Modification of gelcoat based unsaturated polyester resin with functionalized octaspherosilicates to reduce the ice adhesion strength

Many composite structures used in various industries, such as wind turbines, aircraft, watercraft, lifeboats and others face the problem of ice build-up in winter seasons. The mechanical, thermal and chemical methods used so far to remove ice are inefficient, uneconomical and hurt the environment. Recently, surfaces have begun to be designed to eliminate or minimize ice accumulation, namely icephobic surfaces. The key parameter of such surfaces is the lowest possible ice adhesion strength (IA). One of the mechanisms for designing icephobic surfaces is a modification with compounds that direct hydrophobic properties. In this work, unsaturated polyester resin gelcoats modified with compounds from the group of octaspherosilicates with alkyl and methacrylic functional groups proposed as fluorine-free additives were investigated in terms of water repellent and ice adhesion. The surface roughness of the tested materials was measured. The surface zeta potential was also determined, which is new compared to available studies of surfaces for icephobic applications. The work also presents microstructure observations of the surface. Almost all of the modifiers increased the water contact angle (WCA), modifying the reference material from hydrophilic to slightly hydrophobic. The highest WCA was equal to 94°. The most important IA parameter was decreased by 56% compared to the unmodified gelcoat, with a value of 152 kPa. In addition, the study observed that the lowest value of IA correlated with the lowest value of CAH. The highest reduction in CAH was 44% compared to the reference sample. The roughness, wettability and IA parameters were determined before and after UV exposure to investigate modified gelcoats durability.