdom. Synthetic versions of these are also readily available. Linalool, citronellol, and geraniol belong to a class of organic compounds known as terpenoids, which are very popular as flavor and fragrance additives. Eugenol is an allylbenzene molecule, and limonene is a terpene.
Linalool is a naturally occurring substance distilled from essential oils found in various flowers, herbs, citrus fruits, and spice plants (such as coriander and rosewood”>. Linalool possesses a light floral fragrance with a hint of citrus and is used in many products. It also is an intermediate in the synthesis of vitamin E (tocopherol”>, and can also be chemically modified to yield geraniol, citral, geranial, and citronellol. This makes linalool very valuable, not only for its inherent pleasant fragrance but also for its ability to provide the perfumer with a variety of fragrances. Citral (also known as lemonal”> actually exists as two isomers, geranial (citral A”> and neral (citral B”>. Citronellol is derived from rose and geranium plants. Geraniol, also derived from geraniums, is not only popular as a fragrance additive, but also has been found by researchers at the University of Florida to possess significant insect-repellant properties.
Eugenol is primarily extracted from clove oil, but may also be found in nutmeg, cinnamon, and bay leaf. This slightly water soluble molecule is responsible for the distinctive smell of cloves. It may also be chemically modified to form vanillin, which has a vanilla scent. Limonene is distilled from the rinds of citrus plants and has a distinct scent of oranges.
The art of perfumery is one that involves the use of many combinations of different molecules in order to achieve a subtle layering effect of the different scents, with the end result being the desired overall fragrance. For this reason, it is common to see many of these included in a list of ingredients, but more common to simply see “fragrance” as the ingredient. Products which divulge the presence of these specific substances, rather than simply the ubiquitous “fragrance,” may be aimed at a specific market that the company believes would respond favorably to them. One example of this would be some of the product lines marketed as herbal, natural, or organic.
Q: What is hydroxyisohexyl 3-cyclohexene carboxaldehyde?
McKay: While this question came from the same community member, it was particularly relevant to this month’s column because this is also one of the many fragrance ingredients used in cosmetics and toiletries.
Hydroxyisohexyl 3-cyclohexene carboxaldehyde is the INCI name (commercial name is Lyral”>, and it is known for its mild floral and slightly woody fragrance. At the current levels used in most products, this ingredient has been found to be a sensitizing agent and a subsequent cause of allergic dermatitis in almost all of those patients who were sensitized. For this reason, it has been recommended that this substance be used at much lower concentration in formulations, or that it be phased out entirely as an additive in products designed for skin contact.
[1]References [1] Johansen, J.D.; Frosch, P.J.; et al, Contact Dermatitis, 2003, 48: 310-316, “Hydroxyisohexyl 3-cyclohexene carboxaldehyde – known as Lyral: quantitative aspects and risk assessment of an important fragrance allergen”
Proteins absorb onto the surface of hair, forming films which help retain moisture and also absorb additional moisture from the environment, functioning as a humectant. These films also act to smooth and flatten the hair cuticle, making the hair shiny and less prone to snarls. The presence of protein coatings on the outer layer of the hair may also provide some protection from pollutants and thermal or UV damage.
Most proteins are hydrolyzed prior to being added to a formula, a chemical process which makes them much smaller (polypeptides or even single amino acids”> and more readily absorbed into the cortex of the hair shaft. This absorption can be quite profound when the cuticle layer of the hair is damaged due to chemical, thermal, and mechanical processes. The amino acids or smaller protein fragments act as patches and fill in gaps to help provide strength, elasticity, and shine to the hair. A very high percentage of the protein is retained even after rinsing and subsequent shampoos. For this reason, protein deep treatments can be very beneficial to severely damaged hair.
However, for many people (especially those whose hair may be in reasonably good condition”>, an undesirable effect of significant protein absorption and retention can be hair that feels dry and brittle. For this reason, use of a moisturizer or oil is often recommended in conjunction with protein deep conditioning treatments. The moisturizer or oil basically acts as a plasticizer that softens the feel of the hair. Another way to avoid this brittle protein buildup is to use protein-containing products sparingly, especially if your hair is not damaged by excessive use of permanent color, perming or relaxing, or heat-styling. I have personally found that periodic use of a good clarifying shampoo can reverse any protein buildup I may experience, and helps me enjoy the positive effects of various protein-containing products in my regimen.
Gentle surfactants in shampoos
- Sodium cocoyl sarcosinate
- Sodium lauryl sulfoacetate
- Sodium myreth sulfate
- Sodium Xylenesulfonate
- Sodium methyl cocoyl taurate
- Disodium laureth sulfosuccinate
- Cocamidopropyl betaine
- Coco betaine
- Cocoamphoacetate
- Cocoamphodipropionate
- Disodium cocoamphodiacetate
- Disodium cocoamphodipropionate
- Lauroamphoacetate
- Sodium cocoyl isethionate
- Decyl glucoside
- Sorbitol
Q: How can I tell if a shampoo is gentle?
A: The first step in selecting a gentle shampoo is to avoid those containing sodium or ammonium lauryl or laureth sulfate. While it is possible for a formulator to add co-surfactants such as cocamidopropyl betaine or fatty alcohols to the product, which can diminish the harsh detergency effects of those sulfates, there are currently many choices available without them at all. Many “natural” product lines will disguise these sulfates by calling them sodium “coco” sulfate, because the surfactant is in fact derived from coconut fatty acids, but it is still a potentially moisture-stripping surfactant.
When reading labels, look for surfactants on the table we have included. Many of these are from botanical sources, and have been found to be gentle for skin and hair. Often times a combination of two or more surfactants can be even more kind to your tresses. The inclusion of proteins and amino acids, as well as moisturizers such as fatty alcohols, polyquaternium conditioners, silicones (if you shampoo regularly, buildup of these should not be a problem”>, natural oils, and cationic surfactants will also ensure a gentle cleansing experience.
