Synthesis and electrochromism of novel organosoluble polyarylates bearing triphenylamine moieties

A series of novel aromatic polyarylates with triphenylamine units in the main chain and as the pendent group were prepared from the dicarboxylic acid monomer, N,N‐bis(4‐carboxyphenyl)‐N′, N′‐diphenyl‐1,4‐phenylenediamine (1), and various bisphenols. These polyarylates were amorphous and readily soluble in common organic solvents. They had excellent levels of thermal stability associated with moderately high T_g values (182–263 °C). These polymers exhibited strong UV–vis absorption bands at 357–360 nm in toluene solution and the photoluminescence spectra showed maximum bands around 493–503 nm in the green region. The hole‐transporting and electrochromic properties were examined by electrochemical and spectroelectrochemical methods. Cyclic voltammograms of the polyarylates exhibited two reversible oxidation redox couples in acetonitrile solution at E_onset 0.77–0.79 V and 1.12–1.14 V, respectively. The typical polymer 3b film revealed good stability of electrochromic characteristics, with color change from colorless to green and blue at applied potentials ranging from 0.00 to 1.24 V. These anodically polymeric electrochromic materials not only showed excellent reversible electrochromic stability with good green coloration efficiency (CE = 159 cm²/C) and blue coloration efficiency (CE = 154 cm²/C) but also exhibited high contrast of optical transmittance change (ΔT%), 54% in 895 nm for green color and up to 84% in 595 nm for blue color. After over 100 cyclic switches, the polymer films still exhibited excellent stability of electrochromic characteristics. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2004–2014, 2007     

Novel thermally stable poly(amine hydrazide)s and poly(amine‐1,3,4‐oxadiazole)s for luminescent and electrochromic materials

We describe the preparation, characterization, and luminescence of four novel electrochromic aromatic poly(amine hydrazide)s containing main‐chain triphenylamine units with or without a para‐substituted N,N‐diphenylamino group on the pendent phenyl ring. These polymers were prepared from either 4,4′‐dicarboxy‐4″‐N,N‐diphenylaminotriphenylamine or 4,4′‐dicarboxytriphenylamine and the respective aromatic dihydrazide monomers via a direct phosphorylation polycondensation reaction. All the poly(amine hydrazide)s were amorphous and readily soluble in many common organic solvents and could be solution‐cast into transparent and flexible films with good mechanical properties. These poly(amine hydrazide)s exhibited strong ultraviolet–visible absorption bands at 346–348 nm in N‐methyl‐2‐pyrrolidone (NMP) solutions. Their photoluminescence spectra in NMP solutions or as cast films showed maximum bands around 508–544 and 448–487 nm in the green and blue region for the two series of polymers. The hole‐transporting and electrochromic properties were examined by electrochemical and spectroelectrochemical methods. All obtained poly(amine hydrazide)s and poly(amine‐1,3,4‐oxadiazole)s exhibited two reversible oxidation redox couples at 0.8 and 1.24 V vs. Ag/AgCl in acetonitrile solution and revealed excellent stability of electrochromic characteristics, changing color from original pale yellow to green and then to blue at electrode potentials of 0.87 and 1.24 V, respectively. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3245–3256, 2005     

A novel high‐contrast ratio electrochromic material from spiro[cyclododecane‐1,9′‐fluorene]bicarbazole

A novel electroactive spirocyclododecylfluorene monomer named 2,7‐bis(carbazol‐9‐yl)‐9,9′‐spiro[cyclododecane‐1,9′‐fluorene] (SFC) was synthesized and electrochemically polymerized to give a very stable multi‐electrochromic polymer (poly‐SFC). Two separate oxidation processes were observed for both SFC monomer and poly‐SFC that carries two carbazole units. The polymeric film of poly‐SFC was coated onto ITO/glass surface, and it shows different colors (transparent, yellowish green, green, and dark green) upon stepwise oxidations. An electrochromic device based on poly‐SFC was assembled in the sandwich cell configuration of ITO/poly‐SFC//gel electrolyte//PEDOT/ITO. Poly‐SFC exhibits 90% of transparency at neutral state and a high contrast ratio (ΔT = 58% at 800 nm). This device constructed from it represents a response time of about 1 s, high coloration efficiency (1377 cm² C^–1) and retained its performance by 96.4% even after 1000 cycles. Exhibiting high transparency at neutral state, reversible redox behavior, resistance to overoxidation, and especially high contrast ratio at near IR region can make poly‐SFC be useful and promising candidate for electrochromic applications despite having a relatively slow response time. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2010     

