Bio-based non-isocyanate poly(urea)-PEG hybrids for VOC-free waterborne dispersions and fast UV-curable film application

Poly(urethane)-acrylate hybrids are often used to yield high-performing fast UV-curable coatings thanks to their highly reactive acrylate moieties. However, they are usually manufactured from toxic and petro-based isocyanate (e.g. isophorone diisocyanate, hexamethylene diisocyanate) monomers and are dispersed in water using toxic volatile neutralization agent (e.g. triethylamine). To tackle those issues, hydrophobic and bio-based non-isocyanate poly(urea) (NIPUrea) blocks have been synthesized and coupled with hydrophilic poly(ethylene glycol) diacrylate (PEGdA) via aza-Michael reaction to yield VOC-free non-ionic waterborne NIPUrea-acrylate dispersions. Those amphiphilic NIPUrea-PEG hybrids enabled the development of low particle-size waterborne dispersions for fast UV curable films (curing time < 1 min) with high gel content (>98 %) and tunable mechanical properties.