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A diamine containing heterocyclic pyridine and unsymmetrical carbazole substituents, 4-(9-ethyl-3-carbazole)-2,6-bis(4-aminophenyl)pyridine (CBAPP), was prepared for use in the synthesis of poly(pyridine-imide)s PI-1–8 by direct polycondensation with dianhydrides in N,N-dimethylacetamide (DMAc). The poly(pyridine-imide)s derived from the diamine are highly soluble in solvents such as N-Methyl-2-pyrrolidone (NMP) and DMAc at room temperature. Noncoplanar polyimide (PI-1) showed excellent solubility, high transparency, and high-performance mechanical properties. These polymers had relatively high glass transition temperatures and exhibited good thermal stability in both nitrogen (Td10 > 470 °C) and air (Td10 > 450 °C). The PI-3∼5 cannot form flexible and tough films due to the unsymmetrical carbazole moiety, rigid structure, and polar–polar interaction. However, through copolymerization technique these polymers (PI-6∼8) could be enhanced through the solubility, mechanical, and thermal properties. The optical properties included a strong orange fluorescence (540 nm) after protonation with acid. When the HCl concentration was increased, a new absorption band at approximately 350 nm appeared, and the intensity of the fluorescent peak at 380 nm observed in the neutral polymer solution decreased, along with the appearance of the new fluorescent peak at 540 nm. The poly(pyridine-imide)s presented here showed only slight fluorescence quenching in the presence of methanol. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 405–412

Electrochromic polymers are attractive materials with enormous potential in the rapidly developing area of plastic electronics due to their flexibility, low-power consumption, ease of processing and low processing cost. Electrochromic devices created with electrochromic polymers are likely to be alternatives or supplements to the conventional inorganic electrochromic devices, which face challenges of durability and electrochromic properties. Several novel electrochromic polyimides, polyamides, and polynorbornenes prepared via polycondensation, ring-opening metathesis polymerisation (ROMP), etc., are introduced in this article. These various polymer species exhibit high thermal stability and mechanical strength.

A new diamine containing pyridine and carbazole groups was synthesized via a Chichibabin reaction and subsequent reduction; this compound was then used in the preparation of organo-soluble aramides (PA-a–i). The resultant polymers had high glass transition temperatures, which fell within the ranges of 271–287 °C, and Td10 at 510–535 °C in a nitrogen atmosphere. The pristine PA-a exhibited the maximum value in the UV–vis absorption spectrum at 307 nm, and this value shifted to 394 nm after protonation by HCl. When the emission of the polymer in THF solution was observed, the intensity of the emission peak at 420 nm decreased and the intensity of a new emission peak at 552 nm increased as the acid concentration increased. Additionally, the color of the polymer solution changed from blue to yellow after protonation. The intensity of the emission at 552 nm based on excimers increased as MeOH content increased. The color of polymer films also changed irreversibly from yellow, which was indicative of the neutra...

A new electrochromic norbornene derivative (NB) containing symmetrical diphenylamine and unsymmetrical triphenylamine groups, was synthesised from norbornene amine and unsymmetrical triphenylamine-substituted bromide. NB was used to obtain unsaturated PNB via ring-opening metathesis polymerization using different Grubbs' catalysts, followed by hydrogen reduction to obtain saturated HPNB. PNB and HPNB were highly soluble in common organic solvents such as toluene, xylene, benzene, chlorobenzene, 1,2-dichlorobenzene, and tetrahydrofuran at room temperature. The glass transition temperatures ( T g ) of PNB and hydrogenated HPNB were 162 °C and 117 °C, respectively. The 10% weight-loss temperatures of PNB and hydrogenated HPNB were 410 °C and 450 °C, respectively. Cyclic voltammogram of HPNB film cast onto an indium-tin oxide (ITO)-coated glass substrate exhibited three reversible oxidation redox couples at 0.52, 0.85 and 1.30 V versus Ag/Ag + in acetonitrile solution. The electrochromic characteristics of HPNB showed excellent stability and reversibility, with multi-staged colour changes from light yellow to green, dark-blue and purple as the potential changed from 0 to 1.35 V. The colour switching time and the bleaching time of the HPNB were 8.7 s and 4.3 s, respectively, at 1084 nm and 7.9 s and 3.8 s at 879 nm.

