Diphenylmethane diisocyanate → Urethane acrylate

Participants

Reaction Conditions

Reaction Steps

Into a one liter 3-neck flask equipped with a mechanical stirrer, reflux condenser and drying tube, thermometer, and oil bath with temperature control, 130 g (0.1 mole) Sulfoester Polyol A (prepared as described below), was added to 50 g (0.2 mole) bis(4-isocyanatophenyl)methane, 0.03 g dibutyltin dilaurate, and 150 g methyl ethyl ketone. As stirring was initiated, the temperature began to rise. Additional heat was applied to raise the temperature of the contents of the flask to 60° C. and held at this temperature until analysis indicated the disappearance of hydroxyl and formation of isocyanate-terminated sulfopolyester (4 hours). There was then added 65 g pentaerythritol triacrylate and 500 ppm (with respect to the acrylate) of p-methoxy phenol. Stirring and heating was continued for an additional 4 hours at 60° C. The polymer was readily soluble in water from which it could be coated as a film and dried to a non-tacky coating that could be redissolved in water, sodium hydroxide solution, methanol, aqueous methanol, acetone, methylene chloride and other common organic solvents. The dried film had a calculated average molecular weight of 2400 and an acrylic group equivalent weight of about 400.

Provenance & Evidence