Title: Catalyst for Non-Isocyanate Based Polyurethane

 Number/Link:US2015/247004

Applicant/Assignee: Dow; Univ. Northwestern

Publication date: 3-09-2015

“Gist”: The cyclocarbonate-amine reaction is catalysed by a lewis acid/lewis base combination

Why it is interesting: It is well known that polyhydroxyurethanes can be produced from cyclic carbonates and amines.  These “nonisocyanate polyurethanes” can have advantages over conventional polyurethanes, e.g. as coatings with improved chemical resistance. The reactivity of (especially 5-ring)  cyclocarbonates is however much lower than that of isocyanates making the reaction much less practical.  According to this invention that problem can be solved by using a ‘cooperative’ catalyst system consisting of a lewis acid and an organic lewis base. In an example a difunctional cyclocarbonate-capped prepolymer is reacted with 1,3-cyclohexane-bis(methylamine) catalysed by a mixture of  lithium trifluoromethanesulfonate and triazabicyclodecene.
It has been noted before in this blog that Dow, as one of the major isocyanate producers, also appears to be interested in non-iso PU.

Triazabicyclodecene.