Synergistic effect of adipic acid pentaerythritol ester with calcium and zinc stearates on poly(vinyl chloride) thermal stability

Adipic acid pentaerythritol ester (AAPE) was synthesized in this study and confirmed by Fourier transform infrared spectroscopy (FTIR). The synergistic effect of AAPE with calcium and zinc stearates (CaSt(2)/ZnSt(2)) on poly(vinyl chloride) (PVC) thermal stability was evaluated by the conductivity test, thermal aging test, and thermogravimetric analysis (TGA). The results showed that the addition of CaSt(2)/ZnSt(2) combined with AAPE could improve color stability and long-term thermal stability of PVC. The results of UV-visible spectroscopy showed that CaSt(2)/ZnSt(2)/AAPE could prevent the generation of conjugated double bonds. The possible mechanism is that AAPE can chelate ZnCl2 to prevent the thermal degradation via dehydrochlorination. The contrast tests showed that the synergistic effect of AAPE and CaSt(2)/ZnSt(2) is more obvious than that of polyethylene (PE) and CaSt(2)/ZnSt(2), which may be attributed to the lower melting point of AAPE and the better compatibility with PVC. J. VINYL ADDIT. TECHNOL., 22:293-299, 2016. (c) 2014 Society of Plastics Engineers