Most hair and skin care products are composed of ingredients that provide a veritable feast for all types of microorganisms, such as bacteria, fungi, mold and yeast. Water, which is the major ingredient in most shampoos and conditioners, provides a very friendly atmosphere for the growth, propagation, and eventual decay of these microbes.
Once a product becomes contaminated by these types of nasty critters, it becomes — quite literally — a toxic soup. Exposure to a contaminated product can result in both superficial and subcutaneous skin infections and in very rare and extreme cases, systemic infections that can spread to the organs.
The use of various techniques to prevent this type of growth is necessary for the health and well-being of the consumer. Some of the methods used to provide a safe product include the following:
- • Selecting a pH that is inhospitable to organism growth.
- • Creating a hostile environment to the organisms.
- • Adding chemical preservatives.
- • Using sterile ingredients, processes, and packaging.
- • Minimizing water content.
Chemical preservatives are added to almost all commercial formulations, due to their ability to provide long-term, broad-spectrum antimicrobial properties at a range of pH’s and temperatures. It is generally necessary to use a combination of two or three different types of preservatives in order to properly protect against the various microbes that can lead to problems. The formulator must also be certain that the preservatives used will not interact with any other ingredients in the product, resulting in either a toxic byproduct or ineffective preservation.
Because the purpose of chemical preservatives is to discourage the growth of microorganisms, it should not be surprising that they are capable of attacking human cells. Preservatives frequently cause dermatological reactions and sensitizations in users of shampoos, cosmetics, and skin care products. Some even have been implicated in more sinister pathologies, such as hormonal problems and cancer. However, in the world of mass-produced products, which are expected to have shelf lives of up to three years, they are necessary. Scientists are continuously working on the development of safer preservatives, so we can expect to see changes in which ones are popular throughout our lifetimes.
There are a large number of preservative types in current use. Formaldehyde donors, such as diazolidinyl, imidazolidinyl urea and DMDM hydantoin, are one group. The parabens are commonly used antimicrobials, as are the isothiazolinones. Cationic surfactants, such as Quaternium-5, have also been shown to inhibit bacterial growth. Aromatic alcohols, such as benzyl alcohol and phenoxyethanol, various mild acids (such as sorbic acid and citric acid”>, vitamins, and certain essential oils and extracts are also popular. EDTA and other chelators and antioxidants are also part of many preservative combinations found in products.
Formaldehyde donors (diazolidinyl, imidazolidinyl urea, and DMDM hydantoin”>
These chemicals are frequently used because they are considered to be effective, providing broad-spectrum protection against bacteria — particularly Pseudomonas. They are also considered to be safer than formaldehyde itself, because they slowly release only minute amounts of formaldehyde over time. However, dermatologists and allergists do report these to be frequent irritants and allergens in their patients.
A frequently asked question is whether “urea” ingredients are extracted from or somehow related to urine, human or otherwise. The answer to that question is “definitely not.” The word “urea” simply denotes a type of chemical compound that can be found in nature (such as in our metabolic waste”>, and can also be synthesized in a laboratory.
Parabens: (methyl-, ethyl-, propyl-, and butylparaben”>: Considered to be very effective biocides against yeasts, molds, and bacteria, this group of preservatives is also popular with formulators due to good thermal flexibility (they can be added to either hot or cold processes”> and a tendency not to interact with surfactants in the solution. These are esters of a naturally occurring acid (para-hydroxy benzoic acid, found in blackberries and raspberries”>. A recently reported study indicated a possible link to the use of parabens and estrogenic-like activity, as well as possible carcinogenic properties. More study will need to be done to prove or disprove any connection between parabens and these health issues, but some people avoid using products containing these chemicals.
Isothiazolinones (methylisothiazolinone and methylchloroisothiazolinone”>:These chemicals are highly effective against yeasts, molds, and both gram-negative and gram-positive bacteria. However, they are considered to be very strong allergens and irritants of skin and membrane tissue. After a high number of sensitization reports in the 1980s, it was recommended that the isothiazolinones be used in very low concentrations and only in rinse-off products.
Natural preservatives (tea tree oil, grapefruit seed extract, potassium sorbate”>: These types of preservatives are more acceptable to many users who object to some of the potentially toxic effects of synthetic preservatives. However, many of these either have regular preservatives in them as a result of their processing, or they simply cannot guarantee a healthy, microbe-free product for more than a few weeks or months. This is not necessarily a bad thing, especially for the formulator and purveyor of more “natural” products, but it is important for both the formulator and the end user to understand the limitations of these materials.
Preservatives usually comprise no more than 0.5-2.0% of the total solution by weight, but they can be the source of a lot of concern and confusion to consumers. While they have certain drawbacks, they do manage to help companies provide products free from biological spoilage and with long shelf life, which helps to prevent infections and also provides convenience to the customer. An educated consumer can choose to select products that contain the preservative packages with which they feel most safe from irritation, allergic reaction, or later pathology. If a person wishes to minimize contact with chemical preservatives or avoid them entirely due to concerns about their effects, one must be prepared to keep products in the refrigerator and replace them much more frequently than is currently customary.
We always get lots of questions about silicones, as they are in so many products and are of ongoing concern to many curly-haired consumers. I thought this month we could tackle a couple of those questions in a quick, practical manner (hopefully”> to aid in the seemingly never-ending process of ingredient scrutiny and product selection.
Which Silicones are Water Soluble?
