Solvent effect on radical homo- and copolymerization of di-2-[2-(2-methoxyethoxy)ethoxy]ethyl itaconate

Solvent effect on homo- and copolymerization of di-2-[2-(methoxyethoxy)ethoxy]ethyl itaconate (DMEI) was studied at 50 degreesC using dimethyl 2,2'-azobisisobutyrate as radical initiator. The polymerization rate (R-p) highly depended on the kind of solvent; 19 solvents were used. The highest R-p (in 1-tetradecanol) is 13 times the smallest (in chloroform). On the other hand, the solvents did not exert as great an effect on the molecular weight of the resulting polymers. The propagation rate constant (k(p)) was determined in 15 different solvents by means of ESR spectroscopy. The highest k(p) (4.5 l/mol s in toluene) is 5.6 times the lowest (0.8 l/mol s in chloroform). A noticeable solvent effect was also observed in the copolymerization of DMEI (M-1) and styrene (M-2), where nine solvents were used. The highest r(1) (0.46 in 1-butanol) is about 6 times the lowest (0.08 in methanol). The r(2) value falls in the range of 0.2 (dimethyl sulfoxide) and 0.52 (benzene). The solvent effects thus observed were analyzed according to the linear solvation energy relationship proposed by Taft and co workers. (C) 2002 Elsevier Science Ltd. All rights reserved.