Method for controlling color formation during polytetramethylene ether glycol production
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 lik...
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Zusammenfassung: | 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. |
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