It is difficult to actually rank the silicones in order of water solubility, simply because they are usually either soluble or not. Most silicones are water insoluble due to being non-polar, but there are a few that are chemically modified in order to render them more compatible with water. The following table lists the main types of silicones found in hair care formulations. It also indicates whether or not they are water soluble and includes which surfactants can be used to ensure good removal of the silicone from the hair. Studies have found that the water-insoluble silicones show no appreciable buildup when a shampoo containing one of the recommended surfactants was used.
Silicone |
Water soluble? |
Recommended cleansing agents |
Dimethicone |
No |
SLS, SLES, cocamidopropyl betaine, cocobetaine, ALS, or ALES |
Dimethiconol |
No |
SLS, SLES, cocamidopropyl betaine, cocobetaine, ALS, or ALES |
Phenyl Trimethicone |
No |
SLS, SLES, cocamidopropyl betaine, cocobetaine, ALS, or ALES |
Amodimethicone |
No |
SLS, SLES, cocamidopropyl betaine, cocobetaine, ALS, or ALES |
Cyclomethicone |
No |
cocamidopropyl betaine, cocobetaine, other mild surfactants, or conditioner washing |
PEG-modified dimethicone |
Yes |
cocamidopropyl betaine, cocobetaine, other mild surfactants, or conditioner washing |
Dimethicone copolyol |
Yes |
cocamidopropyl betaine, cocobetaine, other mild surfactants, or conditioner washing |
MORE: Water Soluble Silicones 101
Why are Silicones Used in Hair Products?
Many currently available shampoos include silicones in the ingredient list. These additives act as conditioning agents, due to their ability to deposit onto the surface of the hair and form a film during the rinsing phase of the shampooing process.* This helps moisturize the hair by replacing oils stripped from the hair by the cleansing agents in the shampoo. Initially these were marketed as two-in-one products, but now they are found in a wide variety of products, especially as new properties are discovered, such as the ability of some silicones to enhance hair color retention. The inclusion of other oils in a shampoo can have a similarly moisturizing effect.
One interesting thing to note is that a published study in the Journal of Cosmetic science reports finding that the presence of cationic polymer (polyquaternium-10, in this study”> significantly decreased the buildup of dimethicone on the hair over time.** The presence of these cationic polymers also enhances the deposition of the silicone onto the surface of the hair. Due to this synergy between the two types of ingredients, they will often be used together by formulators in shampoos.
Silicones offer many benefits, both to the hair care product formulator and the end-user. Careful reading of labels and understanding which silicones require occasional removal with surfactant-containing shampoos can allow the consumer to enjoy all of the good effects of silicones (softness, shine, better color retention, increased manageability”>, while suffering none of the ill effects of build-up.
MORE: Silicone Free Hair Products
* Marchioretto, S., “Optimizing the Use of Silicones in Haircare Products”, Dow Corning Europe, 1998
** Gruber JV; Lamoureux BR; Joshi N; Moral L, J.Cosmetic Sci; 2004, 52 (2″>, 131-136, “The use of x-ray fluorescent spectroscopy to study the influence of cationic polymers on silicone oil deposition from shampoo”
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It is estimated that at least 65% of Americans have hard water at home. The degree of hardness varies tremendously with geography, but those with extremely hard water know intimately the problems associated with it. Pipes can clog, coffee pots die, clothes get a dingy, gray tinge, and the sinks and tubs develop unattractive residue. It is necessary to use more detergent, more hand soap, more shampoo, and more conditioner and fabric softener to get things clean and soft. Perhaps the most aggravating thing for us curly-haired people (and even our straight-haired friends”> is the insidious build up that develops on our hair, rendering it dry and unmanageable.
Hard water contains dissolved minerals, usually carbonates of the metal ions calcium and magnesium. Calcium sulfate and iron deposits are also not unusual. These minerals react with soaps and surfactants, reducing their effectiveness at cleansing, and forming a salt that precipitates onto your hair (and your clothes, your skin, and your bathtub”>. This means that not only are oils and dirt more likely to accumulate due to your shampoo not working as well as it should, but also a scaly film gradually develops over the surface of the hair. This leads to hair that is dry (due to the inability of moisturizers to penetrate this film”> and prone to tangles and breakage (due to the roughened cuticle surface”>. The best way to remove these alkaline inorganic salts is to use shampoos or rinses containing organic acids with multiple acidic sites (see figures below”>. These sites form a cage around the metal ion of the salt, and the entire complex can then be rinsed from the hair.
These acids are called “chelating agents,” and some examples are EDTA (ethylenediamine tetra acetic acid”> and citric acid. Organic acids containing only one acidic site can also be used for removal of these minerals, but may be less effective and require higher concentrations. Some examples are acetic acid (vinegar”>, salicylic acid, and glycolic acid. Installation of a water softener or shower filter is the ideal method of avoiding this type of problematic mineral buildup at home. However, when that is not an option, the best approach is occasional use of a shampoo with a relatively short ingredient list containing EDTA or citric acid and a strong surfactant such as sodium lauryl sulfate. SLS helps remove any oily buildup that has occurred as a result of the mineral film, and a simple formula without lots of additives prevents interference with the chelating agent. For those who prefer to avoid shampoos and the surfactants found in them, a mixture of distilled water and vinegar can aid in the removal of the minerals. Follow up either treatment with a deep, moisturizing conditioner.
Chlorine DamageOur hair gets exposed to chlorine both in swimming pools and in our shower. The effects of overexposure to chlorine can be excessive dryness, tangling, and breakage, as well as color fading. One way to minimize contact with chlorine in the swimming pool is to wet your hair prior to swimming and to saturate it with a good conditioner. This prevents the chlorine from entering the hair through the cuticle. After swimming, rinse hair immediately, in distilled water if possible. A mildly acidic rinse, in lemon juice, citric acid and water, or vinegar and water can also help remove chlorine from the hair. The acidic rinse also seals the cuticle, helping to maintain shine and minimizing tangling and breakage due to raised cuticle scales. Chlorine strips oil from the scalp and hair, so always follow up with a good conditioning treatment, as well.
If you experience problems with a green tinge to your hair after swimming, it isn’t actually chlorine causing the problem, but copper buildup that occurs when the pH of the pool is too low. It can be removed to some extent via a good chelating agent (EDTA, citric acid”>, but definitely adjust the pH of the pool as well (or recommend it be checked if it is a public pool”>.
As with hard water build-up problems, an ounce of prevention can be worth a pound of cure. Several means of protecting your hair and skin from the ravages of chlorine exposure are:
- Wear a bathing cap in the swimming pool
- Swim in non-chlorinated water where possible
- Install a shower filter that removes chlorine
Since most of us encounter water with less-than-ideal components in it on a fairly regular basis, it is a great idea to have on hand a good clarifying shampoo with some EDTA, citric acid, or other acids and a deep conditioner. Non-shampoo users can try a vinegar rinse with distilled water and vinegar. These can help remove buildup from hard water and/or chlorine and keep hair clean and moisturized. Remember to look for a shampoo containing a chelating agent and without too many extra additives or conditioning ingredients.
Another great option is to buy a water filter. Aquasana filters have so impressed NaturallyCurly editors that we’ve worked out a deal for our readers to purchase the filters at a substantial savings (regular price $84.99; NaturallyCurly price: $67.99″>. here.
“pH” is an abbreviation for “potential hydrogen” and is a scale used for ranking the relative acidity or alkalinity of a liquid solution. The precise mathematical definition of pH is the negative logarithmic value of hydrogen ion (H+”> concentration in the solution.
pH = – log [H+]
pH |
Example |
|
0 |
battery acid | |
1 |
stomach acid | |
2 |
orange juice | |
3 |
vinegar | |
4 |
acid rain | |
5 |
human hair (4.5-5″> | |
6 |
wine, beer, milk, magnesium sulfate | |
7 |
purified water | |
8 |
toothpaste | |
9 |
baking soda | |
10 |
milk of magnesia | |
11 |
ammonia | |
12 |
oven cleaner | |
13 |
bleach | |
14 |
drain cleaner | |
Scanning electron micrograph of a human hair, showing the overlapping scales of the cuticle layer. |
||
A scale of zero to fourteen is used for pH, with 7.0 being a neutral solution (water”>. A number below 7.0 is considered to be acidic, with a lower number being more acidic, and anything above 7.0 is considered to be alkaline or basic, with 14 being the strongest alkaline value. Due to the logarithmic nature of the pH scale, a solution with a pH of 2.0 is ten times more acidic than one with a pH of 3.0. Human hair is a solid material, a composite of protein molecules with three distinct layers. The central portion called the medulla is not present in every hair and is usually just made up of air. The surrounding layer, known as the cortex, is composed of bundles of fibrous coils made of keratin protein molecules that supply the hair strand with its strength and elasticity. The cortex also contains particles of melanin, which impart color to the hair strand. The outer layer is comprised of multiple layers of overlapping, keratinized scales and is called the cuticle, which acts to protect the cortex and medulla. Hair and skin are both covered by a very thin fluid layer comprised of oil, salt and water, called the mantle, which is slightly acidic (pH = 4.5 – 5.0″>. This acid mantle is very important in maintaining the proper moisture balance in our hair and skin. It is also instrumental in making the cuticle scales lie flatter against the surface of the hair shaft, which makes hair smoother and shinier as the flat scales reflect light more coherently. Scales that lie more snugly against the hair shaft also prevent moisture loss more efficiently, which helps hair to be stronger and healthier. With the normal exposure to the environment as well as washing and styling, this acid mantle can become contaminated or removed and must be restored with the use of properly pH-balanced products.
Mildly acidic products can be applied to the hair to harden the outer layer, flatten the cuticles, and shrink the diameter of the hair. This serves to make the hair glossy, shiny and less prone to tangling and snagging on adjacent hair strands. Hair that is close to its ideal pH of 4.5 – 5.0 is also at its peak strength. Shampoos and conditioners that are mildly acidic also have been noted to provide longer life to the color of hair that has been dyed.
Alkaline products cause the hair to swell, the cuticle to lift and remove oils from the air. This results in frizzy, dull, brittle hair that is prone to breakage and tangling. Extremely alkaline solutions cause the disulfide bonds between keratin protein molecules to break down and can eventually dissolve the protein completely. These types of solutions are the ones used to perm or relax the hair and can be extremely damaging, especially to hair that is already fragile.
Most modern shampoos and conditioners are formulated to be slightly acidic, having a pH around that of the hair’s acid mantle (4.0-5.0″>. For this reason, you may see chemicals such as citric acid or sodium hydroxide or triethanolamine towards the end of the ingredient list of products you use. These are added in very tiny amounts in order to adjust the pH of the product to the proper level.
“Polyquaternium” is not a term most consumers can relate to, and is a bit intimidating at first glance. However, once we learn where the word comes from, it is not so daunting. The word is an INCI (International Nomenclature of Cosmetic Ingredients”> name used to generically describe a polymer that has been modified by a process known as quaternization. This process usually involves the addition of alkyl ammonium chloride groups along the polymer chain, which produces positively charged sites (hence: poly-quatern-ium; polymer, quaternized, ammonium”>. Some other polyquaterniums have positively-charged sites in the actual backbone. Those polymers (also called ionenes or polyelectrolytes”> are formed by the condensation reaction of an amine and a halide.
