Epoxidized castor oil-based diglycidyl-phthalate plasticizer: Synthesis and thermal stabilizing effects on poly(vinyl chloride)

Epoxidized castor oil-based diglycidyl-phthalate (ECODP) was synthesized and incorporated into poly(vinyl chloride) (PVC) for the first time. The chemical structure of the ECODP was confirmed. The plasticizing effects of ECODP as a replacement for commercial plasticizer dioctyl phthalate (DOP) were investigated. The thermal stability and mechanical properties of PVC films before and after aging were investigated using thermogravimetric analysis (TGA), TGA-FTIR analysis, dynamic mechanical analysis (DMA), and tensile tests. The results indicated that PVC films plasticized with ECODP significantly improved thermal stability, compatibility, and flexibility. When DOP was substituted with ECODP completely, the initial decomposition temperature, 5, 10, 50, and 70% mass loss temperatures (T_i, T₅, T₁₀, T₅₀, and T₇₀) increased by 24.7, 38.9, 32.0, 30.3, and 102.7 °C, respectively. The functional mechanism of the ECODP as a thermal stabilizing plasticizer and the plasticization mechanism of PVC composites were also investigated. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47142.