Influence of Kevlar pulp on the properties of intumescent flame-retardant polypropylene

Intumescent flame-retardant polypropylene(PP) was reinforced by Kevlar pulp(PPTA-pulp).The composites of PPTA-pulp-intumescent flame retardant(IFR)/PP were prepared by one step blending method. The effects of the PPTA-pulp contents on the mechanical properties, the flame retardant properties and the thermal stability of the composites were studied. The results indicate that the PPTA-pulp-IFR/PP composites show the highest values of mechanical properties, tensile strength 40.0 MPa, impact strength 56.9 J·m^-1, limited oxygen index (LOI) 28% and the vertical firing ranks UL-94 V-0, when the mass fraction of PPTA-pulp treated by silicon coupling agent KH-550 reaches 5%.The thermal stability and the residue mass of the composite are improved respectively. The SEM results show good affinity between the PPTA-pulp treated by KH-550 and the PP matrix.