Abstract:Polyurethane-acrylate hybrid emulsions (PUAs) were prepared by in situ emulsion polymerization method with toluene diisocyanate (TDI-80), polyether binary alcohol (N210), dimethylol propionic acid (DMPA) as the main raw materials, castor oil (C. O.) and aliphatic epoxy resin (RE) as crosslinking agents. Polyacrylate (PA) emulsions were prepared by emulsifier-free polymerization, following to afford the PU/PA blend emulsions by mechanically mixing with polyurethane(PU). The effects of the dosage of C.O., RE on the properties of the hybrid emulsions and films, and sodium 1-allyloxy-2- hydroxypropyl sulfonate (COPS-1) on the properties of the blend emulsions and films were investigated. The results state that the PUAs and PU/PAs present excellent performances when the emulsions were prepared under the following conditions, that is, the percent of C.O. and RE to dried PU was 5.0% -7.0% and 2.0% -3 .0 % (wt%) respectively and the percent of COPS-1 to all monomers was 2.0%. The properties such as flexibility, the elongation at break and adhesion of PUA are superior to that of PU/PA, except the hardness and the cost of PUA is lower and higher respectively. Infrared spectroscopy showed that almost all -NH- of PUA and PU/PA were formed to hydrogen bonds. From TEM, the core-shell particle of PUA could be obtained with lower size. From AFM scanning, the existence of micro phase separation between hard segment and soft segment of PUA was observed.
