Hybrid Polyurethane Elastomer

Patent Title:  PROCESS FOR PRODUCING ELASTOMERS

 Number/Link: WO2018069348 (German)

Applicant/Assignee:  Covestro

Publication date: 19 April 2018

Gist”: Unsaturated polycarbonate polyols are reacted with isocyanates together with a peroxide

Why it is interesting: Unsaturated polyethercarbonate polyols are prepared by reacting alkyleneoxides (e.g. PO) together with carbondioxide and an unsaturated monomer like a glycidylether or -ester or cyclooctadienemonoepoxide. These polyols can then be reacted with isocyanates in the presence of  a free-radical initiator like an peroxide. The resulting material can then be crosslinked in a separate step. The hybrid elastomers are said to have improved tensile properties at same or similar hardness.
A related application is WO2018/069350.

glycidylmethacrylate

Glycidylmethacrylate

Polyurethane with Thermally Reversible Crosslinks

Patent Title: THERMALLY REVERSIBLE CROSSLINKED POLYURETHANE

 Number/Link: WO2016/018956

Applicant/Assignee: Lubrizol

Publication date: 4-02-2016

Gist”: Diels-Alder adducts of furan and maleimide are used as reversible crosslinks

Why it is interesting: Polyurethanes with thermally reversible crosslinks can be useful: these materials can be processed and recycled as thermoplastics while showing increased mechanical properties and the reduced compression set of thermosets. They can also show self-healing properties in certain circumstances.
According to this invention PU with thermally reversible crosslinks can be prepared by reacting a diisocyanate with a diol containing a furan functional group and then incorporating a polymaleimide. For example: the diol can be prepared by reacting furfurylmethacrylate with thioglycerol and the polymaleimide can be 1,1′-(methylenedi-4,1-phenylene)bismaleimide.
Interesting idea but very similar to WO2015119688 discussed before.

1,1'-(methylenedi-4,1-methylene)bismaleimide

1,1′-(methylenedi-4,1-phenylene)bismaleimide