HYDROGEN-BONDING IN POLYBENZIMIDAZOLE POLY(ETHER IMIDE) BLENDS - A SPECTROSCOPIC STUDY

A systematic investigation by FTIR spectroscopy of the blend system consisting of the polybenzimidazole poly[2,2'-(m-phenylene)-5,5'-bibenzimidazole] (PBI) and the poly(ethe imide) poly[2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane-m-phenylenediimine] (Ultem 1000) has been undertaken. Direct evidence of hydrogen bonding involving the N-H groups of PBI and the imide carbonyls of Ultem 1000 is presented. Qualitative as well as quantitative information concerning this molecular interaction has been obtained and is discussed. Finally an FTIR-temperature study of this quasi-miscible system is reported: by monitoring the frequency of the asymmetric stretching vibration of the imide carbonyls as a function of temperature, information has been derived on the phase separation process for various blend compositions.