Exclusive! Comparatively Speaking: Dimethicone vs. Alkyl Dimethicone

Posted: May 7, 2006

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Alkyl dimethicones are made by the hydrosilation reaction of a silicone hydride fluid with an olefin containing terminal double bond. They are not water-soluble, but can be either silicone- or oil-soluble, depending on the ratio of x, y and z. The higher the value of x and the lower the value of z, the more silicone soluble it will be; and the higher value of y and z, the more oil soluble it will be.

As well, by varying the ratio of x, y and z, one can make an alkyl dimethicone that is liquid, a soft paste or a hard wax. Generally, if one uses an olefin with 22 or higher alkyl groups, the product will be a paste or hard wax, depending on the ratio of x to y. The higher the value of x, the lower the melt point of the product.

When one uses an olefin with 18 carbon groups, the alkyl dimethicone can be a liquid to hard wax, depending on the ratio of x to y. Alkyl groups with 16 carbon groups or lower are normally liquids to soft pastes. Alkyl dimethicone provides cosmetic elegance to formulations containing them. They also improve SPF values when added to sunscreens.

The alkyl dimethicones are used when silicone feel and conditioning is desired from an oil or ester based product for which the dimethicones are not soluble. They can also be used in silicone based systems to provide the feel of esters and oils.

Alkyl Dimethicone structure: