Ice-Repellent Silicone Coatings on Epoxy Substrates

Icephobic Silicone Coatings on Epoxy Substrate In winter, as trains move at high speeds, snow on the rails is easily drawn under the train and rapidly forms ice. Researchers are offering a straightforward solution to this problem. Ice buildup on train underbodies can cause serious safety issues. For a new study, epoxy resin was used as the primary coating and hydroxyl-terminated silicone oil (PDMS) was applied on top. To ensure high adhesion strength between the two layers, siloxanes with amino or epoxy terminal groups, designated as KH 550 or KH 560 respectively, were used as crosslinkers for epoxy and PDMS. The hydrophobic, icephobic and mechanical properties of the coatings were characterized by contact angle measurements, ice-adhesion tests and tensile tests, respectively. Results showed that the PDMS coating cross-linked by KH 550 achieved a contact angle of 114.1° and retained good hydrophobic properties even after being submerged in water for 10 days. The adhesion strength of ice on the PDMS coating was only 2.5% of that on the epoxy coating. Low surface energy and low elastic modulus should be responsible for the excellent icephobic properties. Additionally, the bonding strength between the PDMS coating and epoxy primer was also excellent. When KH 560 was used as the common crosslinker, the hydrophobic and icephobic properties of the top PDMS coating were improved due to its weekly polarity when compared with KH 550. As the researchers noted, the study will help address issues related to the operation of high-speed trains in winter or problems with electrical power systems that require resistance to freezing rain. Source: The study has been published in Progress in Organic Coatings, Volume 161, December 2021. https://www.european-coatings.com/articles/2021/12/icephobicsilicone-coatings-on-epoxy-substrate