Preparation And Properties Of New Calcium / Zinc Complex Heat Stabilizer For

Poly(vinyl chloride)(PVC) is one of the five general resins, and also is one of the earliest industrialization resin varieties in the world. Its output is only second to that of polyethylene. Due to the excellent performance and low price, PVC has been widely used in various fields of national economy and people’s daily life. However, due to their structure defects, it is easily degraded by dehydrochlorination in the heating process. Therefore, thermal stabilizer is a necessary additional agent in PVC processing and application. Although traditional thermal stabilizers have excellent effect, they usually contain heavy metal salts such as lead, cadmium and so on, which damage to the environment and people’s health. In comparison, Ca/Zn thermal stabilizer is considered as most safety one. At present, the main research target is to develop new type, high performance and environmentally friendly Ca/Zn thermal stabilizer.In this paper, the main heat stabilizer of the new complex heat stabilizer for PVC is synthesized by the saponification-metathesis reaction based on the deep knowledge of the structural characteristies of PVC and unstable factors, degradation and stablization mechanism. And the influence of the ratio of raw materials, catalyst, synthesis temperature, synthesis time, stirring speed and p H on the performance of the product is investigated, thus obtaining the optimum process condition. The main heat stabilizer is clarified by means of FTIR analysis, EA and AAS, and the epoxy value of it is tested by the employment of the Hydrochloric acid- acetone method. The synergistic effects of epoxidized calcium(zinc) oleate with other additives are studied by means of Congo red test, conductivity test, thermal aging oven test. At last, Calcium/zinc complex heat stabilizer is synthesized by the formulation design and optimization which is used to make the comparative experiment of heat stablization performance with domestic and import products. The result indicates that epoxidized zinc oleate can delay the zinc burn effectively. Epoxidized calcium oleate has good long-term heat stability. The best performance is obtained at the ratio of 3(in weight) betwee epoxidized calcium oleate and epoxidized zinc oleate. It was determined that the epoxy soybean oil as a plasticizer, and pentaerythritol(PER) was best long-term thermal stability, and β-diketone can restrain the early coloring of PVC specimens, and antioxidant 1010 can prevent PVC specimens aging. The optimized formula of calcium /zinc composite heat stabilizer is epoxidized calcium oleate, 1.8phr; epoxidized zinc oleate, 0.6phr; PER, 0.6phr; β-diketone, 0.6phr; LDHs, 0.2phr; Antioxidant, 0.2phr. Compared with other thermal stabilizers, the long-term thermal stability of homemade calcium zinc complex stabilizer is better than that of domestic and import products, and it’s inhibition of early coloring ability is better than that of domestic products, but it is a little lower than that of import products.