Synthesis and characterization of poly(amides) derived from diamines with germanium and silicon

Poly(amides) (PAs) derived from bis(4-aminophenyl)-diphenylgermane and bis( 4-aminophenyl)-diphenylsilane, and terephthaloyl, isophthaloyl, and chlorot erephthaloyl chlorides, were synthesized in N, N-dimethylacetamide solution . The products were characterized by IR and NMR spectroscopy. The results w ere in agreement with the proposed structures. The yields were almost-quant itative for PAs derived from terephthaloyl and isophthaloyl chlorides. Howe ver, the yields from the diacid tetrachloroterephthaloyl chloride were very low due to low reactivity. The inherent viscosity values of all PAs measur ed in o-chlorophenol were very similar. Thermogravimetric analysis indicate d that the Ge-containing PAs were more stable than were those containing Si due to the higher polarity of the C Si bond. The PAs derived from tetrachl oroterephthaloyl chloride are exceptions owing to the influence of the chlo rine atoms. The glass transition temperatures (T-g) were determined for all the PAs. The PAs derived from the Si-containing diamine have a value highe r than that for the Ge-containing diamine.