Evident solvent effect on propagation reactions during radical copolymerization of maleimide and alkene

Abstract

The radical copolymerization of N‐(2,6‐dimethylphenyl)maleimide (DMPhMI) and 2,4,4‐trimethylpentene (TP) was investigated in several solvents at 60°C. The copolymerization rate and the molecular weight of the resulting copolymers were dependent on the kind of solvent used. It was also revealed that the monomer reactivity ratios depended on the solvent; r1 = 0.086 and r2 = 0 in chloroform and r1 = 0.25 and r2 = 0 in benzene, where DMPhMI and TP are M1 and M2, respectively. The propagation rate constants were determined for the homopolymerization and copolymerization in chloroform and benzene using electron spin resonance spectroscopy. The homo‐ and crosspropagation rate constants (k11 and k12, respectively) were revealed to depend on the solvent: k11 is 20 and 37 L/mol·s and k12 is 230 and 150 L/mol·s in chloroform and in benzene, respectively. The interaction between the maleimide moiety and the solvent molecules was discussed based on the acceptivity of the solvents. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1515–1525, 1997

Radical copolymerization ofN-phenylmaleimide and diene monomers in competition with diels-alder reaction

“…As a result, the copolymer was obtained in only 7% yield. Thus, the solvent effect was not valid for the control of the reaction pathways in this study, while the copolymerization behavior of the RMIs significantly depended on the Lewis acidity of the solvents, as reported in the literatures …”

Sequence-Controlled Radical Polymerization of N-Substituted Maleimides with 1-Methylenebenzocycloalkanes and the Characterization of the Obtained Copolymers with Excellent Thermal Resistance and Transparency

“…The values of r 12 > 1 and r 22 < 1 agreed well with the fact that the AAB-type periodic copolymer with a 2:1 composition of BMI and BC7, i.e., poly(BMI- per -BMI- per -BC7), was predominantly produced. The penultimate group effect was indispensable for the production of the 2:1 sequence-controlled copolymers, but the origin of the effect has not been revealed yet. , Both the polar and steric effects are important to determine the monomer reactivity, and a significant solvent effect was also pointed out for the RMI–olefin copolymerization systems. ,,, In this study, we found that the coplanarity of the exomethylene moiety and the benzene ring of BC m s significantly determined the reactivity of the monomer and the corresponding propagating radicals as follows.…”

“…63,64 Both the polar and steric effects are important to determine the monomer reactivity, and a significant solvent effect was also pointed out for the RMI−olefin copolymerization systems. 28,44,65,66 In this study, we found that the coplanarity of the exomethylene moiety and the benzene ring of BCms significantly determined the reactivity of the monomer and the corresponding propagating radicals as follows.…”

Design, Synthesis, and Characterization of Bismaleimide Co-Curing Elastomers

“…Copolymerization Strategies. Alternating copolymerizations of N-substituted maleimides reacting with isobutene, 32 2,4,4-trimethylpentene, 33 cyclohexene, 34 and other donor monomers 35 are well documented, and our analysis of the 2methyl-2-pentene + NPM reaction products suggests that copolymerization is a contributor to the reactivity of high-IP grades of IIR. However, inefficiencies in the IIR system are evident from the relatively poor performance of NPM as a curative, thereby fueling our interest in CC functionality that engages maleimides in more efficient radical copolymerizations.…”