Research On Nano-Al(OH)₃/Mg(OH)₂/Microcapsulated APP/PP Flame Retardant Composites

Polypropylene, as one of the most productive resins, has been widely used in many industries such as automobile, package, textile, and architectural materials. On account of the low oxygen index (OI) value, polypropylene is prone to burn and gives off a lot of heat and toxic gas, which is harmful to environment.The nanoparticles of aluminum hydroxide and magnesium hydroxide were surface-coupled in advance by different coupling agents. The optimum technological parameters for surface coating of ammonium polyphosphate by melamin resins were studied. Polypropylene nanocomposites were fabricated by means of melt blending through optimum design of prescription. The microstructure and performance of the prepared nanocomposites and the influencing factors on the flame retardant and mechanical properties of which were respectively characterized and analyzed by means of SEM, TEM, FT-IR and OI instrument.The experimental results indicated that the nanoparticles of aluminum hydroxide and magnesium hydroxide surface-coupled by KH-550 could be uniformly dispersed in polypropylene matrix and possessed good interfacial combination. Melamin resin on the surface of ammonium polyphosphate could improve the thermal stability and the compatibility between polypropylene and ammonium polyphosphate. It may also enhance the effectiveness of flame retardant. For the system composed of surface-coupled nanoparticles of aluminum hydroxide and magnesium hydroxide, when the weight ratio of them was 1:3, the polypropylene nanocomposites showed the best comprehensive properties with OI value of 22.0 and little decreasing in mechanical properties. For the system composed of nano-aluminum hydroxide, magnesium hydroxide and microcapsulated ammonium polyphosphate, there existed synergistic effect of flame retardant among the three components. When the contents of nano-aluminum hydroxide, nano-magnesium hydroxide and microcapsulated ammonium polyphosphate were respectively 3%, 9%, 8%, the OI value of 26.2 may be obtained. Compared with polypropylene itself,...