Research On Performance Of The MPE/EVA/LDPE Halogen Free Flame Retardant Material

With the progress of science and technology, peoples living standards is alsoimproved, more and more attention has been paid to their living environment andtheir own safety. According to many reports, it has found that in the fire disastermost of the damage is due to the poisonous and harmful gas which is caused bythe combustion of the material that contains halogen. So research of flameretardant materials with low smoke and no halogen has become one of the mostpopular topic. But adding too much inorganic flame retardant materials causesgreat destruction to the mechanical properties and processability. Adding EVA tomodify the resin, and it can effectively improve the compatibility between theadding material and the base, so as to improve the properties of materials; at thesame time adding suitable amount of grafted mPE to replace mPE can improvethe mechanical properties of the materials.In this paper maleic anhydride grafted metallocene polyethylene wasparepared by melt grafting method. It is found that with the increaceing ofconcentration, grafting monomers and inhibitors, the grafting ratio was increasedat first, and then show a tendency of decrease. As a result, the grafting processfor reaction temperature was170℃, reaction time4min, speed60r/min, DCPdosage was0.2wt%, maleic anhydride amount was2wt%, inhibitor dosage was0.2wt%.Taking maleic anhydride grafted metallocene polyethylene and metallocenepolyethylene with no grafting process for tensile testing and rheologicalproperties analysis. The result showed that composite system with after graftingthe metallocene polyethylene mechanical properties and processing propertieshad obviously promoted; Tensile strength increased from7.2N/mm~2to9.8N/mm~2,elongation has promoted; Equilibrium torque decreaced from14.3N·m to14N·m.Analyse the mechanical properties and oxygen index test, the impact of the content of VA in EVA composite system was discussed by SEM, the result showsthat: as the content of VA increase, dispersibility of composite improved, Tensilestrength enhanced, oxygen index increased; However, too much VA will cause adecline in material properties; When the VA content reaches35wt%, the overallperformance of materials achieve the best.Flame retardant formulation was studied by orthogonal design method,According to the data analysis, the major affecting factor of the tensile strength,the oxygen index and the balance torque were determined, and so was the bestformula.