Diane Shell Lewis

US Patent:

49436260, Jul 24, 1990

Filed:

Jul 29, 1988

Appl. No.:

7/226302

Inventors:

James E. McGrath - Blacksburg VA
Youngtai Yoo - Blacksburg VA
Robert B. Turner - Lake Jackson TX
Diane M. Lewis - Lake Jackson TX

Assignee:

The Dow Chemical Company - Midland MI

International Classification:

C08G 8100
C08G 6530
C08G 6532

US Classification:

528408

Abstract:

Polyether active hydrogen compounds having at least two terminal active hydrogen groups on primary carbon atoms are prepared by (a) forming polyoxyalkylene molecules each having at least one active hydrogen precursor, (b) linking at least two of the polyoxyalkylene molecules, and (c) converting the active hydrogen precursor groups to active hydrogen groups on primary carbon atoms. The polyoxyalkylene molecule is formed by exposing a reaction mixture comprising at least one alkylene oxide and at least one protective initiator to conditions effective for the polymerization of the alkylene oxides. Linking is accomplished at polyether chain ends distal to the protected active hydrogen precursor groups, such that the active hydrogen precursors remain on the linked polyether chains until they are converted to active hydrogen groups. The process is particularly useful to produce polyether compounds having at least about 80 mole percent primary active hydrogen groups, which compounds are useful, for instance, in forming polyurethanes.