Superhydrophilic Polyurethane Coatings


 Number/Link: US2015/0344725

Applicant/Assignee: InnoSense

Publication date: 3-12-2015

Gist”: A hydrophilic anti-fog coating is pepared by incorporating silica particles  and organosilicate micelles

Why it is interesting: A superhydrophilic coating composition is made from a polyurethane prepolymer together with 1-5% (w/w) of a ~30nm monodisperse colloidal silica and up to 10% (v/v) of organosilicate micelles having a hydrophilic porous ‘shell’ and a (pref.) hydrophilic ‘core’, all in a solvent. The composition is said to be especially useful for anti-fog coatings on optically-clear plastic substrates (polycarbonate, polyurethane, polyester..).  According to the theory the porous shell of the micelles draws water away from the coated surface while the micelle cores act as a water reservoir.  Very clever.

Superhydrophilic coating accordin to the invention

Superhydrophilic coating according to the invention

Insulating Wood-Aerogel Composites


 Number/Link: WO2015/144267

Applicant/Assignee: Huntsman

Publication date: 1-10-2015

Gist”: Aerogel particles are incorporated in composite wood boards

Why it is interesting: Composite wood products (OSB, MDF..) are  well known and popular construction materials which are produced by compressing wood fibers (or flakes and the like) together with a binder like e.g. a polymeric MDI. Typically these materials show thermal conductivity values of about 50 mW/m.K at densities of around 200 kg/m³.  According to this invention these insulation values can be significantly improved by incorporating (a large amount of) hydrophobic nanoporous particles and binding the composite with an in-water emulsified isocyanate. In the examples silica aerogel particles and wood fibers are mixed an bonded with an emulsifiable MDI. The amount of particles ranges from about 25 to 50% (w/w) resulting in composites with densities below 200 kg/m³ and insulation values of about 20 to 30 mW/mK.

Medium density fibreboard (MDF).

Medium density fibreboard (MDF).

Aerogels from Urethane-Acrylate Star Monomers



Applicant/Assignee: University of Missouri

Publication date: 24-09-2015

Gist”: A trifunctional acrylate-ended urethane monomer is polymerized in solvent and supercritically dried

Why it is interesting: Research related to nanoporous materials has been gaining significant momentum in recent years and both inorganic (usually silica-based) and organic (e.g resorcinol-formaldehyde or polyurethane -based) aerogels are increasingly being used especially for thermal insulation applications. The current invention relates to hybrid PU-AC aerogels prepared from acrylate functional “star” monomers. The monomers are made by reacting a tris(isocyanatoaryl)methane with one or more hydroxyacrylates in a suitable solvent.  The monomer is then radically polymerized and the resulting ‘wet’ gel is supercritically dried into an aerogel. In the examples tris(4-isocyanatophenyl)methane is reacted with 2-hydroxyethylacrylate in ethyl acetate. The monomer solution is polymerized by heating with a radical initiator and the resulting gel is then dried using acetone and supercritical CO2.  The resulting aerogels have a density ranging from about 135 to 650 kg/m³ with a porosity bewteen 90 and 50% (v/v).  The lower density aerogels are flexible and have a thermal conductivity of about 40 mW/m.K.

Star monomer according to the invention

Star monomer according to the invention

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