A renewable and multifunctional eco-friendly coating from novel tung oil-based cationic waterborne polyurethane dispersions

Bio-based waterborne polyurethanes (WPUs) as a novel kind of economic and eco-friendly coating have attracted more attention in recent decades due to their sustainability, availability, and low toxicity advantages. In this work, a tung oil based polyol (TOP) is effectively fabricated without complicated purification process under a relative low reaction temperature, and subsequently used to prepare a series of cationic waterborne polyurethane dispersions (WPUDs) with different TOP contents. The effect of TOP content on the particle size, zeta potential and storage stability of WPUDs is detailly investigated by zeta-sizer and centrifugation measurement. The post-curing behavior of these cured films is tested by tracing the gel content. Thereafter, the WPUDs coating properties including mechanical properties, thermal resistance, hydrophobicity, morphology, pencil hardness, adhesion and solvent resistance are also carefully investigated which demonstrate that more introduction of TOP into the dispersions may help improve tensile strength, thermal stability, hydrophobic capability, phase compatibility, pencil hardness for the cured films. More importantly, antibacterial experiments demonstrate that these WPUDs dispersions exhibit well inhibition effect toward Escherichia coli and Staphylococcus aureus. This study may provide a reference for developing highly effective, renewable, multifunctional and eco-friendly coating.