Synthesis,photoluminescence, and electrochromism of polyamides containing (3,6‐di‐tert‐butylcarbazol‐9‐yl)triphenylamine units

A new carbazole‐derived, triphenylamine (TPA)‐containing aromatic dicarboxylic acid monomer, 4,4′‐dicarboxy‐4″‐(3,6‐di‐tert‐butylcarbazol‐9‐yl)TPA, was synthesized, and it led to a series of electroactive aromatic polyamides with main‐chain TPA and pendent 3,6‐bis(tert‐butyl)carbazole units by reacting it with various aromatic diamines via the phosphorylation polyamidation technique. The polyamides were amorphous with good solubility in many organic solvents and could be solution‐cast into flexible and strong films. They showed high glass‐transition temperatures (282–335 °C) and high thermal stability (10% weight loss temperatures >480 °C). The electroactive polymer films had well‐defined and reversible redox couples with good cycle stability in acetonitrile solutions. The polymer films also exhibited fluorescent and multielectrochromic behaviors. The anodically electrochromic polyamide films had moderate coloration efficiency (～100 cm²/C) and high optical contrast ratio of transmittance change (Δ%T) up to 47% at 813 nm and 48% at 414 nm for the green coloring. After hundreds of cyclic switches, the polymer films still retained good redox and electrochromic activity. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Synthesis,photoluminescence, and electrochromic properties of wholly aromatic polyamides bearing naphthylamine chromophores

A series of novel polyamides with pendent naphthylamine units having inherent viscosities of 0.15–1.02 dL/g were prepared via direct phosphorylation polycondensation from various diamines and a naphthylamine‐based aromatic dicarboxylic acid, 1‐[N,N‐di(4‐carboxyphenyl)amino]naphthalene. These amorphous polyamides were readily soluble in various organic solvents and could be cast into transparent and tough films. The aromatic polyamides had useful levels of thermal stability associated with high glass‐transition temperatures (268–355 °C), 10% weight loss temperatures in excess of 480 °C, and char yields at 800 °C in nitrogen higher than 60%. These polymers showed maximum ultraviolet–visible absorption at 350–358 nm and exhibited fluorescence emission maxima around 435–458 nm in N‐methyl‐2‐pyrrolidinone solutions with fluorescence quantum yields ranging from 0.4 to 15.0%. The hole‐transporting and electrochromic properties were examined with electrochemical and spectroelectrochemical methods. Cyclic voltammograms of the polyamide films cast onto an indium tin oxide coated glass substrate exhibited one oxidative redox couple around 1.08–1.16 V (oxidation onset potential) versus Ag/AgCl in an acetonitrile solution and revealed good stability of the electrochromic characteristics, with a color change from colorless to green at applied potentials ranging from 0 to 1.6 V. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6094–6102, 2006     

Synthesis and photoluminescent and electrochromic properties of aromatic poly(amine amide)s bearing pendent N‐carbazolylphenyl moieties

A series of novel poly(amine amide)s ( IIa – IIl ) with pendent N‐carbazolylphenyl units having inherent viscosities of 0.25–1.06 dL/g were prepared via direct phosphorylation polycondensation from various dicarboxylic acids and a carbazole‐based aromatic diamine. Except for poly(amine amide) IIc , derived from trans‐1,4‐cyclohexanedicarboxylic acid, all the other amorphous poly(amine amide)s were readily soluble in many polar solvents, such as N,N‐dimethylacetamide and N‐methyl‐2‐pyrrolidone (NMP), and could be cast into transparent and flexible films. The aromatic poly (amine amide)s had useful levels of thermal stability associated with relatively high glass‐transition temperatures (268–331 °C), 10% weight loss temperatures in excess of 540 °C, and char yields at 800 °C in nitrogen higher than 60%. These polymers exhibited maximum ultraviolet–visible absorption at 293–361 nm in NMP solutions. Their photoluminescence in NMP solutions exhibited fluorescence emission maxima around 362 and 448–499 nm for aromatic–aliphatic poly(amine amide)s IIa – IIc and aromatic poly (amine amide)s IId – IIl , respectively. The fluorescence quantum yield in NMP solutions ranged from 0.34% for IIj to 4.44% for IIa . The hole‐transporting and electrochromic properties were examined with electrochemical and spectroelectrochemical methods. Cyclic voltammograms of the poly(amine amide) films cast onto an indium tin oxide coated glass substrate exhibited reversible oxidation at 0.81 V and irreversible oxidation redox couples at 1.20 V versus Ag/AgCl in acetonitrile solutions, and they revealed excellent stability of the electrochromic characteristics, with a color change from yellow to green at applied potentials ranging from 0.00 to 1.05 V. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4108–4121, 2006     

