Journal of Polymer Science Part A: Polymer Chemistry, Vol.45, No.24, 5770-5780, 2007
Fluorinated bio-acceptable polymers via an ATRP macroinitiator approach
Polymers derived from bio-acceptable poly(methyl methacrylate) (PMMA), poly(2-methoxyethyl acrylate) (PMEA), and poly(oligo(ethylene glycol) methyl ether methacrylate) (PPEGMA) have been prepared via atom transfer radical polymerization (ATRP) utilizing an initiator prepared from a fluoroalkoxy-terminated oligoethylene glycol. Polymerizations are controlled as seen by both linear first-order kinetics and molecular weight evolution coupled with low polydispersities (< 1.25) with respect to conversion. A range of ligands have been used depending upon the nature of the monomer: N-(n-propyl)-2-pyridyl-methanimine with the methacrylates MMA and PEGMA and 1,1,4,7,10,10-hexamethyltriethylene tetramine (HMTETA) with MEA. In all cases the use of the fluorinated initiator results in a lower apparent rate of propagation (k(p)(aPP)) as compared with the more conventional and nonfluorinated initiator, ethyl 2-bromoisobutyrate. The initiator generally also serves as an internal plasticizer lowering the glass transition temperature from the parent polymers. The surface characteristics of the fluoroinitiator containing polymers are altered compared with the nonfluorinated analogues. This is reflected in a significant increase in the advancing water contact angles of all fluoro-containing polymers. (c) 2007 Wiley Periodicals, Inc.
Keywords:atom transfer radical polymerization (ATRP);biocompatibility;block copolymers;contact angle;kinetics (polymer);thermal properties