Patent Title: CYCLIC DYNAMIC POLYUREAS FOR POLYMERIC UREA PROCESSING

 Number/Link: WO2016/126756

Applicant/Assignee: University of Illinois

Publication date: 11-08-2016

“Gist”: 1K polyurea coatings from thermoreversible cyclic urea oligomers

Why it is interesting: This application is related to W02016/069582 of the same applicant, discussed before on this blog. In this case the sterically hindered ureas are prepared in solvent and at a relatively low concentration. Under these conditions cyclic oligomers will be formed which can be separated and used as powder coatings, or, together with (e.g.) catalysts, polyols and crosslinkers, as liquid coatings. When heated the rings will open and the coating composition will cure. In an example 1,3-bis(isocyanatomethyl)cyclohexane  is reacted with N,N’-di-t-butyl ethylenediamine, in DMF, which forms cyclic oligomers at low-, and linear polymers at high concentrations.

Thermoreversible polyurea according to the invention