| abstract |
To prepare polytetramethylene ether glycols or glycol diesters with degrees of polymerization greater than 2 and HAZEN color numbers less than 40 HAZEN, the polymers obtained by cationic polymerization of tetrahydrofuran in the presence of a hydrogenation catalyst, e.g. of nickel, cobalt, iron, ruthenium, palladium, platinum or copper, subjected to a hydrogen treatment. |