The present invention describes various methods for manufacturing gel composite sheets using segmented fiber or foam reinforcements and gel precursors. Additionally, rigid panels manufactured from the resulting gel composites are also described. The gel composites are relatively flexible enough to be wound and when unwound, can be stretched flat and made into rigid panels using adhesives.

The present invention describes various methods for manufacturing gel composite sheets using segmented fiber or foam reinforcements and gel precursors. Additionally, rigid panels manufactured from the resulting gel composites are also described. The gel composites are relatively flexible enough to be wound and when unwound, can be stretched flat and made into rigid panels using adhesives.

A provided stretched porous polytetrafluoroethylene membrane has an air permeability of 4 cm.sup.3/(sec.Math.cm.sup.2) or more, as expressed in terms of Frazier air permeability, in a thickness direction, and has a total cohesion of 1.9 (N/20 mm).sup.2 or more, the total cohesion being expressed by a product of a peel cohesion in a first in-plane direction and a peel cohesion in a second in-plane direction perpendicular to the first direction. The above stretched porous membrane is highly air-permeable and, for example, when included in a filter member, being less likely to suffer breakage at the time of handling the member or placing the member on a housing or the like.

A provided stretched porous polytetrafluoroethylene membrane has an air permeability of 4 cm.sup.3/(sec.Math.cm.sup.2) or more, as expressed in terms of Frazier air permeability, in a thickness direction, and has a total cohesion of 1.9 (N/20 mm).sup.2 or more, the total cohesion being expressed by a product of a peel cohesion in a first in-plane direction and a peel cohesion in a second in-plane direction perpendicular to the first direction. The above stretched porous membrane is highly air-permeable and, for example, when included in a filter member, being less likely to suffer breakage at the time of handling the member or placing the member on a housing or the like.

Expandable methyl methacrylate resin particles capable of providing a foamed molded product which has excellent surface quality and with which a residue hardly remains after burning are provided. The expandable methyl methacrylate resin particles contain a base resin and a blowing agent. The base resin includes, as constitutional units, a specific amount of a methyl methacrylate unit, a specific amount of an acrylic ester unit, and a specific amount of a constitutional unit derived from a crosslinking agent. The expandable methyl methacrylate resin particles have a volume-average particle size of 0.30 mm to 0.50 mm.

Expandable methyl methacrylate resin particles capable of providing a foamed molded product which has excellent surface quality and with which a residue hardly remains after burning are provided. The expandable methyl methacrylate resin particles contain a base resin and a blowing agent. The base resin includes, as constitutional units, a specific amount of a methyl methacrylate unit, a specific amount of an acrylic ester unit, and a specific amount of a constitutional unit derived from a crosslinking agent. The expandable methyl methacrylate resin particles have a volume-average particle size of 0.30 mm to 0.50 mm.

To provide a collagen sponge excellent in mechanical strength and a production method for the collagen sponge. A collagen sponge including a porous construct having a pore structure, the collagen sponge having a tensile strength of 1 N or more and 5 N or less in every direction including a length direction and a width direction. The collagen sponge may be produced by a production method including the following steps: (1) a step of subjecting a collagen solution obtained by mixing collagen and a solvent to stirring and deaeration treatment; (2) a step of subjecting the collagen solution to freeze-dry treatment; and (3) a step of subjecting a dried collagen product after the freeze-dry treatment to insoluble treatment.

To provide a collagen sponge excellent in mechanical strength and a production method for the collagen sponge. A collagen sponge including a porous construct having a pore structure, the collagen sponge having a tensile strength of 1 N or more and 5 N or less in every direction including a length direction and a width direction. The collagen sponge may be produced by a production method including the following steps: (1) a step of subjecting a collagen solution obtained by mixing collagen and a solvent to stirring and deaeration treatment; (2) a step of subjecting the collagen solution to freeze-dry treatment; and (3) a step of subjecting a dried collagen product after the freeze-dry treatment to insoluble treatment.

Although polyolefin elastomers are widely employed commodity polymers, there are shortcomings of this class of polymers for certain applications. For example, the rheological properties of some polyolefin elastomers may be insufficient to provide the green strength or low shear viscosity necessary to form stable foams, or to provide sufficient viscosity modification effects when present in a solvent. Cationomeric modification of polyolefin elastomers may alleviate these difficulties. Such polyolefin elastomers may feature a random cationomeric polyolefin copolymer comprising at least a first monomer and a second monomer, in which the first monomer is a neutral monomer and the second monomer has a side chain bearing a cationic moiety. The polyolefin elastomers may be present in foamed polyolefin compositions comprising a gas component and/or in liquid compositions comprising a solvent in which the polyolefin elastomer is dissolved.

The present invention relates to new anion exchange polymers and (blend) membranes made from polymers containing highly fluorinated aromatic groups by means of nucleophilic substitution and processes for their production by means of nucleophilic aromatic substitution and their areas of application in membrane processes, in particular in electrochemical membrane processes such as fuel cells, electrolysis and redox flow batteries.