Synthesis Of A Flame Retardnt PSP And Application In The PP

Being one of the common plastics which develops faster, polypropylene(PP) is widely used in the family, household appliances, textile, construction, automobile and other industries because it has a lot of excellent characteristics, such as good mechanical properties, good processing properties, chemical resistance and small density, light weight etc. But PP molecular chain is composed of carbon and hydrogen elements, which makes it easy to combust, and emit large amounts of combustion heat, it is easy to produce molten drips extremely to propagate flame. In recent years, fire occurred frequently and caused great harm to people’s lives and property safety, so it’s necessary to improve the flame retardancy of PP and other synthetic materials and the research work for flame retardant PP and other synthetic resin have been done in the world and great progress has been made.This work is to synthesize an environmental friendly novel intumescent flame retardant—piperazine spirocyclic phosphate from spirocyclic phosphoryl dichloride(SPDPC) and piperazine using liquid-phase method and solid-phase synthesis method respectively and the results were contrasted. The synthetic products were characterized by IR, NMR, elementary analysis and thermogravimetric analysis etc. The optimal reaction condition is the ratio of SPDPC and piperazine is1:1.2(n:n) and the reaction time is6h with yield56%for liquid-phase synthesis and the reaction time is only350s for solid-phase synthesis with yield95.3%. It’s clear that solid-phase reaction method is better than the liquid-phase reaction.PSP is added into PP to make intumescent flame retardant PP composite material(IFR-PP) which combustion performance, mechanical property, thermal stability, fire performance and the surface of the char after burning were tested. The results show that the limit oxygen index(LOI) of the IFR-PP increases from17.5to32.5and vertical burning achieves V-0rate when the load-on is30%. In the mechanical performance testing, in addition to tensile strength decreases, the impact strength and bending strength shows a improved tendency. Through the cone calorimeter test, it is proved that the flame retardant can effectively protect PP, make its fire hazard index drop.The flame retardant PSP and ammonium polyphosphate(APP) were compounded and added into PP to produce IFR-PP. The comprehensive performance of the IFR-PP were tested. The results show that, when the flame retardant and APP ratio is3:1, the oxygen index reaches39.5and vertical burning V-0level. Cone calorimeter data can prove that the heat release rate, total heat release, carbon monoxide emissions are substantially reduced for the IFR-PP. The surface morphology of the residue after Cone test was observed by scanning electron microscope(SEM) and a more compact char layer was observed. The experimental results show that APP and PSP composite flame retardant can preferably improve the flame retardancy of PP.