Polyurethane Acrylate Covalent Adaptable Networks Based on the Autocatalytic Effect of Palm Oil-Based Diol

Abstract

Polyurethane acrylate (PUA) is a type of photocurable material with high curing efficiency, excellent mechanical properties, and good chemical resistance. However, the synthesis of PUA inevitably involves the use of toxic catalysts, such as dibutyltin dilaurate, which imposes a certain burden on the environment. Meanwhile, strategies to achieve the self-healing ability and reprocessability of PUA have attracted considerable attention. In this study, a palm oil-based fatty acid diethanolamide (POEA) with a tertiary amide structure was used as a diol to synthesize catalystfree PUA oligomers and provide an autocatalytic effect for the condensation reaction between isocyanates and diols. Furthermore, hydroxyethyl acrylate was selected as a reactive diluent for copolymerizing with PUA oligomers and introducing free hydroxyl groups to promote the dynamic exchange reaction of carbamates. The autocatalytic effects on both the synthesis and the dynamic exchange reaction of carbamates were revealed by model compounds. The resulting networks exhibited satisfactory mechanical properties, excellent scratch repair capability, and recyclability. Moreover, the prepared PUA films showed superior corrosion resistance with an inhibition efficiency of 99.99%, showing great potential applications as coatings for steel. This work provides a feasible technical strategy for the design and synthesis of catalyst-free PUA covalent adaptable networks derived from plant oils.