GUO Pei, CUI Xuemin, LIN Chaoxu, YANG Sijie, LÜ Xuesen
(College of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, Guangxi, China)

Abstract: Conductive electrothermal coating is a new type of functional coating with excellent electrothermal properties, which has been widely used in production and common life. To solve the high VOC emission and preparation cost of traditional organic electrothermal coatings, as well as the complex preparation process of some inorganic electrothermal coatings and also unstable heating performance, a geopolymer-based environment-friendly electrothermal coating was prepared by using graphite, carbon powder and multi-walled carbon nanotubes as conductive fillers. The conductivity, electrothermal properties and microstructure of the coatings prepared with the three fillers were studied. The results show that the electrical and thermal properties of the coatings manufactured with multi-walled carbon nanotubes are better than those with graphite and carbon powder. The percolation value was reached and the resistivity of the coatings was reduced to 8.956 Ω·cm when 4% carbon nano-tubes were added into the coatings, the temperature of the sample reached 84.9 °C after being worked in 36 V alternating current for 480 second. The coatings own excellent electrothermal properties after 100 electrification cycles. The SEM of the coating shows that the carbon fillers are uniformly distributed in the three-dimensional network structure of geopolymer, which is beneficial for coatings to achieve excellent conductivity but also conducive to maintaining good mechanical properties and durability.

Key words: geopolymers; electrothermal coatings; carbon system; electrothermal properties