Preparation And Properties Of Micro-nano Carbon Composite Water-based Heat Dissipating Coating Materials

As important chemical products,coatings have a significant position in modern industry and our lives,due to their functions such as protection,decoration and so on.With the rapid development of science and technology,new heat-dissipating coatings are needed.Especially in the military,electronics,information and other industrial fields,they can meet the demands for high-efficiency heat dissipation,high stability,high adhesion and high acid and alkali resistance.At present,the development of micro-nano composite coatings is one of the crucial approaches to prepare new heat-dissipating coatings effectively.In general,it is difficult to balance the performance for satisfying the needs by using a nano-filler and a conventional paint to perform composites simply.Therefore,it is necessary to research a kind of coating that combines high heat dissipation,high stability,high adhesion,and high acid and alkali resistance.Based on the deep and mature research of carbon materials,they have different shapes and sizes,and have a high thermal conductivity.They are commonly used as fillers for the preparation of composite heat-dissipating coatings.In this paper,the micro-nano carbon composite water-based heat-dissipating coating was synthesized by in-situ polymerization,whose heat dissipation performance,stability,adhesion and acid and alkali resistance of the samples were tested,to provide a certain theoretical basis for the development of special coatings with high comprehensive performance.The whole studies are as follows.(1)The graphitized solid carbon sphere-epoxy composite coating was prepared by in-situ polymerization using graphitized solid carbon spheres with uniform morphology and size as filler and acrylic as matrix.We investigated the effects of filler loading on the heat dissipation performance,stability,adhesion and acid and alkali resistance of the samples were investigated.The results showed that compared with the simple acrylic coating,the composite coating has good heat dissipation performance,stability,adhesion and acid and alkali resistance.As the amount of filler increases,the heat dissipation performance,stability,adhesion and acid and alkali resistance of the sample first increase and then decrease.When the filler addition amount is 15 wt.%,the thermal conductivity reaches the highest value of 3.2 W/(m·K),the stability can be maintained at level 1 and 2 for 6 and 9 days respectively,the adhesion is evaluated as level 2,acid and alkali resistance is level 1.Comprehensive analysis shows the four indicators of the sample have been improved to some extent.(2)The above findings of hollow carbon material for heat conduction and the first chapter,we adds graphitized hollow carbon spheres with uniform morphology and size as filler,and synthesizes graphitized solid/hollow epoxy composite coating by in-situ polymerization.The effect of different amounts of graphitized hollow carbon spheres on the four performance indexes of the samples was studied.The results show that the addition of graphitized hollow carbon spheres is beneficial to improve the performance,and with the increase of filler dosage,the performance index first increases and then decreases.When the filler addition amount is 3.0 wt.%,the thermal conductivity reaches the highest value of 3.9 W/(m·K),the stability can be maintained at level 1 and 2 from 10 to 13 days respectively,the adhesion is evaluated as level 1,acid and alkali resistance is level 1.The performance of the coating is further improved when the graphitized solid carbon sphere is used as the filler.(3)The three-dimensional heat conduction network is more conducive to the transfer of heat.Keed to add graphene with higher thermal conductivity as filler.Based on the results of the above studies,solid/hollowcarbon sphere graphene-epoxy composite coating was synthesized by in-situ polymerization.The properties of the samples were tested by varying the amount of graphene.The results showed that as the amount of graphene increases,the thermal conductivity,stability and acid and alkali resistance of the sample continue to increase,but the adhesion decreases.When the filler addition amount is 1.5 wt.%,comprehensive performance reaches the highest value of 4.8 W/(m·K),the stability can be maintained at level 1 and 2 from 14 to 18 days respectively,the adhesion is evaluated as level 0,acid and alkali resistance is level 0.The composite coatings prepared can meet the general requirements of practical applications.