High glass transition and thermally stable polynorbornenes containing fluorescent dipyrene moieties via ring‐opening metathesis polymerization

A high-glass-transition-temperature polynorbornene, poly(NBEDPY), containing chromophore groups was synthesized by ring-opening metathesis polymerization (ROMP) using Grubbs' catalysts; poly(HNBEDPY) was obtained by the reduction of poly(NBEDPY). The glass transition temperatures (Tg) of poly(NBEDPY) and hydrogenated poly(HNBEDPY) were as high as 250 °C and 220 °C, respectively, because of the rigid dipyrene groups, which are higher than those of commercially available ring-opened hydrogenated polynorbornenes (JSR ARTON®; 120–165 °C). The 10% weight-loss temperatures of hydrogenated poly(HNBEDPY) and poly(NBEDPY) were up to 450 °C and 400 °C, respectively. A hydrogenated poly (HNBEDPY) film showed excellent transparency (over 91%). The photoluminescence emission spectra of poly(HNBEDPY) showed strong solvent-polarity dependence, revealing that poly (HNBEDPY) underwent remarkable bathochromic shifts with an increase in solvent polarity. Poly(HNBEDPY) also showed remarkable fluorescent solvatochromism (blue in toluene, greenish yellow in dimethyl sulfoxide). The cyclic voltammogram of poly(HNBEDPY) film cast onto an indium tin oxide (ITO)-coated glass substrate exhibited one reversible oxidation redox couple at 0.55 V versus Ag/Ag+ in acetonitrile solution. The electrochromic characteristics of poly(HNBEDPY) showed reversibility, with a color change from its green neutral form to dark red upon the application of potentials from 0 to 1.0 V. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011