cis-1,4 Selective Copolymerization of Butadiene and Functionalized α?Olefins via Polar Group Activation Mechanism
作者：Tiantian Wang, Chunji Wu and Dongmei Cui
關鍵字：Functionalized α?Olefins, Polar Group Activation
論文來源：期刊
發(fā)表時間：2020年
The cis-1,4 selective copolymerizations of butadiene (BD) with naked polar methylthio- and p-tolylthio-functionalized αolefins have been investigated by using the thiophene-fused cyclopentadienyl scandium complex. The substitutes of the α-olefins are critical to govern the performances of the copolymerizations and the chain structures of the resultant copolymers. The copolymerization of polar 4-methylthio-1-butene (MTB) and BD performs in dual high
syndioselectivity and cis-1,4 selectivity. The incorporation of MTB varies from 65.6% to 100% much high than its loading fraction, indicating the privilege of polar MTB coordination?insertion; thus, blocky microstructure is afforded. On the contrary, the copolymerization of 4-(p-tolylthio)-1-butene (pTTB) and BD is more controllable to display high activity and syndioselectivity albeit with slightly lowered cis-1,4 selectivity. The afforded copolymers possess high molecular weights close to the theoretical ones, and pTTB insertion could be precisely controlled by monomer feed ratio, suggesting the random microstructure. The possible mechanisms of copolymerizations are proposed.