Pascual Ana, Sardon Haritz, Veloso Antonio, Ruipérez Fernando, Mecerreyes David
POLYMAT, University of the Basque Country UPV/EHU, Joxe Maria Korta Center, Avda. Tolosa 72, 20018, San Sebastian, Spain.
Ikerbasque, Basque Foundation for Science, E-48011, Bilbao, Spain.
ACS Macro Lett. 2014 Sep 16;3(9):849-853. doi: 10.1021/mz500401u. Epub 2014 Aug 12.
The use of organocatalysts for the polymerization of ethylene brassylate, a commercially available, cheap, and renewable macro(di)lactone is reported for the first time. Ethylene brassylate was polymerized by ring-opening polymerization under bulk and solution conditions at 80 °C. Polymerizations were carried out in the presence of several organic catalysts, such as dodecylbenzenesulfonic acid (DBSA), diphenyl phosphate (DPP), -toluenesulfonic acid (PTSA) and bases, 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 1,2,3-tricyclohexylguanidine (TCHG), and 1,2,3-triisopropylguanidine (TIPG), using benzyl alcohol as initiator. Results agreed with a ring opening polymerization process in which the rate of polymerization was accelerated by the catalysts presence in the order of TBD > PTSA > DBSA > DPP > TIPG > TCHG. Complementary computational studies supported the experimental results. The obtained poly(ethylene brassylate) aliphatic polyesters were characterized by NMR, SEC, MALDI-TOF, DSC, and TGA. They showed molecular weights ranging from 2 to 13 kg mol and polydispersity index between 1.5 and 2. Poly(ethylene brassylate) is a semicrystalline polyester similar to poly(ε-caprolactone) with slightly higher melting and glass transition temperatures ( = 69 °C, = -33 °C) and good thermal stability.
首次报道了使用有机催化剂对乙撑巴西酯进行聚合反应，乙撑巴西酯是一种市售的、廉价且可再生的大环（二）内酯。乙撑巴西酯在本体和溶液条件下于80℃通过开环聚合反应进行聚合。聚合反应在几种有机催化剂存在下进行，如十二烷基苯磺酸（DBSA）、磷酸二苯酯（DPP）、对甲苯磺酸（PTSA）和碱，1,5,7-三氮杂双环[4.4.0]癸-5-烯（TBD）、1,2,3-三环己基胍（TCHG）和1,2,3-三异丙基胍（TIPG），使用苄醇作为引发剂。结果与开环聚合过程一致，其中催化剂的存在按TBD > PTSA > DBSA > DPP > TIPG > TCHG的顺序加速了聚合速率。补充的计算研究支持了实验结果。通过核磁共振（NMR）、尺寸排阻色谱（SEC）、基质辅助激光解吸电离飞行时间质谱（MALDI-TOF）、差示扫描量热法（DSC）和热重分析法（TGA）对所得的聚乙撑巴西酯脂肪族聚酯进行了表征。它们的分子量范围为2至13 kg/mol，多分散指数在1.5至2之间。聚乙撑巴西酯是一种半结晶聚酯，类似于聚（ε-己内酯），具有略高的熔点和玻璃化转变温度（熔点 = 69℃，玻璃化转变温度 = -33℃）以及良好的热稳定性。
