Synthesis and properties of polyimides from 1,3-di(p-dimethylaminobenzyl)-imidazolidine-2-thion

SummaryA synthetic strategy is presented that allows the preparation of dimethylamino functionalized heterocyclic system 1,3-di (p-dimethylaminobenzy1)-imidazolidine-2-thion that was then used to prepare polyimides by the two-stage polycondensation method. The key to this success was the development of an efficient procedure leading highly pure dimethylamino monomer. Polyimides derived from 1,3-di(p-dimethylaminobenzyl)-imidazolidine-2-thion and commercial dianhydrides exhibited excellent solubility in various polar solvents. These polymers showed glass transition temperatures between 290–360°C, and initial decomposition temperature 490–485 °C and 10% mass loss ranging from 505–75°C in air.