Kim Seon-Mi, Park Seul-A, Hwang Sung Yeon, Kim Eun Seon, Jegal Jonggeon, Im Changgyu, Jeon Hyeonyeol, Oh Dongyeop X, Park Jeyoung
Research Center for Bio-Based Chemistry, Korea Research Institute of Chemical Technology (KRICT), Ulsan 44429, Korea.
Advanced Materials and Chemical Engineering, University of Science and Technology (UST), Daejeon 34113, Korea.
Polymers (Basel). 2017 Nov 30;9(12):663. doi: 10.3390/polym9120663.
Carbonate-type macrodiols synthesized by base-catalyzed polycondensation of co-diols and dimethyl carbonate as an environmentally-friendly route were subsequently utilized for the preparation of transparent and self-healable thermoplastic polyurethanes (TPUs) containing a carbonate-type soft segment. Three types of macrodiols, obtained from mono, dual and triple diol-monomers for target molecular weights of 1 and 1.5 kg mol, were analyzed by ¹H NMR integration and the OH titration value. Colorless transparent macrodiols in a liquid state at a room temperature of 20 °C were obtained, except the macrodiol from mono 1,6-hexanediol. Before TPU synthesis, macrodiols require pH neutralization to prevent gelation. TPUs synthesized by a solution pre-polymer method with 4,4'-methylene(bisphenyl isocyanate) and 1,4-butanediol as a chain extender exhibited moderate molecular weights, good transparencies and robust mechanical properties. Especially, the incorporation of 3-methyl-1,5-pentanediol within carbonate-type macrodiols enhanced the transparency of the resultant TPUs by decreasing the degree of microphase separation evidenced by ATR-FTIR and DSC. Interestingly, packing density of hard segments and the degree of microphase separation determined the self-healing efficiency of TPUs, which showed good performances in the case of sourced macrodiols from triple diol-monomers.
通过二醇与碳酸二甲酯的碱催化缩聚反应合成的碳酸酯型大分子二醇作为一种环境友好的路线,随后被用于制备含有碳酸酯型软段的透明且可自愈的热塑性聚氨酯(TPU)。通过单、双和三二醇单体获得的三种类型的大分子二醇,目标分子量为1和1.5 kg/mol,通过¹H NMR积分和OH滴定值进行分析。除了由单1,6 - 己二醇制得的大分子二醇外,在20℃室温下获得了液态无色透明的大分子二醇。在TPU合成之前,大分子二醇需要进行pH中和以防止凝胶化。采用溶液预聚合法,以4,4'-亚甲基(双苯基异氰酸酯)和1,4 - 丁二醇作为扩链剂合成的TPU表现出适中的分子量、良好的透明度和强大的机械性能。特别是,在碳酸酯型大分子二醇中引入3 - 甲基 - 1,5 - 戊二醇,通过ATR - FTIR和DSC证明降低了微相分离程度,从而提高了所得TPU的透明度。有趣的是,硬段的堆积密度和微相分离程度决定了TPU的自愈效率,在由三二醇单体制得的大分子二醇的情况下,TPU表现出良好的性能。