Synthesis, characterization, catalytic and splinting activity of nano Ag end capped L-glutathione bridged amphiphilic diblock copolymer

摘要

L-glutathione, a naturally occurring environmental friendly amino acid, was used as an initiator towards the ring opening polymerization (ROP) of E-caprolactone (CL) followed by the ROP of tetrahydrofuran (THF). The thiol group of L-glutathione reduces Ag+ ions and chemically bound to the surface of Ag nanoparticles. The ROP of CL was carried out at 160 degrees C under nitrogen atmosphere in the presence of stannous octoate(SO) as catalyst whereas the ROP of THF was carried out at 45 degrees C for 24 h in the presence of phthalic anhydride (PAH) as a comonomer. The synthesized homo, di and nano Ag end capped diblock copolymers were characterized by FTIR, DSC, TGA, FESEM, high resolution transmission electron microscope (HRTEM), EDAX, GPC, nuclear magnetic resonance (NMR), Fluorescence and CD. Further the application of diblock copolymer was tested for splinting activity. The catalytic reduction of 4-nitrophenol (NP) in the presence of nano Ag end capped diblock copolymer was carried out with the assistance of sodium borohydride as a reducing agent and the apparent rate constant (k(app)) was determined and compared with the literature values. (C) 2016 Wiley Periodicals, Inc.