All posts in category Rigid Foams

Monolithic Polyurethane Aerogels

Title: POROUS POLYURETHANE NETWORKS AND METHODS OF PREPARATION

Number/Link: US2014/147607

Applicant/Assignee: Aerogel Technologies

Publication date: 29-05-2014

“Gist”: Monomeric tri-isocyanate and aromatic di- and triols dissolved in acetone and catalyzed by DBTDL form a gel which is supercritically dried into an aerogel.

Why it is interesting: Isocyanate-based aerogels have been reported before but because these are usually based on ‘industrial’ oligomeric raw materials like polymeric MDI and oligomeric polyols they have low mechanical properties. In the current invention, PU aerogels are prepared from monomeric tri-isocyanates (e.g. tris(isocyanatophenyl)methane) which is reacted with an aromatic triol (e.g. tris(hydroxyphenyl)ethane) and an aromatic diol (e.g. bisphenol-A) and catalyzed by DBTDL. The reaction takes place in anhydrous acetone which after gelation gets replaced by supercritical CO2. The resulting nanoporous materials are high in density (200-700 kg/m3) with a compressive modulus of more than 50MPa and a thermal conductivity below 50mW/m.K .

A (silica) aerogel.

2 Comments

by Gerhard Bleys on June 4, 2014 • Permalink

Posted in Rigid Foams

Tagged acoustics, aerogel, energy, heat insulation, Insulation, nano, silica

Posted by Gerhard Bleys on June 4, 2014

https://purpatents.com/2014/06/04/monolithic-polyurethane-aerogels/

Sound Absorbing PU-PA Foams

Title: THERMOFORMABLE RIGID POLYURETHANE-POLYAMIDE FOAM

Number/Link: US2014/058005

Applicant/Assignee: BASF

Publication date: 27-2-2014

“Gist”: Rigid, open-celled and thermoformable polyurethane-polyamide foams are produced using short chain di-acids as both chain extender and blowing agent.

Why it is interesting: The reaction of a carboxylic acid group with an isocyanate group results in a mixed anhydride, which after releasing carbon dioxide forms an amide. Because the reaction is relatively sluggish a Lewis base catalyst is used, e.g. N-methylimidazole. In this case a rigid foam-forming formulation based on MDI and (pref.) polyether polyols is further reacted with short chain diacids like azelaic- or glutaric acid. The examples show foam densities of less than 30 kg/m³ without the use of water. The foams are open celled with high air flow and with a Tg of around 90°C, making them thermoformable. This type of foams is used as acoustic bonnet- en roofliners in the automotive industry.

Azelaic Acid

Polyurethane Foam Containing Iron Particles for Improved Oil Absorption

Title: ABSORBENT MATERIAL

Number/Link: WO2014/008554

Applicant/Assignee: Advanced Simplicity Technologies

Publication date: 16-01-2014

“Gist”: Incorporation of iron particles improves the oil-absorbing capacity of PU foams.

Why it is interesting: The mineral-oil absorbing capacity of PU foam is well known and documented (see e.g. WO/1995/031402 and WO/1999/005066 ). Current invention claims that the oil absorbing capacity of the foam can be greatly improved by incorporating inorganic particles, esp. metallic iron or silica. The particle size of the particles is chosen such as to protrude the foam cell walls so that they are exposed inside the foam pores (pref. 50 to 200μm). In an example an MDI-based foam containing 70% (w/w) of iron powder was shown to absorb about 10g of oil per gram of foam.

Oils Spill at Sea

Innovation in Polyurethanes

All posts in category Rigid Foams

Monolithic Polyurethane Aerogels

Sound Absorbing PU-PA Foams

Polyurethane Foam Containing Iron Particles for Improved Oil Absorption

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