Synthesis and characterization of near-monodisperse electron acceptor homopolymers of 2-[(3,5-dinitrobenzoyl)oxy]ethyl methacrylate

Homopolymers of 2-(trimethylsiloxy)ethyl methacrylate of degrees of polymer ization from 5 to 50 were synthesized by group transfer polymerization in t etrahydrofuran (THF) using 1-methoxy-1-(trimethylsiloxy)-2-methyl propene a s the initiator and tetrabutylammonium bibenzoate as the catalyst. These po lymers were first converted to poly[2-(hydroxy)ethyl methacrylate]s by remo val of the trimethylsilyl-protecting groups by acidic hydrolysis, and subse quently transformed to poly{2-[(3,5-dinitrobenzoyl)oxy]ethyl methacrylate}s by reaction with 3,5-dinitrobenzoyl chloride in the presence of triethylam ine. Gel permeation chromatography in THF and proton nuclear magnetic reson ance (H-1 NMR) spectroscopy in CDCl3 and d(6) dimethyl sulfoxide were used to characterize the polymers in terms of their molecular weight and composi tion. The molecular weights were found to be close to the values expected f rom the polymerization stoichiometry and the molecular weight distributions were narrow, with polydispersity indices around 1.1. The hydrolysis and re esterification steps were found to be almost quantitative for all polymers. Differential scanning calorimetry and thermal gravimetric analysis were al so employed to measure the glass transition temperatures (T-g's) and decomp osition temperatures, which were determined to be approximately 80 and 320 degrees C, respectively. (C) 2000 John Wiley & Sons, Inc. J Polym Sci A: Po lym Chem 38: 1457-1465, 2000.