(Polym. Chem.) An Entropy-Driven Ring-Opening Metathesis Polymerization Approach towards Main-Chain Liquid Crystalline Polymers
作者：Deng, L.; Guo, L.; Lin, B.; Zhang, X.; Sun, Y.; Yang, H.*
關鍵字：Liquid Crystalline Polymer
論文來源：期刊
具體來源：Polymer Chemistry, 2016, 7, 5265-5272.
發表時間：2016年
The known synthetic methods of preparing main-chain liquid crystalline polymers (MCLCPs) are rather limited to several polycondensation reactions. However, the nature of step-growth polycondensation endows the corresponding MCLCPs with relatively low molecular weights and broad molecular weight distributions. In this manuscript, an entropy-driven ring-opening metathesis polymerization (ED-ROMP) approach is for the first time applied in producing a MCLCP by polymerizing a macrocyclic olefin monomer containing one cyclohexanecarboxylic acid phenyl ester group as the mesogenic core and one icos-10-enedicarbonyl group as the flexible aliphatic chain. In comparison, Yamaguchi macrolactonization and ring-closing metathesis (RCM) methods are used to synthesize the macrocyclic olefin monomer respectively, which turns out that although the macrolactonization method can prepare a pure macrocyclic monomer, RCM strategy is advantageous in providing a much higher overall reaction yield. Furthermore, compared with a traditional acyclic diene metathesis (ADMET) polymerization of mesogenic α,ω-diene, the ED-ROMP approach starting with the same monomer-to-catalyst ratio, releases no heat or volatiles during the reaction, and can efficiently provide MCLCPs with much higher molecular weights in shorter reaction time.