Characterization of polydimethylsiloxane block copolymers containing hydrophilic polymethacrylate segments

A series of block copolymers, i.e., PHEMA-b-PDMS, PDMM-b-PDMS and PMDID-b-PDMS, were obtained from polymerization of 2-hydroxyethyl methacrylate (HEMA), 2,2-dimethyl-1,3-dioxolan-4-ylmethyl methacrylate (DMM) and 5-(5-hydroxymethyl-2,2-dimethyl-1,3-dioxolan-4-yl)-2,2-dimethyl-1,3-dioxolan-4-ylmethyl methacrylate (MDID) initiated with polydimethylsiloxane type of ate-initiator (VPS). Conversion of PDMM segment in PDMM-b-PDMS and PMDID segment in PMDID-b-PDMS into poly(2,3-dihydroxypropyl methacrylate) (PDHPMA) and poly(2,3,4,5,6-pentahydroxyhexyl methacrylate) (PMDul) segments by hydrolysis with a dilute hydrochloric acid resulted in PDHPMA-b-PDMS and PMDul-b-PDMS, respectively. From XPS measurements of freeze dried PHEMA-b-PDMS, PDHPMA-b-PDMS and PMDul-b-PDMS samples, the hydrophilic segment was found to migrate to the surface of copolymer films in water. The contact angle of water of copolymer films decreased with increasing the amount of the hydrophilic segment. The copolymer with a hydrophilic surface suppressed the adsorption of albumin (Alb) and gamma-globulin (Glo) as well as platelets, less than the polydimethylsiloxane as control.