Novel family of triphenylamine‐containing,hole‐transporting,amorphous, aromatic polyamides with stable electrochromic properties

We report the preparation and characterization of a series of novel electrochromic, aromatic poly(amine amide)s with pendent triphenylamine units. The synthesis proceeded via direct phosphorylation polycondensation between a novel diamine, N,N‐bis(4‐aminophenyl)‐N′,N′‐diphenyl‐1,4‐phenylenediamine, and various aromatic dicarboxylic acids. All the poly(amine amide)s were amorphous and readily soluble in many common organic solvents and could be solution‐cast into transparent, tough, and flexible films with good mechanical properties. They exhibited good thermal stability and 10% weight‐loss temperatures above 540 °C. Their glass‐transition temperatures were 263–290 °C. These polymers in N‐methyl‐2‐pyrrolidinone solutions exhibited strong ultraviolet–visible absorption peaks at 307–358 nm and photoluminescence peaks around 532–590 nm in the green region. The hole‐transporting and electrochromic properties were studied with electrochemical and spectroelectrochemical methods. Cyclic voltammograms of poly(amine amide) films prepared by the casting of polymer solutions onto an indium tin oxide coated glass substrate exhibited two reversible oxidation redox couples at 0.65 and 1.03 V versus Ag/AgCl in an acetonitrile solution. All the poly(amine amide)s showed excellent stability with respect to their electrochromic characteristics; the color of the films changed from pale yellow to green and then blue at 0.85 and 1.25 V, respectively. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2085–2098, 2005     

Highly stable electrochromic polyamides based on N,N‐bis(4‐aminophenyl)‐N′,N′‐bis(4‐tert‐butylphenyl)‐1,4‐phenylenediamine

A new triphenylamine‐containing aromatic diamine monomer, N,N‐bis(4‐aminophenyl)‐N′,N′‐bis(4‐tert‐butylphenyl)‐1,4‐phenylenediamine, was synthesized by an established synthetic procedure from readily available reagents. A novel family of electroactive polyamides with di‐tert‐butyl‐substituted N,N,N′,N′‐tetraphenyl‐1,4‐phenylenediamine units were prepared via the phosphorylation polyamidation reactions of the newly synthesized diamine monomer with various aromatic or aliphatic dicarboxylic acids. All the polymers were amorphous with good solubility in many organic solvents, such as N‐methyl‐2‐pyrrolidinone (NMP) and N,N‐dimethylacetamide, and could be solution‐cast into tough and flexible polymer films. The polyamides derived from aromatic dicarboxylic acids had useful levels of thermal stability, with glass‐transition temperatures of 269–296 °C, 10% weight‐loss temperatures in excess of 544 °C, and char yields at 800 °C in nitrogen higher than 62%. The dilute solutions of these polyamides in NMP exhibited strong absorption bands centered at 316–342 nm and photoluminescence maxima around 362–465 nm in the violet‐blue region. The polyamides derived from aliphatic dicarboxylic acids were optically transparent in the visible region and fluoresced with a higher quantum yield compared with those derived from aromatic dicarboxylic acids. The hole‐transporting and electrochromic properties were examined by electrochemical and spectro‐electrochemical methods. Cyclic voltammograms of the polyamide films cast onto an indium‐tin oxide‐coated glass substrate exhibited two reversible oxidation redox couples at 0.57–0.60 V and 0.95–0.98 V versus Ag/AgCl in acetonitrile solution. The polyamide films revealed excellent elcterochemical and electrochromic stability, with a color change from a colorless or pale yellowish neutral form to green and blue oxidized forms at applied potentials ranging from 0.0 to 1.2 V. These anodically coloring polymeric materials showed interesting electrochromic properties, such as high coloration efficiency (CE = 216 cm²/C for the green coloring) and high contrast ratio of optical transmittance change (ΔT%) up to 64% at 424 nm and 59% at 983 nm for the green coloration, and 90% at 778 nm for the blue coloration. The electroactivity of the polymer remains intact even after cycling 500 times between its neutral and fully oxidized states. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2330–2343, 2009     

