Study On Preparation And Flame Retardancy Of Phosphorus-Silicon Hybrid/Epoxy Resin Composites

The coupling of phosphorus-silicon hybrid coupling agent（DPHA-KH）.（DPHA-KH）with carbon fiber（CF）was synthesized by using diphenyl chlorophosphate（DPCP）,β-hydroxyethyl acrylate（HEA）and aminopropyl triethoxy silane（KH-550）as raw materials.Carbon fiber（CF-DPHA-KH）coupled with phosphorus-silicon hybrid was prepared.The hydroxy terminated polyphenylate（HPSPP）polymer was synthesized by the condensation reaction of phenyldichlorophosphate（PDCP）and diphenyl silyldiol（DPSD）.Epoxy resin was used as the base material.Epoxy resin composites（CF-DPHA-KH/EP）and HPSP polymer flame retardant epoxy resin composites（HPSP/EP）were prepared by coupling carbon fiber with phosphorus-silicon hybrids respectively.CF-DPHA-KH and HPSP were prepared by FT-IR,NMR,SEM,elemental analysis（EDS）and gel permeation chromatography（GPC）.The thermal stability and flame retardancy of CF-DPHA-KH/EP and HPSP/EP composites were studied by TGA,micro calorimeter（MCC）and limit oxygen index（LOI）,respectively.The morphology and composition of carbon layer were characterized by SEM and XPS.The smoke emission of the composites was studied by the smoke density tester.The activation energy of thermal degradation was calculated by Flynn-Wall-Ozawa（FWO）method.The mechanical properties of the composites were studied by tensile testing machine.The results show that with the increase of CF-DPHA-KH content,the maximum decomposition temperature(T_max),carbon yield and limiting oxygen index（LOI）increased of CF-DPHA-KH/EP.The peak heat release rate（PHRR）and Total heat release（THR）decreased,maximum smoke density value（MSD）decreased,the smoke density rating（SDR）lower,thermal degradation activation energy（Ea）with the increase of conversion rate increases,the breaking elongation of the composites increased,the elastic modulus decreased.When the content of CF-DPHA-KH is 15wt%,LOI was 28.5%,the carbon residue rate was18.7%,PHRR 226.5W/g,THR 22.67kJ/g,MSD 90.66%,SDR 66.86,fracture the elongation is 49.5%,the elastic modulus of E was 22.85Mpa.With the increase of HPSP content,HPSP/EP T_max increased,carbon residue rate increased,LOI increased,PHRR decreased,THR decreased,MSD decreased,SDR decreased,Ea increased with the conversion rate increases.When the HPSP content is 15wt%,LOI was 27%,the carbon residue rate 14.5%,PHRR was 208.7W/g,THR was 22.9kJ/g,MSD was 91.98%,SDR was 71.83,and Ea increases with the increase of conversion rate.The comprehensive analysis shows that CF-DPHA-KH synthesized from diphenyl chloride phosphate（DPCP）,β-hydroxyethyl acrylate（HEA）,aminopropyltriethoxy silane（KH-550）,carbon fiber（CF）has flame retardant effect on epoxy resin.The mechanical properties of epoxy resin were also improved by the introduction of carbon fiber.The hydroxy-terminated polyphenyl-phosphatidyl（HPSPP）polymer synthesized by Phenyl dichlorophosphate（PDCP）and diphenyl silanediol（DPSD）,that has improved the thermal stability and flame retardancy of epoxy resin.