Hydrophobic UV-Curable Powder Clear Coatings: Study on the Synthesis of New Crosslinking Agents Based on Raw Materials Derived from Renewable Sources

Abstract

Methods for the synthesis of urethane acrylates used as new crosslinking agents for hydrophobic UV-curable powder clear coatings were developed. In the synthesis of urethane acrylates, isophorone diisocyanate, glycerin, xylitol, polyethylene glycol and polysiloxane KF-6000, as well as 2-hydroxyethyl acrylate or 2-hydroxyethyl methacrylate, were used. In order to increase the functionality of urethane acrylates, glycerin and xylitol derived from renewable sources were introduced. The chemical structure of the urethane acrylates was verified by IR spectroscopy. UV-curable powder clear coatings were obtained through a combination of urethane acrylates with unsaturated polyester resins. The thermal behavior and crosslinking density were examined using DMA. The obtained coatings were evaluated by performing the following tests: roughness, gloss, scratch resistance, hardness, adhesion to steel and water contact angle. As part of this research, high hydrophobicity and scratch resistance of UV-curable powder clear coatings were developed, which are a VOC-free and economically attractive alternative method for low thermal resistance surface protection, such as for composites, wood and wood-based materials.

Preparation and Characterization of Duplex PEO/UV-Curable Powder Coating on AZ91 Magnesium Alloys

“…Standard powder coating systems are cured at high temperatures (180-200 • C) contributing to high energy consumption, which generates high costs. The current trend in the powder coating industry is low temperature, including UV-cured systems (cured at 160 • C and below) [31][32][33][34][35]. This is an important aspect with respect to the reduction in production costs, environmental impact, and the possibility of using powder coatings on highly sensitive materials, such as wood [36] or the magnesium alloy of the AZ series, which lose their mechanical properties at elevated temperatures [37][38][39].…”

Antimicrobial Powder Coatings Based on Environmentally Friendly Biocides

“…Conventional thermosetting powder systems are characterized by good properties, but their disadvantage is the high curing temperature (180–200 °C), which limits their use for painting of heat-sensitive materials such as wood, MDF, and plastics. , UV-curable powder coatings offer a solution to this problem. Ultraviolet (UV) curing is a fast and environmentally friendly hardening technique with many advantages such as a high curing rate and good mechanical properties of cross-linked coatings. − Depending on the modifiers used, powder coatings can have different functional properties. This paper focuses on the antibacterial properties of UV-curable powder coatings.…”

UV-curable powder transparent coatings based on oligo(meth)acrylic resins

“…The UV-cured acrylic systems can be used for modification of e.g. polyurethanes, epoxy, and unsaturated polyester resins [11][12][13][14]. Czachor-Jadacka et al developed synthesis methods of new crosslinking agents based on urethane acrylic for unsaturated polyester resins, for free radical UV-cured powder coatings.…”

“…Czachor-Jadacka et al developed synthesis methods of new crosslinking agents based on urethane acrylic for unsaturated polyester resins, for free radical UV-cured powder coatings. The powder coatings crosslinked using the developed urethane-acrylic were characterized by high hydrophobicity and scratch resistance [11]. Wenning et al described a UV radiation-cured powder composition, that contains amorphous urethane acrylate, which is stable to light and weathering, flexible, hard, and possesses good adhesion to steel panels [12].…”