Effect of water resistant intumescent flame retardant on flame retardant polypropylene

The flame retardant polypropylene(PP) is produced with a new macromolecular charring agent, PAP, which is used to replace the traditional water-soluble dipentaerythritol as char source due to the poor water resistance of flame retardant PP, and ammonium polyphosphate/montmorillonite nanocomposites as acid source. The flame retardancy, mechanical properties, thermal stability, and water resistance of the products are observed. The results show that intumescent flame retardant with PAP as carbon source has good flame retardancy. It can reduce the weight loss after water immersion and improve the water resistance of the agent. The use of PAP can make several samples pass the UL-94 V-0 rating after the water immersion and improve the mechanical properties of flame retardant PP.