Novel electrochromic polynorbornenes poly(NBPYTPAM) and poly(HNBPYTPAM), containing electroactive chromophores, were prepared via ring-opening metathesis polymerization (ROMP) from a new norbornene derivative (NBPYTPAM) using Grubbs’ catalyst and followed by hydrogen reduction. The glass transition temperatures (Tg) of poly(NBPYTPAM) and hydrogenated poly(HNBPYTPAM) were 190 and 175 °C, respectively. The cyclic voltammogram of the poly(HNBPYTPAM) film cast onto flexible graphene-coated polyethylene terephthalene (PET) substrates exhibited two reversible oxidation redox couples at 1.0 and 1.9 V. Flexible electrochromic devices were fabricated from the electroactive polymers and graphene-coated PET substrates. The electrochromic characteristics of poly(HNBPYTPAM) showed excellent stability and reversibility, with multistaged color changes from its yellow neutral form to green and then to dark-blue.

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

Two novel conjugated polymers denoted TAZF2 and TAZBTF, having electron-deficient main chains and electron-rich triphenylamine pendant groups, were designed and synthesized. While TAZF2 was constructed with fluorene and electron-deficient 1,2,4-triazole as the major components of the main chain, fluorene, 1,2,4-triazole, and 2,1,3-benzothiadiazole were employed to form TAZBTF. The number-average molecular weights (Mw) of the polymers fell in the range of 1.28 × 104–2.56 × 104 with polydispersity indexes (PDI = Mw/Mn) of 1.49–1.95. The polymers had glass transition temperatures (Tg) in the range of 153–185 °C. While TAZF2 exhibited blue photoluminescence, TAZBTF exhibited yellow–green emission. Thermal stability of the conjugated polymers was enhanced due to the introduction of rigid bipolar components. The incorporation of 2,1,3-benzothiadiazole into TAZBTF reduced the coplanarity of the conjugated polymer, which prohibited the polymer from aggregation. Intramolecular and intermolecular energy transfer was clearly evidenced by the shift in light emission to the yellow–green region. TAZBTF exhibited maximum electroluminescence efficiency as high as 2.60 cd/A, demonstrating that a good balance of charge carriers is injected into our devices.

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 (Tg) 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.

A series of thermally stable aromatic polyimides containing triphenylamine-substituted triazole moieties (AZTA-PI)s were prepared and characterized. The glass transition temperatures (Tg) of the polyimides were found to be in the range of 262–314 °C. The polyimides obtained by chemical imidization had inherent viscosities of 0.25–0.44 dL g−1 in N-methyl-2-pyrrolidinone. The number average molecular weights (Mn) and weight average molecular weights (Mw) were 1.9–3.2 × 104 and 3.2–5.6 × 104, respectively, and the polydispersity indices (PDI = Mw/Mn) were in the range of 1.70–1.78. A resistive switching device was constructed from the 4,4′-hexafluoroisopropylidenediphthalic dianhydride-based soluble polyimide (AZTA-PIa) in a sandwich structure of indium-tin oxide/polymer/Al. The as-fabricated device can be switched from the initial low-conductivity (OFF) state to the high-conductivity (ON) state at a switching threshold voltage of 2.5 V under either positive or negative electrical sweep, with an ON/OFF state current ratio in the order of 105 at −1 V. The device is able to remain in the ON state even after turning off the power or under a reverse bias. The nonvolatile and nonrewritable natures of the ON state indicate that the device is a write-once read-many times (WORM) memory. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010

