Patent Title: POLYETHER-ACETAL POLYOL COMPOSITIONS

 Number/Link:  WO2016/112274

Applicant/Assignee: Dow

Publication date: 14-07-2016

“Gist”: Lewis-acid catalysis for polyactal-modified polyethers

Why it is interesting: According to this application, acetal-modified polyether polyols can be prepared by first reacting a (pref.) di- or trifunctional initiator with PO until about 500 eq. wt. using DMC catalysis. This ‘starter’ polyol is then further reacted (at a lower temperature) with PO using a (pref.) Boron-based lewis acid as catalyst, e.g. tris(pentafluorophenyl)borane. Under these conditions part of the epoxy will isomerize to the corresponding aldehyde.  The aldehyde can then co-polymerize such that part of the polyol will be functionalized with polyacetal. Polyurethanes prepared with these polyols are said to show improved modulus and other mechanical properties.

tris(pentafluorophenyl)borane