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Study On The Synthesis And Application Of Environment-friendly Dialkyl Phosphinic Acid Aluminum Flame Retardant

Posted on:2018-06-07Degree:MasterType:Thesis
Country:ChinaCandidate:L XuFull Text:PDF
GTID:2321330533959914Subject:Chemical engineering
Abstract/Summary:PDF Full Text Request
A new type of dialkyl group hypophosphite flame retardant was synthesized in this work.The dicyclohexenyl sodium hypophosphite was first prepared via cyclohexene and sodium hypophosphite,and then reacted in free radical initiator and normal pressure conditions with acetic acid as the solvent.Aluminum dicyclohexenyl hypophosphite(ADCP)was obtained by adding aluminum sulfate.Molecular structures were characterized by FT-IR,1H NMR and 31 P NMR spectroscopy.Phosphorus and carbon element contents were measured by energy dispersive X-ray spectroscope.Product thermostability was analyzed via thermogravimetric analyzer.Flame retardant properties were investigated by adding ADCP to polyamide(PA);limiting oxygen index(LOI)and vertical burning were determined,Scanning electron microscopy of the PA material after combustion.The influences of initiator species,initiator dosage,temperature,and reaction time on target product yield were discussed.This article also explore a coinitiator to increase the yield of target products,the synthesis conditions were optimized by orthogonal experimental design,and the optimum reaction conditions were obtained in combination.In addition,the PA material without the addition of flame retardant and added flame retardant after thermal decomposition kinetics results were analyzed by Kissinger method and Flynn-Wall-Ozawa method respectively,then calculated the required thermal decomposition activation energy,verify the calculated activation energy data are accurate and reliable.The Coast-Redfern theory model was used to verify the thermal decomposition mechanism function model,and the kinetic equation and reaction mechanism were obtained.The results showed that the benzoperoxide as radical initiator was best and dosage was 5%,the reaction temperature was 85?,the reaction time was 10 h,and the yield was stable at about 81%.The influence factors on the yield order of reaction temperature,reaction time,dosage of initiator by orthogonal experiment,the reaction temperature is the major factor affecting the yield of the reaction time,initiator dosage minimal impact on the results.The results of coinitiator agent exploration showed that the yield of the product was about 87% when the ratio of the cuprammonium sulfate to the ratio of the initiator was 4%.Flame retardant products added to the PA6,the best flame retardant dosage is 12%,the limiting oxygen index is 34.1%,the burning flame retardant grade is FV-0,the combustion section forming a dense carbon layer,phosphorus and carbon content was 68.36%,achieved the balance of phosphorus and carbon and preferably comprehensive utilization.The kinetic results showed that the flame retardancy of PA is divided into two stages,and the two phases are played by the catalytic effect of metal ions in the flame retardant and the thermal insulation effect of the carbon layer.The mechanism of thermal decomposition function was study by Coast-Redfern model,and get mechanism function are g(?)= [-ln(-?+1)]n,n=2/3,g(?)= [-1+(1-?)-1/3]2,the thermal decomposition reaction of series 2/3 and 2,combined with the limit oxygen index of PA material was 34.1%,the dosage was 12%,and the vertical burning level can reach FV-0 level,fully proved the efficiency of ADCP flame retardant.
Keywords/Search Tags:alkyl, phosphonate, cyclohexene, free, radical, addition, flame retardant, thermal decomposition mechanism
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