Yttrium-Catalyzed cis-1,4-Selective Polymerization of 2-(4-Halophenyl)- 1,3-Butadienes and Their Copolymerization with Isoprene
writer：Jian-Ming Huanga, Chang-Guang Yao, Shi-Hui Li and Dong-Mei Cui
keywords：cis-1,4-Selective, Coordination (co)polymerization, Poly(dienes);
source：期刊
Issue time：2020年
Polymerization of 2-(4-halophenyl)-1,3-butadiene (2-XPB) and their copolymerization with isoprene using a yttrium catalyst have been examined. The β-diketiminato yttrium bis(alkyl) complex (1) activated by [Ph3C][B(C6F5)4] and AliBu3 shows high cis-1,4-selectivity (> 98%) for the polymerization of 2-XPB (2-XPB = 2-FPB, 2-ClPB and 2-BrPB) to afford halogenated plastic poly(dienes) with glass transition temperatures of 30 – 55 oC. Moreover, the copolymerization of 2-XPB with isoprene (IP) has also been achieved by this catalyst, and the insertion ratios of 2-XPB can be facilely tuned in a full range of 0 – 100% simply by changing the 2-XPB–to–IP ratio. Quantitative hydrogenation of cis-1,4-poly(2-XPB) results in perfect alternating ethylene-halostyrene copolymers, and an alternating copolymer of 4-vinylbenzoic acid with ethylene is obtained by a consecutive reaction of ethylene-4-bromostyrene copolymer with nBuLi, CO2 and HCl.