Styrene copolymers silanol groups

Based on this approach Schouten et al. [254] attached a silane-functionalized styrene derivative (4-trichlorosilylstyrene) on colloidal silica as well as on flat glass substrates and silicon wafers and added a five-fold excess BuLi to create the active surface sites for LASIP in toluene as the solvent. With THF as the reaction medium, the BuLi was found to react not only with the vinyl groups of the styrene derivative but also with the siloxane groups of the substrate. It was found that even under optimized reaction conditions, LASIP from silica and especially from flat surfaces could not be performed in a reproducible manner. Free silanol groups at the surface as well as the ever-present impurities adsorbed on silica, impaired the anionic polymerization. However, living anionic polymerization behavior was found and the polymer load increased linearly with the polymerization time. Polystyrene homopolymer brushes as well as block copolymers of poly(styrene-f)lock-MMA) and poly(styrene-block-isoprene) could be prepared. 

The reported grafting of styrene-butadiene copolymers to asbestos has been attributed to a similar type of mechanism in which carbenium ions are deactivated by silanol groups on the substrate. "... 

A series of novel styrene- and siloxane-based silanol polymers and copolymers were synthesized by a selective oxidation of the Si—H bond with a dimethyldioxirane solution in acetone from corresponding precursor polymers. The conversion of the Si—H to Si—OH in the polymer modification proceeded rapidly and selectively. The silanol polymers obtained in situ showed no tendency for self-condensation to form siloxane crosslinks in solution. Moreover, stable silanol polymers in the solid states were obtained by placing bulky substitute groups bonded directly to the silicon atom. It was found that the properties of these novel silanol polymers and copolymers depended largely on substituents bonded directly to the silicon atom and silanol composition in the copolymers as well. 

---