Study on Corrosion Behavior of Waterborne Polyurethane Coating with High Thermal Conductivity

Pan Yi,Jin Gao,Juan Mo,Baozhen Fan,Kui Xiao,Rui Liu,Haifei Zhou

doi:10.3390/app12042021

Abstract

In this paper, the effects of mixture fillers on the thermal conductivity of a coating are studied, and the optimal addition proportion was obtained. Then, the corrosion behavior of the modified waterborne polyurethane coating with high thermal conductivity is investigated by salt spray experiments, pull-off tests, EIS and SKP measurements. The result shows that the coating with 2 wt % composite fillers exhibits the most excellent thermal conductivity (1.222 W·m−1·K−1). In terms of corrosion resistance, there is an absence of obvious corrosion phenomenon for the modified coating, and the polarization resistance is still as high as 1.31 × 107 Ω·cm2 at the final stage, which indicates that the incorporation of 2 wt % composite fillers also markedly enhances the corrosion resistance property of waterborne polyurethane coating. This is mainly attributed to the more compact structure and more excellent shielding action to the electrolyte. The surface Kelvin potential results further confirm the advantageous effects of mixture fillers on the corrosion protective performance. The corresponding protective mechanism of the composite coating is also proposed.

Highlights

With the rapid development of the power industry, the service scope of power transmission and transformation equipment gradually expands, even including the high salt spray, heavy sand, and strong sunshine environment
Kochetov [12] et al studied the thermal behavior of epoxy resin added with AlN and BN, and the results showed that the AlN-filled coating exhibited a higher thermal conductivity than
The waterWhen the composites fillers are added into the waterborne polyurethane coating, the therborne polyurethane coating displays a very low thermal conductivity, and it is 0.1638 mal conductivity markedly increases

Summary

Introduction

With the rapid development of the power industry, the service scope of power transmission and transformation equipment gradually expands, even including the high salt spray, heavy sand, and strong sunshine environment. In this situation, the corrosion reliability problem is prominent [1]. The emission content of volatile organic compounds (VOCs) of these coatings is around 300–500 g/L, which seriously endangers human health and regional ecological environment safety [2]. The environmentally friendly anticorrosive coating is the current main trend. The waterborne anticorrosive coating, such as waterborne polyurethane, has recently obtained increasing attention due to the low VOCs emissions [3,4]

Methods

Results

Conclusion