Ren Yixin, Miller Justin T, Polderman Stefanie T, Vo Trinh D, Wallace Adele C M, Cue John Michael O, Tran Sarah T, Biewer Michael C, Stefan Mihaela C
Department of Chemistry and Biochemistry, The University of Texas at Dallas 800 W. Campbell Rd. Richardson TX 75080-3021 USA
Department of Bioengineering, The University of Texas at Dallas 800 W. Campbell Rd. Richardson Texas 75080-3021 USA.
RSC Adv. 2019 Jan 24;9(6):3345-3350. doi: 10.1039/c8ra10050k. eCollection 2019 Jan 22.
Neodymium-based Ziegler-Natta type catalytic systems are known to produce polydienes with high -1,4 content. It is generally believed that in Ziegler-Natta catalytic systems, a halide or pseudohalide, whether in the catalyst itself or a separate source, is required for the success of the polymerization. In this work, we have synthesized an unusual halide-free neodymium diethyl phosphate catalyst for diene polymerization. This neodymium complex combined with triisobutylaluminum (TIBA), formed a binary catalytic system and was used to polymerize β-myrcene. The catalytic system displays high stereospecificity and produces poly(β-myrcene) with 96% -1,4 content and a relatively narrow molecular weight distribution ( / = 1.80). Also, kinetic studies indicated the catalytic system gives a pseudo-living polymerization. The block copolymer poly(β-myrcene)--poly(isoprene) was successfully synthesized by sequential monomer addition, further demonstrating the pseudo-living nature of polymerization with the neodymium diethyl phosphate catalyst.
基于钕的齐格勒-纳塔型催化体系以生产具有高1,4-含量的聚二烯烃而闻名。人们普遍认为，在齐格勒-纳塔催化体系中，无论是在催化剂本身还是单独的来源中，卤化物或拟卤化物对于聚合反应的成功都是必需的。在这项工作中，我们合成了一种用于二烯烃聚合的不同寻常的无卤化钕二乙基磷酸酯催化剂。这种钕配合物与三异丁基铝（TIBA）结合，形成了二元催化体系，并用于聚合β-月桂烯。该催化体系表现出高立体特异性，生产出1,4-含量为96%且分子量分布相对较窄（/=1.80）的聚（β-月桂烯）。此外，动力学研究表明该催化体系呈现出准活性聚合。通过顺序添加单体成功合成了嵌段共聚物聚（β-月桂烯）-聚（异戊二烯），进一步证明了二乙基磷酸钕催化剂聚合的准活性性质。
