Preparation of intercalated hydrotalcite materials and its effect on thermal stability properties of polyvinyl chloride

Abstract

In this study, ZnAlLa-maleate-LDHs was synthesized using the co-precipitation-hydrothermal method. The effects of aluminum-lanthanum ratio, co-precipitation time, hydrothermal time, and hydrothermal temperature on the crystal structure were investigated. As indicated by the result, the optimal condition was n (Al3+): n (La3+) = 10:1, the co-precipitation time reached 24 h, the hydrothermal time was 8 h, and the hydrothermal temperature reached 180°C. The effect of hydrotalcite on the thermal stability properties and plasticizing properties of PVC was analyzed. The result suggested that ZnAlLa-maleate-LDHs enhanced the thermal stability, plasticizing properties, and mechanical properties of PVC compared with ZnAlLa-CO3-LDHs. The layer spacing of hydrotalcite was increased with the introduction of maleic acid, such that the entry of Cl− into the interlayer guest was facilitated, and the decomposition of PVC was inhibited. Moreover, the long-term thermal stability mechanism was analyzed using FTIR before and after hydrochloric acid treatment. As revealed by the above result, the thermal stabilizer ZnAlLa-maleate-LDHs are capable of hindering the breakage of C-Cl bonds in PVC, inhibiting the formation of HCl, and playing a certain role in thermal stabilization.