Chitosan modification via nitroxide-mediated polymerization and grafting to approach in homogeneous media

A novel and facile strategy to modify chitosan (CTS) with a wide catalog of well-defined molecular weight graft hydrophilic and hydrophobic polymers and copolymers via nitroxide-mediated polymerization (NMP) in homogeneous media is reported. This strategy involves three steps: functionalization of CTS with glycidyl methacrylate (GMA) and sodium dodecylbenzenesulfonate (SDBS) to yield CTS-SDBS-g-GMA, which is soluble in organic media; synthesis of SG1-terminated polymers including poly(styrene) (PS), poly(butyl acrylate) (PBA), poly(acrylic acid) (PAA), poly(styrene-b-acrylic acid) (PS-b-PAA), and poly(styrene-r-acrylic acid) (PS-r-PAA) via SG1-based nitroxide-mediated polymerization; and grafting of the SG1-functionalized polymers or copolymers to CTS-SDBS-g-GMA. Following polymerization, the SOBS was removed from the new CTS-based materials. NMR, TGA, and FT-IR were used to confirm the synthesis of CTS-SDBS-g-GMA, CTS-SDBS-g-GMA-PS, CTS-SDBS-g-GMA-PBA, CTS-SDBS-g-GMA-PAA, CTS-SDBS-g-GMA-PS-b-PAA, and CTS-SDBS-g-GMA-PS-r-PAA. The SOBS was then fully removed from the new CTS-based graft copolymers. New CTS-based materials could find potential applications in fields such as biomedical, water and wastewater treatment, biopharmaceutics and agriculture. (C) 2015 Elsevier Ltd. All rights reserved.