Trimethylolpropane → 2-Ethyl-2-(hydroxymethyl)propane-1,3-diol;bis(prop-2-enoic acid)

Participants

Reaction Steps

2.68 kg of trimethylolpropane, 3.03 kg of acrylic acid, 0.5 kg of an acid ion exchanger (Lewatit 3333 of BAYER AG), 9 g of hydroquinone monomethyl ether and 1.5 liters of petroleum ether (boiling range 60° to 70° C) were heated under a water separator, whilst stirring, in a 10 liter three-necked flask equipped with a stirrer, water separator and gas inlet tube. At the same time, a constant stream of air was passed through the flask at about 2 liters/hour. Over the course of the entire reaction time of 72 hours, during which an acid number of 17 was reached, a total of 20 ml of diallyl phthalate was added dropwise to the reaction mixture. The petroleum ether was distilled off, remnants being removed by applying a vacuum of approx. 4 mm Hg at a product temperature of 40° C. The esterification catalyst was filtered off. The resulting trimethylolpropane diacrylate mixture was pale yellowish and clear. The viscosity corresponded to a time of outflow of 186 seconds, measured in a DIN cup 4, at 20° C.

Provenance & Evidence