中心组合设计优化SG-5型PVC稀土复合热稳定剂的研究

Study on Optimization of Rare Earth Complex Heat Stabilizer for SG-5 PVC with Central Composite Design

采用正交设计与中心组合设计法优化了以硬脂肪酸镧、硬脂肪酸高铈、硬脂肪酸钕为复合热稳定剂的配方,得到了这三种稀土化合物对SG-5型PVC热稳定性产生作用的响应面图,探讨了稀土金属离子对PVC的稳定机理;检测了产品的性能。优化结果表明,以SG-5型PVC0.5g、硬脂肪酸镧为0.013g、硬脂肪酸钕0.0196g及硬脂肪酸高铈0.02g所组合得到的PVC树脂,其热稳定温度达到183.3℃,并能稳定35分钟以上,比正交实验结果180.8℃提高2.5℃,其力学性能优于正交结果。La3+、Ce4+、Nd3+对PVC树脂的热稳定作用与它们离子半径的大小及与自由基成键的能力和吸附能力呈正相关性。

Optimization formula adding lanthanum sterate, cerium sterate, neodymium sterate as the rare earth complex heat stabilier in SG-5 PVC plastics was determined by central composite design and orthogonal design. The response surface figure and interaction mechanism of three components for PVC were obtained, and the function of SG-5 PVC was tested. The results shows that the SG-5 PVC degradation temperature reaches 183.3℃ as lanthanum sterate 0. 013g, cerium sterate 0. 0196g, neodymium sterate 0. 02g, and SG-5 PVC 0. 5g, and it retards over 35 minutes. The PVC thermal stabilisation temperature is 2.5℃ higher and its function is better by central composite design than by orthogonal design. The Nd^3＋ ,Ce^4＋ ,La^3＋ ion for PVC thermal stabilisation is positive to its radius and its bond formation ability with free radical ＆ adsorbability.