Synthesis and characterization of a silarylene–siloxane–diacetylene polymer and its conversion to a thermosetting plastic

The synthesis and characterization of a linear silarylene–siloxane–diacetylene polymer 1 and its conversion to a highly cross-linked thermoset 4 are discussed. The linear polymer was prepared via polycondensation of 1,4-bis(dimethylaminodimethylsilyl)butadiyne, [(CH3)2N–Si(CH3)2–CC–CC–(CH3)2SiN(CH3)2], 2 with 1,4-bis(hydroxydimethylsilyl)benzene 3. Conversion to a thermoset 4 occurs through the diacetylene groups above 300 °C. The thermoset was observed to exhibit long-term thermo-oxidative stability up to 350 °C in air as determined by thermogravimetric analysis.