Fabrication of water-resistance and durable antimicrobial adhesion polyurethane coating containing weakly amphiphilic poly(isobornyl acrylate) Side chains

Polyurethane (PU) coatings are the most preferred systems in widespread applications on account of their great variability and fine-tuning of material properties. In this work, we have developed an eco-friendly antimicrobial polyurethane with natural-sourced isobornyl antifoulant side chains. A key development is the preparation of weakly amphiphilic poly(isobornyl acrylate) (PIBA) with terminal dihydroxy by thiol-ene ‘click’ reaction under UV catalysis. Then, the macro-polyol rich in isobornyl group is incorporated as a chain extender to achieve the functionalized polyurethane resin (PIBA-PU). Our study shows that the introduction of PIBA pendant long chains slightly affects the thermal behaviors of the soft and hard segments of PIBA-PU, and significantly improves the water-resistance of polyurethane coating as expected. The antibacterial and antifungal adhesion performances of the coatings are both substantially enhanced at higher content of PIBA. Leather-finishing application further indicates that PIBA-PU coated leather surfaces exhibit effective and long-lasting antifungal activity. The results suggest that functionalizing polyurethane with weakly amphiphilic acrylate long chains offers novel options for green coating design, whereby surface hydrophobicity and antimicrobial performances are both satisfactory and suitable for surface finishing.