Abstract: An expanded polytetrafluoroethylene substrate comprising a microporous microstructure, an interlayer over at least a portion of the microstructure, the interlayer containing a reactive functionality, and a functional layer attached to the interlayer, the interlayer comprising a sol-gel coating or a polyvinylalcohol. The functional layer of the substrate having functional sites with a density of at least 50 nanomoles/cm2.

Abstract: An expanded polytetrafluoroethylene substrate comprising a microporous microstructure, an interlayer over at least a portion of the microstructure, the interlayer containing a reactive functionality, and a functional layer attached to the interlayer, the interlayer comprising a sol-gel or a polyvinylalcohol. The functional layer of the substrate having functional sites with a density of at least 50 nanomoles/cm2.

Abstract: A composite that includes an expanded polytetrafluoroethylene (ePTFE) membrane having a porous microstructure. The porous microstructure of the ePTFE membrane is impregnated with a stiffening polymer. An acoustic device assembly that includes the composite and an acoustic device is also described. The composite and the acoustic device assembly can exhibit an insertion loss of less than 7 dB at 1 kHz when measured by the Acoustic Response Measurement (“ARM”) Test.

Abstract: Porous air permeable expanded PTFE composite with enhanced mechanical and thermal properties are described. The node and fibril microstructure of expanded PTFE is coated on and within the node and fibril microstructure with a suitably chosen polymer to impart property enhancement while maintaining porosity. The coating polymer content of the composite is maintained between 3 and 25 weight percent of the composite and the areal mass of the composite is less than 75 gm/m2. Exemplary enhancement to properties may include, among others, Average Tensile Strength (ATS) (in MPa)×Z strength (in MPa) of 50 MPa2 or greater, preferably 100 MPa2 or greater, with air flow less than 500 Gurley seconds. Coating polymers with appropriate temperature resistance provides composites which further exhibit shrinkage of less than 10% at temperatures up to 300° C. with air flow of less than 500 Gurley seconds.

Abstract: Porous air permeable expanded PTFE composite with enhanced mechanical and thermal properties are described. The node and fibril microstructure of expanded PTFE is coated on and within the node and fibril microstructure with a suitably chosen polymer to impart property enhancement while maintaining porosity. The coating polymer content of the composite is maintained between 3 and 25 weight percent of the composite and the areal mass of the composite is less than 75 gm/m2. Exemplary enhancement to properties may include, among others, Average Tensile Strength (ATS) (in MPa)×Z strength (in MPa) of 50 MPa2 or greater, preferably 100 MPa2 or greater, with air flow less than 500 Gurley seconds. Coating polymers with appropriate temperature resistance provides composites which further exhibit shrinkage of less than 10% at temperatures up to 300° C. with air flow of less than 500 Gurley seconds.

Abstract: An expanded polytetrafluoroethylene substrate comprising a microporous microstructure, an interlayer over at least a portion of said microstructure, the interlayer containing a reactive functionality, and a functional layer attached to said interlayer, said interlayer comprising a sol-gel coating or a polyvinylalcohol, said functional layer having functional sites with a density of at least 50 nanomoles/cm2.

Abstract: A substrate comprising a microporous microstructure, an interlayer over at least a portion of the microstructure and a functional layer attached to the interlayer, the functional layer having functional sites with a density of at least 50 nanomoles/cm2.

Abstract: An acoustically reactive composite can include an expanded polytetrafluoroethylene (ePTFE) membrane formed of a highly fibrillated ePTFE microstructure with an elastomer fully impregnated within the ePTFE membrane. The composite can have an acoustic loss of less than 7 dB at 1 kHz and a water entry pressure (WEP) of at least 20 PSI. A layered assembly for protecting an acoustic device can include an acoustically reactive composite as described above and an adhesive layer arranged to define an acoustic cavity. An acoustic device can incorporate an acoustically reactive composite or layered assembly as described above, with the acoustically reactive composite or layered assembly arranged to span an acoustic cavity proximate to a transducer of the acoustic device.

Abstract: Porous air permeable expanded PTFE composite with enhanced mechanical and thermal properties are described. The node and fibril microstructure of expanded PTFE is coated on and within the node and fibril microstructure with a suitably chosen polymer to impart property enhancement while maintaining porosity. The coating polymer content of the composite is maintained between 3 and 25 weight percent of the composite and the areal mass of the composite is less than 75 gm/m2. Exemplary enhancement to properties may include, among others, Average Tensile Strength (ATS) (in MPa)×Z strength (in MPa) of 50 MPa2 or greater, preferably 100 MPa2 or greater, with air flow less than 500 Gurley seconds. Coating polymers with appropriate temperature resistance provides composites which further exhibit shrinkage of less than 10% at temperatures up to 300° C. with air flow of less than 500 Gurley seconds.

Abstract: Porous air permeable expanded PTFE composite with enhanced mechanical and thermal properties are described. The node and fibril microstructure of expanded PTFE is coated on and within the node and fibril microstructure with a suitably chosen polymer to impart property enhancement while maintaining porosity. The coating polymer content of the composite is maintained between 3 and 25 weight percent of the composite and the areal mass of the composite is less than 75 gm/m2. Exemplary enhancement to properties may include, among others, Average Tensile Strength (ATS) (in MPa)×Z strength (in MPa) of 50 MPa2 or greater, preferably 100 MPa2 or greater, with air flow less than 500 Gurley seconds. Coating polymers with appropriate temperature resistance provides composites which further exhibit shrinkage of less than 10% at temperatures up to 300° C. with air flow of less than 500 Gurley seconds.

