Synthesis and characterization of thermooxidatively stable poly(dimethylsilyleneethynylenephenyleneethynylene) with o-carborane units

Carborane-containing poly(dimethylsilyleneethynylenephenyleneethynylene) (CB-PSEPE) with o-carborane in main chains was prepared by a coupling reaction between poly(dimethylsilyleneethynylenephenyleneethynylene) (PSEPE) and decaborane (B(10)H(14)) in the presence of acetonitrile (CH(3)CN). The chemical structures of CB-PSEPE were determined by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopies. The glass transition temperature (T(g)) and thermal curing behavior of CB-PSEPE were evaluated with differential scanning calorimetry (DSC). The thermal and thermooxidative stabilities were examined by thermogravimetric analysis (TGA). The results show that CB-PSEPE polymer could be converted into a thermoset below 250 degrees C. The thermoset exhibits excellent heat resistance especially under air atmosphere. The residue yield at 800 degrees C arrives at 95.8% for CB-PSEPE thermoset in air. When the thermoset was oxidized at 800 degrees C for 1 h in air, a protective layer would be formed on the surface of the oxidized product according to scanning electron microscopy (SEM) observations. (C) 2011 Elsevier Ltd. All rights reserved.