Side Group Modified Polysiloxanes

The chemistry and technology of siloxane-based polymers, or silicones, is a very broad and still growing research area owing to their many unique properties such as thermal and oxidative stability, low surface tension, gas permeability, excellent dielectric properties, physiological inertness and moisture resistance [1–3]. Because of these properties silicones find a tremendous number of applications. Modifications of polysiloxane side groups are extensively explored in order to obtain polymers with special properties or to make them chemically active, thus giving access to new industrial applications. Polysiloxanes may be silicon-functional, i.e. the functional group, X, is directly attached to the silicon atom (Si-X), or organofunctional, i.e. the functional group is fixed via a Si-C alkylene or arylene group (Si-R-X). The most important functional groups include hydrogen, vinyl, chloro, hydroxy, mercapto, alkoxy, cyano, methacryloxy and amino groups. There are three general routes to obtain side groups modified polysiloxanes: modification of polysiloxanes, polycondensation of bisilafunctional monomers and ring-opening polymerisation of functional cyclosiloxanes.