Abstract: Porous air permeable expanded PTFE composite with enhanced mechanical and thermal properties are described. The node and fibril microstructure of expanded PTFE is coated on and within the node and fibril microstructure with a suitably chosen polymer to impart property enhancement while maintaining porosity. The coating polymer content of the composite is maintained between 3 and 25 weight percent of the composite and the areal mass of the composite is less than 75 gm/m2. Exemplary enhancement to properties may include, among others, Average Tensile Strength (ATS) (in MPa)×Z strength (in MPa) of 50 MPa2 or greater, preferably 100 MPa2 or greater, with air flow less than 500 Gurley seconds. Coating polymers with appropriate temperature resistance provides composites which further exhibit shrinkage of less than 10% at temperatures up to 300° C. with air flow of less than 500 Gurley seconds.

Abstract: The present invention is directed to a thermally insulative material comprising PTFE, including an expanded PTFE (ePTFE), having a thermal conductivity of less than or equal to 25 mW/m K at atmospheric conditions. In one embodiment, the insulative material of the present invention includes aerogel particles and polytetrafluoroethylene (PTFE). The insulative material may be formed into articles that are hydrophobic, highly breathable, possess high strength, and which may be used in non-static applications such as dynamic flexing and the like. The insulative articles are flexible, stretchable, and bendable. Also, the insulative material has little to no shedding or dusting of fine particles. Aerogel particles having a particle density of less than about 100 kg/m3 and a thermal conductivity of less than or equal to about 15 mW/m K at atmospheric conditions (about 298.5 K and 101.3 kPa) may be used in the insulative material.

Abstract: Thermally insulative materials and articles are described. In one embodiment, the thermally insulative material comprises a polymer matrix, aerogel particles and expanded microspheres, wherein the aerogel particles are present in an amount of 30% by weight or greater, the polymer matrix is present in an amount of greater than or equal to 20% by weight and the expanded microspheres are present in an amount of 0.5% to 15% by weight, the percentages being based on the total weight of the polymer matrix, the aerogel particles and the expanded microspheres; and wherein the thermal conductivity of the thermally insulative material is less than 40 mW/m K at atmospheric conditions.

Abstract: Porous air permeable expanded PTFE composite with enhanced mechanical and thermal properties are described. The node and fibril microstructure of expanded PTFE is coated on and within the node and fibril microstructure with a suitably chosen polymer to impart property enhancement while maintaining porosity. The coating polymer content of the composite is maintained between 3 and 25 weight percent of the composite. Exemplary enhancement to properties may include, among others, Average Tensile Strength (ATS) (in MPa)×Z strength (in MPa) of 50 MPa2 or greater with air flow less than 500 Gurley seconds. Coating polymers with appropriate temperature resistance provides composites which further exhibit shrinkage of less than 10% at temperatures up to 300° C. with air flow of less than 500 Gurley seconds.

Abstract: Porous air permeable expanded PTFE composite with enhanced mechanical and thermal properties are described. The node and fibril microstructure of expanded PTFE is coated on and within the node and fibril microstructure with a suitably chosen polymer to impart property enhancement while maintaining porosity. The coating polymer content of the composite is maintained between 3 and 25 weight percent of the composite and the areal mass of the composite is less than 75 gm/m2. Exemplary enhancement to properties may include, among others, Average Tensile Strength (ATS) (in MPa)×Z strength (in MPa) of 50 MPa2 or greater, preferably 100 MPa2 or greater, with air flow less than 500 Gurley seconds. Coating polymers with appropriate temperature resistance provides composites which further exhibit shrinkage of less than 10% at temperatures up to 300° C. with air flow of less than 500 Gurley seconds.

Abstract: A substrate comprising a microporous microstructure, an interlayer over at least a portion of the microstructure and a functional layer attached to the interlayer, the functional layer having functional sites with a density of at least 50 nanomoles/cm2.

Abstract: A substrate comprising a microporous microstructure, an interlayer over at least a portion of the microstructure and a functional layer attached to the interlayer, the functional layer having functional sites with a density of at least 50 nanomoles/cm2.

Abstract: A substrate comprising a microporous microstructure, an interlayer over at least a portion of the microstructure and a functional layer attached to the interlayer, the functional layer having functional sites with a density of at least 50 nanomoles/cm2.

Abstract: A material comprising aerogel particles and a polytetrafluoroethylene (PTFE) binder is formed having a thermal conductivity of less than or equal to 25 mW/m K at atmospheric conditions. The material is moldable or formable, having little or no shedding of filler particles, and may be formed into structures such as tapes or composites, for example, by bonding the material between two outer layers. Advantageously, composites may be flexed, stretched, or bent without significant dusting or loss of insulating properties.

Abstract: A material comprising aerogel particles and a polytetrafluoroethylene (PTFE) binder is formed having a thermal conductivity of less than or equal to 25 mW/m K at atmospheric conditions. The material is moldable or formable, having little or no shedding of filler particles, and may be formed into structures such as tapes or composites, for example, by bonding the material between two outer layers. Advantageously, composites may be flexed, stretched, or bent without significant dusting or loss of insulating properties.