Research Of Polyurethane Microcellular Elastomer Halogen-free Flame Retardant Properties

Polyurethane microcellular elastomer widely used in many fields, but it haspoor flame retardancy.Simultaneously When the polymer combustion, large amountsof toxic gases will be produced, so limiting its development and application. Thispaper focused on non-halogen flame retardant microporous polyurethane elastomerresearch. Through the study of different dosage and conditions for preparing a flameretardant system combined flame retardancy and physical and mechanical properties ofmicroporous polyurethane elastomer. The properties of samples were characterized bythe limit oxygen index, vertical burning test, tensile test and thermal gravimetricanalysis, the results showed that:(1) Ammonium polyphosphate (APP), the expandable graphite (EG) and zincborate (ZB) three single component flame retardant system all can make microcellularelastomers to improve flame performance. in the same amount of flame retardant, theoxygen index of the EG flame system is higher than and ZB APP system.While threekinds of flame tensile strength and elongation at break decreased with increasingtrends in the amount of the flame retardant were, hardness increases with the amountof the flame retardant.(2) Different mesh EG is somewhat different effect on the flame microporouspolyurethane elastomer. Wherein EG50mesh and80mesh have better flameretardancy.And the flame effect of100mesh and120mesh are not significant.Theresults of the oxygen index level is less than fire-retardant materials. Meanwhile, withthe increaseing in the same amount of EG mesh, hardness and tensile strength of thesystem increases.(3) Ammonium polyphosphate and expandable graphite complex system hasgood flame retardant synergy. Synergy exists between the two proportions, the best complex ratio of1:1, While the compound effect of zinc borate and expandablegraphite complex system is not too significant, In the ammonium polyphosphate andexpandable graphite complex system, thermal gravimetric analysis also shows that theAPP to join can effectively enhance the amount of carbon residue after thermaldegradation of polymers.