The castor oil polyurethane-acrylate hybrid emulsion (PUA) was prepared by the emulsion co-polymerization of castor oil polyurethane dispersion and methyl methacrylate (MMA). The effects of castor oil polyurethane dispersion

MMA content

the initiator and polymerization temperature on the properties of PUA emulsion and its film were investigated. The structure of PUA was characterized by Fourier transform infrared (FTIR). It was found that the PUA emulsion with excellent properties could be obtained by using PU dispersion with opalescent or translucent appearance

and the oil-soluble initiator (AIBN) was better than water-soluble initiator (K2S2O8) in the polymerization system.The mechaniscal properties and water resistance of PUA coating film were improved

while the average particle size

viscosity of PUA emulsions and PUA film gloss decreased as with increasing MMA content.The optimal MMA content was determined as 20%—30% of the total solid content of PUA emulsion.The mechanisms of particle formation and particle size growth of PUA emulsion polymerization were proposed.