Hydrophilic PET Surfaces by Aminolysis and Glycopolymer Brushes Chemistry

Poly(ethylene terephthalate) (PET) is a semiaromatic thermoplastic polyester used in many fields. For specific applications, controlled of the surface wettability (hydrophily/hydrophoby) could be a great challenge. Aminolysis of PET surfaces with branched polyethylenimine gives amino functional groups on the surface with high grafting density. Then, in a second step, atom transfer radical polymerization (ATRP) initiator was grafted by reaction with 2-bromoisobutyryl bromide. Surface initiated ATRP of 2-lactobionamidoethyl methacrylate (LAMA) was performed in solution in the presence of a sacrificial initiator or an appropriate amount of Cu(II) species that act as deactivator. The efficiency of all reactions was confirmed by X-ray photoelectron spectroscopy. Wetting properties and surface energy were found to vary systematically depending to the type of functionalization and grafting. The quantity of grafted carbohydrate was determined by phenol/ sulfuric acid colorimetric titration. The sugar graft density was observed to vary according to the ratio (monomer)/(free initiator). High graft density could be obtained yielding to superhydrophilic polymer brushes. (C) 2016 Wiley Periodicals, Inc.