Study On Preparation And Properties Of Graphene/Polystyrene Composites

In recent years,graphene has attracted great attention due to its excellent mechanical,electrical,thermal and optical properties and its potential application value.In this paper,low-oxidation graphene was prepared by environmentally friendly electrochemical method.The microscopic properties and morphology of graphene were studied by various testing methods.It was found that ammonium sulfate was used as electrolyte to produce graphene with few layers and high quality.In addition,a large number of studies have shown that graphene can be used as a suitable filler for polymer nanocomposites.When properly incorporated,these atomically thin nanosheets can significantly improve the physical properties of the polymer matrix under extremely small loadings.However,since the interlayer bonding energy(van der Waals interaction)causes the irreversible stacking of graphene sheets,solving the problem of dispersion and agglomeration of graphene is a key challenge for preparing a large number of composite materials.Non-covalent modification of graphene is a feasible and effective method to overcome this problem,because it can not only improve the dispersibility of graphene in different media while maintaining the original state and performance of graphene,and enhance graphite.The interface between the olefin and the polymer matrix interacts,and the modification process is simple and convenient,which greatly reduces the process cost and has important theoretical and engineering application value.In this paper,the non-covalent modification of graphene prepared by electrochemical method was carried out by using PS resin in styrene monomer.The dispersing effect of graphene in monomer after non-covalent modification of PS resin was studied.The mechanism of non-covalent modification hindered the agglomeration and sedimentation of graphene was analyzed.Then the graphene/polystyrene composites were prepared by suspension polymerization using styrene as raw material.The influence of PS resin on the compatibility and dispersion of graphene in matrix and the addition of dispersant,initiator and graphene were discussed.Non-covalently modified graphene/polystyrene composite beads having uniform particle size and high dispersibility were finally obtained.In order to study the mechanical properties,thermal stability and flame retardant properties of graphene/polystyrene composite beads more conveniently,this paper uses hot pressing and extrusion processing to form them.The mechanical tensile test results show that the tensile strength of the composite can be enhanced by 40% under the addition of 0.3% graphene.The results of TG-DSC and UL-94 indicate that the initial thermal decomposition temperature and glass transition temperature of the composite are relative to The pure PS is increased by 35 °C and 10.6 °C respectively,and the lightburning time is significantly reduced.The thermal conductivity and thermal diffusivity of the composite will fluctuate within a certain range with the increase of graphene,and there will be no significant change.Under the thermal radiation,the thermal equilibrium temperature of the composite can be reduced by 8.5 °C at most,and the time to reach the thermal equilibrium temperature will decrease with the addition of graphene,so that the heat insulation capacity is improved.