| abstract |
Polytetramethylene ether glycols with molecular weights of from 300 to 4500 are produced by polymerizing tetrahydrofuran with an adduct of antimony pentachloride with carboxylic acids or carboxylic acid esters as the catalyst in the presence of a carboxylic acid anhydride, e.g., acetic anhydride, as the promoter. Esterified, e.g., acetylated, polytetramethylene ether glycols produced are subsequently converted to polytetramethylene ether glycols by saponification or transesterification. The process causes substantially less environmental pollution than do prior art methods, yet it is both economical and flexible. |