Thermal stability and thermal aging of poly(vinyl chloride)/MgAl layered double hydroxides composites

MgAl-LDH (layered double hydroxides) were prepared with CO(NH2)2, NH4Cl and NH3·H2O by the coprecipitation method, respectively. Corresponding composite membranes were prepared by the coating method. LDHs were characterized by WAXS, CO2-TPD and SEM. The morphology of the PVC/LDHs composite membranes were characterized by means of SEM. The thermal stability of the membranes was analyzed by air aging box and TGA-FTIR. The SEM results show that nano-particles can be compatible with poly(vinyl chloride) (PVC) matrix homogeneously by the stirring-ultrasound blend method with two steps. Furthermore, the air aging box results proved that MgAl-CO(NH2)2-LDH has the best effect on thermal stability of PVC. TGA-FTIR results show that MgAl-CO(NH2)2-LDH could adsorb more HCl that resulted from the degradation of PVC and improve the pyrolysis temperature of the first degradation stage by 15 K compared with PVC.