Preparation of Diblock and Triblock Copolymers of Styrene, 2,5-Norbornadiene, Ethylmethacrylate and Polyethylene Glycol by Nitroxide-Controlled Free Radical Polymerization
A. A. Entezami, M. Adeli – 2001
Norbomadiene has been polymerized in bulk at 125 'C in presence of a low molar mass of polystyrene-TEMPO as macroinitiator . The structure and poly- dispersity of theobtained diblock copolymer (PSt-PNB-TEMPO) were determin- ed by IR, 'H NMR spectroscopy and GPC measurement,respectively, where TEMPO is 2,2,6,6tetramethylpiperidinyl-l-oxyand PNB is polynorbomadiene. The triblock copolymer of styrene-2,5-norbomadiene-ethylmethacrylate (PSt- PNB-PEMA) using a PSt-PNB-TEMPO as the macroinitiator in the presence of camphorsulphonic acid (CSA) was prepared . Also the triblock copolymer containing polyethylmethacrylate and poly(ethylene glycol) designated as PEMA-PEG-PEMA was synthesized by a novel method . The 'H NMR and FTIR studies of triblock copolymers confirmed their structures and the absence of TEMPO end groups for PEMA.