Fire Performance of Poly Propylene Treated With Ammonium Polyphosphate and Kaolin

Abstract

IntroduetionPolypropylene (PP) is one of the popular members of thermoplastic polymers which are widely used in various applications due to their interesting mechanical properties. However, its low thermal stability and high flammability hazard attributed to restriction in its use in other industrial applications [1]. Hence, flame retardant additives have to incorporate in polymer matrix improving their flame retardancy and enhancing their thermal stability such as phosphate-nitrogen materials and aluminosilicates based materials [2][3]. On the other hand, ammonium polyphosphate (APP) have been used as flame retardant materials for polypropylene either in nanoscale or microscale form [1,4]. Also, it is previously reported that optimum mass loading of APP achieving good flame retardancy is 10 wt.% [5]. Interestingly, addition of kaolin to APP as flame retardant system has been reported [6][7]. Recently, the APP incorporated with zeolite has been used as flame retardant filler for polywood coating [8].In this study APP nanoparticles have used as flame retardant for PP. Also, APP nanoparticles A MMONIUM polyphosphate was prepared and used as flame retardant materials for polypropylene nanocomposites. Then, kaolin was incorporated with ammonium polyphosphate nanoparticles as synergistic flame retardant system for polypropylene. This is in addition to modification of kaolin with sulfuric acid then incorporated with polyphosphate nanoparticles as good flame retardant materials for polypropylene. Flammability properties of polymer and developed polymer nanocomposites were improved achieving 26.4 and 10.2 % reduction in peak heat release rate (PHRR) compared to virgin polymer and polymer composite with ammonium polyphosphate nanoparticles alone. The synergistic effect of modified kaolin and nanoparticles was evaluated. The dispersion of ammonium polyphosphate and kaolin in polymer matrix were studied using microscopic techniques. have been used in conjunction with kaolin layers. Moreover kaolin layers have been modified using sulfuric acid and then incorporated with APP nanoparticles as potential flame retardant system for PP. Flammability properties of the various polymer composites were evaluated and their synergistic effect was investigated. Materials and Methods MaterialsPolypropylene (PP) has a chemical formula (CH 2 -CH-CH 3 ) n according to IUPAC nomenclature. It has molecular formula (C3H6) n ,its density in the range of 0.855 to 0.946 gm.cm -3 for the amorphous or the crystalline form. It melts at about 130-171ºC. The kaolin in this study was supplied from Wadi El Hamadiya region, Egypt. Synthesis of Ammonium polyphosphate (APP)APP was prepared by mixing certain amount of ammonium dihydrogen phosphate (NH4H2PO4) with urea (NH2)2CO solution at ratio 1/2 and heated at 280oC. The ammonia solution (25%) were added slightly (2ml/2min) with continuous heating for 45 min, a white precipitate was formed

Retarding the flammability of polypropylene based on the synergistic effect of montmorillonite and carbon nanotubes

“…In our previous studies [20][21][22], the MMt clay and the ammonium polyphosphate were used as flame retardants for polypropylene (PP). It was found that adding 10% of ammonium polyphosphate to PP could improve its thermal stability and the flame retardancy without considerable effects on the mechanical properties of the PP.…”