E.i. Dupont De Nemours and Company

James D Verbsky

Richard E Ernst

Leon S Scott

Anne Irisa Breikss

Albert M Stock

Peter A Bloxham

John D Super

A process for removing precursors, such as low boiling alkyl glycols (e.g., ethylene glycol and/or 1,2-propylene glycol), to undersirable color forming acetal impurities (e.g., 1,3 -dioxolane and 4-methyl-1,3-dioxolane) from technical grade 1,4-butanediol/2-methyl-1,4-butanediol mixtures and the like by distillative topping of the diol mixture prior to ring closing cyclization to corresponding tetrahydrofuran/3-methyl tetrahydrofuran mixture and subsequent polymerization to polytetramethylene glycol ether polymers. Such a process is useful to produce THF and PTMEG having a APHA color index of nearly zero.

Method for controlling color formation during polytetramethylene ether

In the ethynylation of formaldehyde in the presence of a copper acetylide catalyst to produce butynediol, pH is controlled by the incremental or continuous addition of an alkali metal hydroxide and an alkali metal carbonate at an equivalent ratio of hydroxide ion to carbonate ion of 1:1-4:1.

Process for the control of pH in the ethynylation of formaldehyde

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Seabrook, TX, United States of America

James D Verbsky