Novel bi-triphenylamine-containing aromatic dibro- mide M3, N,N-bis(4-bromophenyl)-N 0 ,N 0 -dipheny-l,4-phenylene- diamine, was successfully synthesized. The novel conjugated polymer P1 having number-average molecular weight of 1.31 � 10 4 was prepared via Suzuki coupling from the dibromide M3 and 9,9-dioctylfluorene-2,7-diboronic acid bis(1,3-propane- diol) ester. Polymer P1 had excellent thermal stability associ- ated with a high glass-transition temperature (Tg ¼ 141 � C). The hole-transporting and UV-vis-near-infrared electrochromic properties were examined by electrochemical and spectroelec- trochemical methods. Cyclic voltammograms of the conjugated polymer films cast onto indium-tin oxide-coated glass sub- strates exhibited two reversible oxidation redox couples at E1/2 values of 0.73 and 1.13 V versus Ag/Ag þ in acetonitrile solu- tion. The hole mobility of the conjugated polymer P1 revealed � 10 � 3 cm 2 V � 1 s � 1 , which is much higher than that of other conjugated polymer systems. The observed UV-vis-near- infrared absorption change in the conjugated polymer film P1 at applied potentials ranging from 0.00 to 1.23 V are fully reversible and associated with strong color changes from pale yellowish in its neutral form to green and blue in its oxidized form. Using a combination of experimental study and theo- retical investigation, we proposed an oxidation mechanism based on molecular orbital theory, which explains the cyclic voltammetry experimental results well. V C 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4654- 4667, 2010

A series of novel organosoluble polyimides and copolyimides with a propeller-shaped triarylamine unit were prepared from diamine and various aromatic dianhydrides via direct polycondensation. All of the polymers possessed tough, flexible, and strong films with high molecular weights. The polyimide and copolyimide films revealed electrochromic characteristics, with a color change from pale yellowish at its neutral state, to green, and finally to blue at its oxidized state, at applied potentials ranging from 0 to 1.50 V. The polyimide (Ib) film exhibited switching times of 4.5 s at 1.08 V at 424 and 877 nm and 1.9 s for fast bleaching due to a pendent substituted 2-phenyl-2-isopropyl group. Cyclic voltammetry (CV) of the polymer films showed two reversible redox couples at potentials of 0.91–0.99 V and 1.30–1.38 V, respectively. The CV results of the model compound M1 and model polyimide M2, were not a match to the oxidation peaks of polyimide Ib, indicating that the contribution of the oxidation was not only from the electron removal of nitrogen atoms.

A novel unsymmetrical diamine, 1,3-bis(4-aminophenoxy)naphthalene, was prepared through the nucleophilic displacement of 1,3-dihydroxynaphthalene with p-fluoronitrobenzene in the presence of potassium carbonate, followed by catalytic reduction with hydrazine. A series of novel aromatic polyimides containing bis(phenoxy)naphthalene units were synthesized from the unsymmetrical diamine and a range of aromatic tetracarboxylic dianhydrides via the usual two-step procedures that included ring-opening polyaddition and thermal/chemical cyclodehydration. The poly(amic acid)s had inherent viscosities ranging from 0.65 to 2.01 dL/g. All the poly(amic acid)s could be converted thermally into transparent, flexible, and tough polyimide films. Most of the polyimides were soluble in organic solvents, such as dimethylacetamide, N-methyl-2-pyrrolidone, m-cresol, or o-chlorophenol due to the unsymmetrical and bulky pendant naphthalene groups. The tensile strength and elongation at break of the polyimide films ranged from 74 to 97 MPa and 4 to 7%, respectively. These polyimides had glass transition temperatures ranging from 221 to 312 °C. Thermogravimetric analysis revealed these polymers to be fairly stable up to 500 °C, and the 10% weight loss temperature were recorded in the range of 531–580 °C in nitrogen and 522–570 °C in air. The substituted position effect of bis(phenoxy)naphthalene on the properties of the polyimides were investigated. The polyimides derived from unsymmetrical 1,3-substituted bis(4-aminophenoxy) naphthalene showed better solubility without sacrificing their thermal and mechanical properties due to the unsymmetrical and bulky pendant effects.

This work reports the synthesis and characterization of a series of functional aromatic polyimides (OXTA-PI)s containing triphenylamine and 1,3,4-oxadiazole moieties. All the polyimides exhibit high glass transition temperatures of 309−319 °C. A resistive switching device with the sandwich structure of indium−tin oxide/polymer/Al was fabricated using the soluble polyimide from 4,4′-hexafluoroisopropylidenediphthalic anhydride (OXTA-PIa). The device exhibits two conductivity states and can be switched from the initial low-conductivity (OFF) state to the high-conductivity (ON) state at the threshold voltages of 1.8 V under both positive and negative electrical sweeps, with an ON/OFF state current ratio in the order of 105. The ON state of the device is nonvolatile and can withstand a constant voltage stress of −1 V for 6 h and 108 pulse read cycles at −1 V under ambient conditions. Upon reversing the bias, the ON state cannot be reset to the initial OFF states. The nonvolatile and inerasable nature of the O...

