Effect of halogen-free nanoparticles on the mechanical, structural, thermal and flame retardant properties of polymer matrix composite

In this work, polypropylene (PP) nanocomposites were reinforced with 30 wt% of halogen-free flame retardants, which were prepared by melt compounding in a twin-screw extruder followed by injection molding technique. It was aimed to produce flame retardant nanocomposites by reinforcing different halogen-free nanoparticles with various compositions and to investigate the usability of the nanocomposites in industrial applications. Within this scope, halogen-free nano sized huntite/hydromagnesite, antimony trioxide, bentonite and zinc borate particles were reinforced to polypropylene matrix. The influence of different mineral type/content was investigated for polypropylene nanocomposites containing halogen-free flame retardants on the structural, thermal, mechanical and flame retardant properties. The nanocomposites were analyzed with X-ray diffraction (XRD), scanning electron microscopy (SEM), thermo-gravimetric analysis (TGA), tensile and UL94 flame retardancy tests to characterize the structural, thermal, mechanical and flame retardant behaviour of the PP composites. TGA and flame retardant tests showed that the decomposition temperature was increased in the presence of huntite/hydromagnesite in comparison to neat PP and PP composites comprising other mineral types. It was concluded that the flame retardancy behaviour of PP composites was improved within creasing mineral content, indicating that the UL94 rating reached V-0 via a good compatibility between huntite/hydromagnesite and PP.