Study On The Effect Of Graphene On Flame Retardancy And Smoke Of Polyurethane Foam

Currently,Polyurethane foam is widely used in the development of our society.It has been used in various fields due to its unique advantages in heat preservation,sound insulation,cushioning and simple manufacturing processes.However,the shortcomings of polyurethane foam,including flammability,high smoke and the smoke is highly toxic,have limited its application range.Based on the purpose of optimizing the flame retardancy and smoke suppression of polyurethane foam,adopting one-step preparation process,isocyanate and polyether polyol are used as the main raw materials to prepare graphene modified polyurethane foam by premixing and adding.At the same time,the graphene is modified to obtain a graphene oxide/polyurethane foam.The flame retardancy and smoke’s characteristics of the materials are characterized by using different apparatuses such as limiting oxygen index meter,cone calorimeter,thermogravimetric analyzer,UL-94 vertical horizontal burner and scanning electron microscope.The effects of graphene and improved graphene on the flame retardant,pyrolysis,smoke and other problems of polyurethane foam are discussed.Under the premise of minimizing the damage to thermal insulation performance and cell structure,comprehensive analysis is conducted to find the best ratio of flame retardant and smoke suppression.The results show that the use of appropriate amounts of GNS and GO can significantly reduce the heat release and smoke release of the material compared to pure polyurethane foam.When 1wt% is added,the flame-retardant effect is the best,and the Peak Heat Release Rate(PHRR)of the material is reduced by 50% and 55%.When 2wt% GNS or 0.5wt% GO is added,the smoke suppression effect is the best,with the Peak Smoke Production Rate(PSPR)decreasing by 25% and 21%,and the carbon monoxide production rate(COP)decreasing by 40%.Due to the increase of GNS and GO,the initial pyrolysis time of the material is delayed by about 20 s and is more favorable for the formation of carbon layer,showing good flame retardant and smoke suppression effect.