Preparation And Performance Study Of Epoxy Resin/molybdenum Disulfide Nanocomposite

Molybdenum disulfide（MoS₂）,as a graphene-like layered two-dimensional nano-filler,has attracted extensive research interest in the application of polymer matrix composites due to its ultra-thin nanometer size and excellent physical and mechanical properties.There are two key factors to make the polymer/MoS₂ nanocomposite achieve high performance:（1）MoS₂ forms a good dispersion state in the polymer matrix;（2）to construct an appropriate interface force between the polymer matrix and MoS₂.However,because the commercial MoS₂ itself is granular and inert,it is difficult to achieve good phase solubility with the polymer matrix.The stripped MoS₂ nano-sheet layer is easy to be restacked,and the agglomeration phenomenon is obvious in the polymer matrix,so the nano-size effect of MoS₂ cannot be fully exerted.Therefore,it is necessary to select appropriate organic modifier to modify MoS₂ nano filler,improve its compatibility with polymer and interface force,and adopt special material preparation process.In this paper,epoxy resin（EP）was selected as the matrix,and polypropylene glycol diglycidyl ether（PPGDGE）was used as the softener.By changing the ratio of the two,different polymer matrix modulus was obtained."Lithium ion intercalation layer-stripping method"was used to prepare MoS₂ nanochip layer.The surface of the stripped MoS₂ nanochip layer was negatively charged,and 2,4,6-trimethylaminomethyl phenol（DMP-30）and Melamine were selected as organic modifiers.The Melamine was partially protonated and grafted onto the surface of MoS₂nanochip layer.Acetone was used as solvent to preserve MoS₂ and organic modified MoS₂ nano-sheet layer prepared by stripping by solvent displacement method.Epoxy resin/molybdenum disulfide nanocomposites were prepared by slurry recombination.On this basis,the influences of different layer opening methods and MoS₂ treated with different organic treatments on the thermal/mechanical properties of nanocomposites were investigated.The main research results are as follows:1.Molybdenum disulfide was prepared by"li-ion-intercalation stripping method".Meanwhile,by controlling intercalation and stripping time,the stripping effects of different molybdenum disulfide sheet layers,G-MoS₂ and E-MoS₂,were obtained.The aqueous molybdenum disulfide was converted into organic molybdenum disulfide by solvent displacement method to keep the stripping state of molybdenum disulfide.Using PPGDGE as flexible agent（EP/PPGDGE（m/m）=60/40）,flexible EP/MoS₂ nanocomposites were prepared by slurry compounding.The dispersion of MoS₂ in epoxy resin with different stripping types was studied.At the same time,compared with the original MoS₂,the influence of MoS₂ strip on the thermal and mechanical properties of the composite was studied.The results show that,compared with the original molybdenum disulfide,the dispersion degree of molybdenum disulfide in epoxy resin matrix is improved,but there is still obvious agglomeration phenomenon of G-MoS₂ and E-MoS₂ in the resin matrix.DSC test shows that the original MoS₂ mass fraction of 1.0%of EP/MoS₂ composite Tg compared to the pure epoxy resin by 3.2℃;And add the same mass fraction of G-MoS₂ and E-MoS₂ Tg of epoxy resin nanocomposites was increased 9.5℃and 13.3℃respectively.Compared with pure resin,the tensile strength of G-MoS₂ and E-MoS₂ nanocomposites with mass fraction of 1.0%was increased by 220%and 550%respectively.2.Firstly,a melamine functionalized molybdenum disulfide（M-MoS₂）was prepared as the filler,and epoxy resin（EP/PPGDGE（m/m）=55/45）/MoS₂ nanocomposite was prepared by slurry compounding method.FT-IR,XRD and TGA confirmed the successful preparation of M-MoS₂.Through optical microscope,XRD and TEM,the dispersion of M-MoS₂ in matrix was significantly better than that of molybdenum disulfide.DSC test results show that the mass fraction of 1.0%of MoS₂ can make the glass transition temperature of the nanocomposites increased by7.26℃;With a mass fraction of 0.8%,the tensile strength and modulus of EP/M-MoS₂nanocomposite increased by 450%and 400%respectively compared with pure epoxy resin.In addition,the elongation at break of nanocomposites also increased by 175%.These results can be attributed to the good dispersion and strong interface adhesion of M-MoS₂ in EP matrix.Therefore,this work provides a feasible method to prepare EP nanocomposites with high performance.3.DMP-30 was selected as the modifier to organically modify the original Clay and the open layer MoS₂,respectively,to prepare the acetone silting slurry of D-clay and D-MoS₂.At the same time,according to clay/MoS₂（m/m）=1:2,D-clay/D-MoS₂ mixture was prepared by co-precipitation method.EP/D-clay,EP/D-MoS₂ and EP/D-clay/D-MoS₂ nanocomposites（epoxy resin matrix EP/PPGDGE（m/m）=70/30）were prepared by slurry recombination process.FT-IR,XRD and TGA tests confirmed the successful preparation of D-clay and D-MoS₂.Optical microscope,transmission electron microscope and scanning electron microscope showed that D-clay promoted the dispersion of D-clay in epoxy resin.The layer of D-clay was dispersed between the layers of D-MoS₂,which hindered the agglomeration of the layer.The DMA test results show that the EP/D-MoS₂ and EP/D-clay/D-MoS₂ nanocomposites compared to the glass transition temperature of pure epoxy resin polymer increased 6.1℃and 7.1℃respectively.When the mass fraction was 0.8%,the tensile strength and energy storage modulus of the composite were increased by 100%and 150%respectively by D-MoS₂.The D-clay/D-MoS₂ with the same mass fraction increased the tensile strength and energy storage modulus of the composite by 130%and 200%respectively.This method effectively solves the agglomeration problem of molybdenum disulfide in the matrix,and also provides a feasible method for the preparation of EP nanocomposites with high performance.