Study On Preparation And Properties Of Polymer Composites Based On Graphitic Carbon Nitride

As a new type of two-dimensional material,graphite-phase carbon nitride has attracted wide attention due to its high hardness,large specific surface area and stable structure.It has been found that graphite-phase carbon nitride can be mixed with organic polymers to prepare polymer composites with remarkable improvements in some properties.In this work,graphite phase carbon nitride was prepared from melamine Graphite phase carbon nitride nanosheets?g-CNNS?,and graphite phase carbon nitride?g-C₃N₄?was characterized by fourier transform infrared spectroscopy?FTIR?,scanning electron microscope?SEM?and X-ray diffraction?XRD?.PVA/g-CNNS polymer composites was prepared by mixing g-CNNS with polyvinyl alcohol?PVA?And PVA/g-CNNS polymer composites were tested by thermal stability and mechanical properties.SIR/g-C₃N₄and SIR/g-C₃N₄-A171 polymer composites were prepared by g-C₃N₄ as filler and ethenyltrimethoxy?A171?as coupling agent with silicone rubber?SIR?.The cross-section morphology,electrical breakdown,dielectric and mechanical properties of the composite were analyzed.For PVA/g-CNNS polymer composites,after adding g-CNNS,the tensile strength of the polymer composites has been significantly improved,when the filler content is 0.5%,it is about twice as high as that of pure PVA.And the glass transition temperature of the polymer composites has also been significantly increased.The reaction enthalpy of PVA/g-CNNS polymer composites with g-CNNS is higher than that of pure PVA,which indicates that PVA/g-CNNS polymer composites have better thermal stability.For SIR/g-C₃N₄ and SIR/g-C₃N₄-A171 polymer composites,the electrical breakdown strength of SIR/g-C₃N₄-A 171 polymer composites increased by about 20%after adding g-C₃N₄and A171;g-C₃N₄ can improve the dielectric constant of polymer composites.The tensile strength of polymer composites increases with the increase of g-C₃N₄fraction.Under the same g-C₃N₄ fraction,SIR/g-C₃N₄-A171 polymer composites have better reinforcing effect.