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

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Reaction Steps

In a 10 l three-necked flask with a stirrer, a water separator and a gas inlet tube, 2.68 kg of trimethylolpropane, 3.03 kg of acrylic acid, 0.5 kg of an acid ion exchanger (Lewatit 3333 from Bayer AG), 9 g of hydroquinone monomethyl ether and 28.6 g of cinnamyl chloride, together with 1.5 l of petroleum ether (boiling range 60°-70° C.) were heated under the water separator, whilst stirring. At the same time a continuous stream of air was passed through at a rate of about 2 l/hour. After a reaction period of 72 hours, an acid of 17 was reached. The petroleum ether was distilled off, residues being removed by applying a vacuum of about 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 flow time of 186 seconds, measured according to DIN 53,211 in a DIN cup 4, at 20° C.

Provenance & Evidence