Functionalization of polymeric surfaces by simple photoactivation of C?H bonds

A universal photoassisted pathway to functionalize polymeric surfaces is presented by transferring the inert surface sp 3 C  H bonds into reactive groups, such as  SO 3 H,  NH 2 ,  SH, and  COOH. The proposed method uses acetone as photoinitiator and different phenols with a para substituent XR as the reactants. Acetone excited by UV irradiation acts as a pair of scissors cutting both the surface C  H bonds of the polymer substrate and the O  H bonds of phenol, leading to the formation of carbon-centered surface chain free radicals and oxygen-centered phenoxy free radicals. By coupling of these two radicals, a variety of functional X groups with an R spacer from XR species of different phenol reactants were readily bonded to the polymeric surfaces, where phenol reactants included 4-hydroxylbenzene sulfonic acid for  SO 3 H, p -aminophenol and tyramine for  NH 2 , 4-hydroxythiophenol for  SH, and tyrosine for  COOH. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011