Porous breathable Polytetrafluoroethylene Composites with improved mechanical and thermal properties

摘要

To provide porous air permeable expanded PTFE composite with improved mechanical and thermal properties.SOLUTION: A 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 kept between 3 and 25 mass% of the composite, and the area mass of the composite is less than 75 g/m. Exemplary enhancement in properties may include, among others, average tensile strength (ATS) (in MPa) times Z strength (in MPa) of 50 MPaor more, preferably 100 MPaor more, with an air flow less than 500 Gurley seconds. Coating polymers with appropriate temperature resistance provide composites which further exhibit shrinkage of less than 10% at temperatures up to 300°C with an air flow of less than 500 Gurley seconds.SELECTED DRAWING: Figure 1