Polystyrene crosslinked with oligomeric and polymeric poly(dimethyl siloxane) derivatives. Thermal and dynamic mechanical studies

Styrene has been copolymerized with various bifunctional poly(dimethyl siloxane) cross‐linkers having molar masses in the range 200–35,000. Calorimetric and rheological measurements show that the crosslinkers change Tg, Tll, and Texo, as well as melt viscosity and elasticity of polystyrene. These changes are strongly dependent on the molar mass of the crosslinker. Increasing the length of the siloxane crosslinker lowers Tg and melt viscosity, if the molar mass of the crosslinker is in a range 200–2000. Copolymerizing styrene with a bifunctional poly(dimethyl siloxane) having molar mass near 35,000 leads to a phase‐separated polymer where polystyrene phase largely retains its original properties.