基于CO_(2)二元醇的无屈服、高强度、自修复聚氨酯弹性体的制备和表征

Preparation and Characterization of Non-yielding, High-strength, Self-healing Polyurethane Elastomers Based on CO_(2) Diols

以聚碳酸亚丙酯二醇(PPCD)为软段,以4,4′-二硫代二苯胺(APS)为扩链剂以及对称性较好的二苯基甲烷-4,4′-二异氰酸酯(MDI)为硬段,通过一步法制备了聚氨酯弹性体。所制备的聚氨酯弹性体硬段中含有大量的苯环结构,芳环之间产生π-π堆叠作用,使材料中形成更为集中的硬相区,因此材料的机械强度较好,其最高断裂强度可以达到14 MPa。DSC表征显示聚氨酯的玻璃化转变温度都在-5℃左右,在动态二硫键以及氢键的协同作用下,在80℃下392 min内可以实现完全自修复。样品的热分解温度都在240℃左右,具有极好的热稳定性。

Using polypropylene carbonate diol(PPCD)as the soft segment, 4,4′-dithiodiphenylamine(APS)as the chain extender, and diphenylmethane-4,4′-diphenylmethane(MDI)with better symmetry isocyanate, the polyurethane elastomer was prepared by one-step process.The prepared polyurethane elastomers hard segment contained a large number of benzene ring structures, and the π-π stacking effect was generated between the aromatic rings, so that a more concentrated hard phase region was formed in the materials, so the mechanical strength of the materials was good, and its highest breaking strength could reach 14 MPa.Differential scanning calorimetry(DSC)characterization shows that the glass transition temperature of PUs is around-5 ℃,and it can achieve complete self-healing within 392 min at 80 ℃ under the synergistic effect of dynamic disulfide bonds and hydrogen bonds.The thermal decomposition temperature of the samples is around 240 ℃,which has excellent thermal stability and can meet a variety of usage scenarios.