THE SYNTHESIS OF POLY(PHENYLENESILCARBO)O RGANOCYCLOSILOXANES AND SOME OF ITS PROPERTIES

A series of new polymers with a cyclolinear structure, containing a di silylphenylene fragment in the main chain, were synthesized by hydrosi lylation of divinylorganocyclotetrasiloxanes with 1,4-bis(dimethylsily l)benzene. The composition and structure of poly(phenylenesilcarbo)org anocyclosiloxanes were confirmed by Si-29 and H-1 NMR, and by IR spect roscopy. It was been shown that both high-molecular-mass polymers and oligomeric products, with a definite length n of the chain and the ter minal Si-H and Si-CH=CH2 groups, can be obtained by hydrosilylation. T he physicochemical properties of poly(phenylenesilcarbo)organocyclotet rasiloxanes, which are given in comparison with the properties of othe r cyclolinear polysiloxanes, are characterized by the presence of the disilylphenylene fragment and the nature of the organocyclotetrasiloxa ne side groups.