Hybrid Modification of Unsaturated Polyester Resins to Obtain Hydro- and Icephobic Properties

Abstract

Ice accumulation is a key and unsolved problem for many composite structures with polymer matrices, e.g., wind turbines and airplanes. One of the solutions to avoid icing is to use anti-icing coatings. In recent years, the influence of hydrophobicity of a surface on its icephobic properties has been studied. This solution is based on the idea that a material with poor wettability maximally reduces the contact time between a cooled drop of water and the surface, consequently prevents the formation of ice, and decreases its adhesion to the surface. In this work, a hybrid modification of a gelcoat based on unsaturated polyester resin with nanosilica and chemical modifiers from the group of triple functionalized polyhedral oligomeric silsesquioxanes (POSS) and double organofunctionalized polysiloxanes (generally called multi-functionalized organosilicon compounds (MFSC)) was applied. The work describes how the change of modifier concentration and its structural structure finally influences the ice phobic properties. The modifiers used in their structure groups lowered the free surface energy and crosslinking groups with the applied resin, lowering the phenomena of migration and removing the modifier from the surface layer of gelcoat. The main studies from the icephobicity point of view were the measurements of ice adhesion forces between modified materials and ice. The tests were based on the measurements of the shear strength between the ice layer and the modified surface and were conducted using a tensile machine. Hydrophobic properties of the obtained nanocomposites were determined by measurement of the contact angle and contact angle hysteresis. As the results of the work, it was found that the modification of gelcoat with nanosilica and multi-functionalized silicone compounds results in the improvement of icephobic properties when compared to unmodified gelcoat while no direct influence of wettability properties was found. Ice adhesion decreased by more than 30%.

Hydro- and Icephobic Properties and Durability of Epoxy Gelcoat Modified with Double-Functionalized Polysiloxanes

“…The fabrication method of samples containing MFSC was presented in a previous paper [ 36 ]. The only difference is the type of polymer gelcoat matrix.…”

“…These coatings, with low post-surface energy, have been studied for years for minimizing ice deposition [ 32 , 33 , 34 , 35 ]. Kozera et al in 2020 [ 36 ] showed that the chemical modification of a gelcoat based on unsaturated polyester resin with compounds from the MFSC group (triple functionalized polyhedral oligomeric silsesquioxanes (POSS) and double organofunctionalized polysiloxanes) enables one to significantly increase the surface wetting angle and reduce the adhesion to ice compared to the unmodified resin. Linear polysiloxanes (also called oligosiloxanes, depending on the number of structural units) have a chain structure composed of D units, where the inert group is usually the methyl group -OSiMe 2 O- (the most popular poly(dimethylsiloxane), PDMS) or, less commonly, the phenyl group, and terminated groups of type T (usually -OSiMe 3 ) containing both inert and functional building units in the chain structure [ 37 , 38 ].…”

“…Additional advantages of their wide application are the low price, high availability and wide range, good thermal stability, low surface energy, and the ability to operate in a wide temperature range [ 39 ]. At present, on the market, there are a variety of chemical components dedicated to specific classes of polymers, e.g., epoxy resins, to improve the mechanical properties or flexibility of composites [ 40 , 41 , 42 ], as a blend of epoxy and silicone resin compatibilizers [ 43 ], and as modifiers of polyester resins toward icephobic properties [ 36 , 44 ], as well as hydrophobic [ 45 ] and mechanical properties and impact strength [ 46 ]. The synergistic effect of the low surface energy of the functional group bonds to the chain and the low elastic modulus can result in an effective and durable improvement in the icephobic properties [ 12 , 47 ].…”

Role of Surface Topography in the Superhydrophobic Effect—Experimental and Numerical Studies

“…The most dominant theory is that superhydrophobic surface with high water repellence exhibit improved anti-icing properties. Due to their potent ability to delay and/or reduce ice accumulation, snow, and frost, they are reported as coatings with high ice phobic potential [31][32][33][34][35][36]. Among many publications, several authors highlighted the effect of contact angle hysteresis on the ice adhesion strength [18,[31][32][33]36], while others have reported reduced ice adhesion for high water contact angle values [31][32][33][34][35].…”

Improving Anti-Icing and De-Icing Performances via Thermal-Regulation with Macroporous Xerogel

“…In recent decades, passive anti-icing materials have been developed greatly, and multitudinous surface materials and approaches were widely used in the anti-icing field. Inspired by Nepenthes pitcher plants, a slippery liquid-infused porous surface (SLIPS) was built and achieved an ultralow ice adhesion strength (0.15–15 kPa). − To solve the migration, evaporation, or leakage of infused liquids on SLIPS, a regenerable sacrificial alkane solid organogel surface has been put forward as inspired by the regenerable epicuticular wax on a leaf . The solid-state wax layer could avoid the loss of infused liquid and provide the durable low ice adhesion property.…”