Thermally stable,light‐emitting,triphenylamine‐containing poly(amine hydrazide)s and poly(amine‐1,3,4‐oxadiazole)s bearing pendent carbazolyl groups

A series of new organosoluble poly(amine hydrazide)s were synthesized via the Yamazaki phosphorylation reaction and were solution‐cast into transparent films. Differential scanning calorimetry indicated that the hydrazide polymers could be thermally cyclodehydrated into the corresponding oxadiazole polymers in the range of 300–400 °C. The resulting poly(amine‐1,3,4‐oxadiazole)s exhibited glass‐transition temperatures in the range of 276–297 °C, 10% weight loss temperatures in excess of 520 °C, and char yields at 800 °C in nitrogen higher than 67%. The hole‐transporting and electrochromic properties were examined with electrochemical and spectroelectrochemical methods. Cyclic voltammograms of these polymers prepared by the casting of polymer solutions onto an indium tin oxide coated glass substrate exhibited two reversible oxidative redox couples at 1.10–1.19 and 1.35–1.60 V versus Ag/AgCl in an acetonitrile solution, respectively. The poly(amine hydrazide)s revealed excellent stability of the electrochromic characteristics, changing color from the original pale yellow to green and then to blue. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 48–58, 2007     

Synthesis of a new class of triphenylamine‐containing poly(ether‐imide)s for electrochromic applications

A novel triphenylamine (TPA)‐containing bis(ether anhydride) monomer, namely 4,4′‐bis(3,4‐dicarboxyphenoxy)triphenylamine dianhydride, was synthesized and reacted with various aromatic diamines leading to a series of new poly(ether‐imide)s (PEI). Most of these PEIs were soluble in organic solvents and could be easily solution cast into flexible and strong films. The polymer films exhibited good thermal stability with glass‐transition temperatures in the range 211–299 °C. The polymer films exhibited reversible electrochemical processes and stable color changes (from transparent to navy blue) with high coloration efficiency and contrast ratio upon electro‐oxidation. During the electrochemical oxidation process, a crosslinked polymer structure was developed due to the coupling reaction between the TPA radical cation moieties in the polymer chains. These polymers can be used to fabricate electrochromic devices with high coloration efficiency, high redox stability, and fast response time. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 825–838     

Synthesis and properties of new aromatic polyamides with redox‐active 2,4‐dimethoxytriphenylamine moieties

A new triphenylamine‐based diamine monomer, 4,4′‐diamino‐2″,4″‐dimethoxytriphenylamine ( 2 ), was synthesized from readily available reagents and was reacted with various aromatic dicarboxylic acids to produce a series of aromatic polyamides ( 4a–h ) containing the redox‐active 2,4‐dimethoxy‐substituted triphenylamine (dimethoxyTPA) unit. All the resulting polyamides were readily soluble in polar organic solvents and could be solution cast into tough and flexible films. These polymers exhibited good thermal stability with glass transition temperatures of 243–289 °C and softening temperatures of 238–280 °C, 10% weight loss temperatures in excess of 470 °C in nitrogen, and char yields higher than 60% at 800 °C in nitrogen. The redox behaviors of the polymers were examined using cyclic voltammetry (CV). All these polyamides showed two reversible oxidation processes in the first CV scan. The polymers also displayed low ionization potentials as a result of their dimethoxyTPA moieties. In addition, the polymers displayed excellent stability of electrochromic characteristics with coloration change from a colorless neutral state to green and blue‐purple oxidized states. These anodically coloring polyamides showed high green coloration efficiency (CE = 329 cm²/C), high contrast of optical transmittance change (ΔT% = 84% at 829 nm), and long‐term redox reversibility. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3392–3401, 2010     

Synthesis and evaluation of photoluminescent and electrochemical properties of new aromatic polyamides and polyimides with a kink 1,2‐phenylenediamine moiety

A series of novel triphenylamine‐containing aromatic polyamides and polyimides having a crank and twisted noncoplanar structures were synthesized in inherent viscosities of 0.14–0.64 dL/g and 0.11–0.67 dL/g, respectively. These polymers had useful levels of thermal stability associated with relatively high glass‐transition temperatures (174–311 °C). They exhibited strong UV–Vis absorption bands at around 300 nm in NMP solutions. The PL spectra of these polymers in NMP solutions (1 × 10^?5 M) showed maximum peaks around 396–479 nm. The hole‐transporting and electrochromic properties were examined by electrochemical and spectroelectrochemical methods. Cyclic voltammetry (CV) of the polymer films cast onto an indium‐tin oxide (ITO)‐coated glass substrate exhibited two reversible oxidation redox couples at potentials of 0.70–1.01 V and 1.10–1.46 V, respectively, vs. Ag/AgCl in acetonitrile solution. The polymer films revealed electrochromic characteristics, with a color change from neutral pale yellowish to green and then to a blue oxidized form at applied potentials ranging from 0.00 to 1.75 V. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2587–2603, 2006     

