C. Avadhani, P. Wadgaonkar, S. P. Vernekar
Jul 15, 1992
Citations
0
Influential Citations
10
Citations
Journal
Journal of Applied Polymer Science
Abstract
Four new formal-group-containing diisocyanates, namely, bis(3-isocyanatophenoxy) methane, bis(4-isocyanatophenoxy)methane, bis[2-(3-isocyanatophenoxy)ethyl] formal, and bis[2-(4-isocyanatophenoxy)ethyl] formal, were synthesized by the Curtius rearrangement from the corresponding dicarboxylic acids. The diisocyanates were polycondensed with pyromellitic dianhydride (PMDA) and benzophenonetetracarboxylic dianhydride (BTDA) in dimethylacetamide (DMAc) to obtain formal-group-containing polyimides. These polyimides were characterized by viscosity measurements, IR spectroscopy, X-ray diffraction, and thermogravimetric analysis.