Abstract: Effect of titanate coupling agent on mechanical properties and flame retardancy of polypropylene/intumescent flame retardant (PP/IFR) composites was studied. Micromorphology and crystallization behavior of the composites were analyzed by scanning electron microscope, polarization microscope and X-ray diffraction. It showed that dispersion of IFR and spherulite size of PP became uniform, and TTOPP could promote the formation of β-form crystal. The adhesions between PP and IFR was enhanced by TTOPP. PP/IFR/TTOPP(75/25/0.375) composite had the optimal properties, and its impact strength and tensile strength were improved by 14.0 ％ and 12.0 ％ than that of PP/IFR, respectively, and its extinguish time decreased to 24 s.

Key words: titanate coupling agent, flame retardancy, polypropylene, intumescent flame retardant, mechanical property, crystallization behavior