Fibrous mats composed of polymeric fibers comprising an aromatic polymer are provided. Further, articles and methods of use of the fibrous mats, including, but not limited to filters and membranes for sampling of fluid samples, are also provided.

Fibrous mats composed of polymeric fibers comprising an aromatic polymer are provided. Further, articles and methods of use of the fibrous mats, including, but not limited to filters and membranes for sampling of fluid samples, are also provided.

A nonwoven fabric that is fabricated is described, which includes a non-melting fiber A having a high-temperature shrinkage rate of 3% or less and a thermal conductivity conforming to ISO22007-3 (2008) of 0.060 W/m.Math.K or less and a thermoplastic fiber B having a LOI value conforming to JIS K 7201-2 (2007) of 25 or more and having a density of more than 50 kg/m.sup.3 and less than 200 kg/m.sup.3, where the nonwoven fabric exhibits high flame-shielding performance and has a heat insulating property.

A nonwoven fabric that is fabricated is described, which includes a non-melting fiber A having a high-temperature shrinkage rate of 3% or less and a thermal conductivity conforming to ISO22007-3 (2008) of 0.060 W/m.Math.K or less and a thermoplastic fiber B having a LOI value conforming to JIS K 7201-2 (2007) of 25 or more and having a density of more than 50 kg/m.sup.3 and less than 200 kg/m.sup.3, where the nonwoven fabric exhibits high flame-shielding performance and has a heat insulating property.

In order to provide a non-woven fabric with excellent flame retardancy and flame shielding performance, and even also with carding process-passing and durability, there is provided a non-woven fabric including: a non-melting fiber A that has a high-temperature shrinkage ratio of 3% or less; a thermoplastic fiber B that has an LOI value of 25 or more in accordance with JIS K 7201-2 (2007); and a thermoplastic fiber C that has an LOI value of less than 25 in accordance with JIS K 7201-2 (2007) and a crimp number of 8 (crimps/25 mm) or more in accordance with JIS L 1015 (2000).

In order to provide a non-woven fabric with excellent flame retardancy and flame shielding performance, and even also with carding process-passing and durability, there is provided a non-woven fabric including: a non-melting fiber A that has a high-temperature shrinkage ratio of 3% or less; a thermoplastic fiber B that has an LOI value of 25 or more in accordance with JIS K 7201-2 (2007); and a thermoplastic fiber C that has an LOI value of less than 25 in accordance with JIS K 7201-2 (2007) and a crimp number of 8 (crimps/25 mm) or more in accordance with JIS L 1015 (2000).

A composite polymer electrolyte membrane has a high proton conductivity even under low-humidity, low-temperature conditions, a reduced dimensional change rate, a high mechanical strength and high chemical stability, and produces a solid polymer electrolyte fuel cell with a high output and high physical durability, a membrane electrode assembly, and a solid polymer electrolyte fuel cell containing the same. This composite polymer electrolyte membrane contains a composite layer composed mainly of a polyazole-containing nanofiber nonwoven fabric (A) and an ionic group-containing polymer electrolyte (B), the polyazole-containing nanofiber nonwoven fabric (A) being basic.

A composite polymer electrolyte membrane has a high proton conductivity even under low-humidity, low-temperature conditions, a reduced dimensional change rate, a high mechanical strength and high chemical stability, and produces a solid polymer electrolyte fuel cell with a high output and high physical durability, a membrane electrode assembly, and a solid polymer electrolyte fuel cell containing the same. This composite polymer electrolyte membrane contains a composite layer composed mainly of a polyazole-containing nanofiber nonwoven fabric (A) and an ionic group-containing polymer electrolyte (B), the polyazole-containing nanofiber nonwoven fabric (A) being basic.

Provided are: a resin fiber sheet and a prepreg which use a laminated sheet as a raw material and which achieve excellent heat resistance, dielectric constant, dielectric loss tangent and dimensional stability (little warping); and a method for producing a prepreg using the resin fiber sheet. In one embodiment of the present invention, provided is a resin fiber sheet constituted from a poly(phenylene ether) composition fiber. The poly(phenylene ether) composition fiber contains more than 0 mass % and not more than 95 mass % of a poly(phenylene ether) and a total of not less than 5 mass % and less than 100 mass % of a liquid crystal polyester and/or a syndiotactic polystyrene, and has a single fiber diameter of 1-50 m.

Provided are: a resin fiber sheet and a prepreg which use a laminated sheet as a raw material and which achieve excellent heat resistance, dielectric constant, dielectric loss tangent and dimensional stability (little warping); and a method for producing a prepreg using the resin fiber sheet. In one embodiment of the present invention, provided is a resin fiber sheet constituted from a poly(phenylene ether) composition fiber. The poly(phenylene ether) composition fiber contains more than 0 mass % and not more than 95 mass % of a poly(phenylene ether) and a total of not less than 5 mass % and less than 100 mass % of a liquid crystal polyester and/or a syndiotactic polystyrene, and has a single fiber diameter of 1-50 m.