Bio-based, sustainable, green, and UV-curable polymer formulations for coating applications.

The goal of bio-based, sustainable, and green coating formulations is to replace conventional petrochemical-based materials, thereby reducing VOC emissions and dependence on non-renewable resources. The present research focuses on the synthesis and characterization of UV-curable, bio-based, sustainable, green coating formulations derived from plant oils and other sustainable feedstock. This system uses bio-based epoxidized soybean oil (ESBO) and itaconic acid as major renewable precursors. We prepared the resin by ring-opening of ESBO with polyol, involving an etherification reaction and finally esterification with a bio-based acid. The progress of the reaction was monitored by the oxirane oxygen content (OOC) and acid value. Several formulations were attempted by varying the ratio of oil and polyol. The resin thus prepared was used for coating formulations by varying percentages of the photoinitiator and reactive diluents. Thus, the prepared formulations were applied to the substrate and cured by exposure to the UV radiation source.

The cured films on the substrate were investigated for mechanical and chemical properties. Properties such as scratch hardness, pencil hardness, adhesion, gel content, solvent rub resistance, and gloss were studied. The chemical changes during the reaction and after curing were confirmed by FTIR. The increased renewable content (above 70%) and non-volatile matter in the coating formulations demonstrate their sustainability and green nature. The mechanical properties were observed to be on par with the traditional petroleum-based coatings, showing their enormous potential in UV-curable coating applications. This work demonstrates that incorporating bio-based components into UV-curable systems can produce high-performance, sustainable coatings that contribute to environmental conservation and resource efficiency. This advancement contributes to the development of greener coating technologies that align with global sustainability goals.