How does Biosilk keep your hair smooth?
Although that particular brand name includes shampoos and hair sprays, we are talking about the conditioners and de-tanglers in this section.
To allow wet hair strands to easily slide past one another, conditioners and de-tanglers use two strategies.
First, they have ingredients that make the tiny scales on the hair shaft lie down, so they don’t have rough surfaces that grip other hair shafts. Citric acid is sometimes used for this purpose.
Second, they coat the hair shaft with slippery oils and silicones to make the hair shafts glide across one another easily during combing and brushing.
In Biosilk, cyclomethicone and dimethicone are the slippery silicone oils that help the strands untangle.
These are often used in other products as carrier fluids in hair sprays, or as skin protectants to act as a moisture barrier and prevent chafing.
Conditioners that you leave in the hair (instead of rinsing out) will contain mostly silicones and alcohol. To make the silicones feel less greasy, alkyl benzoates such as lauryl benzoate are used.
Alkyl benzoates are lubricants in themselves, and also serve as solvents to carry sunscreens, and they are emollients, keeping the skin from drying out. Alkyl benzoates are esters, compounds that result when an alcohol reacts with an acid, in this case a fatty acid from vegetable oil. The alcohol end (in this case the hexagonal benzyl alcohol at the bottom of the drawing) modifies the fatty end, so that it can join together oils and silicones, and also help retain the fragrance molecules.