碳纳米管/高岭土改性水性环氧树脂三元复合散热涂料的制备与性能

Preparation of Heat Dissipation Coatings of Carbon Nanotubes Modified Waterborne Epoxy Resin

水性环氧树脂由于具有许多优异性能,从而在水性涂料中的地位越来越重要,但由于其热导率低,导致涂料的耐热性差,从而将其用于散热涂料还存在一定的缺陷。碳纳米材料由于其优异的导热性能,近年来成为高性能散热涂料研究领域的热点。碳纳米管的亲水性是其应用于水性环氧树脂涂料时面临的最大问题。本工作尝试用表面活性剂对碳纳米管进行亲水性改性,并将其与具有良好可塑性和耐火性的高岭土相结合,制得一种新型的碳纳米管/高岭土/环氧树脂水性复合功能型涂料。利用Hotdisk瞬态平面热源法测试该涂料层的散热降温效果,通过对比分析单一添加和协同添加导热填料制得的复合涂料的导热特性,对其中导热性能最佳的产品,辅以TEM、SEM、TG等手段来表征碳纳米管在聚合物中的分散状态。得到的最佳工艺配方为(按1kg产品计算):双组分水性环氧树脂44%(wt%),环氧树脂与固化剂配比为3∶1(wt%),改性碳纳米管分散液17.6%(wt%),改性高岭土分散液26.4%(wt%),助剂12%(wt%)。制得的复合涂料散热温差达45℃。

Nowadays,the preparation of high-performance water-based coatings has a very broad prospect in the pursuit of environmental protection.Water-based epoxy resin exhibits increasingly importance because of its excellent performances.However,due to its low thermal conductivity,the thermal resistance of the coating is poor,so there are some defects in the use for heat dissipation coatings.Due to the excellent thermal conductivity,carbon nanomaterials have become a hot spot in the research field of high-performance heat dissipation coatings in recent years.The hydrophilicity of carbon nanotubes is the biggest problem in their application to water-based epoxy coatings.This work attempts to modify the hydrophilicity of the carbon nanotubes with surfactants,and to produce a new carbon nanotube-kaolin-epoxy water-based composite coating.The heat dissipation and cooling effect of the composite was measured by Hotdisk.The thermal conductivity characteristics of the coatings with a single addition and collaborative addition of thermal filler were compared and analyzed.For the product with the best thermal conductivity,the dispersion state of carbon nanotubes in the polymer was characterized by TEM,SEM,TG and other methods.It was concluded that the optimal process formula(calculated according to 1 kg product)was:two-component water-borne epoxy resin 44%(wt%),epoxy resin and curing agent 3∶1(wt%),modified carbon nanotube dispersion 17.6%(wt%),modified kaolin dispersion 26.4%(wt%),and assistant agent 12%(wt%).The temperature difference of heat dissipation is 45℃.