Red,green, and blue electrochromism in ambipolar poly(amine–amide–imide)s based on electroactive tetraphenyl‐p‐phenylenediamine units

A series of novel poly(amine–amide–imide)s (PAAIs) based on tetraphenyl‐p‐phenylenediamine (TPPA) units showing anodically/cathodically electrochromic characteristic with three primary colors [red, green, and blue (RGB)] were prepared from the direct polycondensation of the TPPA‐based diamine monomer with various aromatic bis(trimellitimide)s. These multicolored electrochromic polymers were readily soluble in polar organic solvents and showed excellent thermal stability associated with high glass‐transition temperatures (288–314 °C) and high‐char yield (higher than 60% at 800 °C in nitrogen). The PAAI films revealed electrochemical oxidation and reduction accompanied with high contrast of optical transmittance color changes from the pale yellow neutral state to the green/blue oxidized state and red reduced state, respectively. The electrochromic films had high‐coloration efficiency (CE = 178 and 242 cm²/C at the first and the second stages, respectively), low‐switching time, and good redox stability, which still retained a high electroactivity after long‐term redox cycles. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

High solubility,low‐dielectric constant,and optical transparency of novel polyimides derived from 3,3′,5,5′‐tetramethyl‐4,4′‐diaminodiphenyl‐4″‐isopropyltoluene

A series of novel polyimides (PIs) ( 3a–d ) were prepared from 3,3′,5,5′‐tetramethyl‐4,4′‐diaminodiphenyl‐4 ″ ‐isopropyltoluene ( 1 ) with four aromatic dianhydrides via a one‐step high temperature polycondensation procedure. The obtained PIs showed excellent solubility, with most of them dissoluble at a concentration of 10 wt % in amide polar solvents and chlorinated solvents. Their films were nearly colorless and exhibited high‐optical transparency, with the UV cutoff wavelength in the range of 328–353 nm and the transparency at 450 nm >80%. They also showed low‐dielectric constant (2.49–2.94 at 1 MHz) and low‐water absorptions (0.44–0.65%). Moreover, these PIs possessed high‐glass transition temperatures (T_g) beyond 327 °C and excellent thermal stability with 10% weight loss temperatures in the range of 530–555 °C in nitrogen atmosphere. In comparison with some fluorinated poly(ether imide)s derived from the trifluoromethyl‐substituted bis(ether amine)s, the resultant PIs 3a–d showed better solubility, lower cutoff wavelength, and higher T_g. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3309–3317, 2009     

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

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⁺ 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. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011.     

Enhancement of redox stability and electrochromic performance of aromatic polyamides by incorporation of (3,6‐dimethoxycarbazol‐9‐yl)‐triphenylamine units

New series aromatic polyamides with (carbazol‐9‐yl)triphenylamine units were synthesized from a newly synthesized diamine monomer, 4,4′‐diamino‐4″‐(3,6‐dimethoxycarbazol‐9‐yl) triphenylamine, and aromatic dicarboxylic acids via the phosphorylation polyamidation technique. These polyamides exhibit good solubility in many organic solvents and can be solution‐cast into flexible and strong films with high thermal stability. They show well‐defined and reversible redox couples during oxidative scanning, with a strong color change from colorless neutral form to yellowish green and blue oxidized forms at applied potentials scanning from 0.0 to 1.3 V. They show enhanced redox‐stability and electrochromic performance as compared to the corresponding analogs without methoxy substituents on the active sites of the carbazole unit. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 272–286     

New polyimides incorporated with diphenylpyrenylamine unit as fluorophore and redox‐chromophore

A series of novel polyimides based on N,N‐di(4‐aminophenyl)‐1‐aminopyrene and aromatic or alicyclic tetracarboxylic dianhydrides were synthesized. The polymers exhibited good solubility in many polar organic solvents and could afford robust films via solution casting. The polyimides derived from aromatic dianhydrides exhibited high thermal stability and high glass‐transition temperatures (333–364 °C). Cyclic voltammetry studies of the polymer films showed that these polyimides are both p and n dopable and have multicolored electrochromic states. For the polyimides derived from alicyclic dianhydrides, they revealed a strong blue‐light emission with high fluorescence quantum yields (?_PL > 45%) and a marked solvatochromic behavior. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Click synthesis and reversible electrochromic behaviors of novel polystyrenes bearing aromatic amine units

