What Is the Chemical Formula for Dimethicone?

Dimethicone has a silky, non-greasy texture, so is used in hair care products.

If you have used a hair product meant to boost shine, then you have likely had first-hand contact with polydimethylsiloxane, or dimethicone, a polymer with a silicone backbone.

Formula

The chemical formula for dimethicone is [-Si(CH3)2O-]n.

Dimethicone Versus Methicone

Dimethicone is sometimes used interchangeably with methicone, which has similar properties. The difference between these two polymers is that the repeating unit of dimethicone contains two methyl groups (CH3), while methicone has one.

Dimethicone Versus Carbon Polymers

Carbon polymers, such as nylon and polyester, tend to be more solid than silicone-based rubbers; still, silicone rubber is more widely used in medical supplies and generally holds up better in harsh environments than carbon-based rubber.

Properties

Like many silicones, dimethicone has a silky, non-greasy texture, making it popular for hair products, personal lubricants and sunscreens.

Other Uses

Dimethicones may be formulated with other agents for new uses; examples include cetyl dimethicone as an anti-foaming agent and stearamidopropyl dimethicone as a corrosion inhibitor for metal.

References

• Cosmetics Info
• Oxford University
• Sci-Toys: Silicones