COMPATIBILITY OF POLYETHER SULFONE AND POLYIMIDE DERIVED FROM ISOMERIZATION OF POLYISOIMIDE - AN APPROACH TO IN-SITU GENERATED RIGID-ROD MOLECULAR COMPOSITE

An approach to in-situ generated rigid-rod molecular composites (RRMC) was investigated. This method requires a coil-like aromatic polyisoim ide (PII) which soluble and compatible with an amorphous matrix polyme r and can undergoes thermal isomerization to the corresponding rigid-r od polyimide CPI) in the solid composite state. PII was prepared by th e ring-opening polyaddition of pyromellitic dianhydride (PMDA) and 2,2 ',6,6'-tetramethylbenzidine (TMBZ) followed by treatment with trifluor oacetic anhydride-triethylamine in NMP. A miscible solution blend of P II and poly(oxy-1,4-phenylenesulfonyl- 1,4-phenylene) (PES) was obtain ed. The compatibility of blend films was investigated by transmission electron microscopy (TEM). The diameter of PI domain for the PI/PES, 4 /96 was found to be approximately 0.2 mu m, and the formation of an in terpenetrating structure was confirmed by the elemental analysis on th e domain part. Transparent composite films were obtained at PI content of 2 to 10wt%.