Ethyl Polysilsesquioxane
INCI: ETHYL POLYSILSESQUIOXANE
Reviewed by Daisy · Last updated 18 Aug 2026
What Is Ethyl Polysilsesquioxane?
Ethyl Polysilsesquioxane is a resinous material composed of a mixture of three-dimensional siloxane polymers and oligomers with cage structures. For the oligomers, each silicon atom in the polysilsesquioxane is connected via oxygen atoms to three other silicon atoms and can be represented by the empirical formulation RSiO3/2, where R represents the ethyl group. For the larger polymeric polysilsesquioxanes, some of the silicon atoms are not connected to other silicon atoms and instead have a silanol (SiOH) group. Ethyl Polysilsesquioxane is prepared by the hydrolysis and condensation of ethyl trimethoxysilane.
Its declared cosmetic function is nail conditioning.
Source: European Commission CosIng inventory.
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