Article by: Perry Romanowski
Cosmetic Science in 300 Seconds – Silicones
Welcome to Cosmetic Science in 300 seconds brought to you by Chemists Corner.
Today’s topic is silicones.
In the cosmetic industry, the term silicone applies to a group of compounds that contain the element silicon. First introduced into cosmetics in the 1950’s, these materials have a number of unique characteristics that make them useful for improving the feel and appearance of skin and hair.
Silicon is abundant and found in over 90% of minerals that make up the Earth’s crust. Since it was readily available, people living during the Stone Age used silica based stones for making tools. Silicon technology was first begun by then Ancient Egyptians around 3000 BCE when they converted sand, which is primarily silicon dioxide, into glass.
Silicon wasn’t identified as an element until 1824 when Jí¶ns Jacob Berzelius isolated it. Later in the 1850’s, H.E. Saint-Claire Deville developed a method for obtaining pure silicon. In the late 1800’s, Dr. Frederick Kipping began synthesizing a number of silicon-carbon polymers that he called “silicones”. In the 1930’s, the first commecial silicone was introduced by Corning Glass and “silly putty”, a silicone based toy was accidentally developed in the 1940’s.
Silicone compounds were first applied to cosmetics in the 1950’s with the introduction of Dimethicone. In the 1970’s, silicones were incorporated into hair products and now silicones can be found in over half of all new cosmetic products.
The silicone compounds used in cosmetics are polymers which feature a monomer with a silicon bonded to two oxygen atoms. This silicone backbone can be chemically reacted with different kinds of ingredients to produce a wide variety of materials with unique characteristics. Common types of silicones include Dimethicone, Cyclomethicone, and Dimethicone copolyol.
The most basic silcone in cosmetics is Dimethicone. It has a silicone backbone which is surrounded by methyl groups. It is a clear, non-reactive, liquid product that can range in thickness, depending on the length of its polymer backbone, from watery thin to taffy thick. Cyclomethicone is a shorter cyclic molecule which has many of the same properties of dimethicone except that it evaporates while dimethicone does not.
Dimethicone copolyol is a silicone which contains an -OH group which makes it more soluble in water. This makes it easier to incorporate into formulations but also reduces the usefulness of the silicone.
Most silicones are incompatible with water and will readily form thin films when put on most any surface. This characteristic leads to some of the most useful properties of silicones.
Silicones are incredibly slippery and slick. Water slides right off them so surfaces covered with silicones can be made essentially waterproof. This is useful for make-up and styling products. This slickness also makes silicones ideal for hair products that make combing easier and skin products that improve the feel of dry skin.
Since silicones make nice, even films they impart a natural shine to surfaces on which they are put. This makes them ideal for cosmetics that where shine is desired such as in hair shine products, color cosmetics, and nail polishes. Other uses of silicones include foam reduction, skin oil control, and hair color protection. Silicones can also be used to reduce the irritation of other cosmetic ingredients because they are non-reactive and non-toxic.
While there is the potential for negative effects of silicones due to build-up, the proper use of these compounds has led to significantly better performing cosmetic products.
New silicone compounds are always being synthesized and tested by raw material manufacturers. In the future, silicones may be developed that will significantly reduce hair damaged by heat, provide anti-aging benefits, make hair stronger, and create cosmetics that work faster and last longer.
This brings us to the end of Cosmetic Science in 300 Seconds. I’d like to thank the people at Xiameter Silicones for help in making this video. If you want to learn more about cosmetic science and formulating please visit our website Chemists Corner.com.
I’m Perry Romanowski, thanks for watching.