All posts in category Elastomers

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

Polyurethane Foams with Reduced Acetaldehyde Emissions

Patent Title: POLYURETHANES WITH REDUCED ALDEHYDE EMISSION

Number/Link: WO2015/189095

Applicant/Assignee: BASF

Publication date: 17-12-2015

“Gist”: A polymer with pending -O-NH2 groups is used as additive

Why it is interesting: The reduction of VOC emissions, especially emissions of aldehydes from PU foams, remains an important topic of research. A number of solutions have been proposed, for example the use of polyamines as scavengers as discussed before. There still appears to be a need for improvement however, especially for the reduction of acetaldehyde emissions. According to this invention acetaldehyde emissions can be reduced by using a relatively high mole-weight polymer with pending aminooxy groups as an additive during foaming. In an example a copolymer of 4-aminooxymethylstyrene and methacrylic acid with a Mn of about 15,000 is used as an additive.

4-aminooxymethylstyrene

Novel Aliphatic Polyester Polyols for TPU

Patent Title: POLYESTER POLYOLS AND POLYURETHANES

Number/Link: WO2015/185744

Applicant/Assignee: DSM

Publication date: 10-12-2015

“Gist”: Polyester polyols from succinic- and sebacic acid mixtures

Why it is interesting: Aliphatic polyester polyols used in polyurethane elastomers, are usually based on adipic acid and diols like MEG, DEG, butanediol or mixtures of these. Since recently, succinic acid has become a commercially avaible renewable compound and it makes sense to use it in polyester polyol production. Replacing adipic acid by succinic acid however, results in polyesters with a reduced hydrolysis resistance (at the same polyol molecular weight). According to this invention this can be solved by using blends of succinic acid with C8 to C36 diacids, most preferably with sebacic (C10) acid.
Not a spectacular innovation and probably not as such patentable but a solid, useful idea.

Sebacic acid

Innovation in Polyurethanes

All posts in category Elastomers

Polyurethane with Thermally Reversible Crosslinks

Polyurethane Foams with Reduced Acetaldehyde Emissions

Novel Aliphatic Polyester Polyols for TPU

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