Polycarbonate PU Foams with Reduced VOC Emissions

Title: POLYURETHANE FOAMS BASED ON POLYETHER CARBONATE POLYOLS

Number/Link: WO2017/085201 (German)

Applicant/Assignee: Covestro

Publication Date: 26-may-2017

“Gist”: Use of urea reduces the formation of propylenecarbonate from polycarbonate polyols

Why it is interesting: Covestry is betting heavily on polyethercarbonate polyols for use in polyurethane foams, using the carbon-negative footprint as a selling point. The use of polyethercarbonate polyols in PU foams can, however, result in the formation of propylenecarbonate resulting from a retro reaction promoted by conventional amine catalysts. Propylenecarbonate will contribute to the total VOC emissions of foams and other materials. According to this invention, the retro reaction can -surprisingly- be prevented or reduced by using urea or urea-derivatives in the foam formulation. In the examples urea and dimethylaminopropylurea are used together with a tin catalyst,  polyethercarbonate polyols and TDI to produce flexible foams with reduced propylenecarbonate content.

Propylenecarbonate

 

 

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