Aziridine cure of acrylic colloidal unimolecular polymers (CUPs)

Polymers were synthesized with a 1:7 or 1:8 ratio of acrylic acid to acrylate monomers to produce an acid-rich resin. The polymers were water-reduced and solvent-stripped to produce colloidal unimolecular polymers (CUPs). These particles are typically 3–9 nm in diameter, depending upon the molecular weight, and have different rheological behavior from micelles, polyelectrolytes, fullerenes, and latex particles, due to their charged surface and large surface areas. They were then formulated into ambient cure clearcoatings with aziridine crosslinking. These aziridine-cured acrylic CUPs were either solvent-free or very low VOC. The coatings were evaluated for their MEK resistance, adhesion, hardness, gloss, flexibility, wet adhesion, and abrasion and impact resistance properties.