The Study Of The Synergism Of PP/Intumescent Flame Retardant Compounds Based On Zinc Compounds

This paper takes PP and IFR as research objects. With EG, ZnO and ZB,composites such as PP/IFR、PP/IFR/EG、PP/IFR/ZnO、PP/IFR/ZB、PP/IFR/EG/ZnO、PP/IFR/EG/ZB are prepared by melt-blending process. By analyzing the mechanicalproperties, the limiting oxygen index, vertical burning test and thermal analysis, thisarticle studies the optimum proportion of IFR/EG、IFR/ZnO、IFR/ZB、IFR/EG/ZnO、IFR/EG/ZB and the effects of added ratio of flame retardant on the mechanicalproperties and combustibility of composites. By observing the carbon layer’s SEMmorphology and thermal performance analysis of the sample after burning, this paperaims to investigate the flame retardant mechanism of different flame retardantsystems.The study indicates that the effect of synergistic flame retardant is best when theadded ratio of IFR and EG is1:1. Under this condition, LOI achieves31%when theadded ratio is40wt%, thermal stability of composites also increases at the same time.The mechanical property of PP/IFR/EG increases too, compared with adding IFRalone. When the added ratio of mixing retardants reaches40wt%, the tensile modulus,bending strength and impact strength increase by31%,49.8%and13%respectivelycompared with adding IFR alone.The research shows that the flame retardant properties of composites areimproved by adding synergistic agents ZnO and ZB. The effect of synergistic flameretardant is best when the added ratio of IFR and ZnO, IFR and ZB is17.5:2.5and18:2. In this mass ratio, when the content of IFR/ZnO and IFR/ZB is40wt%, thelimiting oxygen index is35%and33.5%, the initial decomposition temperature is433.4℃and426.4℃, the amount of residual carbon is24.5%and22.8%respectively.The mechanical property of composites increases after adding synergistic flameretardant. When the added ratio of IFR/ZnO and IFR/ZB achieves40wt%, the tensilemodulus increases37.2%and30.9%, the flexural modulus increases24%and38%compared to adding IFR alone.The essay indicates that the effect of synergistic flame retardant is best when theadded ratio of IFR/EG and ZnO, IFR/EG and ZB is18.5:1.5and19:1respectively, inthis mass ratio, after adding ZnO and ZB to IFR/EG, the flame retardant ofcomposites can be improved under both conditions, when the added ratio of IFR/EG/ZnO and IFR/EG/ZB are40wt%, the limiting oxygen index is39%and37%,the mechanical property of composites also increases compared to PP/IFR/ZnO andPP/IFR/ZB.By observing the carbon layer’s SEM morphology of the sample PP/IFR、PP/IFR/EG、PP/IFR/EG/ZnO、PP/IFR/EG/ZB, the carbon layer density of flameretardant system IFR/EG、IFR/EG/ZnO、IFR/EG/ZB can all be improved, amongthose, the IFR/EG/ZnO is the best.