SG-7型PVC稀土复合热稳定剂的研究

Study on Rare Earth Complex Heat Stabilizer for SG-7 PVC

通过正交设计与中心组合规则实验优化了SG-7型PVC树脂中添加苹果酸镧、硬脂肪酸铈、柠檬酸钕为稀土复合热稳定剂的配方,得到了各因素之间的相互作用的响应面图,探讨了物质之间相互作用机理,检测了产品的性能。结果表明:当苹果酸镧、硬脂肪酸铈、柠檬酸钕和树脂质量分数分别为3.3%、3.71%、3.47%和89.52%时,所得产品的热分解温度达到185.8℃,并能持续40 min以上;稀土离子Nc3+、C34+、La3+离子半径的增大,对产品的热稳定作用越明显;稀土离子与聚氯乙烯大分子成键能力和吸附能力的强弱与聚氯乙烯树脂加工的热稳定性成正相关性;稀土阴离子配体对聚氯乙烯树脂力学性能的改善也有一定的促进作用。

The formula of rare earth complex heat stabilier for SG-7 PVC plastics from lanthanum malate, neodymium citrate and cerium sterate was optimized by central composite design and orthogonal design.The Response surface figure and interaction mechanism of four components were obtained. The property of SG-7 PVC was tested.The results showed when the mass fractions of lanthanum malate, cerium state, neodymium citrate and SG-7 PVC 3.3%, 3.71%, 3.47% and 89.52% respectively, the degradation temperature of the PVC product was up to 185.8℃, and could be retarded for more than 40 minutes; The thermal stabihsation of the PVC improved highly as the ion radius of rare earth Nd^3＋ , Ce^4＋ , La^3＋ increased. The relation between of the ‘bondability ＆ adsorbability of rare earth ion with PVC macromolecule was a positive dependence on the thermal stability of the PVC resin; rare earth anionic complex had promotive effect on the improvement of the mechanical properties of the PVC resin.