复合稳定剂对PVC膜热稳定性的影响

Effect of composite stabilizer on thermal stability of PVC film

将硫醇甲基锡(DX-181)、硬脂酸钙(CaSt2)与双季戊四醇(Di-PE)在不同比例下进行复配,采用等温变色和刚果红实验,在195℃下对添加不同稳定剂的PVC样品的耐热性进行了研究。结果表明:加入复配比例为m(DX-181)∶m(CaSt_2)∶m(Di-PE)=0.5∶0.5∶1.0～2.0的稳定剂后,样品热稳定性较好;稳定剂DX-181和助剂CaSt_2有协同作用,CaSt_2可以部分取代DX-181,且在一定范围内随着CaSt2投料量的增加,复合稳定剂对PVC的稳定效果增强;向单一稳定剂DX-181中加入助稳定剂Di-PE不能显著提高PVC的耐热性,若向DX-181/CaSt_2复合稳定剂中添加适量的Di-PE,三者之间将产生强烈的相互作用、进而增强稳定剂的稳定效果。

The mercaptide methyl tin(DX-181),calcium stearate(CaSt2)and dipentaerythritol(Di-PE)were compounded at different ratios.The heat resistance of the PVC sample to which the composite stabilizer was added was investigated at 195°C using isothermal discoloration and Congo red experiments.The results show that the thermal stability of the sample is better after adding the stabilizer with the ratio of m(DX-181)∶m(CaSt2)∶m(Di-PE)=0.5∶0.5∶1.0~2.0.The stabilizer(DX-181)and additive CaSt2 have synergistic effect,and CaSt2 can partially replace DX-181,and within a certain range,with the increase of CaSt2 dosage,the stability effect of composite stabilizer on PVC is enhanced.The addition of the stabilizing agent Di-PE to the single stabilizer DX-181 does not significantly improve the heat resistance of PVC.If an appropriate amount of Di-PE is added to the DX-181/CaSt2 composite stabilizer,a strong interaction occurred among the three substance,thereby enhancing the stabilizing effect of the composite stabilizer.