Thermal Stability of Polyimide-benzothiazoles

Polyimide-benzothiazoles were prepared by the reaction of pyromellitic dianhydride with 2, 5- and 2, 6-diaminobenzothiazoles. Simillarly, polyamide-imide-benzothiazoles were obtained from 4-chloroformyl phthalic anhydride and the diaminobenzothiazoles. Thermal stability of these polymers was studied by thermogravimetric analysis. Polyimide-benzothiazoles are thermally stable up to 500°C in air, and the thermal stability is nearly comparable to that of well-known polypyromellitimide derived from 4, 4′-diaminodiphenyl ether. Polyamide-imidebenzothiazoles are less thermally stable than polyimide-benzothiazoles due to the existence of amide linkages in the polymer main chain.