Study On Preparation And Thermal Conductivity Of High Thermal Conductivity Styrene Acrylic Resin Composite

Laser printers and copiers release a lot of heat when they are running,heat dissipation is one of the key factors restricting its miniaturization.when the toner melts and solidifies at a relatively high temperature,which will react with oxygen in the air to generate ozone.At the same time,a part of the toner volatilizes and condenses to form tiny particles,which can cause lung damage when inhaled with ozone.The improved thermal conductivity of toner will help it quickly soften during fixing,thereby reducing the emission of harmful gases(such as ozone)and helping to reduce the energy consumption of the printer.The toner is mainly composed of styrene acrylic resin(70-80%),carbon black(10-20%)and other additives.Among them,styrene acrylic resin and carbon black play a decisive role in the thermal conductivity of the toner.Styrene acrylic resin polymer has good mechanical properties,processability and chemical stability.However,the thermal conductivity of polymers is usually low.The introduction of high thermal conductivity fillers into polymers can significantly increase thermal conductivity.To this end,this article first uses multi-walled carbon nanotubes(MWCNTs)and graphene to improve the thermal conductivity of styrene acrylic resin.The experimental results show that when MWCNTs is added at 0.75wt%,the thermal conductivity of styrene acrylic resin is 0.1644 W/(m·K),and the thermal conductivity is increased by 24.26%.After carboxyl modification of MWCNTs,the experimental result shows that when 1.0wt% carboxyl modified multi-walled carbon nanotubes(MWCNTs-COOH)is added,the thermal conductivity of styrene acrylic resin is0.1751 W/(m·K)and the thermal conductivity increased to 39.86%.The modified MWCNTs-COOH has better dispersibility in the styrene acrylic resin,which can reduce the thermal resistance of the interface between carbon nanotubes and the styrene acrylic resin and can also improve the thermal conductivity of the styrene acrylic resin.Based on this,composite filler consisting of 1.0wt%MWCNTs-COOH and 0.75wt%graphene added to styrene acrylic resin increased the thermal conductivity of styrene acrylic resin to 0.2093W/(m·K)with an increase of 67.61%.The composite filler composes of MWCNTs-COOH and graphene forms a uniform dispersion system in the styrene acrylic resin,which can form a bridge between the two enabling the composite filler to form a connected thermal conductivity network in the styrene acrylic resin and further improves the thermal conductivity of the composite material.Experimental result shows that when the content of boron nitride filler is 20.0wt%,the thermal conductivity of styrene acrylic resin increases to 0.2299 W/(m·K)with an increase to 83.63%.Adding 1.5wt% MWCNTs-COOH and1.0wt% graphene to the 3wt% boron nitride /styrene acrylic resin composite material can increase the thermal conductivity of the styrene acrylic resin composite material by 69.57%and 87.14% respectively.The composite filler formed by the hybridization of inorganic filler and carbon-based filler at low filling level can build a three-dimensional thermal conductivity network inside the styrene acrylic resin to form an effective heat transfer channel.In addition,we also prepared three-dimensional foamed graphene by hydrothermal reaction and used it as a filler to further improve the thermal conductivity of styrene acrylic resin.The results show that the thermal conductivity of the foamed graphene/styrene acrylic resin composite material can reach 0.251 W/(m·K)and the thermal conductivity is increased by 100.5%.The styrene acrylic resin composite material with foamed graphene as the skeleton can effectively prevent the aggregation of graphene in the polymer,thereby improving the thermal conductivity of the styrene acrylic resin.