| abstract |
Polytetramethylene ether glycol diester of the formula wherein R and R1 are identical or different and are alkyl radicals having 1-4 carbon atoms, and n is an integer from 2 to 200, are prepared by polymerizing tetrahydrofuran in the presence of i) an acid-activated polymerization catalyst selected from synthetic amorphous aluminum silicates, zeolite and kaolin, which has been calcined at from 350 DEG to 700 DEG C. before use, ii) a carboxylic anhydride, and iii) from 1 to 10% by weight, based on the weight of the polymerization catalyst, of a metal from the 8th group of the Periodic Table of the Elements as a hydrogenation catalyst. |