Described herein is a process for producing a hydrophilic flexible polyurethane foam. Also described herein is a flexible polyurethane foam obtainable by such a process and a method of using such a flexible polyurethane foam for treating wounds.

Described herein is a process for producing a hydrophilic flexible polyurethane foam. Also described herein is a flexible polyurethane foam obtainable by such a process and a method of using such a flexible polyurethane foam for treating wounds.

This invention relates to a preparation for a polyurethane foam and a polymer polyol preparation for a polyurethane foam, each of which exhibits high coloration and discoloration inhibition properties over a long period of time when stored, and to a composition for a polyurethane foam, which is excellent in storage stability and is preferable as a resin premix. The composition comprises (i) at least one polyol, (ii) a compound having a PN bond, (iii) an antioxidant having a hydroxyphenyl group, (iv) at least an acid and/or its salt, (v) a catalyst for polyurethane foam production and (vi) a blowing agent.

This invention relates to a preparation for a polyurethane foam and a polymer polyol preparation for a polyurethane foam, each of which exhibits high coloration and discoloration inhibition properties over a long period of time when stored, and to a composition for a polyurethane foam, which is excellent in storage stability and is preferable as a resin premix. The composition comprises (i) at least one polyol, (ii) a compound having a PN bond, (iii) an antioxidant having a hydroxyphenyl group, (iv) at least an acid and/or its salt, (v) a catalyst for polyurethane foam production and (vi) a blowing agent.

An electronic article comprises an electronic component bonded to a composite composition. The composite composition comprises a crosslinked silicone foam having polydimethylsiloxane segments, and electromagnetically responsive particles retained in the crosslinked silicone foam. Composite compositions comprising carbon nanotubes and electromagnetic wave shielding articles including them are also disclosed.

A process for manufacturing a solid thermoset foam includes the following successive stages: (a) providing an expandable and thermosetting composition including a first reactant chosen from reducing sugars and a second reactant chosen from primary amines, primary amine acid addition salts, secondary amines, secondary amine acid addition salts, and ammonium salts of formula R.sup.n(NH.sub.4.sup.+).sub.n where n is an integer at least equal to 1 and R.sup.n represents the residue of an organic or inorganic acid; (b) introducing the expandable and thermosetting composition into a mold or applying the expandable composition to a support so as to form a film having a thickness at least equal to 1 mm; and (c) heating the expandable and thermosetting composition to a temperature at least equal to 140 C. to react the first reactant with the second reactant and to form, by polymerization and chemical foaming, a block of solid thermoset foam.

A process for manufacturing a solid thermoset foam includes the following successive stages: (a) providing an expandable and thermosetting composition including a first reactant chosen from reducing sugars and a second reactant chosen from primary amines, primary amine acid addition salts, secondary amines, secondary amine acid addition salts, and ammonium salts of formula R.sup.n(NH.sub.4.sup.+).sub.n where n is an integer at least equal to 1 and R.sup.n represents the residue of an organic or inorganic acid; (b) introducing the expandable and thermosetting composition into a mold or applying the expandable composition to a support so as to form a film having a thickness at least equal to 1 mm; and (c) heating the expandable and thermosetting composition to a temperature at least equal to 140 C. to react the first reactant with the second reactant and to form, by polymerization and chemical foaming, a block of solid thermoset foam.

Porous three-dimensional networks of polyurea and porous three-dimensional networks of carbon and methods of their manufacture are described. In an example, polyurea aerogels are prepared by mixing an triisocyanate with water and a triethylamine to form a sol-gel material and supercritically drying the sol-gel material to form the polyurea aerogel. Subjecting the polyurea aerogel to a step of pyrolysis may result in a three dimensional network having a carbon skeleton, yielding a carbon aerogel. The density and morphology of polyurea aerogels can be controlled by varying the amount of isocyanate monomer in the initial reaction mixture. A lower density in the aerogel gives rise to a fibrous morphology, whereas a greater density in the aerogel results in a particulate morphology. Polyurea aerogels described herein may also exhibit a reduced flammability.

Porous three-dimensional networks of polyurea and porous three-dimensional networks of carbon and methods of their manufacture are described. In an example, polyurea aerogels are prepared by mixing an triisocyanate with water and a triethylamine to form a sol-gel material and supercritically drying the sol-gel material to form the polyurea aerogel. Subjecting the polyurea aerogel to a step of pyrolysis may result in a three dimensional network having a carbon skeleton, yielding a carbon aerogel. The density and morphology of polyurea aerogels can be controlled by varying the amount of isocyanate monomer in the initial reaction mixture. A lower density in the aerogel gives rise to a fibrous morphology, whereas a greater density in the aerogel results in a particulate morphology. Polyurea aerogels described herein may also exhibit a reduced flammability.

The invention pertains to a process for manufacturing a glycerol-tricarboxylic acid polyester foam which comprises the steps of combining glycerol and a tri-carboxylic acid to provide a liquid reaction mixture and contacting the reaction mixture with a substrate under polymerization conditions, wherein the substrate has a top layer comprising one or more of metal, metal oxide, and metal halide. The invention also pertains to a glycerol-tricarboxylic polyester foam, in particular a glycerol-citric acid polyester foam, which has a closed cell foam structure wherein at least 90 vol. % of the foam, preferably at least 95% of the foam, is built up from cells having a diameter below 2 mm. The foamed polyester of the present invention is green, biodegradable, and non-toxic, and can be cleanly combusted. It finds application in, int. al., packaging materials, insulation materials, and materials with a short life cycle.