Basics of Polyurethane Coating
摘要
Polyurethane-based coatings represent a class of high-performance protective and decorative materials extensively utilized across various industrial sectors. Their widespread adoption is attributed to their exceptional versatility, mechanical durability, and resistance to environmental degradation. These coatings are synthesized through the polyaddition reaction between polyols and isocyanates, resulting in a crosslinked polymeric network capable of strong adhesion to a broad range of substrates, including plastics, wood, metals, and concrete. The performance attributes of polyurethane coatings include excellent corrosion resistance, hydrophobicity, resistance to ultraviolet (UV) radiation, moisture impermeability, protection against biological deterioration (e.g., fungal or microbial attack), and outstanding abrasion resistance. Additionally, their superior aesthetic qualities, such as gloss retention and surface smoothness, make them highly suitable for demanding applications in the automotive, industrial, and architectural sectors [1]. Polyurethanes (PUs) were first discovered in 1937 in Germany by ‘Otto Bayer’ and his colleagues at I.G. Farbenindustrie. Their work emerged as a significant development in polymer science, parallel to the research being conducted by ‘Wallace Carothers’ on polyamides (nylon) at DuPont. While Carothers focused on condensation polymers, Bayer’s team pioneered the synthesis of polyurethanes through step-growth polymerization involving isocyanates and polyols, marking a foundational advancement in the field of polymeric materials [2].