Preparation And Properties Of Styrene Series Polymer Conductive Composite

Filled conductive plastic is an ideal antistatic and electromagnetic shielding material,which is widely used in the fields of portable power,plastic chip,robot,display,life science,aerospace and solar energy and is considered as the most promising polymer materials.Because of its unique two-dimensional structure,GNFs have become the focus of research in optical,thermal,electrical,mechanical and other fields.Compared with carbon nanotubes(CNTs),GNFs have larger specific surface area.Therefore,GNFs are superior to CNTs in many aspects.In this paper,a series of conductive composites were of polystyrene(PS),polyacrylonitrile-styrene copolymer(AS)and polyacrylonitrile-butadiene-styrene copolymer(ABS)prepared by solution-mixing mothod with GNFs and CNTs as conductive filler.The results show that:In the polystyrene composites,there was poor compatibility with the matrix and CNTs and the phase interface is obvious,which had a pull-out effect and agglomeration phenomenon.GNFs and polystyrene compatibility is better and the filler and matrix combined closely to form the interpenetrating network structure.When the two fillers were added into the matrix,the viscosity(?*),storage modulus(G')and loss modulus(G")of the system increased with the increase of the filler content.The results of the composites filled with GNFs show that the volume fraction of the composites was 1.5 vol.%up to the percolation thershold.And the percolation threshold is 2 vol.%.There was no change of the conductivity of composites with the conductivity of the PS/CNTs is up to 0.1 S/m and the conductivity of PS/CNFs is up to 0.16 S/m.The PS/GNFs composites exhibited better mechanical properties and thermal conductivity than those of the PS/GNFs composites.When the amount of PS/GNFs was 5 vol.%,the thermal conductivity of PS/GNFs was 0.88 W/(m-K),while PS/GNFs are only 0.56 W/(m K).In the AS composite system,the two kinds of fillers showed good compatibility because of the polar interaction of the AS and the filler,so the filler and the matrix were tightly integrated and dispersed evenly.Due to the similar structural properties of AS and PS,both exhibit similar rheological properties.the volume of the filler was 0.5 vol.%up to the percolation threshold and there was no change when the the volume of the filler was 2.0 vol.%.The conductivity of the AS/CNTs was 0.14 S/m when the the volume of the filler was 5.0 vol.%,And the conductivity of the AS/CNTs was 0.154 S/m.And the conductivity of AS/GNFs is 0.154 S/m.As a result of the large specific surface area of GNFs,AS/GNFs have a thermal conductivity of 0.88 W/(m·K)and AS/GNFs only 0.44 W/(m·K)when the amount of filler is 5 vol.%.The tensile strength of the composites increased and then increased,but the impact strength of the composites changed in the opposite direction as filled filler.AS/CNTs show better mechanical properties.The solution mixing method and the melt blending method are compared in the ABS composite system.The results of SEM showed that the CNTs have better compatibility with the ABS matrix and the interface is blurred by the solution mixing method,and the exfoliation of GNFs was well and evenly interspersed into the matrix.The packing is evenly dispersed.The rheological results showed that the sample prepared by the solution method has higher the viscosity(?*),storage modulus(G')and loss modulus(G"),lower frequency dependence.The results of conductivity showed that the sample prepared by the solution method has higher conductivity.The volume of filler was 3 vol.%,the conductivity of the ABS/CNTs obtained by the two methods differs by 3 orders of magnitude.The volume of filler was 2 vol.%,the thermal conductivity of ABS/GNFs was 0.62 W/(m·K),which the thermal conductivity of ABS/GNFs was only 0.47 W/(m·K)by melt blending.The melt-mixing method of the samples are shown to have better performance through the test of mechanical properties and thermal stability.