Thermosensitive water‐soluble poly(ethylene glycol)‐based polythiophene graft copolymers

Diethyleneglycol methylethermethacrylate(MeO₂MA) and oligoethylene glycol methylethermethacrylate(OEGMA) are polymerized on polythiophene(PT) backbone to produce water‐soluble PT‐g‐PMeO₂MA(PTD) and PT‐g‐P(MeO₂MA‐co‐OEGMA)(PTDO) using atom transfer radical polymerization. They are characterized by ¹H NMR and GPC techniques. TEM micrographs indicate that PT‐chains self‐organize as nanospheres, and atomic force micrographs suggest that aggregated PT‐chains are present at the centre surrounded by dispersed PMeO₂MA fibers producing miceller‐type aggregates. Dynamic light scattering study indicates an initial decrease followed by sharp increase of Z‐average particle size of PTD with temperature for attaining lower critical solution temperature (LCST) at 20 °C. The LCST increases with OEGMA concentration in PTDO. The temperature dependent PL emission of PTD shows a minimum at 19 °C, followed by a sharp increase till 21 °C, and in the cooling cycle, it shows a complete reversibility. In the PTDO copolymers, the PL intensity shows the hike at progressively higher temperatures due to the increase of LCST with increasing OEGMA concentration. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013