Study on the Organic-Inorganic Hybrid Polyphosphazene Nanotube as a Flame Retardant for Polypropylene

Hybrid polvhosphazene nanotubes (HPPN) were synthesized via a facile one-pot polymerization in an ultrasonic bath at room temperature. The thermal properties of HPPN were investigated by thermogravimetric analysis, which showed that HPPN had good thermal stability and excellent char performance. The char yield of HPPN could reach 70% even at a high temperature of 800 C. HPPN were incorporated into polypropylene (PP) as aflame retardant by a Haake Rheometer system. The HPPN had good compatibility with PP and dispersed well in it. The combustion behaviors of the blends were evaluated by the UL-94 test on a CZF-3 horizontal and vertical bunting tester and a V-0 rating was achieved for the blends.