Preparation Of Functionalized Cyclophophazeneand Its Application In Flame Retardant Epoxy Resin

The P and N synergistic flame retardants synthesized with cyclophosphazene as the matrix are reactive and additive,including four reactive cyclophosphazene flame retardants:BPAPCP?HHMPCP?HQPCP and DPSPCP,and synthesis of an additive cyclophosphazene flame retardantadditive type is DHBPCP,To this end,this article starts from the synthesis of flame retardants,synthesizes P and N-containing EP derivatives,chemically grafts or physically blends flame retardants to obtain EP composites with different addition ratios,prepares functional epoxy resins,explores The difference of flame retardant effect on EP performance and mechanism to produce good flame retardant effect.The main work of this article are as follows:1.In this paper,four reactive cyclophosphazene flame retardants BPAPCP,HHMPCP,HQPCP and DPSPCP have been successfully synthesized.The functional cyclophosphazene synthesized in this paper reacts with the EP matrix.Thereby preparing phosphazene epoxy resin and maked thermal performance,flame retardancy and mechanical performance tests.Among them,in order to optimize the chemical stability,the ratio of functionalized cyclophosphazene flame retardant to E-51 resin is controlled to be 5%?7.5%.The results show that the phosphazene-based epoxy resin has good heat resistance and the flame retardancy reaches UL-94V0.2.In order to achieve industrialization,design new synthetic schemes to prepare reactive cyclophosphazene flame retardants to optimize experimental procedures and conditions.Synthetic hydroxyl-terminated reactive flame retardants can impart permanent flame retardancy and maintain original physical properties for better application.3.The thermal stability and flame retardancy of different systems of phosphazene flame retardant/epoxy resin were discussed.The results showed that the ratio of hexa(4-hydroxymethylphenoxy)cyclotriphosphazene(HHMPCP)to E-51 at 7.5%,its thermal stability is the best.Its initial decomposition temperature,maximum decomposition temperature,and residual carbon ratio were 314?,457? and 48%,respectively,and its limiting oxygen index(LOI)was 27.2%.