Thermal studies of poly(carbonates) and poly(thiocarbonates) containing silicon or germanium in the main chain

Abstract

The thermal properties of poly(carbonates) and poly(thiocarbonates) containing silicon or germanium in the main chan, derived from thediphenolsbis(4-hydroxy-phenyl)-dimethylsilane, bis(4-hydroxyphenyl)-dimethylgermane, bis(4-hydroxy-phenyl)-diphenylsilane and bis(4-hydroxyphenyl)-diphenylgermane, and phosgene or thiophosgene, were studied by differential scanning calorimetry and dynamic thermogravimetry. Polymers containing phenyl groups bonded to the heteroatoms showed higher Tg values, and the same was valid for those with Ge in respect to Si. Poly(carbonates) showed higher Tg values than poly(thiocarbonates). The thermogravimetric curves revealed that poly(carbonates) are more stable than poly(thiocarbonates)and the same is valid for those containing Ge with respect to the silicon-containing polymers. The kinetic parameters associated with the degradation process, showed that probably there are complex degradation mechanisms, which depend on the heteroatom in the main chain, Si or Ge, and the groups bonded to it, and the nature of the functional group, carbonate or thiocarbonate.