Synthesis and thermal properties of fully aromatic polysilarylenesiloxanes

Abstract

A new type of fully aromatic polysilarylenesiloxanes showing high T g was synthesized via the solution polymerization from the bis(diphenylhydroxysilyl)arylene monomers. And the thermal properties of these monomers and polymers were investigated by using differential scanning calorimetry (DSC), and thermogravimetry analysis (TGA). The monomers containing the diphenylsilanol group showed higher melting temperatures and thermal degradation temperatures than those of the monomers containing the dimethylsilanol group, The obtained fully aromatic polysilarylenesiloxanes were insoluble powders, and showed no weight loss in air below 500 °C. No glass transition was detected according to the DSC measurements, whereas 3a and 3b showed melting points at 323 and 391 °C, respectively. However, 3b held solid-state at melting point. It would be caused by a cross-linking reaction occurring with melting simultaneously. It was found that these were the thermally stable polymer-solids consisted of the organosiloxane polymers.