Solventless, rapid-polymerizable liquid resins from solid carboxylic acids through low-viscosity acid/base complexes

Abstract

Bio-based carboxylic acids are some of the most available renewable chemicals, but since they are solids with high melting temperatures, they cannot be directly used as liquid resins. To this end, we report the formation of supramolecular complexes between an amino methacrylate and various solid carboxylic acids. The ionically bonded methacrylates exhibit low viscosities and rapid reaction kinetics for free-radical mediated polymerization, showing quantitative methacrylate conversions within one minute of irradiation at 5 mW cm⁻² 405 nm light. We demonstrate the implementation of these acid-base complexes as a neat resin system that comprises orthogonal polymerization reactions (free-radical methacrylate polymerization and epoxy-acid polymerization reactions), which yields high-strength network polymer materials.