Study On Risisting Molten Dropping Flame Retardant Polyamide6Composites

The paper focus on various high flame performance, risisting molten dropping polyamide6composites filled with melamine cyanurate（MCA） and organic silica gel（SG）/K₂CO₃, whichwere obtained by melt extrusion. The effect of flame retardant and risisting molten droppingof PA-6/MCA composites and PA-6/MCA/SG/K₂CO₃composites were studied.The effect of which, the amount of MCA, the amount and ratio of SG/K₂CO₃wereinvestigated. The properties of PA-6composites, which including flame retardant, risistingmolten droping, mechanical properties, rheological behaviors etc, were sthdied by LOI,vertical burning, mechanical tests, rheological behaviors, OL and SEM. At the same time, therisisting molten droping flame mechanism of SG/K₂CO₃and the kinetics of thermaldegradation of PA-6composites were investigated.The results showed that the flame property of PA-6composites was increased withingincreasing the amount of MCA, and the rheological behaviors were improved. But theviscosity and impact strength were decreased by filling MCA, meanwhile, situation ofburning drops were aggravate. The problems of burning drops of PA-6/MCA composites weresolved by filling SG/K₂CO₃. SG/K₂CO₃can improve the LOI and the grade of verticalburning, so it can improve the flame property of PA-6/MCA composites. SG/K₂CO₃is theuseful synergist because it not only incesased the viscosity but also formed the charred layerswhen the composites were burning. The charred layers have the function of Barring oxygenand heat. the amount and ratio of SG/K₂CO₃were effect the properties of PA-6/MCAcomposites. When amount and ratio of SG/K₂CO₃were8and65:35, the flane retardentperformance and risisting molten droping of PA6/MCA composites were the best; mechanicalproperties were better, grade of vertical burning reached UL-94V0. The results of kinetics ofthermal degradation showed that the thermal degradation activation energy of various stages of PA-6/MCA/SG/K₂CO₃were higer than the PA-6/MCA, so the SG/K₂CO₃improved thethermal stability of PA-6/MCA composites.