Illustration of cationic polymers. a.”> linear polymer with charges along the backbone, such as Polyquaternium-10; b.”> a comb-shaped polymer,with positive charges pendant to the backbone, such as Polyquaternium-4. |
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Due to the positive charges on these polymers, they are very substantive to the negatively-charged surfaces of human hair and skin. For this reason, many of these cationic polymers have been found to be very useful in hair styling and hair conditioning applications, as well as in skin creams and lotions. They are also used in formulations for forming clear, glossy films on the hair and for decreasing or eliminating static-charge buildup and fly-away hair.
There are many different polyquaternium polymers. Some are made by modifying naturally occurring materials such as cellulose or guar gum. Others are very specifically tailored synthetic molecules. Their properties vary widely according to the structure of the polymer, the molecular weight (size”> of the polymer and the charge density.
Cellulose-derived Cationic Polymers
Cellulose is a naturally-occurring, straight-chain polymer composed of repeating units of anhydroglucose. This polymer in its natural state is not very water soluble at all, due to its crystalline structure, but the addition of hydroxyethyl groups allows this crystalline structure to be disrupted, which allows the polymer to become somewhat soluble in water, which makes it more easily used by personal care product formulators. The solubility of the polymer is dependent upon the polymer chain length as well as the degree of substitution of the hydroxyethyl groups on the chain. This family of polymers can be recognized by INCI names such as hydroxyethyl cellulose (HEC”>, hydroxymethyl cellulose, hydroxypropylmethylcellulose, and hydroxypropylcellulose. These polymers are used to thicken the shampoo or conditioner, to stabilize emulsions, and also occasionally to impart conditioning properties. A chemical modification of these cellulosic polymers (quaternization”>, produces several of the better known polyquaternium polymers used in conditioning and styling products today, such as Polyquaternium-10 and Polyquaternium-4.
Polyquaternium-4 is a cellulosic (derived from natural cellulose”> polymer modified to have positive charges along the backbone. The positively charged groups in this polymer are pendant to the backbone (are suspended down from the backbone”>, giving it an appearance similar to that of a hair comb.
This polymer is a superior film-former on the hair, and has been found to exhibit very high curl retention even in humidity. Due to its unique polymer architecture, it has a fairly high charge density in comparison to some of the other polyquats. It is very substantive (sticks to the hair well”>, but exhibits little build-up when studied using a non-disclosed method of testing (one can assume it involved washing the substrate with a typical anionic surfactant”>. Due to its molecular structure, it is very stiff, so is outstanding for use in styling fixatives and also imparts soft feel and easier wet and dry combing.
Polyquaternium-10 is a cellulosic polymer with small positive charges attached along the backbone in a different manner than polyquat-4. These polymers do not have the comb shape that polyquat-4 has, but are linear with small charged-side groups along the backbone. These polymers have lower charge density than polyquat-4. They do not form films as stiff as those formed by polyquat-4 or polyquat-11, which means they give a softer hold, but are more susceptible to not retaining the style or curl. They are somewhat more prone to build-up than polyquat-4. They are more compatible with surfactants, so they are great to use in shampoos in order to thicken the formula and to provide a conditioning effect with the shampoo. They are excellent conditioners and impart shine and good detangling and combability.
Guar hydroxypropyltrimonium chloride is a quaternized modification of another naturally occurring polymer, guar gum, which functions in a very similar manner to Polyquaternium-10. Some studies have shown that this polymer can provide superior detangling and wet combing properties to Polyquaternium-10 when used in a conditioning shampoo.
Non-Cellulosic Polyquaternium IngredientsPolyquaternium-11 is a non-cellulosic copolymer of VP/DMAEMA (vinyl pyrrolidone and dimethylaminoethyl methacrylate”>. This polymer has a medium charge density and often has quite high molecular weight. It gives good wet and dry combing results and imparts a smooth feel to the hair. The fact that it is a copolymer of VP and an acrylate means it will be somewhat less susceptible to humidity than just VP would be, but it may be more susceptible to failure by humidity than the polyquat-4 due to the fact that some VP is present in it. Polyquat-11 is generally recommended for mousses and creams, where it can moisturize as well as aid in styling. This polymer is water miscible, but not water soluble. This could lead to some build-up over time if one were not using a clarifying shampoo occasionally.
Polyquaternium-16 and Polyquaternium-44 are both copolymers of vinyl pyrrolidone and quaternized vinyl imidazole. These polymers have both been found to exhibit excellent conditioning and detangling properties, yet are not as useful in styling applications that require hold.
Polyquaternium-46 is a terpolymer (containing three different types of monomers”> composed of vinyl caprolactam, vinyl pyrrolidone, and quaternized vinyl imidazole. This polymer has been found to contribute good setting and hold to styling products such as hair gels and mousses.
Polyquaternium-5 is a copolymer of an alkyl ammonium methosulfate and acrylamide, Polyquaternium-6 is a polymer of dimethyl diallyl ammonium chloride (DMAC”>, andPolyquaternium-7 is a copolymer of dimethyl diallyl ammonium chloride (DMAC”>and acrylamide, which has a lower overall percentage of cationic sites on the polymer chain (lower charge density”>.
Water solubility and build-up
Polyquaternium materials range from water miscible to water soluble, in varying degrees. However, it is important to realize that these are used in products because they form a complex with your hair due to electrostatic interactions. The resultant complex between the hair keratin and the polymer can actually be more stable than any complex that might be formed by attraction between a Polyquaternium polymer and an anionic surfactant such as sodium lauryl sulfate. This means that some of these polymers can be resistant to removal, even with clarifying shampoos. Polystyrene sulfonate, a negatively charged polymer, has been found to aid in removal of these polymers in cases where they are resistant to removal by traditional means. Some studies have shown that Polyquaternium-4 is particularly good about not causing build-up.
