title: Enhancement of Surface Wettability by Incorporating Polar Initiator Fragments at Chain Ends of Low-Molecular-Weight Polymers.
abstract: Simple methods for enhancing hydrophilicity of hydrocarbon polymers are of broad scientific and technological interest. Polystyrene was synthesized via free radical polymerization with initiator fragments incorporated at chain ends. Compared with high molecular weight polystyrene or chains with nonpolar ends, the dynamic receding water contact angle is reduced by as much as ∼30° in ∼4 kg/mol polystyrene with -COOH and nitrile chain ends. This remarkable enhancement results in surface hydrophilicity that is higher than that of poly(methyl methacrylate). This effective methodology incorporating polar moieties at chain ends of nonpolar polymers can be adapted to existing formulations for enhanced surface properties.
authors.affiliation: Department of Materials Science and Engineering and ‡Department of Chemical and Biological Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Lanhe
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Materials Science and Engineering and ‡Department of Chemical and Biological Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: John M
authors.identifier: http://orcid.org/0000-0002-2273-5396
authors.initials: JM
authors.lastname: Torkelson
keywords: chain end; free radical polymerization; hydrogen bonding; hydrophilicity; low-molecular-weight polymers; polystyrene; receding contact angle; surface wettability