Research On Prepregs Meeting The Flame Retardant Standards Of Rail Transit

With the increasing requirements for light weight of rail transit components,the application of carbon fiber reinforced plastics(CFRP)in this industry has become more and more extensive.However,the resin matrix of the composite material is flammable,which limits its application.In this paper,the international flame retardant standard EN 45545 was used as a background to carry out research on flame retardant prepregs for rail transportation.Generally,only professional third-party flame-retardant testing institutions have the EN 45545 flame-retardant testing instruments and equipments in China,but the test equipments such as oxygen index and smoke density can be easily obtained.Based on the test data of basic oxygen index and smoke density,the index decomposition of EN 45545 flame retardant standard was studied,and the corresponding relationships between the properties of flame retardant and EN 45545 standard were explored.The main research results obtained are as follows:The ATH,ZB2335,AP422,AP462,SPB-100 or S1500W were added to TF1710 prepreg resin system respectively.Prepregs and laminates were prepared and tested.The results of the study showed that with the increase of the addition amount,the compression strength of the samples with ATH increased first and then decreased.The addition of other flame retardants all caused the compression strength and interlayer shear strength to decrease in a nearly linear trend.From the perspective of the influence of the limit oxygen index(LOI)and self-extinguishing time of the composite materials,the flame retardant performance was:S1500W>ATH≈AP462>ZB2335>AP422>SPB-100;from the perspective of the smoke density of the composite materials,the ability to suppress smoke was:ZB2335>AP462>AP422>ATH>SPB-100>S1500W.The requirements of EN 45545 flame retardant standard were analyzed from the mechanism,and then the relationship between the combination of flame retardant and the performance of the laminate was studied with reference to the basic oxygen index and smoke density test data.The study found that,when the content of ATH,AP422 and ZB2335 were 5%,7.5%and 12.5%,respectively,after the modified prepreg was cured,the heat release of the laminate was 76 kW/m2,the smoke density was 236,the smoke concentration was 492,the critical radiation energy was 26 kW/m2,and the smoke toxicity was 0.124.It met the HL2 level required by R1 in the EN 45545 standard,and had good practicability.