The Preparation And Application Research Of Organic Compounds From Acetonedicarboxylic Acid As Association Thermal Stabilizer For PVC

In recent years, in the context of increasing demands from PVC industry, environment protection and energy saving, Ca-Zn stabilizers have become a hot spot in the field of PVC thermal stabilizers. It's non-toxic but has a low thermal stability against decomposition of PVC. In order to improve it, association effect stabilizer will be used together.In this study, Acetonedicarboxylic Acid and its derivatives were obtained. This derivatives have been used in the Ca-Zn system as synergistic stabilizer, we picked out the best synergistic effect formula with the Ca-Zn system through A variety of thermal stability testing.The main results are:Acetonedicarboxylic Acid was obtained from the improvement of traditional process. The best condition is:mass ratio4:1of concentrated sulfuric acid and citric acid reaction time is8hrs; the temperature is33℃. Acetonedicarboxylic Acid Diethyl Ester was obtained by thionyl chloride. The characteristics of this method are mild experimental condition, high rate of product, and good purity. Acetonedicarboxylic Acid Diethyl Ester:molar ratio1:10of Acetonedicarboxylic Acid, Anhydrous alcohol and thionyl chloride, reaction time is2h, the temperature is35℃. Acetonedicarboxylic Acid Dipentaerythritol Ester:molar ratio1:2.1:2.5of Acetonedicarboxylic Acid, pentaerythritol and thionyl chloride, reaction time is8h; the temperature is35℃.The best formulate for Calcium zinc stabilizer was selected by static oven aging test, Congo red test and electrical conductivity test. Flexible PVC:ratio2:3of Ca and Zn, the best amount percentage of Acetonedicarboxylic Acid Diethyl Ester is10%. Rigid PVC:ration2:3of Ca and Zn, the best amount percentage of Acetonedicarboxylic Acid Dipentaerythritol Ester is10%. Its thermal stability was verified by dynamic torque rheometer and DTA, and the feasibility was discussed. The result shows that when used together with other additives, it has better initial color effect and long-term stability.The mechanism of synergy of Association effect stabilizer and Calcium zinc stabilizer was explored and proved.