Process for preparing capped polyoxyalkylene block polyethers
AssigneeBASF SE
InventorsJay G. Otten, Roger A. Ott
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Abstract
A process is disclosed for the preparation of capped polyoxyalkylene block polyethers with exceptionally low hydroxyl numbers and correspondingly high capping efficiency. This improvement is accomplished through the use of cesium hydroxide catalysis during oxyethylation.
Claims20
A process for the preparation of capped polyoxyalkylene block polyethers, comprising:
- (a) sequentially oxyalkylating an initiator molecule having one or more active hydrogens
- (i) with ethylene oxide in the presence of a basic cesium-containing catalyst;
- and
- (ii) one or more higher alkylene oxides in the presence of a basic oxyalkylation catalyst;
- and
- (b) capping the product of step (a) to form an alkyl, cycloalkyl, or aralkyl ether terminated polyoxyalkylene block polyether.
A process for the preparation of a capped polyoxyalkylene block polyether comprising (a) sequentially oxyalkylating an initiator having the formula ##STR11## wherein R is alkyl, cycloalkyl, alkyl or aralkyl, R' is ethylene, propylene, isopropylene, or butylene, and n is a natural number from 0 to about 30, with two or more alkylene oxides at least one of which is ethylene oxide, wherein said oxyalkylation with ethylene oxide take place in the presence of a basic cesium-containing catalyst, and (b) capping the resulting monohydroxyl functional polyoxyalkylene block polyether to form an alkyl, cycloalkyl, or aralkyl ether terminated polyoxyalkylene block polyether.
Dependencies are inferred from the claim text.