Microstructure determination and thermal studies ofn‐acryloylcarbazole/vinyl acetate copolymers

Abstract

AbstractCopolymers ofN‐acryloylcarbazole (A) and vinyl acetate (V) were synthesized by bulk polymerization using benzoyl peroxide (BPO) as free‐radical initiator at 65°C in different in‐feed ratios. The composition of the copolymer was determined by1H‐NMR spectrum. The comonomer reactivity ratios, determined by Kelen–Tudos (KT) and nonlinear error‐in‐variables (EVM) methods, wererA= 16.75 ± 1.38,rV= 0.015 ± 0.002, andrA= 16.36,rV= 0.015, respectively. Complete spectral assignments of the1H and13C{1H} NMR spectra of the copolymers were done by the help of distortionless enhancement by polarization transfer (DEPT) and two‐dimensional NMR techniques such as heteronuclear single quantum coherence (HSQC) and total correlation spectroscopy (TOCSY). The methine and methylene carbon resonances were found to be compositional as well as configurational sensitive. The signals obtained were broad pertaining to the restricted rotation of bulky carbazole group. The thermal stability and glass‐transition temperatures (Tg) of the copolymers were found to be dependant on polymer composition and characteristic of rotational rigidity of the polymer chain. Variation in the values ofTgwith the copolymer composition was found to be in good agreement with theoretical values obtained from Johnston and Barton equations. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2720–2733, 2007