Preparation, Structure And Properties Of GO Modified MCA/High Fluidity PA6Flame Retardant Composite

Graphene oxide (GO), organic modified graphene oxide (OGO),melamine cyanurate (MCA), GO modified MCA, high fludity OGO/PA6nanocomposite, high fludity MCA/PA6/PER flame retardant composites andmodified MCA/high fludity PA6/PER flame retardant composites wereprepared, and the resultant materials were characterized. The details asfollows:Graphite oxide (GO) was prepared using improved Hummers method,and organic grapheme oxide (OGO) was obtained by modifying GO with cetyltrimethyl ammonium bromide (CTAB), and high fludity PA6/OGOnanocomposites were obtained by blending OGO with high fludity PA6. Thestructures and properties of composites were charatcterized by universaltensile tester, TG, DSC, SEM and capillary rheometer instrument. The resultsshow that the mechanical properties of composite materials was optimize asthe OGO content was0.6wt%, the tensile strength of the nanocomposite wasimproved by17.8%and the elongation at break was improved by4.7%,the flexural modulus increased by40.8%and the flexural strength increasedalways. The presence of OGO caused the crystallinity of the compositematerial decrease. Initial thermal decomposition temperature of the compositematerial is higher than that of pure high fludity PA6, while the addition ofOGO enhancing the charring when the composites were buring. Understationary state composites showed pseudoplastic fluid, when the loading was0.6wt%the viscosity reached minimum.Using traditional and improveded method of MCA and modified MCAwere prepared respectively, the resultant materials were characterizated byFT-IR, TG, XRD, SEM. The result of IR and XRD were similar largely exceptfor the intensity of FT-IR peak were different. It confirmed that unmodifiedMCA and modified MCA had some difference in molecular structure, and itproved that the GO sol may be combined with MCA on molecular level. TheGO can improve the thermal stability of the MCA effectively and reduce theinitial decomposition temperature of MCA. GO can also play a role ofenhancing charring effect during the buring process. The presence of GO cancontrol the size of the crystals and make MCA crystal particles small. small MCA particles can be dispersed more evenly in the high fludity PA6, and itwould improve the flame retardant MCA efficiency and high fludity PA6thermal stability furtherly.Two kinds of flame retardant composites were prepared respectively bymelt blending method with the different loadings of MCA, GO modifiedMCA, PER and high fludity PA6. The resultant materials were characterizedby universal tensile tester, SEM, XRD, TG, DSC, vertical combustion andoxygen index tester. The results showed that the modified MCA particle wassmaller and evenly dispersion. When the modified MCA content was14wt%,he flame retardant properties of composite materials achieved UL94V-0, andthe limited oxygen indix (LOI) was32. The tensile strength, flexural strengthand flexural modulus of the composite unmodified MCA were improved andthe “wick effect " dispeared. Flame retardant composites combustionphenomena, burning charcoal layer showed that the addition of modifiedMCAand PER was effectively in charring and reduced the droplet formation.