COMPATIBLE POLYNAPHTHIMIDAZOLE BLENDS WITH A BENZOPHENONE-BASED POLYIMIDE AND THEIR FILM PROPERTIES

A series of new blends of the aromatic polynaphthimidazole (PNI) from 3,3'-diaminobenzidine (DAB) and dimethyl 2,6-naphthalenedicarboxylate, and the polyimide (PI) from 1,4-phenylenediamine and 3,3',4,4'-benzop henonetetracarboxylic dianhydride has been prepared by film casting fr om methanesulfonic acid solution mixture. The compatibility of PNI/PI blends is evidenced in the form of change in FTIR spectroscopy and sin gle tan delta relaxation from dynamic mechanical analysis (DMA). The i ntermolecular interaction involving the N-H and carbonyl groups played an important role in the compatibility between polynaphthimidazole an d polyimide. The tensile test in a series of PNI/PI blend films confir ms that PNI/PI = 80/20 wt.% has the highest tensile strength and modul us.