Hossein Behniafar
J Appl Polym Sci 101, 869–877 (2006)
Publication year: 2006
The direct preparation of various aromatic poly(urethane-imide)s from 4-p-biphenyl-2,6-bis(4-trimellitimidophenyl) pyridine (1) using diphenylphosphoryl azide (DPPA) was investigated. The polymers were mainly obtained by the conversion of imide ring-containing diacid 1 to corresponding di(carbonyl azide) 2 with DPPA and then to diisocyanate 3 through the Curtius rearrangement of compound 2 followed by polyaddition of 3 in different amounts with aromatic dihydroxy compounds. The molecular weights of the resulting poly(urethane-imide)s were evaluated viscometrically. All of the resulted polymers were thoroughly characterized by spectroscopic methods and elemental analyses. The poly(urethane-imide)s exhibited an excellent solubility in a variety of polar solvents. Crystallinity nature of the polymers was estimated by means of WXRD. The glass-transition temperatures of the polymers determined by DSC method were in the range of 191–202 °C. The 10% weight loss temperatures of the poly(urethane-imide)s from their thermal gravimetric analysis curves were found to be in the range of 392–416 °C in nitrogen. The films of the resulting polymers were also prepared by casting the solution.