Abstract

Poly(imide-amides) (PIAs) were obtained from aspartic and glutamic acids containing both a 1,8-naphthlimidyl side group and the diamine bis(4-aminophenyl) diphenylsilane, according to the Yamazaki method and characterized by elemental analysis, optical activity, IR and H-1, C-13 and 29Si NMR spectroscopy. PIAs were soluble at room temperature in common aprotic polar solvents (DMSO, DMAc, DMF, NMP) and in other of lower polarity but low boiling point (CHCl3, THF) after heating. The inherent viscosity values were low, which was indicative of low molecular weight species of oligomeric nature. The Tg values were relatively high considering the aliphatic nature of the diacids and the bulky side groups, which cause an impediment to the rotation. It is possible to suppose a weak hydrogen bond interaction between the NH groups of the amide and the carbonyl groups of the imide. When the Tg of both PIAs was compared, it was possible to see a decrease when the main chain was increased in one -CH2-group. PIAs were not thermostable but the TDT values were relatively high considering the aliphatic nature of the diacid moiety, being PIA-As more thermostable than PIA-Gl with a longer aliphatic chain. Both PIAs showed a similar optical behavior and high transparence at 450 nm, which can be explained by the aliphatic character of the diacid moiety.