Study On Bromine Carbon Polyurethane Flame Retardant Materials

Through analyzing and researching the current situation of fire-retardant coatingsand elastomers both at home and abroad,in order to resolve the problem of flameretardant durability of the materials,bromine carbon polyurethane resin was preparedby molecular design and material design and was used in steel structure fire retardantcoatings and elastomer.Excellent property of fire-retardant materials was prepared andachieved the purpose of long-term efficient flame retardant.The low molecular weight of tetrabromobisphenol A polyurethane prepolymerwas synthesized with toluene-2,4-iso-cyanate,tetrabromobisphenol A,polyethyleneglycol-400,trimethylolpropane as raw materials by step addition and the structure ofthe product was charactered by infrared spectra.The infrared spectra showed that C-Brring vibrating appearanced in 1071cm^-1,1062cm^-1and C-Br features telescopicvibrating peaks appearanced in 569cm^-1.The results showed that the optimumpreparation conditions of the tetrabromobisphenol A polyurethane prepolymerwere:when n(PEG-400):n(TBA):n(TMP)was 0.25:0.5:0.25, n(NCO):n(OH) was1.8:1,the reaction time was 1.5h at 60℃,the NCO value reached the stablestate.Hydroxyl acrylic resin of 50.2mgKOH/g,solidity of 54.6% as curing agent, whenn (NCO) : n (OH) = 1.1:1,the optimal performance of the paint was obtained. The TGand DSC showed that the weight lose of two-component bromine carbon polyurethaneresin was mainly concentrated 290 600℃,no longer weightlossness after 600℃.Thisindicated that the two-component bromine carbon polyurethane resin wasadvantageous as the resin of the fire-retardant coatings for steel structure.The two-component polyurethane fireproof paint for steel sructure which wascured at room temperature was prepared after compoment A and component B mixedby certain proportion,with hydroxyl acrylic resin,ammoniumpolyphosphate,melamine,pentaerythritol and other additives as B component,tetrabromobisphenol A polyurethane prepolymer as A component.The effect ofvarious components for flame retardant property of fireproof coatings were studiedand the flame retardant property of fireproof coatings was tested by a self-madesimulate burning device. The optimal formula of fire-retardant coating wasdetermined and various performances were compared with polyurethane fireproofcoatings which did not contained bromine.when the thickness of the coating was2.0mm,the fire resistant limit could reach 150min,which was 30min promoted thanpolyurethane fireproof paint for steel structure without bromine.A series of bromine carbon polyurethane prepolymers were prepared with N-220,N-330,TBA,and TDI as raw materials and the structure of the prepolymers wascharactered by infrared spectra.The infrared spectra showed that C-Br ring vibratingappearanced in 1107cm^-1and C-Br features telescopic vibrating peaks appearanced in568cm^-1.A series of bromine carbon polyurethane flame retardant elastomers wasprepared with 3,3'-dichloride-4,4'-methylene diamine as co-crosslinker.The influenceof polymerization reaction temperature,reaction time,material ratio,curing conditions and other factors on the performance of mechanical properties and fire-retardantproperties of elastomer were studied.The optimal formula of flame retardantelastomers were determined.The result showed that when n(N-220):n(N-330):n(TBA)was 0.53:0.22:0.25,isocyanate index R was 2.0,reaction temperature was 80℃andreaction time was 4hours, NH2/NCOwas 0.9,cure at 110℃for 2 hours,the mechanicalproperties of elastomers achieved the best.The tensile strength and elongation at breakwere 12.9Mpa and 480% respectively,the average time of flame continued for 0second,the average burning time continued for 1 second.The TG and DTA of thebromine carbon polyurethane resin showed that the weight lose of two-componentbromine carbon polyurethane resin was mainly concentrated 290⁶00℃,noweightlossness after 600℃.This indicated that the two-component bromine carbonpolyurethane elastomers was excellent thermal stable.