Study On Flame Retardant Rigid Polyurethane Foam With Amino Trimethylene Phosphonate

Rigid polyurethane foam(RPUF)has the characteristics of high obturator rate,low density,high compressive strength and low thermal conductivity,which makes it have the properties of compression resistance,light weight,water resistance,thermal insulation and so on.Therefore,it is widely used in transportation pipelines and building wall insulation and other fields.However,flammability severely limits the application of RPUF.Hence,it is necessary to give RPUF flame retardancy.In this paper,three kinds of amino trimethylene phosphonate flame retardants were synthesized and introduced into rigid polyurethane foams to prepare foam materials modified by amino trimethylene phosphonate alone and expandable graphite(EG),and further compounded amino trimethylene phosphonate with expandable graphite to obtain synergically modified rigid polyurethane foams.By means of oxygen index analysis,UL-94 vertical and horizontal combustion,smoke toxicity analysis,cone calorimeter analysis,thermogravimetric analysis and other characterization methods,the thermal stability,smoke toxicity and flame retardant properties of foam materials were studied.The results showed that amino trimethylene phosphonate and expandable graphite single-component modified rigid polyurethane foam can make rigid polyurethane foam have good flame retardancy,thermal stability and smoke toxicity.When the amount of EG was 20%,the oxygen index of modified RPUF can reach 28.8%.When the amount of EG was 15%,the heat release rate of RPUF was 34.8%lower than that of RPUF without flame retardant.The apparent activation energy of modified RPUF increased first and then decreased when amino trimethylene phosphonate was introduced into RPUF.When the total amount of flame retardant added was 15%,the three amino trimethylene phosphonate were synergistically compounded with EG,and all the RPUF co-modified by amino trimethylene phosphonate and EG reached FH-1 level.When the addition amount of amino trimethylene phosphonate and EG was 1:5,the synergistic effect was the best;when the addition amount of amino trimethyl calcium phosphate and EG was 1:5,the peak heat release rate of modified RPUF decreased by 52.4%,which was 17.6%lower than that of modified RPUF with 15%EG.In summary,the flame retardant performance of RPUF synergically modified by amino trimethylene phosphonate and EG was better than that of RPUF modified by amino trimethylene phosphonate alone and EG.