화학공학소재연구정보센터
Reactive & Functional Polymers, Vol.127, 94-112, 2018
Living anionic polymerization of 1,4-divinylbenzene and its derivatives
The living anionic polymerization of 1,4-divinylbenzene and its derivatives was reviewed. With the use of a specially-designed initiator system prepared from oligo(a-methylstyryl) lithium and potassium tert-butoxide, the living anionic polymerization of 1,4-divinylbenzene was successfully realized for the first time. During this polymerization, one of the two vinyl groups was selectively polymerized in a living manner, while the other vinyl group remained completely intact in the main chain. Soluble linear polymers with well-controlled molecular weights up to 60.5 kg mol(-1) and narrow molecular weight distributions (M-w/M-n < 1.05) were obtained under such conditions. The success of the living polymerization may possibly result from the formation of the less reactive by less dissociation and bulkier anionic species and the reactivity differentiation between the two vinyl groups before and after the polymerization. It was also demonstrated that a variety of divinylbenzene derivatives, such as 1,2-divinylbenzene, 1,4-divinylnaphthalene, 2-methoxy-1,4-divinylbenzene, 4-methoxy-1,2-divinylbenzene, 4-methoxy-1,3-divinylbenzene, 1,4-diisopropenylbenzene, 4-(alpha-methylethenyl)styrene, 4-(aethylethenyl)styrene, 4-(alpha-butylethenyl)styrene, 4-(alpha-isopropylethenyl)styrene, and 4-(alpha-tert-butylethenyl) styrene, underwent the living anionic polymerization with the same designed initiator system under similar conditions. New well-defined block polymers and star-branched polymers with reactive poly(1,4-divinylbenzene) segment(s) could be successfully synthesized by using the living anionic poly(1,4-divinylbenzene). Throughout the block copolymerization study, it was found that the reactivities of 1,4-divinylbenzene and the generated chain-end anion were comparable to those of 2-vinylpyridine. Although 1,4-divinylbenzene is a styrene derivative, it was higher in monomer reactivity than styrene, but its chain-end anion was less reactive than that generated from styrene.