Abstract: The thermal stabilization mechanism and compound principles of ester-tin in PVC were discussed based on its structure. The mechanisms for ester-tin could inhibit the degradation of PVC including: (1) substituting unstable chloride; (2) reacting with HCl forming thiol, which may be added onto the conjugate structure of PVC. The ester-tin showed excellent synergistic effect with thiols, some antioxidants such as bisphenol a, β-diketone compounds, and HLDs, and its thermal stability was increased by composing with these compounds. The product's quality, unsafe of its production, and shortage of its thermal and toxic mechanism research, and shortage of its environmental assessment were the urgent problems to be solved in the domestic industry of ester-tin.

Key words: thermal stability, poly(vinyl chloride), ester-tin, compound principle, application