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

 

Scorch-Proof Polyurethane Foams

Patent Title:  LOW EMISSIONS SCORCH INHIBITOR FOR POLYURETHANE FOAM

 Number/Link: WO2018/064521

Applicant/Assignee:  Vanderbilt Chemicals

Publication date: 5 April 2018

Gist”: A synergistic mixture of antioxidants prevents scorch

Why it is interesting: “Scorch” is a discolouration of the center of (especially low-density flexible) polyurethane slabstock foams as a consequence of excessive heat build-up during production. It is believed to be the result of free-radical reactions of foaming components and additives, like the dimerisation of BHT – a common antioxidant. According to this invention the combination of three to (optionally) 5 specific antioxidants show an unexpected synergy towards prevention of scorch. The inventive composition consists of 2,2,4-trimethyl-1,2-dihydroquinoline, a lactone (e.g. 3-alkyl- benzofurane-2-one), a phenolic compound (e.g. an alkylated monophenol) and optionally a tocopherol (a vitamine E-type phenolic compound) and a phosphite compound.  The composition is said to have the added advantage of showing low volatile chemical emissions.

quinoline

2,2,4-trimethyl-1,2-dihydroquinoline

Oxidation-Proof TPU

Patent Title: POLYURETHANE, METHOD OF PREPARATION, AND ARTICLE COMPRISING THE POLYURETHANE

 Number/Link:  WO2018/057488

Applicant/Assignee:  THE UNIVERSITY OF MASSACHUSETTS

Publication date:  29 March 2018

Gist”:  TPU based on hydrogenated diene diols

Why it is interesting: TPUs based on polyether- or polydiene-diols are prone to oxidative degradation and therefore less useful for e.g. medical applications.  According to this invention, oxidation-stable TPUs can be prepared from hydrogenated polydiene diols with an Mn of 500 to 2000, combined with 5-25% (w/w) polyether diols, chain extender and diisocyanate.  In an example a hydogenated polybutadienediol with Mn of 2000 Da was reacted with 4,4′-MDI together with PTMEG 1000 and BDO in toluene.  At a hardblock content of 35% the TPU showed a Shore hardness of 80A, 250MPa tensile strength and an elongation at break of 520%.

PIB

Hydrogenated (1,2) polybutadiene

 

Free Download: Polyurethane Science Scan Nr.11 – February & March 2018

You can now download the 11th issue of my monthly PU Science Scan for FREE from my webshop at http://sellfy.com/GeertBleys.

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TPU for RTM

Patent Title: THERMOPLASTIC PUR WITH HIGH TG FOR REACTION TRANSFER MOLDING (RTM)

 Number/Link: WO2018/050433

Applicant/Assignee:  Henkel

Publication date: 22 march 2018

Gist”:  High Tg TPU from polycyclic diols

Why it is interesting: The invention is about thermoplastic polyurethanes with high Tg and high stiffness that are useful for fiber-reinforced composites made by (reactive) resin transfer moulding.  The TPU is prepared from an isocyanate, a conventional diol chain extender and at least 25% (w/w) of a bridged- fused- or spiro- polycyclic diol. In the examples MDI is reacted with 1,2-propanediol or 2,3-butandiol and 4,8-bis(hydroxymethyl)tricyclo[5.2.1.02,6]decane. The resulting TPUs show a Tg of more than 135°C.

tricylodecane

4,8-bis(hydroxymethyl)tricyclo[5.2.1.02,6]decane