Organosilicon Copolymers with Cyclosiloxane Fragments in the Side Chain

Organosilicon Copolymers with Cyclosiloxane Fragments in the Side Chain 

Organodichlorosiloxyorgano-cyclotri(tetra-penta)siloxanes have been prepared by heterofunctional condensation of hydroxyorganocyclotri(tetra-penta)-siloxanes with organotrichlorosilanes in the presence of amines. The hydrosilylation of methylvinyltetra-phenyltrisiloxane with methyldichlorosilane in the presence of platinum chlorohydric acid leads to dichloroorganosilacarbocyclotrisiloxane. The composition and structure of difunctional organocyclosiloxanes was determined by elementary and functional analysis, molecular mass determination, IR, NMR ( H, C) and mass spectral data. 

The heterofunctional condensation of dichlororganosiloxycyclotri(tetra-penta)siloxanes and dichlororganosililcarbocyclotrisiloxane with dihydroxydimethylsiloxanes in the presence of pyridine has been investigated. It was shown that for short lengths of the linear dimethylsiloxane link (n 4), the reaction of heterofunctional condensation proceeds both intermolecularly with formation of copolymers and intramolecularly with formation of bicycloorganosiloxanes. 

The catalysed reaction of the dehydrocondensation of a,co-bis(trimethylsiloxy) ethylhydridsiloxanes with hydroxyorganocyclosiloxanes in the presence of an alkaline metal catalyst has been investigated and organosiloxane copolymers with various amounts of cyclic fragments in the side chain has been obtained. Dehydrocondensation reaction order, rate constants and activation energy were measured. 

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