Study On The Flame Retardancy Of Natural Rubber With Highly Effective Intumescent Flame Retardant

With the development of today's era,it is urgent to prepare a flame retardant that is effective and environmentally friendly for rubber materials,especially natural rubber materials.Based on this,this work successfully designed and prepared several new intumescent flame retardant systems and conducted research in natural rubber to verify its excellent flame retardant properties and good mechanical reinforcement properties.The first part studied the preparation of a new graphene/intumescent flame retardant system(AGT): In this experiment,plant polyphenol tannic acid(TA)was used as the liquid phase dispersion aid of graphene(GE)to prepare functional graphene with good dispersibility(TGE).Then,the other component of AGT,ammonium polyphosphate(APP),was evenly dispersed in natural rubber(NR)by mixing,and NR@AGT composites were successfully prepared.The experimental results show that the new AGT intumescent flame retardant system has synergistic flame retardancy and smoke suppression for NR.When the same amount of flame retardant was added,NR@AGT showed a higher oxygen index value and a higher flame retardant grade compared with pure APP flame retardant.The vertical combustion performance shows that with the addition of 60 phr AGT,the flame retardancy grade of the composite material can reach UL-94V-0,and the oxygen index value is much higher than the pure APP flame retardant/NR composite.Raman,infrared results and SEM-EDX results of residues show that the AGT flame retardant system can significantly promote the high carbonization of residual carbon after combustion and the formation of phosphorus-containing carbonaceous structure carbon layer,thereby effectively reducing the flammability of NR.At the same time,the experimental results show that the effect of the AGT flame retardant system on the mechanical properties of NR is weaker than that of pure APP flame retardants withthe same loading of flame retardant.The second part studies the preparation of a new polyurethane intumescent flame retardant smoke suppression protective coating(PU/TGA): the first experiment is to blend the prepared TGE with APP to prepare graphene/intumescent flame retardant(TGA).Then,the TGA intumescent flame retardant is evenly dispersed in the polyurethane(PU)prepolymer solution to prepare the polyurethane intumescent flame retardant liquid.Finally,PU/TGA was evenly coated on the surface of natural rubber to prepare polyurethane intumescent flame retardant/NR composites(PU@TGA).The experimental results show that in this work,the developed polyurethane intumescent flame retardant smoke suppression protective coating PU/TGA has good flame retardant smoke suppression effect for NR.In the case of the same loading of flame retardant,compared with pure APP,NR coated with PU/TGA showed a sharp decline in all combustion parameters.The third part studies the preparation of a new type of clay/ intumescent flame retardant system(ACT): the first experiment is to use plant polyphenol tannic acid(TA)as the liquid dispersion aid of clay(Clay).The well-dispersed clay(TCY)is then compounded with APP to prepare ACT.Finally,the ACT was added to the natural rubber by blending,and ACT/NR composites were successfully prepared.The results show that in this work,the prepared ACT intumescent flame retardant system has a good flame retardant effect on NR.When the same amount of flame retardant was added,NR@ACT showed a higher oxygen index value and a higher flame retardant grade compared with pure APP flame retardant.The vertical combustion performance shows that with the addition of 60 phr ACT,the flame retardancy grade of the composite material can reach UL-94V-0,and the oxygen index value is much higher than the pure APP flame retardant/NR composite.And through the thermogravimetric test,it is proved that the thermal stability of the NR composite added with ACT intumescent flame retardant system is higher.