A new rapid switching near-IR electrochromic conjugated propeller-shape polymer (PBTPAFL) with lower oxidation potential containing a di-triarylamine group was synthesized via Suzuki coupling approach. The observed UV-vis-NIR absorption changes in the PBTPAFL film at various potentials are fully reversible and associated with strong color changes from the original light green to dark green and then to a Prussian blue. Excellent continuous cyclic stability of the electrochromic characteristics with a rapid color switching time 2.58 s and bleaching time 1.76 s was found as well. Compared with P1 and P2, the introduction of more electron-donating propyl phenyl group in the para position of PBTPAFL lowered the oxidative potential and prevented coupling reaction during the electrochromic procedure. The high molecular weight conjugated polymer having high thermal stability with T d10 more than 450 °C has excellent solubility in common organic solvents such as NMP, THF, chloroform, toluene, xylene, and benzene at room temperature (25 °C) due to the propeller-shape structure and long alkyl chain on fluorene. Herein, from the combination of the experimental and computational study, we proposed a mechanism on the basis of the molecular orbital theory to explain the electrochromic oxidation behavior.

A novel dibromo compound containing unsymmetrical substituted bi-triarylamine was synthesized. A conjugated polymer was prepared via the Suzuki coupling from the newly prepared dibromo compound and 9,9-dioctylfluorene-2,7-bis(tri-methyleneboronate). The glass transition temperature (T g ) of the conjugated polymer was 140 °C, 10% weight-loss temperatures (T d10 ) in nitrogen was 458 °C, and char yield at 800 °C in nitrogen higher than 64%. Cyclic voltammogram of the polymer film cast onto an indium-tin oxide (ITO)-coated glass substrate exhibited two reversible oxidation redox couples at 0.70 and 1.10 V versus Ag/Ag + in acetonitrile solution. The polymer films revealed excellent stability of electrochromic characteristics, with a color change from yellow green of the neutral form to the dark green and blue of oxidized forms at applied potentials ranging from 0 to 1.3 V. The color switching time and bleaching time were 4.25 and 7.22 s for 860 nm and 5.51 s and 6.48 s for 560 nm.

A novel N,N,N′,N′-tetraphenyl-1,4-phenylenediamine (TPPA)-containing aromatic dibromide (3), N,N-bis(4-bromophenyl)-N′,N′-bis(4-(2,4,4-trimethylpentan-2-yl)phenyl)-1,4-phenylenediamine, was successfully synthesized. The novel conjugated polymer (4) having number-average molecular weight of 2.05 × 104 was prepared via Suzuki coupling from the dibromide (3) with 9,9-dioctylfluorene-2,7-diboronic acid bis(1,3-propanediol) ester. The conjugated polymer (4) exhibited excellent solubility in common organic solvents such as N-methyl-2-pyrrolidinone (NMP), tetrahydrofuran, chloroform, and toluene at room temperature. The conjugated polymer (4) had useful levels of thermal stability associated with their relatively high glass transition temperature (Tg = 144 °C), 10% weight-loss temperatures (Td10) in nitrogen (Td10 = 445 °C), and char yields at 800 °C in nitrogen (59.0%). The hole-transporting and electrochromic properties were examined by electrochemical and spectroelectrochemical methods. Cyclic voltammograms o...

A bipolar dibromo monomer, bis-(4-bromophenyl)[4-(3,5-diphenyl-1,2,4-triazole-4-yl)-phenyl]amine (9), containing electro-rich triphenylamine and electro-deficient 1,2,4-triazole moieties was newly synthesized and characterized. Two fluorescent fluorene-based conjugated copolymers (TPAF, TPABTF) were prepared via facile Suzuki coupling from the dibromo bipolar monomer, 4,7-dibromo-2,1,3-benzothiadiazole (BTDZ), and 9,9-dioctylfluorene. They were characterized by molecular weight determination, IR, NMR, DSC, TGA, solubility, absorption and photoluminescence spectra, and cyclic voltammetry. The polymers showed good solubility in common organic solvents such as dichloromethane, chloroform, tetrahydrofuran, and dichlorobenzene at room temperature. They had glass transition temperatures (T g ) higher than 135 °C and 5% degradation temperatures in nitrogen atmosphere were higher than 428 °C. Single layer polymer light-emitting diodes (PLED) of ITO/ PEDOT:PSS/polymer/metal showed a blue emission at 444 nm and Commission Internationale de I'Eclairage (CIE) 1931 color coordinates of (0.16, 0.13) for TPAF. The device using TPABTF as emissive material showed electroluminescence at 542 nm with CIE1931 of (0.345, 0.625), low turn-on voltage of 5 V, a maximum electroluminance of 696 ed/m 2 , and a peak efficiency of 2.02 cd/A.

