Abstract: Epoxidized sun?ower oil was synthesized through a nonsolvent method and the synthesis conditions were optimized by orthogonal experiments. The influence of epoxidized sun?ower oil on the thermal stability and mechanical properties of PVC was studied using torque rheometer and DSC. The epoxy value of the sun?ower oil reached 6.78 % when the synthesis temperature and time were 60 ℃ and 5 h, the mole ratio of hydrogen peroxide to sunflower oil was 2:1, the dosage of catalyst was 3 % of the total mass. Epoxidized sun?ower oil exhibited good synergistic effects with Ca-Zn soap in long-term thermal stability of PVC and showed greater efficiency than epoxidized soybean oil. In addition, epoxidized sun?ower oil could decrease tensile strength, glass transition temperature and hardness of PVC, but increased elongation at break of PVC, thus could be used as a plasticizer for it.

Key words: epoxidized sunflower oil, poly(vinyl chloride), thermal stability, mechanical property, synergistic effect