ABSTRACT
This chapter attempts to describe the structure, preparation, and surfactancy properties of the fascinating class of surfactants incorporating the substantial advances. Siloxane surfactants consist of a permethylated siloxane group coupled to one or more polar groups. This class of surfactants finds a variety of uses in applications where other types of surfactants are relatively ineffective. Siloxane surfactants were introduced to the marketplace in the 1950s for the manufacture of polyurethane foam. Polydimethylsiloxane is itself surface active. Gruning and Koerner suggest a broad definition of siloxane surfactants to include all surface active copolymers containing a siloxane entity. Siloxane surfactants are prepared by attaching one or more polar organic groups to a permethylated siloxane backbone. The first step in the synthesis of a siloxane surfactant is to prepare a siloxane backbone containing reactive sites at which to attach the polar groups. There are two ways to do this—cohydrolysis of the appropriate chlorosilanes and the equilibration reaction.
