E.i. Dupont De Nemours and Company

Donald C Paul

Richard E Ernst

Howard E Bellis

An improved process for the ring-opening polymerization of ring-opening polymerizable cyclic compounds using a fluidized bed.

Fluidized bed ring-opening polymerization process

Process for preparing high purity solvent-free cyclic esters from alpha hydroxycarboxylic acids via an intermediate oligomer wherein a fluorocarbon or a mixture of fluorocarbons is employed to strip the ester from the oligomer as well as a refrigerant to quench lactide from a gaseous reaction stream comprising, besides cyclic ester, unconverted alpha-hydroxycarboxylic acid and water.

Process for preparing cyclic esters using a fluorocarbon

Color-forming materials or their precursors present in crude 1,4-butanediol are reduced more efficiently by subjecting the crude 1,4-butanediol to distillation under conditions wherein substantially all the water present in the crude 1,4-butanediol is first removed and then the 1,4-butanediol with reduced water content is further distilled to remove the color-forming materials.

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Landenberg, PA, United States of America

Donald C Paul