The Effect Of Modified Graphene On The Flame Retardancy And Smoke Suppression Properties Of Polymer

With the rapid development of society,people have more and more attention on protection of environmental.Therefore,the environmental friendly flame retardant has received wide attention.In this article,MgAl-LDH loaded on the surface of graphene by hydrothermal method,enhancing the dispersion of graphene.Then the LDH on the surface of graphene was modified with heptaheptamolybdate ion by ion-exchange method,studing the effect of thermal,flame retardancy and smoke suppression on polyurethane composites;the H2PO₄-was intercalated into the interlayer space of LDH by ion exchange to synthesize RGO-LDH/P.RGO-LDH/P was added into the epoxy resin,studing the effect of dispersibility,thermal,flame retardancy and smoke suppression on epoxy rasin;RGO-LDH/CuMoO₄ was added into the epoxy resin and study its effect on the properties of thermal flame retardancy and smoke suppression of the epoxy resin.?1?The MgAl-layered double hydroxide loaded graphene hybrid?RGO-LDH?was prepared through the co-precipitation method,and then heptaheptamolybdate?Mo7O246-?modified RGO-LDH hybrid?RGO-LDH/Mo?was synthesized by the ion exchange method.X-ray diffraction?XRD?,Fourier transform infrared?FTIR?spectra,Laser Raman spectroscopy?LRS?and Transmission electron microscop?TEM?micrograph results showed the RGO-LDH/Mo was synthesized successfully.RGO-LDH/Mo was added into the polyurethane elastomer?PUE?for improving the flame retardancy and smoke suppression properties.The results showed that the char yield of PUE with RGO-LDH/Mo was increased significantly compared with pure PUE.The peak heat release rate and the maximum smoke density of the PUE composites decreased drastically.The reasons were attributed to the physical barrier of graphene and LDH,and the metal oxide generated from LDH could restrain the diffusion of inflammable gas.Meanwhile,MoO3 formed in the decomposition process of RGO-LDH/Mo promoted the catalytic carbonization and smoke suppression effect.?2?A hybrid with MgAl-layered double hydroxide loaded graphene?RGO-LDH?was synthesized by the co-precipitation method,and then dihydrogen phosphate anion?H2PO₄-?modified RGO-LDH hybrid?RGO-LDH/P?was prepared through the ion exchange method.X-ray diffraction,Fourier transform infrared spectra,and Transmission electron microscope-energy-dispersive X-ray spectroscopy results showed that RGO-LDH/P was synthesized successfully.RGO-LDH/P was added into epoxy resin?EP?for an investigation into the effect of flame retardancy and smoke suppression.The results showed that the limit oxygen index and char yield of EP with RGO-LDH/P was increased notably,compared with EP.Meanwhile,the heat release rate and smoke production rate of the EP composite was decreased significantly.The improved flame retardancy and smoke suppression were attributed to the physical barrier of graphene and LDH,and the catalytic carbonization effect of LDH.In addition,H2PO₄-had a role in promoting carbonization and further improving flame retardancy and smoke suppression.?3?The co-precipitation method are used to synthesize a hybrid with MgAl-layered double hydroxide loaded graphene?RGO-LDH?.And then CuMoO₄ onto the surface of RGO-LDH,prepared a hybrid with CuMoO₄ modified the RGO-LDH?RGO-LDH/CuMoO₄?.The composition,structure and morphology of RGO-LDH/CuMoO₄ are characterized by X-ray diffraction,Laser raman spectroscopy?LRS?and Transmission electron microscope-energy-dispersive X-ray spectroscopy.The research results indicated that the hybrid of RGO-LDH/CuMoO₄ was prepared successfully.The effect of flame retardancy and smoke suppression of epoxy resin was studied with added RGO-LDH/CuMoO₄.Results show that the PHRR and THR of EP composite with added RGO-LDH/CuMoO₄ was decreased dramatically.And the char yield and LOI of EP composite increased significantly,the flame ratardancy was improved.In addition,The SPR,TSP,Ds,max of EP composite was decreased drastically with added RGO-LDH/CuMoO₄.Flame retardancy and smoke suppression performance of EP composite was improved,it mainly due to the physical barrier of graphene and LDH,and the catalytic carbonization function of LDH.Meanwhile,Cu₂ O and MoO₃ generated in combustion process RGO-LDH/CuMoO₄ could enhance the production of char residue and raised the compactness of the char layer.