Patent Title: PHOTORESPONSIVE POLYURETHANES

 Number/Link: WO2018/039453

Applicant/Assignee:  Univ of Akron

Publication date: 1-March-2018

“Gist”: PU coatings or adhesives with built-in coumarin or phenacyl groups 

Why it is interesting: According to this invention, polyurethane coating- and adhesive systems with two ‘levels of strength’ can be made by incorporating photoresponsive groups like coumarin into the PU backbone.  The coumarin groups will dimerize when irradiated with UV light of about 340nm and can be cleaved again with light of about 250nm. Alkoxyphenacyl groups can also be built into the PU backbone, allowing photocleavage with UV light of 250-350nm. The use of coumarin in (self-healing) coatings is not new and has been discussed before in this blog, so I doubt that this is patentable.

Hydroxy functional coumarin monomer