Synthesis And Flame Retardant Properties Of The Derivatives Of Cyclotriphosphazene

With the wideiy used of synthesized organic polymer materials,the related fire accident is also rising.It is more and more important to research and development the nonflameable polymer materials.The traditional halogen flam retrandants is efficient,but it would be harmful to people and environment.This contrary to green and environmental idea and the efficient and green flame retardant has been the tendency.The cyclotriphosphazene compounds have been the focus because of its high thermal stability.Hexachlorocyclotriphosphazene can derive varieties of cyclotriphosphazene derivative because of its active chemical property.The phosphor and nitrogen atoms in the cyclotriphosphazene skeleton can generate the synergies during the process of combustion.First of all,the hexakis[p-(aldehyde)phenoxy]cyclotriphosphazene(PN-CHO)is synthesized which refer to the literature and the target product,hexakis[p-(aldehyde)phenoxy]cyclotriphosphazene-melamine(MPN-CHO)was successfully synthesized with PN-CHO and melamine(MH)through the scheff reaction.The flame retardant,MPN-CHO,couple d with polyphosphate(APP)and pentaerythritol(PER)were blended withpolypropylene(PP)to prepare of halogen-free nonflamble materials.The MPN-CHO/APP/PER/PP materials exhibits high flame-retardant efficiency,and the best limiting oxygen index(LOI)is 34.4%.We test the thermal stability of flame retardant materials by thermo-gravimetric(TGA)and the result indicate that the materials has a good thermal stability.The carbon residue of nonflamabel materials is 15.2% at 600?.The impact strength and bending strength test results show that the parts of mechanical properties of nonflamble materials are enhanced.The SEM test shows that the internal carbon layer is unbroken and the internal carbon is dense and hard.It is an ideal heat insulation structure.Second,the hexakis[p-(methylol)phenoxy]cyclotriphosphazene(PN-OH)is synthesized by restoring PN-CHO.The epoxy resion(PNEP)is synthesized with PN-OH and epichlorohydrin(ECH)through phase-transfer catalysis.This method is simple,green and saves a lot of organic solvents.The PNEP are cured by two diffrernt cuiong agent and prepare two curing materials.We study the influence of thermal stability,fire resistance and mechanical property,which produced by the two curing agent.The test show that the PNEP material cured by 4,4-diamino diphenyl methane(DDM)have a better fire resistance.its limiting oxygen index is 27.1% and the carbon residul rate is 54.71% at 600?.The SEM test indicat tha internal carbon layer is dense and hard,which is the ideal heat insulation structure.The last,p-aminophenol and phenol are introduced to hexachlorocyclotriphosphazene and obtain a kind of flame retardant which could be also chemical intermediate.The epoxy resion based cyclotriphosphazene(HPAP)is synthesized by obtained flame retardant and epichlorohydrin.We study the influence of thermal stability,fire resistance and mechanical property,which produced by the two curing agent.The test results show that the fire resistance of DDM-HPAP materials cured by 4,4-diamino diphenyl methane has a better preference and the LOI is 26.8%.The thermal stability of DDM-HPAP is high and the intial decomposition temperature(Tonset)of DDM-HPAP is 235 ?.Its carbon residul rate is 45.23%.The SEM test indicates that the carbon layer of DDM-HPAP is more compact and dense which can play a good thermal insulation resistance.