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

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1635
Author(s):  
Rafał Kozera ◽  
Bartłomiej Przybyszewski ◽  
Katarzyna Żołyńska ◽  
Anna Boczkowska ◽  
Bogna Sztorch ◽  
...  

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%.

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1642
Author(s):  
Rafał Kozera ◽  
Bartłomiej Przybyszewski ◽  
Zuzanna D. Krawczyk ◽  
Anna Boczkowska ◽  
Bogna Sztorch ◽  
...  

Ice accumulation on wind turbine blades due to the impact of supercooled water droplets can be reduced by the application of surfaces with anti-icing properties. Hydrophobic surfaces are considered as a promising solution because of their water repellent behavior. In recent years, short-pulsed laser technologies have been developed as an efficient technique to modify the surface properties of materials. However, the anti-icing properties of such surfaces have not yet been validated. In this work, a hybrid modification of polyester resin-based gelcoats was adopted. Laser patterning (LP) was used to produce periodic surface structures on modified unsaturated polyester resin (UPR) substrates. One of the innovations of this research is the utilization of novel purpose-made chemical modifiers for gelcoats. The implementation of linear polymethylhydrosiloxane (PMHS) as a building block is a key improvement in terms of durability and functionality of the coating, since there is an option of introducing not only groups bonding in the polyester into one molecule, but also groups that increase hydrophobicity. The other novelty is a successfully conducted experiment combining such chemical modification with laser texturization of the surface. The influence of the laser energy, pattern shape, and spatial periods on the topographical characteristics and hydrophobicity as well as the anti-icing properties of the produced surfaces were investigated. To characterize the surface topography of the produced structures, scanning electron microscopy (SEM) and profilometer were utilized. Measurements of the wettability parameters (static contact angle and contact angle hysteresis) on the treated surfaces allowed the identification of the influence of wetting behavior and laser parameters on the investigated materials. Anti-icing properties were characterized by ice adhesion (IA) and freezing delay time (FDT) tests. It was found that hybrid modification of unsaturated polyester resin by chemical modifiers and laser treatment increased the hydrophobic and anti-icing properties of polyester gelcoats.


2012 ◽  
Vol 291 (2) ◽  
pp. 427-435 ◽  
Author(s):  
Mohammad Amin Sarshar ◽  
Christopher Swarctz ◽  
Scott Hunter ◽  
John Simpson ◽  
Chang-Hwan Choi

1983 ◽  
Vol 137 ◽  
pp. 1-29 ◽  
Author(s):  
E. B. Dussan V. ◽  
Robert Tao-Ping Chow

It is common knowledge that relatively small drops or bubbles have a tendency to stick to the surfaces of solids. Two specific problems are investigated: the shape of the largest drop or bubble that can remain attached to an inclined solid surface; and the shape and speed at which it moves along the surface when these conditions are exceeded. The slope of the fluid-fluid interface relative to the surface of the solid is assumed to be small, making it possible to obtain results using analytic techniques. It is shown that from both a physical and mathematical point of view contact-angle hysteresis, i.e. the ability of the position of the contact line to remain fixed as long as the value of the contact angle θ lies within the interval θR [les ] θ [les ] θA, where θA [nequiv ] θR, emerges as the single most important characteristic of the system.


Author(s):  
Halar Memon ◽  
Kiana Mirshahidi ◽  
Kamran Alasvand Zarasvand ◽  
Kevin Golovin ◽  
Davide S. A. De Focatiis ◽  
...  

AbstractA comparative study of de-icing evaluation methods was conducted in this work, and their variations in response to surface characteristics were investigated. The mechanical de-icing measurements include centrifugal, push, and tensile methods. The centrifugal and the horizontal push (shear) methods suggested a linear relationship of ice adhesion strength with surface roughness, whereas the tensile (normal) method indicated an inverse curvilinear relationship with contact angle hysteresis. A partial correlation of contact angle hysteresis on the shear-based methods was also indicated over a specified range of surface roughness. Further attempts were also made on 1H,1H,2H,2H-perfluorooctyltriethoxysilane-coated surfaces, and the ice adhesion indicated a clear reduction in the normal de-icing method, whereas the shear-based methods did not show a considerable change in ice adhesion, highlighting their mechanical forces-centric response. Lastly, a further evaluation using a hybrid de-icing method was conducted, to verify the influence of surface characteristics on ice removal involving heating, which demonstrated a partial correlation of energy consumption with the ice adhesion strength over a specified range of surface roughness. The results obtained in this study provide crucial information on the influence of surface characteristics on ice adhesion and offer material-dependent correlations of the popular de-icing evaluation methods. The conclusions could be applied to define an appropriate testing method for the evaluation of icephobic surfaces and coatings. Graphical abstract


Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 771 ◽  
Author(s):  
Qiang Xie ◽  
Tianhui Hao ◽  
Jifeng Zhang ◽  
Chao Wang ◽  
Rongkui Zhang ◽  
...  

Coatings with anti-icing performance possess hydrophobicity and low ice adhesion strength, which delay ice formation and make ice removal easier. In this paper, the anti-icing performance of nano/microsilica particle-filled amino-terminated PDMS (A-PDMS)-modified epoxy coatings was investigated. In the process, the influence of the addition of A-PDMS on the hydrophobicity and ice adhesion strength was investigated. Furthermore, the influences of various weight ratios of nanosilica/microsilica (Rn/m) on the hydrophobicity and ice adhesion strength of the coating were investigated. Hydrophobicity was evaluated by contact angle (CA) and contact angle hysteresis (CAH) tests. Ice adhesion strength was measured by a centrifugal adhesion test. The addition of A-PDMS markedly increased hydrophobicity and decreased ice adhesion. The size combination of particles obviously affects hydrophobicity but has little effect on ice adhesion. Finally, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were used to reveal the anti-icing mechanism of the coatings.


Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5687
Author(s):  
Bartlomiej Przybyszewski ◽  
Rafal Kozera ◽  
Zuzanna D. Krawczyk ◽  
Anna Boczkowska ◽  
Ali Dolatabadi ◽  
...  

Ice formation on the aerodynamic surfaces of an aircraft is regarded as a major problem in the aerospace industry. Ice accumulation may damage parts, sensors and controllers and alter the aerodynamics of the airplane, leading to a range of undesired consequences, including flight delays, emergency landings, damaged parts and increased energy consumption. There are various approaches to reducing ice accretion, one of them being the application of icephobic coatings. In this work, commercially available polyurethane-based coatings were modified and deposited on NACA 0012 aircraft airfoils. A hybrid modification of polyurethane (PUR) topcoats was adopted by the addition of nanosilica and three-functional spherosilicates (a variety of silsesqioxane compound), which owe their unique properties to the presence of three different groups. The ice accretion on the manufactured nanocomposites was determined in an icing wind tunnel. The tests were performed under three different icing conditions: glaze ice, rime ice and mixed ice. Furthermore, the surface topography and wetting behavior (static contact angle and contact angle hysteresis) were investigated. It was found that the anti-icing properties of polyurethane nanocomposite coatings strongly depend on the icing conditions under which they are tested. Moreover, the addition of nanosilica and spherosilicates enabled the reduction of accreted ice by 65% in comparison to the neat topcoat.


2018 ◽  
Author(s):  
Qiao Liu ◽  
Abbasali Abouei Mehrizi ◽  
Hao Wang

2021 ◽  
Vol 923 ◽  
Author(s):  
Vanessa R. Kern ◽  
Joshua B. Bostwick ◽  
Paul H. Steen

Abstract


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