Electric heating performance of nanodoped polyurethane coatings

Abstract

The thermo-electrical behavior of polyurethane coatings doped with graphitic nanofillers has been studied. They show an excellent electric heating performance, such as rapid temperature response, high electric power efficiency, and operational stability at different voltages applied. The influence of several experimental conditions, such as voltage and electrical power applied, distance between electrodes, heated area, thickness of coating, between among, have been analyzed.The increment of temperature caused by Joule´s effect is directly proportional to power applied and inversely proportional to the coating´s surface exposed to the air. Coatings with higher graphitic nanofillers content present higher electrical conductivity, implying higher increment of temperature when the same voltage is applied. However, these systems show lower efficiency on the Joule´s effect due to the lower heating at the same power applied. An increment of the distance between electrodes induces an exponential decrease of temperature reached. In practice, thinner coating induces that heating is more heterogeneous and the increment of thickness seems to induce a decrease of the electrical conductivity of the coating.