Study On Preparation And Properties Of Carbon-based Electrothermal Paint

The electrolthermal paint is a kind of special functional coating,which can change electrical energy into thermal energy and widely used in industry,agriculture,aerospace fields.But the traditional electrolthermal paint has many shortcomings,such as low heating temperature,poor aging resistance,poor corrosion resistance and so on,which greatly restricted the development and application of the electrolthermal paint.Graphite has excellent electrical conductivity,thermal conductivity,wide sources,low price and graphene has a more excellent electrical conductivity,mechanical strength,therefore this thesis uses graphite and graphene as conductive filler to prepare the electrolthermal paint with excellent properties by the way of high-speed shear technology.This thesis uses vinyl modified resin and modified isocyanate as adhesive,graphite and graphene as conductive filler to prepare the carbon electrolthermal paint.Then explores the content of conductive filler,binder content technological parameter,drying method,shear rate,shear time preparation parameters and DC voltage,coating thickness performance test parameter on the thermal performance of the coating and study the aging resistance,corrosion resistance and adhesion performance of different formulations.After that uses the scanning electron microscopy to analyze the microstructure of the samples;finally select the comprehensive performance of the formula to explore the thermal self limiting temperature properties and make simple electrothermal membrane.Experimental results show that when using vinyl modified resin as binder,graphite as single conductive filler of 60%,the electrolthermal paint has best coating performance.It has the heating rate of 52.2 degrees per minute,the highest surface temperature of 157.7 degrees,the heating power of 29.4W,the volume resistivity of 4.7Q cm,the best aging resistance.What's more it can resistant the corrosion of weak acid and alkali;when the binder content is more than 40%,the adhesion of the coating can meet the national standards.When the electrolthermal paint has natural drying for 7 days,sheering rate of 12krd/min,sheering time between 30 and 40 minutes and coating thickness between 0.2mm and 0.3mm,it has the best performance;the addition of graphene can improve the performance of the electrothermal coating.And if grephene is 20%of conductive filler,the heating rate of coating increased 7.8 degrees per minute.When using isocyanate as binder,graphite as single conductive filler of 60%,the electrolthermal paint has best coating performance.It has the heating rate of 84.6 degrees per minute,the highest surface temperature of 183.2 degrees,the heating power of 35.1 W,the volume resistivity of 3.7?·cm,the best aging resistance.And it can resistant the corrosion of weak acid and alkali;when the binder content is more than 40%,the adhesion of the coating can meet the national standards.When the electrolthermal paint has sheering rate of 12krd/min,sheering time between 20 and 30 minutes and coating thickness between 0.2mm and 0.3mm,it has the best performance.The addition of graphene can improve the performance of the electrothermal coating and if grephene is 15%t of conductive filler,the heating rate of coating increased 6.5 degrees per minute.Then this thesis select the optimal electric heating coating formula to study the self limiting temperature property,when the applied voltage is between 30V and 40V,the coating self limiting temperature performance is the best and the range of the stable surface temperature is between 60 and 160 degrees.The stable surface temperature of electrothermal membrane is 7 degrees lower than experiment temperature,which is mainly due to convection heat.