Preparation of Magnesium-Aluminum Hydrotalcite by Mechanochemical Method and Its Application as Heat Stabilizer in poly(vinyl chloride)

The traditional methods for preparing magnesium aluminum layered double hydrotalcite (Mg₂Al-CO₃LDHs) in industry include coprecipitation and hydrothermal methods. Both these methods have the disadvantages of high preparation cost and complicated water washing process. Using Mg(OH)₂, Al(OH)₃, and CO₂ as raw materials in this work, the Mg₂Al-CO₃ LDHs are successfully prepared by mechanochemical method, which solves the shortcomings of traditional preparation method and realizes the conversion and utilization of CO₂ resource. The prepared Mg₂Al-CO₃ LDHs are evaluated as a heat stabilizer in poly(vinyl chloride) (PVC). The result indicates that, when 2.4 phr Mg₂Al-CO₃ LDHs, 0.3 phr ZnSt₂, and 0.3 phr of zinc acetylacetonate are added to the PVC, the thermal stability time of PVC can reach 190 min, which is better than PVC containing commercial Mg₂Al-CO₃ LDHs. Meanwhile, its processing performance is basically the same as the PVC containing commercial Mg₂Al-CO₃ LDHs.