软质PVC加工用油酸-辛酸钙/锌液体热稳定剂的制备与性能

Preparation and Performance of Oleic Acid-Octanoic Acid Ca/Zn Liquid Heat Stabilizer for Flexible PVC Processing

以油酸、辛酸两种长链脂肪酸为原料,在变压器油中一步合成了油酸-辛酸混合酸钙/锌液体稳定剂,并将其用于聚氯乙烯(PVC)热加工过程。采用刚果红实验法和烘箱热老化法考察了液体稳定剂对PVC静态热稳定性的影响,并研究了辅助热稳定剂的协同稳定作用;通过转矩流变测试评价了其对PVC动态热稳定性的影响;通过扫描电镜观察了稳定剂在PVC中的分散性。结果表明,当液体稳定剂中钙锌比(物质的量比)为2.8∶1时,PVC的静态热稳定性最佳;保持液体稳定剂钙锌总物质的量一定,研究了单独添加有机酮、季戊四醇、三亚磷酸苯酯时PVC体系的静态热稳定性,结果表明,季戊四醇对刚果红变色时间的提高最明显,三亚磷酸苯酯对初始白度影响最大;复合稳定剂热降解时,由于产生HCl而使PVC表面留有均匀分布的微孔,表明复合稳定剂在PVC中分散较为均匀。

Oleic acid-octanoic acid mixed calcium/zinc liquid stabilizer was synthesized in transformer oil with oleic acid and octanoic acid as raw materials,and used in the hot processing process of polyvinyl chloride(PVC).The effect of liquid stabilizer on the static thermal stability of PVC was investigated by Congo red experiment method and oven heat aging method,and the synergistic stabilization effect of auxiliary heat stabilizer was studied.The effect on the dynamic thermal stability of PVC was evaluated by torque rheological test.The dispersion of the stabilizer in PVC was observed by scanning electron microscopy.The results show when the calcium-zinc ratio in the liquid stabilizer is 2.8∶1,the static thermal stability of PVC is the best.Maintaining the amount of total calcium and zinc of the liquid stabilizer,the static thermal stability of adding organic keto,pentaerythritoland phenyl triphosphite alone is studied,and the results show that pentaerythritol has the most obvious improvement on the Congo red experiment,and phenyl triphosphate has the greatest impact on the initial whiteness of PVC sheets.When the composite stabilizer is thermally degraded,the surface of the PVC is evenly distributed with micropores due to the generation of HCl,indicating that the composite stabilizer is more uniformly dispersed in the PVC.