Preparation And Thermal Conductivity Of Boron Nitride@Polystyrene Composites

With the rapid development of industry and technology,electronic devices are moving toward miniaturization,integration and multifunction.Due to the increased operating rate and efficiency,the accumulated heat generated in the electronic devices cannot be dissipated in time,thereby reducing their working life and operational stability.In order to ensure the normal operation of electronic equipment,it is necessary to use high thermal conductivity composite materials,which can quickly dissipate the accumulated heat.Polymer composites,as heat conducting packaging material,have been widely applied in aerospace,chemical heat exchanger,microelectronics industry,LED lighting and so on.In order to improve the heat transfer performance of composite materials,it is very meaningful to explore the preparation method of high thermal conductivity composite materials to improve the working life and stability of equipment.In this paper,boron nitride with stable chemical properties and high thermal conductivity was used as the filler,and polystyrene with good formability was used as the matrix.Thermally conductive composite material with core-shell structure was prepared,and the thermal conductivity of the thermally conductive composite material was measured.In this paper,a series of polystyrene thermal conductive composites,such as boron nitride@polystyrene,boron nitride@poly(styrene-methyl methacrylate),boron nitride@poly(styrene-acrylic acid)and boron nitride@poly(styrene-acrylic acid),were synthesized by suspension polymerization using boron nitride and hydroxylated boron nitride as thermal conductive fillers and styrene,methyl methacrylate and acrylic acid as polymer monomers.The effect of the addition amount of boron nitride on the polystyrene composites was investigated.When the mass fraction of boron nitride was 14.3%,boron nitride@polystyrene composite with a good core-shell structure was obtained.In addition,the effect of the addition amount of boron nitride on the thermal conductivity of different types of polystyrene matrix composites was investigated to obtain a composite material with the highest thermal conductivity.when the content of BN was 33.3 wt%,the thermal conductivity of boron nitride@polystyrene,boron nitride@poly(styrene-methyl methacrylate)copolymer,boron nitride@poly(styrene-acrylic acid)copolymer and hydroxylated boron nitride@poly(styrene-acrylic acid)copolymer were 0.559 W/m K,0.761 W/m K,0.833W/m K and 0.877 W/m K,respectively,which were 2.96,4.03,4.41 and 4.64 times than that of polystyrene matrix.The results show that the hydroxylated boron nitride@(styrene-acrylic acid)composite has the highest thermal conductivity.