Study On The Preparation And Mechanism Of Epoxy Matrix With Smoke Suppression And Flame Retardant

The flammability and smoke release of epoxy resin severely limited their application in the field of carbon fiber composite materials for rail transit.The research on the preparetion and mechanism of flame retardant and smoke suppression epoxy resin has become a research hotspot.A new flame-retardant and smoke-suppression method combining molecular with cross-linked network structure design of epoxy matrix were proposed and used.Based on phosphorus-containing epoxy resin(PEP),PEP-benzoxazine copolymer(COP)and interpenetrating polymer network(IPN),three kinds of epoxy matrix with flame retardancy and low smoke release were prepared.The thermal degradation,flame retardant mechanism of epoxy matrix were studied,and the mechanism model of flame retardant and smoke suppression of the epoxy matrix were constructed.1.Phosphorus-containing epoxy(PEP)was molecularly designed and prepared by Di-Glycidyl Ether of Bisphenol A(DGEBA)and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO).Using PEP and benzoxazine(BZ),the copolymer(COP)and interpenetrating network polymer(IPN)were prepared by cross-linking network structure design.The preparation process and structure of PEP,COP and IPN were verified,and the flame retardant of three kinds of,epoxy matrix reached UL94V0 grades.The heat release,smoke release of PEP system were higher than those of COP and IPN,which were reduced by nearly 30%and 60%.2.The thermal decomposition products from condensed phase and gas phase of common epoxy matrix(CEP),PEP,COP and IPN were analyzed by infrared spectroscopy,pyrolysis/gas chromatography-mass spectrometry,and the thermal decomposition model of four kinds of epoxy matrix was proposed.The chemical composition and the morphology of char residue was analyzed by XPS and SEM,and The mechanism model of flame retardant and smoke suppression of epoxy matrix was proposed by combining with the aforementioned thermal decomposition mechanism.PEP,COP and IPN all exhibited flame retardancy effect with condensed phase and gas phase.For PEP,flame retardant effect with condensed phase was weak.For COP,the flame retardant effect with condensed phase was relatively strong,whereas weak with gas phase.For IPN,The flame retardant effect with condensed phase was the strongest,and the flame retardant effect with gas phase was strongly suppressed.