Conclusion
Polyquaternium polymers are cationic polymers that perform well in hair and skin applications due to the interaction of their positive charge with the negative charge on the surface of skin and hair at neutral pH. Generally, they impart good moisturizing and conditioning effects and can add hold and setting effects to gels and mousses if they have an appropriate molecular structure. Some of these polymers can cause build-up on the hair over time, so proper clarifying steps must be taken periodically in order to remove them from the hair surface.
Hopefully, this article provided a good introduction as to what polyquaterniums are and how they function. This is in no way an exhaustive treatment of the topic. There are many of these polymers recognized by INCI (more than 50″>, and several books have been written that provide more in-depth information on these materials.
Natural Oils in Hair Products
Natural oils have been used for thousands of years by humans to soothe skin, smooth hair, provide medicinal benefits, to enhance cooking and supplement nutrition. In this day of technology and laboratory-synthesized ingredients, it is often easy to overlook or underestimate these marvels of nature. Natural oils are mixtures of chemical compounds, often quite remarkable in their degree of complexity and in the functions performed by each constituent identified as a component of the oil. The exact proportions of each different molecular structure in any particular natural oil often varies by its location of origin, as well as the process used for extracting the oil from the plant, tree, seed, or animal.
Natural oils are composed of esters, which are known for their emolliency, fatty acids, which are excellent conditioning agents, triglycerides, and fatty alcohols. All of these materials are inherently insoluble in water. However, a few of the natural oils contain high amounts of dissolved water in their natural state, accomplished by some of the chemical components acting as emulsifiers. For this reason, some natural oils are used as water-in-oil emulsifiers in products that are extremely heavy and creamy, such as hand creams and heavy hair creams. Although they are not water soluble, most natural oils should remove fairly easily from the hair if one uses a mild shampoo or a conditioner with emulsifying oils in its ingredients.
Not only are natural oils excellent emollients (definition: soothing, smoothing, capable of holding in moisture”>, but they can act as sunscreens, cleansers, protectors, and nourishing agents for our scalps, skin, and hair. They form films on the surface of the hair or skin and act as a barrier to the environment and hold in moisture. They can provide antimicrobial benefits to products used on skin and hair as well.
As there are many, many natural oils and it would be impossible to do a comprehensive survey of them in the space we have allotted for this discussion, this article will only examine a few common natural oils used in hair care products. Most of these will be vegetable-based oils, with one being an animal-derived product.
Lanolin
Lanolin is an oily material produced by the sebaceous glands of sheep. As it is a byproduct of wool-gathering and refining, it is fairly easily obtained without having to harm the animal (unless the sheep has a phobia about being shaved”> and is a renewable resource. This has made lanolin a popular ingredient in skin creams and hair products for many centuries. Many consider animal oils to be more compatible with human skin and hair than vegetable or mineral oils. Lanolin has received some bad press, resulting from a very small study among allergy patients, indicating that it may cause allergic reaction in a small percentage of users. However, when one delves deeper into the literature, it becomes apparent that this has not been consistently borne out in other studies.
Lanolin is a mixture of fatty acids and wax esters, diesters and hydroxy esters of high molecular weight, as well as fatty alcohols (33 different alcohols and 36 different fatty acids alone have been identified as being present in lanolin”>. In its natural state, lanolin contains about 25-30% water, by weight. When applied to skin or hair, it is very effective at helping retain moisture. It forms very stable water-in-oil emulsions and can be used as an emulsion stabilizer and dispersing agent in creamy formulas. It can also be chemically modified to enhance its ability at stabilizing emulsions. Many different modified forms of lanolin are approved for use in hair care and skin care products. Acetylated lanolin, PEG-75 lanolate and hydrogenated lanolin are some examples.
Lanolin is considered by many to be too thick and greasy to be used in very high concentrations on hair, as it would weigh down the curls. However, some users who have very fine, dry and extremely curly hair have reported it to be very beneficial to their hair.
Shea butter
Shea butter is a fatty substance extracted from the seed of the shea tree (Karite tree”>. It is a highly complex mixture of fatty acids, esters, triterpenic alcohols, and cinnamates. It contains vitamins A and E (tocopherol”>. The cinnamates in shea butter absorb UV radiation which is extremely useful in skin care applications and for color preservation in hair products. The fatty acids in shea butter are in the range of fourteen to twenty carbons per chain, which is slightly higher on average than the composition of coconut oil. This makes shea butter a creamier, heavier moisturizer, highly esteemed for its ability to provide great conditioning effects without being too heavy. Read more about shea butter here.
Jojoba Oil
Jojoba is a unique natural oil from the jojoba plant. This material is distinct in that its composition is primarily straight-chain, monounsaturated esters, making it a liquid at room temperature. It is in the chemical category of “waxes” (as is lanolin”> rather than oils and contains virtually no triglycerides. The majority of the esters present are much larger than in most natural oils, ranging from 38-44 carbons per ester. It is chemically very similar to oil from sperm whales, and has replaced those oils in products since the ban on commercial whaling in the 1970’s.
Jojoba oil is extremely lubricative (slippery”>, but not greasy. It is very thermally stable which is ideal for people who use heat styling frequently. It contains Vitamin E and antioxidants, which can help preserve the color and structural integrity of the hair. It also has been found to contain phospholipids, which are found naturally on human skin. Jojoba is extremely similar in make-up to human sebum, excreted by our sebaceous glands. As a result, it can dissolve sebum and help remove it from the skin and hair, keeping surfaces cleaner and shinier.
Olive Oil
Olive oil is pressed from olives, and is made up mostly of fatty acid oils (triglycerides”>. Monounsaturated oils make up about 90% of the oils in olive oil, with polyunsaturated fatty acids comprising the remainder. It also contains some vitamins (A, E, D, K”> as well as some antioxidants in the form of various polyphenols. Olive oil is one of the lighter oils, with its fatty acids being predominantly composed chains containing 16-22 carbon atoms. The lightweight nature of olive oil as well as its thermal stability due to its monounsaturated fatty acids make is a highly effective moisturizer for hair.
