The Preparation Of Modified Melamine Cyanurate And Study On The Flame Retardant Polyamide 6

Polyamide 6(PA6) has been used widely in industry for its excellent properties. However, PA6 has low limited oxygen index, hence the investigations on the fire retardancy PA6 is always a hot topic in PA6 industry.Melamine cyanurate(MCA), an important nitrogen fire retardant, was tooken much attention by many researches for its high efficiency and environmental friendly. Unfortunately, the mechanical properties of the traditional MCA fire retardant PA6 were reduced for the high filling content of MCA to reach the degree of UL-94V0.To improve the properties of MCA, a modified MCA has been prepared. Silica sol was used to modify the MCA during the produce process of melamine cyanurate. The structure of modified MCA had been characterized by the viscosity test,the conversion test,FT-IR analysis,Scanning electron microscope (SEM) analysis and the technique had been optimized. The results show that the reaction time of modified MCA had been greatly reduced than that of traditional technique, the viscosity had been reduced by 50%, and the conversion reached 99.5%.The properties of modified MCA fire retardant PA6 had been characterized with UL94 vertical burning analysis,the limited oxygen index analysis,mechanical property analysis,vicat softening point analysis,thermal gravimetric (TG) analysis,SEM analysis,differential scanning calorimetry (DSC) analysis and the rheological behaviors analysis. The result shows that the fire retardant PA6 reached UL-94V0 level when the content of modified MCA was 12% (wt%) , and the mechanical and thermal properties had been improved greatly than traditional MCA fire retardant PA6,The tensile strength, izod impact strength and the vicat softening point had been increased by 50%, 40% and 50% respectively too.