镁铝水滑石及其复合体系对PVC热稳定性能的调控

Retardation of Thermo-oxidative Degradation of Paste PVC Resin by Mg-Al Layered Double Hydroxides

采用比色法、热失重法等研究了不同镁铝摩尔比的水滑石(LDHs)对PVC糊热稳定性能的影响。结果表明,在镁铝比分别为2、3、4的样品中,镁铝比为2的LDHs对PVC的热稳定效果最佳;将其与传统的铅盐、有机锡稳定剂复配,均具有良好的协同效应,可以实现对PVC糊热稳定性能的控制。其中,PVC/Mg-AlLDHs/Sn以100∶1.5∶1.5(质量份数,下同)比例复合后的体系,不仅热稳定性能优于传统的的铅盐体系,而且具有较低的糊黏度及较好加工流变性能。

The effect of molar ratio of Mg^(2+)/Al^(3+) in hydrotalcites (LDHs), a layered double hydroxide, on the thermal stability of paste PVC resin was investigated using colorimeter and TGA. It was found that the molar ratio Mg^(2+)/Al^(3+)=2 constituted the optimum one. When the hydrotalcite was used together with lead salt or organotin, a synergistic effect on the thermal stability was observed. A system with weight ratios of PVC/LDHs/organotin=100/1.5/1.5, better higher tensile strength and lower viscosity were achieved in addition to excellent thermal stability.