稀土-协效配体-有机锡三位一体的分子内结合型PVC热稳定剂的制备及机理研究

The polyvinyl chloride (PVC) is one of the most important global general plastics, its production and consumption in China is already ranked first. The PVC have structure defect, resulting in its molding processing have poor thermal stability. For giving more thermal stable PVC, indispensable additive is required during processing. Now lead salt stabilizers for PVC gradually be eliminated, and new environmentally friendly non-toxic heat stabilizers for PVC realistic is need and inevitable trend. Following this new trend, this project design and synthesis of a new class of molecules within the collaborative PVC composite heat stabilizer according to the active factor superposition principle (Stabilizer contain excellent heat effect on the stability of organic rare earth compounds, organotin compounds and also have good auxiliary heat stabilizer effect of active bridging ligand unit ). PVC plastic thermal stabilization and intramolecular cooperativity mechanism will be investigated deeply. With the development of heat stabilizers for PVC structure type, the universal preparation method and technology are obtained at the same time. We also illustrate the mechanism of thermal stabilization. This mechanism can provide the theory basis and the technical support of the whole process of preparation and application of PVC composite heat stabilizer. This project has important theory significance and the better application prospect.

聚氯乙烯（PVC）塑料是全球最重要的通用塑料之一，在中国的产量和消费量名列第一。但是由于PVC的结构缺陷，导致其成型加工的热稳定性差，致使热稳定剂成为PVC树脂加工过程中必不可少的加工助剂。本项目针对目前国内主打铅盐类PVC热稳定剂逐渐被淘汰，急需研究和开发新型环境友好无毒PVC热稳定剂的现实需要和必然趋势，根据活性因子叠加原理，设计和合成一类有机稀土稳定剂-协效稳定剂-有机锡稳定剂三位一体的分子内结合协同型PVC热稳定剂，并对其应用于PVC塑料的热稳定效果和热稳定机理进行深入研究，在拓展PVC热稳定剂的结构类型、获得其普适性制备方法和技术的同时，阐明该类新型热稳定剂的热稳定机理和分子内协同机理，为PVC用多功能复合型热稳定剂的制备和应用提供理论依据和技术支撑，具有重要的理论意义和较好的应用前景。

聚氯乙烯（PVC）塑料是全球最重要的通用塑料之一，但由于其内部结构的缺陷，导致其热稳定性不足，致使热稳定剂成为PVC树脂加工过程中必不可少的添加剂。本项目针对目前国内主打铅盐类热稳定剂逐渐被淘汰，急需研发新型环境友好无毒热稳定剂的现实需要和必然趋势，根据活性因子叠加原理，设计和合成了一系列稀土-含硫羧酸类协效桥联配体-有机锡三位一体的分子内结合协同型PVC热稳定剂，并对其应用于PVC树脂的热稳定效果和热稳定机理进行了深入研究，在拓展PVC热稳定剂的结构类型、获得其普适性制备方法和技术的同时，阐明该类新型热稳定剂的热稳定机理和分子内协同机理，为PVC用多功能复合型热稳定剂的制备和应用提供理论依据和技术支撑，具有重要的理论和现实意义。. 项目组设计并合成了巯基乙酸、巯基丙酸、硫代苹果酸、季戊四硫醇基乙酸、巯基丙酸季戊四醇酯等一系列含巯基（或硫）羧酸（或酯）类多官能团桥联配体与稀土和二烷基锡三位一体的新型共配物新产品，在利用电导率法对其用作PVC加工热稳定剂性能初筛的基础上，进一步采用电导率法、红外光谱法、热重分析法、差热分析法和热烘箱老化法对其用作PVC热稳定剂的效果和稳定机理进行了研究，探讨了该类新型热稳定剂的热稳定机理和分子内协同机理。. 研究结果表明：在控制好的反应条件下合成稀土-含硫羧酸配体-有机锡三位一体的新型PVC用热稳定剂是可行的；这些三位一体的新型配合物对PVC树脂中的热稳定效果显著，能在使PVC树脂玻璃化温度下降的同时，使其分解温度提升，从而有效地抑制了PVC树脂的降解作用，同时具有良好的保色性能，多种产品单独添加使用后都能使PVC树脂在180℃条件下经受90 min的加热而保持初期的白色不变。在抑制PVC树脂的热降解过程中，稀土元素骨架、二烃基锡骨架和含硫羧酸多官能团桥联配体骨架之间存在着一定的协同效应，综合应用效果良好。