摘要 |
A process for rendering a normally hydrophobic polyolefinic open celled microporous film relatively permanently hydrophilic, improving the water flow rate therethrough, and reducing the electrical resistance thereof, comprises chemically fixing a controlled amount of at least one hydrophilic organic hydrocarbon monomer to the surface of the micropores of the film with ionizing radiation. The amount of hydrophilic monomer which is chemically fixed to the surface of the micropores is controlled to avoid plugging of the pores subsequent to the radiation treatment. Preferred monomers are acrylic acid, methacrylic acid and vinyl acetate. |