Study On Flame Retardant Properties Of Wood Fiber/Jute Fiber/Polypropylene Fiber Composites

With the development of low carbon and green-energy saving-environmental friendly economy, green environmental composites have become a hotspot in the area of new material research. Lignocellulosic composite is a new kind of green environmental composites, reconstructing one or more lignocellulosic material in a different physical form, or add one or several chemical fibrous material into the composite in a micro or macro may. Wood fiber/jute fiber/polypropylene fiber composite material for automobile interior decoration belongs to the composite material. These composites not only have the high strength and modulous of wood fibers, but have the High toughness and fatigue strength of polymers, however, the flammability greatly restrict their applied areas. Therefore, the flame resistance of natural fiber composites is gradually received wide attention.In this study, the combustion characteristics of wood fiber, the jute fibers, the polypropylene fibers as well as their composites are characterized,and then flame retardants are added into the composites by wood-based panels flat press technology to prepare flame retardant composite plate. To investigate the effect of flame retardant on the mechanical properties and flame retardant properties, the composites were charecterized by the universal mechanical testing machine, oxygen index instrument, thermogravimetric analyzer, cone calorimeter and other equipment for tests. The main works are described as following:(1) Combustion test showed that the combustion speed of composite was not over 100 mm per minute,which could meet the technical requirement required in the《Flammability of Automotive Interior Materials》, but their combustion phenomena was different, the composite without flame retardant could burn very easily, but the composites with flame retardant could extinguish soon after taking away from fire source, even and the composites could’t be burnt at all with high flame retardant.(2) Adding APP(Ammonium Polyphosphate) into wood fiber/jute fiber/polypropylene fiber ternary composite is contirbuted to its flame retardance, its char yield and limited oxygen index(LOI) increase with the APP loading, the LOI could over 27%, what’s more, APP could help to improve the latter’s water resistance, which would tend to increase with the weight gain rate of APP; however, its mechanical properties decrease, but not to a very large extent, and could still meet the application of composites;(3) Adding DOT(Disodium Octoborate Tetrahydrate) into wood fiber/jute fiber/polypropylene fiber ternary composite is also conducived to its char yield and LOI in some extent, but its LOI just reach 26.55% when the weight gain rate of DOT was 82.38%, less than that of APP with the weight gain rate was 43.9, the flame retardant efficiency was not obvious. Moreover, the water resistance and mechanicla properties also decreased with the loading of DOT.(4) When compounding APP and DOT as flame retardant, it was found that when APP:DOT=1.5:1,the composite showed better comprehensive properties. In the further research,it was found that the LOI was 31.24% with the weight gain rate of flame retardant was 30.69%. It can be refered that the composite could not only meet the flame retardant efficiency requirement, but also retain good mechanical property.