Waterborne Oil-Modified Polyurethane Coatings via Hybrid Miniemulsion Polymerization

摘要

As part of a wider effort to develop a new class of waterborne coatings, hybrid miniemulsion polymerizaiton was carried out with acrylic monomers (methyl methacrylate, butyl acrylate, and acrylic acid) in the presence of oil-modified polyurethane resin. Latexes with different ratios of resin to acrylic monomers were synthesized. The monomer emulsions prepared for hybrid miniemulsion polymerization showed excellent shelf-life stability (>5 months) and the polymerization was run free of coagulation. Solvent extraction indicated that the grafting efficiency of polyacrylics was greater than 29% for all the samples produced. A ~13C solution NMR spectrum showed that a substantial fraction of the orginal carbon double bonds (>61%) in oil-modified polyurethane remained after polymerization for film curing. Films obtained from the latexes presented good adhesion properties and fair hardness properties.