Water-repellent and oil-repellent composition as well as preparation and application thereof

The invention provides a water-repellent and oil-repellent composition and application thereof in oil-repellent enhancement treatment of an ePTFE (enhanced polytetrafluoroethylene) membrane. The composition comprises a perfluorinated copolymer and a fluorine-containing solvent, the perfluorinated copolymer is dissolved in the fluorine-containing solvent, the perfluorinated copolymer is a copolymer prepared from tetrafluoroethylene and perfluorinated ethyl vinyl ether through emulsion polymerization and fluorination end-capping post-treatment, the molar percentage content of PEVE is higher than 30%, and the fluorine-containing solvent is a partial fluorine-containing solvent or a perfluorinated solvent. The water-repellent and oil-repellent composition disclosed by the invention is used for carrying out oil-repellent enhancement treatment on the ePTFE membrane in a spraying or dip-coating manner, and the treatment capacity is 0.2-5%. At least a portion of at least one surface of the resulting ePTFE membrane co