Almond Oil
Almond oil is made up of the same fatty acids as olive oil, but is only 20-30% monounsaturated, in contrast to the 90% monounsaturation of olive oil. It is very lubricative and gives a nice slippery feel to the hair and is moisturizing, but is not as thermally stable as olive oil.
Castor Oil
Castor oil is made up of hydroxylated fatty acids, which gives it some unique properties. The placement of a hydroxyl (oxygen-hydrogen”> group near the double bond imparts additional oxidative stability to these molecules, making them thermally stable and capable of protecting the hair against the elements somewhat. However, it is very viscous and can be perceived as greasy on the hair. Some users have reported that it caused buildup on their hair as well.
Coconut Oil
Coconut oil is mainly fatty acid triglycerides in the range of twelve-to-eighteen- carbon chains. It is usually over 50% lauric acid (12 carbons”>. It is noted for being exceptionally light and non-greasy feeling, while still being very moisturizing. Palm kernel oil is similar in composition and properties to coconut oil.
Summary
Natural oils provide a lot of diversity in their benefits, all in one convenient package. It is difficult, if not impossible, to replicate this degree of complexity and delicacy in the laboratory. However, there are some drawbacks in using oils in formulations, such as the fact that there may be significant variability in composition, since they are derived from natural sources. For many of us this is not a concern, and we have found natural oils to be a wonderful tool for making our curly hair soft and shiny.
Figure 1. Simple schematic of a polymer.
Imagine that it has millions of the same repeat units. |
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Figure 2. A model of a dendrimer,a “hyper-branched” polymer | |
Polymers can be found in most hair care products, performing a variety of different functions. Shampoos, conditioners, and styling products all rely upon polymers in order to achieve their desired effects. So what are polymers and what is so special about them?
Polymers are very large molecules that are made up of many repeating units of small molecules chemically bonded together. A polymer can be composed of many units of a single type of small molecule (called a homopolymer”> or can be composed of many units of two or three different types of small molecules (called a copolymer”>. Many polymers are found in nature, such as DNA and RNA, spider silk, cellulose (found in cotton fibers, starches, and tree bark, just to name a few places.”>, proteins, natural rubber, etc. Polymers can also be synthesized in a lab or manufacturing plant to have linear forms, branched forms, and even three-dimensional hyper-branched forms resembling 3-d snowflakes, known as dendrimers.
The neat thing about polymers is that they can be specially made or modified to serve many different purposes, from applications as diverse as structural materials on airplanes and automobiles, bullet-proof glass, bullet-proof vests, time-released drug-delivery agents, temporary bone-replacement or reinforcement in the body, fibers for clothes we wear, super absorbent materials in diapers, paint and coatings for many uses, and also in hair care products.
Conditioning polymers
Cationic polymers are quite popular for use as conditioning agents for the hair. These polymers have been chemically modified to have positive charges along their backbone. Since hair is negatively-charged, these polymers become bound electrically to the surface of your hair when applied in the shower and resist being rinsed off by the water. This causes the cuticles on the surface of your hair to lie flat, which gives a smooth texture and shiny appearance to the hair. It also helps separate and protect each strand from adjacent strands, which prevents tangling and tearing and makes both wet and dry combing easier. These types of polymers, known as polyquaterniums in the INCI naming system, are most often modified versions of naturally occurring cellulose and guar gum.
Silicones are also a highly popular ingredient used by hair care product formulators for conditioning properties. These polymers deposit onto the surface of the hair and act to reduce combing friction, provide an emollient effect, impart gloss and reduce static charge between hair strands.
Examples include:
Polyquaternium-10, Polyquaternium-7, Polyquaternium-11, Guar hydroxypropyltrimonium chloride. Examples of silicones include dimethicone, amodimethicone, cyclopentasiloxane, cyclomethicone, dimethicone copolyols, dimethiconol
Viscosity modifiers
Many polymers are very useful in shampoos and conditioning products because they help to thicken and maintain the viscosity of the product, which gives the desired product consistency for the consumer. It is much easier to apply a shampoo or conditioner to one’s hair if it doesn’t escape from between your fingers when poured from the bottle into your hands. Some of these polymers are also used as emulsion stabilizers, as they help to maintain the oil-in-water formulation that is most typical of hair products.
Examples include:
Hydroxyethylcellulose, hydroxypropylmethylcellulose, carboxymethyl hydroxyethylcellulose, harboxymethyl hydroxypropyl guar and carbomer (poly acrylic acid, acrylates/C10-130 alkyl acrylate crosspolymer”>.
PEG-modified materials
PEG is polyethylene glycol, a water-soluble polymer that is fairly easily chemically reacted with a variety of other molecules. The number associated with the PEG in the INCI nomenclature is indicative of the number of PEG repeat units present. The higher the number is, the greater the water solubility of the modified molecule. These modified molecules can be used as emulsifiers, viscosity modifiers, surfactants, and humectants.Examples include PEG-150 distearate, PEG-100castor oil, PEG-100 lanoli and PEG-10 sorbitan laurate.
Film-formers
Polymers are often the source of “hold” in styling products such as hair gels and hairsprays. These polymers deposit onto the surface of the hair and cause hairs to be attracted to one another through capillary forces. The polymers then dry to form clear films that are strong and hold the hairs together until the film is either removed via washing or the film is broken due to mechanical forces on the hair (combing”>.
Examples include:
PVP (poly N-vinyl-2-pyrrolidone”> – excellent film-former, substantive to hair, forms clear films, completely water soluble, but it absorbs water which in humid weather can make it sticky or tacky to the touch and can cause frizz and a dull appearance to the hair. In dry weather, it can become brittle and flakey.
