Halogen Free Flame Retardant PP Composites

PP flame retardant composites were prepared with polypropylene and different components by a twin-screw extruder under melting state. The effects of Mg(OH)2,POE and PP-g-MAH on the thermal behaviors, crystalline structure and micro structure of non-halogen flame retardant PP composites were characterized by differential scanning calormetry(DSC), polarized optical microscopy(POM) and scanning electron microscopy(SEM). 

The results showed that the crystal temperature and nucleation rate of PP were improved by adding Mg(OH)2 and POE acted as nucleation agent. The spherulites of the crystal became small and smashed with Mg(OH)2 in PP, the spread and accumulation of PP molecular chain were hindered by the POE macromolecular chains, and the growth of the spherulites of the crystal was also hindered; then the crystalline degree of PP/ Mg(OH)2,POE was decreased. The interfacial compatibility between PP and Mg(OH)2 by adding PP-g-MAH. When the ration of PP/ Mg(OH)2/POE/PP-g-MAH was 80/100/20/2, the mechanical properties and flame retardant performance of PP/ Mg(OH)2/POE/PP-g-MAH non-halogen flame retardant composites were good.