POLYCARBOSILANES CONTAINING SILOXY AND OR SILANAMINE UNITS BY POLYCONDENSATION USING HYDROSILYLATION/

Poly(1,1-dimethyl-1-silylethylene) : -(SiMe2-CH2-CH2)-(n) was prepared by polycondensation of HSiMe2-CH2-CH2-SiHMe2 (A) with CH2=CH-SiMe2-CH 2-CH2-SiMe2-CH=CH2 (B) under suitable hydrosilylation conditions. Func tional oligomers with either two SiH or two Si-CH=CH2 end groups were obtained by using an excess of A or B respectively. These bifunctional oligomers were used as precursors for the preparation of well-defined networks by reaction with different tetrafunctional crosslinking agen ts such as D4H, D(4)Vi(b)) and tetravinylsilane (TVS). They were also used for the preparation of multiblock copolymers by reaction with dim ethylsiloxane oligomers. Alternating copolymers were obtained from mon omers containing siloxy or silanamine units. Thermal properties of the se polymeric materials are presented.