Surface grafting of polyacrylamide from polyethylene-based copolymer film

Atom transfer radical polymerization (ATRP) was used to grow polyacrylamide from the surface of ethylene-acrylic acid copolymer (EAA) film. The surface functionalization constituted initiator immobilization and surface graft polymerization. All reaction steps were conducted at 24 +/- 3degreesC; polymerization was done in aqueous solution. For initiator immobilization, the carboxylic acid groups on EAA film were converted to acid chloride groups; further reaction with ethanolamines gave hydroxyl groups onto which 2-bromoisobutyryl bromide initiator was attached. ATR-FTIR data indicated that 1.64 +/- 0.09 times higher initiator density was achieved by using diethanol-amine, relative to ethanolamine. Acrylamide monomer was polymerized from the initiator by ATRP to yield nondistorted, transparent films with polymerization times of up to 1 h. For films prepared using diethanolamine, 1 h polymerization time reduced the static water contact angle by more than 50degrees, significantly increasing the hydrophilicity of the film surface. (C) 2004 Wiley Periodicals, Inc.