A series of novel amphiphilic fluorescent CBABC-type pentablock copolymers ( Py – PMMA – PEG4600 – PMMA – Py ) were prepared from BAB-type amphiphilic triblock copolymer ( PMMA – PEG4600 – PMMA ) as macroinitiator with various contents of 1-(methacryloyloxyethylamino-carboxylmethyl) pyrene ( PyMOI ) by atom transfer radical polymerization (ATRP) in toluene using CuBr/2,2-bipyridine as catalyst system. Triblock copolymer ( PMMA – PEG4600 – PMMA ) was prepared by ATRP and obtained from Br – PEG4600 – Br as macroinitiator with methyl methacrylate in tetrahydrofuran using the same catalyst. The molecular weights of pentablock copolymers which were reinitiated by PMMA – PEG4600 – PMMA macroinitiator were calculated from 1 H NMR spectra up to 42,400 gmol −1 . The polydispersity of pentablock copolymers obtained from GPC analysis was narrow between 1.10 and 1.38. The crystallinity of triblock copolymer ( PMMA – PEG4600 – PMMA ) was decreased slightly with incorporating PMMA segment. Introducing the bulky pyrene substituent into pentablock copolymer, the melting temperature was not observed and all pentablock copolymers showed amorphous patterns in wide-angle X-ray scattering (WAXS) due to decrease in the degree of crystallinity of polymer chain because of disturbing regular packing. The temperatures at 10% weight loss (Td 10 ), examined by TG analysis, showed values ranging from 265 to 323 °C in nitrogen and 264 to 313 °C in air. Fluorescence spectra of Py – PMMA – PEG4600 – PMMA – Py exhibited stronger excimer emission at ca . 480 nm due to the aggregations of pyrene group formed via interaction of the hydrophobic chains. The more content of PyMOI segment in pentablock copolymers can obtain the higher emission intensity ca . 480 nm. When there were higher PyMOI contents (84.9 wt% PyMOI ) in pentablock copolymers, they formed larger aggregates (210 nm) in SEM micrographs. On the other hand, while increasing the concentration of the polymer solution in THF, the morphology was changed from spherical (0.1 mg/mL) to chainlike (1.0 mg/mL) aggregates.

A solution-processable functional polyimide, P(BPPO)-PI, containing oxadiazole moieties (electron donors) and phthalimide moieties (electron acceptors) was synthesized. A switching device, based on a solution-cast thin film of P(BPPO)-PI sandwiched between an indium−tin oxide (ITO) bottom electrode and an Al top electrode, exhibits two accessible conductivity states and can be switched from the low-conductivity (OFF) state to the high-conductivity (ON) state when swept positively or negatively, with an ON/OFF current ratio on the order of 1 × 104. The device exhibits ON state “remanence”, with the ON state retainable for a period of about 4 min after turning off the power. The ON state can be electrically sustained either by a refreshing voltage pulse of −1 V or by a continuous bias of −1 V. The “remanent” but volatile nature of the ON state and the ability to write, read, and sustain the electrical states with bias are characteristic features observed in a static random access memory (SRAM). The mechanis...

