polyurethane trimerization catalysts in coatings: formation of isocyanurate structures abstract: polyurethane (pu) coatings are ubiquitous in various industries due to their excellent mechanical properties, chemical resistance, and versatility. a key factor influencing these properties is the crosslinking density, which can be significantly enhanced through the trimerization of isocyanate groups, forming isocyanurate rings. this process requires...