PVA (polyvinyl acetate”> – resists absorption of water in high humidity which leads to better hold in damp weather conditions, more flexible in dry weather so it doesn’t flake, not as substantive to hair.
PVP/VA copolymer – This polymer provides the best of both worlds. It is a copolymer of PVP and PVA and is used to get around a lot of the limitations of the two polymers exhibit when used individually.
Summary
As you can see, polymers are everywhere in our world, including in our hair care products. Many of the qualities we most desire in our products are given to us by polymers. They can be specifically tailored to meet the required need, and thus will most likely continue to be used and continue to provide us with the benefits we have come to expect.
Many people with naturally curly hair are practitioners of shampoo free hair care routines. This is an abbreviated term for a regimen that eliminates or reduces the use of traditional shampoos for hair cleansing. While many curlies have known for years that shampooing too often can be detrimental to our fragile hair, the idea of drastically reducing the frequency of shampooing or eliminating it altogether became popularized with the publication of Lorraine Massey’s book, “Curly Girl”.
The reason Massey advises skipping the shampoo is that curly hair is already fairly moisture-deprived due to its unique shape and structure. If hair is not especially oily (which we know our curly hair usually is not”>, traditional shampoo can strip needed oil and moisture away from the hair and raise the cuticle of the hair making the surface very rough, which leads to tangling and breakage. The primary ingredients responsible for the removal of oils from the hair are known as surfactants.
Surfactants possess the trait of having one distinct portion of the molecule that is polar and hydrophilic (water-loving”> and one portion that is non-polar and hydrophobic (water-fearing”>. This dual nature is the basis for detergency—the removal of oil from a surface. At sufficiently high concentrations in water, surfactant molecules group together to form three-dimensional structures known as “micelles”. These structures are clusters of molecules with an oily center made up of the non-polar tail, surrounded by a shell formed by the polar portion of the molecule. These micelles absorb oils from your skin, hair or clothes, and trap them inside until they are removed from the surface by the rinsing phase of the process. Another very important property of surfactants is their ability to produce significant foaming effects, an attribute considered to be desirable by many product developers.
The most commonly used materials for this purpose are called “anionic surfactants”, which have a negatively-charged head group (sulfate, sulfonate, isethionate”>, with a positively-charged counterion (typically sodium or ammonium”>. By learning the conventions for naming these surfactants, one can learn to recognize what they are. The accepted cosmetic nomenclature system (INCI”> adheres to the following format for naming anionic surfactants: positive counterion name, followed by a term that denotes the structure of the non-polar tail portion, ended by the name of the anionic head group (example: ammonium lauryl sulfate”>.
Perhaps the harshest anionic surfactant, and also the one most commonly used in shampoos until recently, is sodium lauryl sulfate (SLS”>. “Lauryl” means 12 carbons in the nonpolar portion of the molecule, and is the shortest length of chain used in most surfactants. This surfactant is extremely efficient at removing oils from the hair, and can lead to dry, brittle hair. Sodium laureth sulfate (SLES”> is a modified version of SLS, containing 2-3 ether units in the molecule. This modification reduces the efficiency of the detergency action, decreasing its drying tendencies compared to SLS. Ammonium lauryl sulfate and ammonium laureth sulfate are the same surfactant molecules as SLS and SLES, respectively, simply with a different positively-charged counterion (ammonium vs. sodium”>. Thus, ALS and ALES can be expected to give very similar results to SLS and SLES in terms of removing oils from the hair.
Some anionic surfactants can provide comparatively gentle cleansing to the hair because they do not remove as many oils and fats. Anything with a carbon count above 12 (in even increments”> is considered to be less harsh. Some examples of this are sodium myreth sulfate and sodium C14-16 olefin sulfonate. Also, sodium coco sulfate, derived from coconut oil, contains a mixture of chains containing anywhere from 8-18 carbons. This makes it gentler than SLS. There are also numerous nonionic surfactants, such as sorbitol, decyl glucoside, laureth 4-20, and decyl polyglucose, which contain no positively or negatively-charged groups. These surfactants are considered to be much less drying to the hair.
Another group of surfactants has recently been finding much use in formulations made specifically to provide extremely gentle cleansing while imparting an emollient feel, such as Jessicurl’s Hair Cleansing Cream. These are amphoteric surfactants, which have both a positive and negative charge. Some examples of these are cocamidopropyl betaine, cocobetaine, and lauroamphoacetate. These surfactants aid in foam-boosting without stripping too much oil or irritating the skin, and are thus valuable for mild formulations.
Summary
As we become more educated about our hair and about the ingredients used in many traditional shampoos, many curlies with especially dry hair are electing to use a shampoo free method of cleansing with conditioners. While this works for many, some still seek the option to wash their hair with shampoo. More and more people are seeking alternatives to shampoos containing harsh, sulfate-based surfactants such as sodium lauryl sulfate (SLS”>, sodium laureth sulfate (SLES”>, and ammonium lauryl sulfate (ALS”>. Fortunately, many new products are being marketed that provide gentle cleansing, such as Jessicurl’s Hair Cleansing Cream, Mastey Traite’s Moisturising Crème Shampoo and Aubrey Organics to name a few.
Commonly used surfactants
- Ammonium lauryl sulfate
- Ammonium laureth sulfate
- Ammonium Xylenesulfonate
- Sodium C14-16 Olefin Sulfonate
- Sodium cocoyl isethionate
- Sodium cocoyl sarcosinate
- Sodium laureth sulfate
- Sodium lauryl sulfate
- Sodium lauryl sulfoacetate
- Sodium myreth sulfate
- Coco betaine
- Cocamidopropyl betaine
- Cocoamphoacetate