Hydrophilic polypropylene membranes
AssigneeThe Penn State Research Foundation
InventorTze-Chiang Chung
Life of this patent
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Abstract
Polypropylene (PP) membranes having a hydrophilic surface have been prepared by extracting a fugitive hydrophilic pore-forming agent from a gelled film prepared by evaporating the solvent from a homogeneous solution of isotactic polypropylene, functionalized polypropylene an the fugitive agent in a solvent, such as xylene. Most of the functional groups, such as --OH, --NH.sub.2 and --COOH, in the functionalized polypropylene are located on the surfaces of the membrane, including pore surfaces. The resulting membranes, especially membranes having an asymmetric structure, are useful for ultrafiltration, dialysis and/or microfiltration.
Claims9
A porous hydrophilic polypropylene membrane structure which has been prepared by removing fugitive pore-forming agent from a film comprised of a physical mixture of hydrophobic polypropylene, functionalized polypropylene and fugitive pore-forming agent, wherein said fugitive pore-forming agent (a) is soluble in water or in a non-solvent for said hydrophobic polypropylene and said functionalized polypropylene and (b) exhibits a chemical affinity for functional groups in said functionalized polypropylene, wherein said functionalized polypropylene (a) has a viscosity average molecular weight (Mv) between about 30,000 and about 1,000,000 and (b) comprises from about 0.3 to about 10 mole % of functional groups selected from the group consisting of --OH, --NH.sub.2, --COOH and mixtures thereof, and wherein said functionalized polypropylene is concentrated within the portions of the membrane structure that had been occupied by said fugitive pore-forming prior to the removal thereof from the physical mixture of said hydrophobic polypropylene, functionalized polypropylene and fugitive pore-forming agent.
Dependencies are inferred from the claim text.