Study On Flame Retardant TPU Based On Modified Molecular Sieve With Ionic Liquid

Benifited from the excellent physical and chemical properties,thermoplastic polyurethane elastomers（TPU）have been widely used in various fields.However,the flammability and melt drip limit limit the further applications.Molecular sieve and ionic liquids have been proven to have flame retardant effect as an environmentally friendly materials.Therefore,3A molecular sieve was used as flame retardant agent in thermoplastic polyurethane elastomer（TPU）by melt blending method.And the hermal stability performance and smoke performance of flame retardant TPU composites under different conditions were characterized by cone calorimetry（CCT）,smoke density test（SDT）,thermogravimetric analysis（TGA）and thermogravimetric infrared（TG-IR）.Furthermore,1-ethylacetate-3-methylimidazolium hexafluorophosphate（[EOOEMIm][PF₆]）andmolecularsievewasmodifiedby1-Ethylacetate-3-methylimidazolium tetrafluoroborate（[EOOEMIm][BF₄]）repectively to obtain MS&[EOOEMIm][PF₆]and MS&[EOOEMIm][BF₄]composite flame retardant,and they were added into TPU as new fleme retardant agents.The experimental results showed that the molecular sieve can exert better flame retardant and smoke suppression effect in the TPU system.When the molecular sieve addition amount is 1.0 wt%,the effect is the best.At this time,the total heat release was reduced by 51.5%,and the total smoke release was reduceby 48.4%,the luminous flux was increased by 5.53%compared to pure TPU,and the thermal stability of TPU can be effectively improved under nitrogen conditions,reducing the release of toxic gases.MS&[EOOEMIm][PF₆]can exert flame retardant effect by promoting the formation of carbon layer and improving the structure of carbon layer,and it has the best flame retardant effect when the addition amount is 1.0 wt%,the total smoke release was 54.9%lower than that of pure TPU,the luminous flux increased by 9.12%;MS&[EOOEMIm][BF₄]can exert better flame retardant and smoke suppression effect with less usage.When the addition was 0.5 wt%,the parameters of heat and smoke were improved best.The peak heat release rate was reduced by 65%,the total smoke release was reduced by 57%,and the residual amount of carbon residue was increased by 28.92%compare with pure TPU.