2006 Volume 55 Issue 4 Pages 391-396
Block copolymers, Poly (HPMA-b-DMS)-1∼7, were obtained from polymerization of N- (2-hydroxypropyl) methacrylamide (HPMA) initiated with polydimethylsiloxane (PDMS) type of azo-initiator [4,4’-azobis (polydimethylsiloxane)-4-cyanopentanoate (azo-PDMS)]. From XPS measurements of freeze dried samples, the hydrophilic PHPMA segment was found to migrate to the surface of Poly (HPMA-b-DMS) films in water. Poly (HPMA-b-DMS) showed lower contact angle (θ = 54°∼100°) than PDMS itself (θ = 103°). It was also found that the contact angle of block copolymers was changed in response to change in temperature, i.e., θ = 64°∼79° at 40°C and θ = 54°∼69° at 20°C for Poly (HPMA-b-DMS). The amount of adsorption of albumin on the Poly (HPMA-b-DMS) film was depressed at 20°C compared to the case at 40°C. For the purpose of an application to a thermo-responsive drug delivery system, copolymer hydrogel Gel (HPMA-b-DMS) was also prepared by radical copolymerization of HPMA and N,N’-ethylenebisacrylamide initiated with azo-PDMS.