Thermal resistance of polyphenylenequinazolines

Studied was the thermal degradation of quinazolin-containing polymers and 2,4- diphenylbenzquinazolin modeling the elementary link of polymer. It was revealed that the thermal stability of investigated phenylbenzquinazolins depends on the extent of phenyleneoxid fragments and heterocycle, as a predominant substitution of a phenyl radical in position 2 of heterocycle - coplanar, whereas the substitution of a phenyl radical in position 4 of the heterocycle - orthogonal.