Highly efficient and eco‐friendly enhancement of polyvinyl chloride thermal stability: A renewable cinnamate‐intercalated calcium aluminum hydrotalcite stabilizer

Abstract

With the development of green chemistry, PVC thermal stabilizers should be developed in the direction of non‐toxic, environmental protection, and high efficiency. This study utilized natural Cinnamic acid to successfully synthesize an eco‐friendly and high‐performance cinnamate‐intercalated calcium aluminum hydrotalcite through the coprecipitation method. The structure of CaAl‐cinnamate‐LDHs was analyzed via XRD, IR, SEM, and thermogravimetric analyses. The CaAl‐cinnamate‐LDHs/PVC sample was thoroughly investigated using multiple techniques, including tests, such as oven aging, thermogravimetric analysis, Congo red analysis, and conductivity analysis. Compared with the commercial thermal stabilizers CaSt2/ZnSt2 and CaAl‐CO3‐LDHs, CaAl‐cinnamate‐LDHs demonstrated superior initial whiteness and exceptional long‐term thermal stability, it did not completely blacken until 120 min. Dynamic mechanical analysis showed that the addition of CaAl‐cinnamate‐LDHs could improve the plasticizing performance of PVC. CaAl‐cinnamate‐LDHs also had a synergistic effect with ZnSt2, with a static thermal stabilization time of up to 40.5 min. Through HCl absorption experiments to investigate the thermal stabilization mechanism, the results showed that CaAl‐cinnamate‐LDHs can effectively absorb HCl released during PVC degradation.Highlights By utilizing natural organic Cinnamic acid, Calcium nitrate, and Aluminum nitrate as raw materials, all from a wide range of sources, the reaction process eliminated the need for toxic solvents and a large number of chemicals. The preparation process of CaAl‐cinnamate‐LDHs was simple and the reaction time was short. Comprehensive tests showcased the exceptional long‐term thermal stability of the CaAl‐cinnamate‐LDHs/PVC sample. The addition of CaAl‐cinnamate‐LDHs can improve the plasticizing property of PVC. The mechanism of CaAl‐cinnamate‐LDHs was capable of absorbing HCl released during PVC degradation.