Synthesis of Poly(Ethyl vinyl ether) with high molecular weight by rare-earth metal cationic catalysts
作者：Yang Jianga, Shihui Li* , Dongmei Cui*
關(guān)鍵字：Ethyl vinyl ether,Rare-earth metal, Cationic polymerization, Ultra-high molecular weight, High activity
論文來(lái)源：期刊
具體來(lái)源：Polymer 226 (2021) 123790
發(fā)表時(shí)間：2021年
Ethyl vinyl ether (EVE) polymerizations by rare-earth metal complexes were studied. The metallocene complexes1–3 activated by organoborate displayed extremely high catalytic activities (≤1.50×106 g mol-1h-1) for EVEpolymerization at 25 ?C. The non-metallocene complexes 4–6 were nearly inert under the same conditions. Theresultant molecular weights produced by 1/[Ph3C][B(C6F5)4] increased from 2.98 ×104 to 19.3 ×104 g mol-1 with the temperature declining from 0 to 45 ?C and the addition of 10 equivalents of AliBu3 to the binary system 1/[Ph3C][B(C6F5)4] resulted in the higher molecular weight product (32.5 ×104 g mol-1) at .45?C.With the molar ratio of EVE-to-1 increased from 2000:1 to 10000:1, the resultant molecular weight reached107.3 ×104 g mol-1 but the catalytic activity dropped dramatically from 7.60 ×105 to 0.57 ×105 g mol Sc-1 h-1.The dicationic species formed by the reaction of 1 with 2 equivalents of [Ph3C][B(C6F5)4] displayed high catalytic activity for EVE
polymerization and gave high molecular weight product in the presence of AliBu3.