月桂酸稀土复合热稳定剂对PVC热稳定作用的研究

Thermal Stability of Rare Earth Laurate Composite on Thermal Stabilizers in PVC

合成了月桂酸镧/铈/钕,分别与硬脂酸钙、季戊四醇复配得到了硬质PVC用月桂酸稀土复合热稳定剂。采用刚果红法、转矩流变仪、动态力学谱仪等考察其对PVC热稳定性、流变性能、力学性能的影响,利用红外光谱初步探讨了其热稳定机制。结果表明:稀土复合热稳定剂中月桂酸镧(铈/钕)/硬脂酸钙/季戊四醇最佳比例为3∶1∶1;具有良好的热稳定性,静态、动态热稳定时间均达到为90和50 min以上;其加工性能和力学性能与铅盐体系相当,断裂伸长率明显高于铅盐体系。

Rare earth laurate composite thermal stabilizers for rigid PVC were prepared from lanthanum（ cerium / neodymium） laurate,calcium stearate and pentaerythritol respectively. Influence of these stabilizers on PVC was determined by means of Congo red testing method,torque rheometer process tests and dynamic mechanics spectrometer. Thermal stability mechanism was discussed preliminarily by infrared spectrum. The result showed that the best ratio of composite was confirmed as follow： Lanthanum（ cerium / neodymium） laurate∶ calcium stearate∶ pentaerythritol was 3∶ 1∶ 1. The rare earth laurate compound thermal stabilizers had good thermal stability. Static and dynamic thermal stability time could reach about 90 and 50 min. Processing performance and mechanical property were similar to those of lead salt system,while elongation at break was significantly higher.