Novel electrochromic polymers were prepared by the click postfunctionalization of poly(4‐azidomethylstyrene) with alkyne‐containing aromatic amine units in the presence of Cu(I) catalysts. Two kinds of aromatic amine units, tris(4‐alkoxyphenyl)amine and N,N,N′,N′‐tetraphenyl‐p‐phenylenediamine, were introduced into polystyrene side chains, which were completely characterized by gel permeation chromatography–multiangle light scattering, nuclear magnetic resonance, and infrared spectroscopies, and elemental analysis. Thermal analyses demonstrated the high stability with the decomposition temperatures exceeding 300 °C even after postfunctionalization. The UV–vis absorption spectra of the polymer thin films revealed negligible absorption in the visible region, as reasonably confirmed by visual observation. The polymer thin films were prepared by spray‐coating on an indium tin oxide‐coated glass plate. Cyclic voltammograms of these films exhibited anodic peaks ascribed to the oxidation of the side‐chain aromatic amine moieties. The tris(4‐alkoxyphenyl)amine unit displayed one‐step oxidation at 0.287 V (vs. Ag/AgCl), while the N,N,N′,N′‐tetraphenyl‐p‐phenylenediamine unit showed two‐step oxidations at 0.297 and 0.641 V. These oxidation processes produced new colors of the polymer films. The former triarylamine‐based chromophore provided a blue color after the oxidation, while the latter phenylenediamine‐based chromophore showed a potentially controlled green and dark blue colors. The reversibility and switching behaviors of these color changes were also comprehensively investigated. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

New electroactive and electrochromic aromatic polyamides with ether‐linked bis(triphenylamine) units

A new class of electroactive polyamides with ether‐linked bis(triphenylamine) [O(TPA)₂] units were prepared through the direct phosphorylation polycondensation from N,N‐di(4‐aminophenyl)‐N′,N′‐diphenyl‐4,4′‐oxydianiline and aromatic dicarboxylic acids. These polyamides were amorphous with good solubility in many organic solvents, such as NMP and DMAc, and could be solution‐cast into strong and flexible polymer films. Their decomposition temperatures (T_d) at a 10% weight‐loss in nitrogen and air were recorded at 556–568 °C and 537–555 °C, respectively. The glass‐transition temperatures (T_g) of all the polyamides were observed in the range of 218?253 °C by DSC. Cyclic voltammograms of the polyamide films cast onto an indium‐tin oxide (ITO)‐coated glass substrate exhibited two reversible oxidation redox couples at 0.80–0.82 V and 0.96–0.98 V versus Ag/AgCl in an electrolyte containing acetonitrile solution. The polyamide films showed excellent electrochemical and electrochromic stability, with a color change from a colorless or pale yellowish neutral form to green and purple oxidized forms at applied potentials ranging from 0 to 1.2 V. These polymers can also be used to fabricate electrochromic devices, and they showed high coloration efficiency, high redox stability, and fast response time. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 496–510     

Near‐infrared electrochromic poly(aryl ether)s based on isolated electroactive tetraphenyl‐p‐phenylenediamine moieties

A series of near‐infrared (NIR) electrochromic aromatic poly(aryl ether)s containing N,N,N′,N′‐tetraphenyl‐p‐phenylenediamine (TPPA) moieties in the backbone were prepared from the high‐temperature polycondensation reactions of a biphenol monomer, 2,5‐bis(diphenylamino)hydroquinone, with difluoro compounds. The obtained polymers were readily soluble in many organic solvents and showed useful levels of thermal stability associated with high glass‐transition temperatures (182–205 °C) and high char yields (higher than 40% at 800 °C in nitrogen). The polymer films showed reversible electrochemical oxidation with high contrast ratio both in the visible range and NIR region, and also exhibited high coloration efficiency (CE), low switching time, and stability for electrochromic operation. The polyether TPPA‐a thin film revealed good CE in visible (CE = 217 cm²/C) and NIR (CE = 192 cm²/C) region with reversible electroactive stability (over 500 times within 5% loss relative to its initial injected charge). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5378–5385, 2009