Research and Preparation of Halogen-free Flame-retardant Polypropylene

Two different types of magnesium hydroxide namely, platy magnesium hydroxide (MH) and magnesium hydroxide sulfate hydrate (HMOS) whiskers were used to fill with Polypropylene (PP) in this study. Addition of MH and HMOS enhanced flame retardancy of PP, but the filler content needed to reach 40wt% loading. Either MH or HMOS reduced the mechanical properties of PP, due to the poor adhesion between PP matrix and filler in SEM observation. However, PP/HMOS composites showed higher tensile strength than PP/MH composites.