Study of UV-cured tung oil-based polyalcohol resin with isophorone diisocyanate as crosslinker

Abstract

Petroleum-based resins are associated with increasing energy demands and biodegradability issues. Resins produced from biomass raw materials are a suitable alternative and hold significant potential across various applications, including the manufacture of molding materials, oil-based resins, and adhesives. Particularly in the field of coatings, biomass-based resins are recognized for their environmental friendliness and renewability, although there remains room for improvement in terms of strength and curing speed compared with petroleum-based resins. In this study, we developed a high-strength tung oil-based polyurethane photocurable resin (TOPP). To produce the resin, tung oil was first converted into tung oil polyol, and then acrylic ester along with isophorone diisocyanate was used as a bridging agent to confer photocuring properties. Analysis via infrared and nuclear magnetic resonance spectroscopy confirmed the TOPP structure and demonstrated the reaction of carbon–carbon double bonds to form polyol. TOPP exhibited impressive mechanical properties, including a tensile strength of 21.02 MPa and an elastic modulus of 954.63 MPa, achieved through the optimization of the amount of hydroxyethyl methacrylate added. Additionally, TOPP exhibited excellent hydrophobicity with a maximum water contact angle of 88.78° and a low thermal conductivity of 0.26 W·(mK)−1. As a wood coating, TOPP significantly enhanced resistance to oil and improved waterproof performance. The curing speed was notably accelerated without emissions of volatile solvents, which demonstrates the substantial potential of the resin for coating applications on wooden products, particularly in the furniture industry.