Polyurethanes with Reduced Aldehyde Emissions

Title: POLYURETHANES HAVING REDUCED ALDEHYDE EMISSION

 Number/Link:WO2015/082316 (German)

Applicant/Assignee: BASF

Publication date: 11-06-2015

Gist”: Use of CH-acidic compounds as aldehyde scavengers

Why it is interesting: Reducing VOC emissions, and especially aldehyde emissions, from polyurethane systems remains an important research topic and has been discussed before on this blog (see e.g.  here and here). To reduce aldehyde emissions, scavenger molecules are used which are often amines or hydrazine compounds.  In this invention however the aldehyde scavenger is a CH-acidic compound of the form R-CH2-R’ in which R and R’ are electron-withdrawing groups. The R-groups can be iso-reactive and the molecule can (preferably) contain more than one acidic CH2 group, like e.g. trimethylolpropane triacetoacetate. Other examples are N,N-dimethylacetoacetamide and dimethyl 1,3-acetonedicarboxylate. The compounds are used in an amount of 0.5 to 1 pphp, are said to have advantages over the prior art like less or no catalytic activity and do not lead to extra emissions.

Trimethylolpropane triacetoacetate

Trimethylolpropane triacetoacetate

Polyols from Urethane Alcohols

Title: USE OF URETHANE ALCOHOLS FOR PREPARATION OF POLYETHER POLYOLS

 Number/Link: WO2015075057

Applicant/Assignee: Bayer

Publication date: 28-05-2015

Gist”: Urethane alcohols prepared from cyclocarbonates are used as starters for polyether polyols

Why it is interesting: Urethane diols are prepared by reacting cyclic carbonates like ethylene- or propylene carbonate with an alkanolamine like e.g. ethanolamine. The alcohols are then further reacted with propylene oxide and/or ethylene oxide to make polyether polyols, useful for the production of flexible foams a.o.  No comparison of the properties of these polyols (or of the resulting foams), with ‘conventional’ polyether polyols, is given. The only advantage (at least for Bayer) being that the polyols are partly based on cyclocarbonates which are by-products of the polycarbonate polyol production.

A Urethane Alcohol

A Urethane Alcohol

Reducing Aldehyde Emissions from Polyurethane Foams

Title: USE OF PENTAETHYLENE HEXAMINE IN THE PRODUCTION OF POLYURETHANE SYSTEMS

 Number/Link: WO2015/071065 (German)

Applicant/Assignee: Evonik

Publication date: 21-05-2015

Gist”: Use of pentaethylenehexamine to reduce aldehyde emissions

Why it is interesting: As mentioned in previous posts, the reduction of formaldehyde and acetaldehyde emissions from polyurethane foams remains a pressing environmental issue. According to this patent application the problem can be solved by adding some (1 pphp in the examples) of pentaethylene hexamine to the polyol formulation. The polyamine will act as a formaldehyde scavenger and has some advantages over the prior art.  In the related case WO2015/071063, the pentaethylene hexamine is first reacted with guanidine chloride before being added to the formulation.

Pentaethylene hexamine

Pentaethylene hexamine

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