基于配位作用的木质素基阻燃/自修复聚氨酯弹性体的制备及性能研究

Preparation and Properties of Self-healing Lignin-based Flame Retardant Polyurethane Elastomers Based on Coordination Reaction

关键词:  聚氨酯弹性体  木质素  自修复  阻燃  金属配位

Key Words:polyurethane prepolymer  lignin  self-healing  flame retardant  metal coordination

摘要:通过控制以三氮唑基团封端的星形结构木质素（L-TA）和聚氨酯预聚体（P-TA）的比例，在不同金属离子的配位作用下制备了木质素基自修复弹性体，并通过加入内含三氮唑基团的阻燃剂DT以提高弹性体的阻燃性能。当用DT代替10% L-TA时，在Fe³⁺配位作用下，70P-TA/20L-TA/10DT的拉伸强度相比于纯P-TA提高了88.4%。同时，70P-TA/20L-TA/10DT的极限氧指数值达29.5%，UL-94测试达V-0级。然而，L-TA和DT的加入增加了分子链段的空间位阻，降低了分子链迁移率，70P-TA/20L-TA/10DT的自修复效率由纯P-TA的91.1%下降至81.3%。此外，相比于其他金属离子，Zn²⁺—N较低的配位键强度使得70P-TA/20L-TA/10DT: Zn²⁺的玻璃化转变温度（T_g）随之降低，从而提高了聚合物链的流动性，使其具有较高的自修复效率（87.7%）。

Abstract:By controlling the ratio of star structure lignin （L-TA） sealed with triazole group and polyurethane prepolymer （P-TA）， lignin-based self-healing elastomers were prepared under the coordination reactions with different metal ions， and the flame retardant properties of the elastomers were improved by adding flame retardant DT containing triazole group. The tensile strength of 70P-TA/20L-TA/10DT with DT instead of 10% L-TA was 88.4% higher than that of pure P-TA under the coordination reaction with Fe³⁺， and the LOI value of the sample 70P-TA/20L-TA/10DT reached 29.5%， and the UL-94 reached V-0 level. However， the addition of L-TA and DT further increased the steric hindrance inside the sample and decreased the molecular chain mobility， so that the self-healing efficiency of 70P-TA/20L-TA/10DT decreased to 81.3% from 91.1% of 100P-TA. In addition， compared with other metal ions， the lower coordination bond strength of Zn²⁺—N decreased the glass transition temperature （T_g） of the elastomer 70P-TA/20L-TA/10DT：Zn²⁺， which improved the fluidity of the polymer chain and entitled it a higher self-healing efficiency （87.7%）.