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

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Isocyanate-Free Polyaminal-Polyurethane Foams

Patent Title: SYSTEM FOR DIMENSIONALLY STABLE ISOCYANATE-FREE POLYURETHANE FOAM

 Number/Link: WO2018/005142

Applicant/Assignee:  Dow

Publication date: 4 January 2018

Gist”: Polyaldehydes are reacted with polycarbamates in the presence of an acid catalyst, a metal oxide powder and a blowing agent.

Why it is interesting: According to this invention hydrolytically-stable foams can be prepared from a low molecular weight difunctional aldehyde and a polycarbamate with a functionality of about 3.5 to 4 and an equivalent weight of about 200 to 300, in the presence of a blowing agent and a protic acid as catalyst. Surprisingly the foams are rendered hydrolytically stable by the incorporation of a metal oxide powder with a specific particle size. In the examples polycarbamates are prepared by capping high functionality polyols with methylcarbamate and are then reacted with 1,4-cyclohexanedicarbaldehyde together with p-toluensulfonic acid as catalyst, HFC245fa as blowing agent and MgO powder. The foams show densities of 130-170 kg/m³ and are said to be useful as sealants.

CHDA

Cyclohexanedicarbaldehyde

Hydrolysable Ureas

Patent Title: DYNAMIC UREA BONDS WITH FAST HYDROLYTIC KINETICS FOR POLYMERS

Number/Link: WO2017/155958

Applicant/Assignee: Univ. Illinois

Publication Date: 14 September 2017

“Gist”: Hindered urea bonds with fast hydrolysis kinetics are prepared from aromatic-sbstituted diamines and diisocyanates

Why it is interesting: Polyurethanes containing thermally reversible hindered urea bonds (HUBs) have been discussed before in this blog. In the current case the HUBs are prepared from aromatic (e.g aryl-) substituted amines and are said to show fast, pH-independent, hydrolysis kinetics. The HUBs can be built into linear or crosslinked polyurethanes or other polymers like polyamides, polycarbonates etc.  The resulting materials are useful for medical applications like drug delivery, water-degradable packaging, self-healing materials and the like.

HUB hysdrolysis

Hydrolysis reaction of phenyl-N-tetrabutyl-N-ethyl urea