Phosphorus-Containing Flame-Retardant Copolyesters/Montmorillnite Nanocomposites

Poly(ethylene terephathalate) (PET) is a polymer material with high modulus, strength, elasticity and other good properties. It is used widely in fields of fibers and plastics, but its use is limited owing to its combustibility, which can be reduced by adding flame retardants in it. However, most of those flame retardants will reduce the other properties of materials at the same time. To overcome this drawback, a reactive flame retardant, which was incorporated in the main chain of PET, was used and an intercalative polymerization to layered silicates was conducted so as to prepare novel flame-retardant copolyesters/layered silicate nanocomposites. The flame retardancy and the comprehensive performance of polyesters were improved.The reactive flame retardant used is 2-carboxyethl(phoyl)phosphinic acid (CEPP), and the layered silicate selected is organic montmorillnite(O-MMT). When the contents of CEPP and O-MMT are 3wt%, respectively, LOI value of the copolyester/montmorillnite composite reaches 32%. Because the flame retardant contains no halogen, no poisonous gas will not been emitted in combustion.The structures and morphology of composites were characterized by FI-IR, SEM, TEM, etc. DSC and TG were used to investigate the thermal behaviors of composites, whose kinetics of oxidative degradation were studied by thermal analysis.