LDHs-MoO3复合粉体的制备及对聚氯乙烯阻燃抑烟性能的影响

High Speed Ball Mill LDHs/MoO3 and Its Effect on the Performance of Soft Polyvinyl Chloride

通过高速球磨法制备了不同配比的三氧化钼(MoO3)和钙铝水滑石(LDHs)复合粉体。考察不同配比复合粉体对聚氯乙烯(PVC)体系热稳定性能、阻燃抑烟性能和力学性能的影响。结果表明,高能振磨使LDHs与MoO3分子间产生了化学键合,部分MoO42-进入LDHs片层结构,可以抑制MoO3纳米片之间容易团聚的问题;当LDHs∶MoO3质量比为10∶1时,MoO3在LDHs片层中分散效果最佳;当添加6 phr时PVC烟密度较纯PVC降低了29%,极限氧指数(LOI)提高了28%,对力学性能影响不明显;LDHs-MoO3/PVC(质量比10∶1)的热分解活化能(Ea)由纯PVC的129.1 kJ/mol提高至136.2 kJ/mol;根据Kissinger分解动力学原理分析,复合材料补偿参数(Sp*)基本恒定,说明其未改变PVC降解机理。

The composite powders of MoO3 and calcium alumina hydrotalcite(LDHs) with different mass ratios were prepared by high speed ball milling. The effects of composite powders with different mass ratios on thermal stability, flame retardant, smoke suppression and mechanical properties of polyvinyl chloride(PVC) systems were investigated. The results show that the high energy vibratory grinding makes the bonds between LDHs and MoO3 molecule bonds. Some Mo+6 enter the lamellar structure, the problem of easy aggregation between MoO3 nanometer sheets can be suppressed. When the LDHs∶MoO3 mass ratio is 10∶1, MoO3 has the best dispersing effect in LDHs slice. The density of PVC smoke is decreased by 29% and the LOI is increased by 28%, when 6 phr is added which could inhibit the superposition of the nanoparticles between MoO3 and effectively, solve the problem of easy agglomeration of MoO3 nanoparticles and promote the dispersion of composite powders in PVC. When adding 6 phr of LDHs∶MoO3 with the mass ratio of 10∶1, and the mechanical properties are not affected obviously. The heat decomposition activation energy(Ea) of LDHs-MoO3/PVC increases from 129.1 kJ/mol of pure PVC to 136.2 kJ/mol. According to the analysis of Kissinger decomposition kinetics, the compensation parameter(Sp*) of composites is basically constant, and the degradation mechanism of PVC has not been changed.