Oxazoline-functional polymers for waterborne crosslinker

摘要

Waterborne reactive polymers having pendant 2-oxazoline groups were prepared by radical copolymerization of 2-alkenyl-2-oxazoline and unsaturated co-monomers. By varying the composition of co-monomers, a series of emulsion polymers with the various glass transition temperatures (Tg) or water-soluble polymers with high oxazoline contents were prepared. The crosslinking reactions of these oxazoline-functional polymers with waterborne carboxylated polymers were examined. As a result, the oxazoline-functional polymers show sufficient reactivity and stability to be used as a low-toxic, one-packed crosslinker providing improved properties for waterborne carboxylated polymer. The pH value of the formulation has important effect on its reaction rate and pot-life. It is also found that the mechanical property of cured film can be controlled by selecting the composition of backbone polymer in the oxazoline-functional polymer. Furthermore, the performances of waterborne acrylic adhesives using these oxazoline-functional polymers as the crosslinker were discussed.