Spectroscopic and thermal characterization of poly(glycidyl azide) converted from polyepichlorohydrin

Poly(glycidyl azide) (PGA) was synthesized by reaction of polyepichlorohydrin (PECH) with sodium azide (NaN3) by using phase-transfer catalysis. A detailed analysis was performed to follow the polymer-polymer conversion reaction. Conversion of -CH2-Cl to -CH2-N-3 was achieved completely in 6 h, as determined from FTIR assignment, UV-VIS spectroscopy, and thermal analysis. In FTIR and UV-VIS spectroscopy studies, the reaction was followed from the change in characteristic peak intensities. Thermal analysis also showed that the first thermal decomposition process of PGA, which is due to the exothermic cleavage of pendant -N-3 groups, was Shifted to higher temperatures, and the exothermicity was increased as the conversion proceeded. It was also found that the extent and completion of -Cl to -N-3 conversion could be easily followed by measuring the glass transition temperature and exothermic decomposition of the polymers. The quantitative analysis of the data collected from FTIR and DSC measurements showed that PECH --> PGA conversion is a first-order reaction with a rate constant of K = 0.74 h(-1). (C) 1996 John Wiley & Sons, Inc.