超支化硅氧烷核壳阻燃剂的制备及阻燃性能研究

Preparation and Flame Retardant Properties of Hyperbranched Siloxane Core-Shell Flame Retardants

基于沸石咪唑骨架-8(ZIF-8)表面带正电荷的特性,通过静电组装方法将表面带负电荷的植酸(PA)吸附在ZIF-8的表面,制备了含磷的ZIF-8基核壳阻燃剂(ZIF-8@PA);然后,将NH_(2)-HBPSi接枝到ZIF-8@PA表面,构建了双层核壳阻燃剂ZIF-8@PA@NH_(2)-HBPSi。研究了ZIF-8@PA@NH_(2)-HBPSi对热塑性聚氨酯(TPU)热稳定性、防火性能和力学性能的影响。由于Zn、N、P、Si元素对聚合物复合材料的协同阻燃作用,相比纯TPU,TPU/ZIF-8@PA@NH_(2)-HBPSi纳米复合材料的热释放速率、总释放热和总产烟量分别降低了35.2%、25.1%和65.5%。TPU/ZIF-8@PA@NH_(2)-HBPSi的拉断伸长率为1211.9%,维持了TPU基体的高延展性。

Based on the positive charge on the surface of zeolite imidazole framework-8(ZIF-8),a negatively charged phytic acid(PA)was adsorbed on the surface of ZIF-8 by electrostatic assembly to prepare a phosphorus-containing ZIF-8-based core-shell flame retardant(ZIF-8@PA);then NH_(2)-HBPSi was grafted onto the surface of ZIF-8@PA to construct a double-layer core-shell flame retardant ZIF-8@PA@NH_(2)-HBPSi.The effects of ZIF-8@PA@NH_(2)-HBPSi on thermal,fire-resistant and mechanical properties of thermoplastic polyurethane(TPU)were investigated.Due to the synergistic flame retardant effect of Zn,N,P,Si elements on the polymer composites,the HRR,THR and TSP of TPU/ZIF-8@PA@NH_(2)-HBPSi nanocomposites were reduced by 35.2%,25.1%and 65.5%respectively compared with pure TPU.The elongation at break of TPU/ZIF-8@PA@NH_(2)-HBPSi was 1211.9%,a slight decrease of 10.3%,maintaining the high ductility of the TPU matrix.