Study On Phosphorus-silica Flame Retardant Polyurethane Foam

Developing a new type of multiple elements or multiple synergistic flame retardant on rigid polyurethane foam?RPUF?is one of the focuses in recent years for the research scholars.Multiple synergistic flame retardant can not only improve the flame retardant efficiency,but also expand the scope of application of RPUF.The P-Si synergistic flame retardant RPUF was prepared by directly adding P-Si integrated flame retardant?SiSPEPA?and phosphorus-containing polyol?P-polyol?combinated with Kaolin?KL?,and the effects of them on the properties of RPUF cell structure,flame retardant and mechanical properties were studied.In the Si-SPEPA/RPUF,the effect of different contents and ratio of P,Si on RPUF performance was studied.The results showed that Limited Oxygen Index?LOI?increased gradually with the increase of the amount of Si-SPEPA.Si-SPEPA could effectively reduce the amount of heat released of RPUF carbon layer decomposition,and promoted the formation of sable carbon layer,the residual carbon rate increasing to 37.5%.In the Triethyl phosphate?TEP?/Si-SPEPA/RPUF system,P/Si=3.6 was the best ratio.At the same time,the foam cell structure was better,and LOI was 26.9%,showing the characteristics of condensed phase and gas phase flame retardant,when the impact strength reached to 0.152 k J·m^-2,and compressive strength was 0.200 MPa.The properties of P-polyol/RPUF with the phosphorus content of 1.82% were tesed.The results showed that the LOI reached 24.7%.The heat release capacity,total heat release and heat release peak decreased,and the amount of residual carbon was more than prue RPUF,when the compressive strength increased by 130% and the original impact strength was retained.On the basis of it,KL/P-polyol/RPUF's LOI increased not obviously,but smoke density rating?SDR?decreased significantly with the compressive strength up to 0.294 MPa.The thermal stability improved,so that KL and P-polyol had synergistic effect.