Synthesis of High Molecular Weight Vinylphenyl-Con Taining MQ Silicone Resin via Hydrosilylation Reaction

To overcome the inherent limitation that the preparation of high molecular weight MQ copolymers (Mw ≥ 30,000 g/mol) via the hydrolysis and condensation of solicate salts generally results in an intractable gel, vinylphenyl-containing MQ silicone resin with a high molecular weight was designed and synthesized through the hydrosilylation reaction of vinyl-containing MQ silicone resin and linear poly(diphenylsiloxane) with two terminal Si–H bonds. The weight average molecular weight of these modified copolymers reported here is at least 30,000 dal·mol−1. These polymers have favorable thermal stability and a higher refractive index than that of the base resin due to the formation of novel regular macromolecular structures and the introduction of phenyl groups. These inorganic/organic hybrid materials could be used as a potential component for temperature-resistance electronics adhesive, heat-resistant coatings and high-performance liquid silicone rubber. Moreover, the proposed process also provides a possibility to choose higher molecular weight MQ silicones according to application requirements.