Flexible- and Viscoelastic Foams from CO2-Based Polyols

Title: HIGH STRENGTH POLYURETHANE FOAM COMPOSITIONS AND METHODS

 Number/Link: WO2014/074706

Applicant/Assignee: Novomer

Publication date: 15-05-2014

Gist”: The mechanical properties of flexible foams can be improved by replacing up to 50% of the polyol with CO2-based polycarbonate polyols.

Why it is interesting: Novomer (http://www.novomer.com) is a ‘sustainable chemistry company’ which produces aliphatic polycarbonate polyols from CO2 and epoxides. In this 215 page patent application they claim that hardness and mechanical properties viz. tensile- and tear strength of flexible and VE foams are improved by replacing between 2 and 50% of the polyol by their polycarbonate polyol. Other properties are supposedly not affected much, although resilience (e.g.) clearly drops for HR foams.
While the first claim may be technically new, it is – in my opinion- not patentable because not surprising to “a person skilled in the art”.

Reaction of CO2 and PO showing various 'head-to-tail' orientations

Reaction of CO2 and PO showing various ‘head-to-tail’ orientations

Flexible Foams from Renewable Polyester Polyols

Title: METHOD FOR PRODUCING SOFT POLYURETHANE FOAM BASED ON POLYESTER POLYOLS

 Number/Link: WO2014/064130

Applicant/Assignee: Bayer

Publication date: 1-05-2014

Gist”: Flexible foams can be prepared from polyester polyols based on two different diacids and with a limited ester group content.

Why it is interesting: According to this invention flexible foams can be based on polyester polyols only if the polyols are not too polar or too ‘symmetrical’. This is achieved by preparing the polyols from at least two diacids chosen from (preferably) succinic-, adipic-, azeleic- or sebacic acid,  together with (e.g.) diethylene grlycol and some trimethylolpropane. Both the acids and the alcohols are preferably bio-based. The polyester polyols have an OH value of about 60 and an ester group content (polarity) of less than 9.8 mol/kg.  In comparative examples flexible foams based on polyester polyols containing only one diacid showed collapse.

Sebacic Acid

Sebacic Acid

“Green” Isocyanate: Renewable and Phosgene-Free

Title: POLYISOCYANATES FROM FUSED BICYCLIC POLYOLS AND POLYURETHANES THEREFROM

 Number/Link: WO2014/062631

Applicant/Assignee: IOWA STATE UNIVERSITY

Publication date: 24-04-2014

Gist”: Isocyanates from acyl azides derived from isosorbide

Why it is interesting:  Fused bicyclic polyols are reacted with anhydrides to form polyacids which are converted to acyl halides which in turn are converted to acyl azides.  The acyl azides rearrange to isocyanates (Curtius Rearragment).  For example isosorbide is reacted with succinic anhydride, then with thionylchloride (SOCl2) to form the di-acylchloride and then with sodium azide (NaN3) to form the di-acylazide which rearranges into the di-isocyanate under liberation of nitrogen. The isocyanate can be reacted with more isosorbide to form a polyurethane. Clever chemistry but hard to judge if it is industrially viable.

Completely renewable polyurethane according to the invention . Click to enlarge.

 

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