Thermal behavior of epoxidized cardanol diethyl phosphate as novel renewable plasticizer for poly(vinyl chloride)

A novel plasticizer, epoxidized cardanol diethyl phosphate (ECEP), based on cardanol was synthesized. Chemical structure of ECEP was characterized by fourier transform infrared (FTIR), 1H -nuclear magnetic resonance(1H NMR) and 13C -nuclear magnetic resonance(13C NMR). Effects of ECEP substitution for the petroleum-based plasticizer dioctyl phthalate (DOP) in soft poly(vinyl chloride) (PVC) films were studied. Thermal stability and mechanical properties before and after aging of PVC films plasticized with different content of ECEP were investigated with thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and tensile tests. The results indicated that PVC films plasticized with ECEP showed increased thermal stability. When DOP was substituted for ECEP completely, glass transition temperature (Tg) of PVC films decreased from 41.07 °C to 33.20 °C, the 10% and 50% weight loss temperatures (T10 and T50) increased by 31.57 °C and 23.09 °C respectively. The mechanical properties of PVC films before and after aging were also investigated.