Characterization, properties, and processing of LaRC (TM) PETI-5 as a high-temperature sizing material. I. FTIR studies on imidization and phenylethynyl end-group reaction behavior

The imidization and phenylethynyl end-group reaction behavior of phenylethy nyl-terminated imide oligomers (LaRC(TM) PETI-6) with a number-average mole cular weight of 2500 g/mol has been extensively interpreted in terms of the disappearance and appearance of several characteristic absorption peaks. M ost characteristic FTIR absorption bands including the phenylethynyl end gr oup occurring via imidization and cure during dynamic and isothermal heat t reatments of LaRC(TM) PETI-6 were clearly resolved and assigned in the pres ent study. The results give some information on temperature- and time-depen dency of the cure of LaRC(TM) PETI-5, which may be useful for determining t he processing conditions necessary for use as a high-temperature fiber-sizi ng material. This study also measures the extent of imidization and the act ivation energy of cure reaction of this material. (C) 2000 John Wiley & Son s, Inc.