Study On Preparation And Fire Behavior Of High Flame Retardant Carbon Fiber Reinforced Epoxy Composites

Due to the advantages of low density,high specific strength and specific modulus,and strong designability,carbon fiber reinforced epoxy resin matrix composites show broad application prospects and development potential in the lightweight of transportation equipment.However,its fire performance is poor,easy to be ignited,combustion releases a large number of toxic and harmful smoke,can not meet the fire standards of China’s rail transit,civil aviation and other transportation industry,greatly limiting its application in the field of transportation.Therefore,researching and developing highly flame-retardant carbon fiber reinforced epoxy resin-based composite materials and promoting"replacing steel with plastic"can effectively reduce energy consumption and carbon emissions in the transportation industry,and help the country to achieve"carbon peak and carbon neutrality as soon as possible""strategic goals.In this paper,the preparation and fire behavior of high flame-retardant carbon fiber reinforced epoxy resin matrix composites were studied.The main research results are as follows:1.Two kinds of high flame retardant epoxy resins were prepared by physical blending with epoxy resin as matrix material,ammonium polyphosphate（APP）as flame retardant,cuprous oxide（Cu₂O）and talc as flame retardant synergist.The study found that for the APP/Cu₂O flame retardant epoxy resin system,when the total amount of flame retardant added was 10wt%,with the continuous reduction of the mass ratio of APP and Cu₂O,The LOI value of the flame retardant epoxy resin first increased and then decreased,reaching the maximum value of 28.7%at 8:2.Keeping the mass ratio of APP to Cu₂O at 8:2,the LOI value of the flame retardant epoxy resin increases with the increase of the amount of flame retardant.In addition,For the APP/Talc flame retardant epoxy resin system,with the continuous reduction of the APP/Talc mass ratio,the LOI value curve of the flame retardant epoxy resin shows two peaks,and the maximum value appears when APP/Talc=9:1,The peak value is 33.7%,and the UL-94 test reaches V-0 level.Keep the mass ratio of APP to Talc at 9:1,with the increase of the total amount of flame retardant,the LOI value of flame retardant epoxy resin continues to increase.2.Two kinds of high flame retardant carbon fiber reinforced epoxy resin matrix composites were prepared by hand pasting process with high flame retardant epoxy resin as matrix material and carbon fiber fabric as reinforcement material.The study found that under the condition of keeping the mass ratio of flame retardants（APP/Cu₂O,APP/Talc）unchanged and the total addition amount of 35wt%,with the increase of the number of carbon fiber fabric layers,the flame retardant performance of the composite material continued to deteriorate.In addition,keeping the number of layers of carbon fiber fabric at 6 and changing the ply direction of carbon fiber fabric,different ply directions of carbon fiber fabric will have a certain impact on the flame retardant properties of the composites.3.The fire behavior of two high flame retardant carbon fiber reinforced epoxy resin matrix composites was analyzed from three aspects:heat release behavior,smoke production behavior and smoke toxicity behavior through cone calorimetry test.The results show that both EP/35APP-Cu₂O/CF6 and EP/35APP-Talc/CF6 have excellent properties of reducing heat release,smoke suppression and smoke toxicity,and EP/35APP-Talc/CF6 is better.In addition,the fire hazard was evaluated by fire growth parameters and flame retardant index.Both EP/35APP-Talc/CF6 and EP/35APP-Cu₂O/CF6 have good fire safety performance,which can greatly reduce the fire spread speed.And the fire safety of EP/35APP-Talc/CF6 is obviously higher than that of EP/35APP-Cu₂O/CF6.Finally,through the smoke density and smoke toxicity test of the material,it is checked whether it meets the airworthiness requirements of civil aviation,and it is found that the smoke density and smoke toxicity of the smoke produced by EP/35APP-Talc/CF6 and EP/35APP-Cu₂O/CF6 when exposed to fire All meet the airworthiness standard HB 7066 of the Civil Aviation Administration of my country,and can also meet the airworthiness requirements of Boeing BSS 7239 and Airbus AITM 3-005.