Preparation of neutrally colorless, transparent polynorbornenes with multiple redox‐active chromophores via ring‐opening metathesis polymerization toward electrochromic applications

Abstract

A new electrochromic norbornene derivative containing triphenylamine groups (NBDTPAC8) was synthesized using norbornene amine and bromotriphenylamine. NBDTPAC8 was used in ring-opening metathesis polymerization to obtain poly (NBDTPAC8) using different Grubbs' catalysts and followed by hydrogen reduction to obtain poly(HNBDTPAC8). The glass transition temperatures (T g ) of poly(NBDTPAC8) and hydrogenated poly(HNBDTPAC8) were 132 and 89 C, respectively. Poly (HNBDTPAC8) film exhibited a fluorescence maximum around 416 nm with a quantum yield of up to 60%. Hydrogenated poly (HNBDTPAC8) film showed excellent transparency (up to 93%). Poly(HNBDTPAC8) showed cyclic voltammetric and electrochromic behaviors similar to those of poly(NBDTPAC8). The cyclic voltammogram of a poly(HNBDTPAC8) film cast onto an indium tin oxide (ITO)-coated glass substrate exhibited three reversible oxidation redox couples at 0.69, 0.94 and 1.38 V versus Ag/Ag þ in an acetonitrile solution. The electrochromic characteristics of poly(HNBDTPAC8) showed excellent stability and reversibility, with multi-staged color changes from its colorless neutral form to green, light blue and dark blue upon the application of potentials ranging from 0 to 1.60 V. The color switching time and bleaching time of the poly(HNBDTPAC8) film were 6.2 s and 4.3 s at 1175 nm and 6.6 s and 4.4 s at 970 nm, respectively. V C 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: [3248][3249][3250][3251][3252][3253][3254][3255][3256][3257][3258][3259] 2011

Low Dielectric Fluorinated Polynorbornene with Good Thermostability and Transparency Derived from a Biobased Allylphenol (Eugenol)

“…As depicted in Figure , both PNBE-TFVE and PNBE–PFCB films show good transmittance (>90%) from 550 to 1100 nm. This result based on a PNBE–PFCB film is comparable to the reported transparent PNBs. − The transmittance quickly decreases to near 0% in the UV region (<380 nm) due to the absorption of the aromatic rings of polymers. The cross-linking procedure had no effect on the transparency of the polymer.…”

Electrochromic enhancement of poly(3,4‐ethylenedioxythiophene) films functionalized with hydroxymethyl and ethylene oxide

“…Conducting polymers (CPs) have been extensively studied in both fundamental and practical perspectives due to their applications in various fields, such as solid electrolyte capacitors, printed wiring boards, indium tin oxide (ITO) substitution, organic light‐emitting diodes, organic solar cells, electrochromics, biosensors, and organic field‐effect transistors . CPs as eletrochromic materials have attracted many scientists' attention because of their outstanding advantages over transition metal oxides, such as long‐term stability, high contrast ratio and coloration efficiency (CE), fast response time, low switching potential, and the ease of color control through structure modification …”

Recent advances in electrochromic polymers

“…Another study was the bis-2,4,4-trimethylpentan-2-ylsubstituted TPA moiety [56] (see 21 in Fig. 16, Table 3).…”