Because of the excellent properties and wide application

the water borne polyurethane emulsion modified by acrylate has become the research hot spot in coating industries.First

the water borne polyurethane prepolymer(PU) was prepared with the method of emulsion polymerization in situ

then through the free-radical emulsion polymerization

polyurethane-acrylate(PUA) hybrid emulsion was synthesized by adding initiator and methyl methacrylate(MMA).The hybrid emulsion was characterized by FT-IR

gel permeation chromatography(GPC) and Malvern particle size analyzer.Such factors as:NCO/OH ratio

the amounts of dimethylol propionic acid (DMPA) and methyl methacrylate

and triethylamine(TEA)/DMPA mole ratio

which affected the properties and appearance of the PUA emulsion were discussed.Prepared with the technology parameters 1.3—1.4 of NCO/OH ratio

about 2.6% of —COOH content

20%—30% of MMA content

and 90%—100% of mole ratio of TEA/DMPA

the PUA emulsion showed good overall properties.