A new diiodo monomer containing heterocyclic pyridine and carbazole groups was synthesized via Chichibabin reaction and used in the preparation of a conjugated polymer via Suzuki coupling approach. The conjugated polymer was highly soluble in common organic solvents such as NMP, THF, dichloromethane, chloroform, toluene, xylene, and benzene at room temperature. The polymer had high glass transition temperature at 191 °C and Td10 at 434 °C in nitrogen atmosphere. The pristine polymer exhibited the UV–vis maximum absorption at 355 nm and shifted to 420 nm after protonation. The emission of the polymer in THF solution changed from the blue region with maximum peak at 400 nm to the yellow region with maximum peak at 540 nm after protonated by HCl, and the intensity of emission depended on the concentration of acid. The polymer also showed electrochromic behavior under applied voltage. The emission color of the polymer film changed from blue (435 nm) to yellow (570 nm) when 2.5 V bias voltage was applied. The polymer also exhibited write-once and read-many-times (WORM) polymer memory effect with tristable states. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 991–1002, 2009

A series of poly(aryl ether)s were successfully prepared via aromatic nucleophilic substitution reaction from various bisphenols and a novel bipolar aryl difluoride monomer containing electron-donor triphenylamine and electron-acceptor 1,2,4-triazole moieties. The poly(aryl ether)s exhibited excellent solubility in organic solvents such as dimethylformamide, chloroform, and tetrahydrofuran at room temperature. The poly(aryl ether)s showed high thermal stability with T d10 higher than 500 °C and glass transition temperatures (Tg) higher than 187 °C. The thin films of the poly(aryl ether)s indicated bistable resistive switching behavior with ON/OFF current ratios as high as 10 3 . The switching on and switching off bias voltages of the poly(aryl ether)s were affected by the bisphenol moiety. The good resistive switching behavior of the poly(aryl ether)s made them promising candidates for future nonvolatile memory applications.

A new triphenylamine-containing AB 2 type monomer with one carboxylic acid and two amino groups, 4-(bis(4-aminophenyl)amino)benzoic acid ( 3 ), was synthesized and used for the preparation of hyperbranched poly(triphenylamine amide)s. The self-polycondensation of the AB 2 monomer ( 3 ) afforded hyperbranched poly(triphenylamine amide) with amino end groups. The molecular weight of the hyperbranched poly(triphenylamine amide) was 21,000 Da determined by light scattering. End-capped hyperbranched polyamides were isolated by the chemical modification of unreacted amino groups with various acid chlorides. All the hyperbranched poly(triphenylamine amide)s exhibit excellent solubility in organic solvents such as NMP, DMF, DMSO, and DMAc at room temperature. The viscosities of hyperbranched poly(triphenylamine amide)s are as low as about 0.15 dL/g due to their dendritic structures. Poly(triphenylamine amide)s end-capped with rigid benzene ring have higher thermal stability than those with amino or aliphatic end groups. The photoluminescence of the hyperbranched polyamides is blue-yellow emissions around 430–510 nm. The energy gaps of the hyperbranched poly(triphenylamine amide)s with different end groups are about 2.93 eV and are independent on the end groups, but the HOMO and LUMO energy levels are dependent on the end groups.

A new diamine monomer containing heterocyclic pyridine and triphenylamine groups, 4-(4,4′-diaminotriphenylamine)-2,6-bis(4-methylphenyl)pyridine (4), was synthesized by Chichibabin and nucleophilic fluoro-displacement reactions. The diamine was used to prepare a series of novel polyimides via polycondensation with various aromatic tetracarboxylic dianhydrides in N-methyl-2-pyrrolidinone. The polyimide 4a derived from the diamine 4 with 4,4′-hexafluoroisopropylidenediphthalic anhydride and having high Tg (313 °C), mechanical, and thermal properties was soluble in various organic solvents, such as N-methyl-2-pyrrolidinone, N,N-dimethylacetamide, N,N-dimethylformamide, pyridine, chloroform, tetrahydrofuran, at room temperature. The polyimide (4a) could be cast into a self-standing film from DMAc solution and was thermally converted into tough and flexible film. The film had high tensile modulus of 2.2 GPa and exhibited excellent thermal stability in both nitrogen and air (Td10 > 550 °C). The pristine polymer exhibited the UV–vis absorption bands in the region 240–400 nm and protonated polymer exhibited absorption in the region 390–500 nm. The protonated polymer possessed strong orange fluorescence (around 600 nm) in THF solution after protonation with acids as excited at 438 nm. The fluorescent intensity was influenced by the acid concentrations and the chemical structure of conjugated bases. The fluorescent intensity at 600 nm increased as acid concentration from a lower to a moderate concentration and decreased at higher concentrations.

Novel highly stable polynorbornenes with self-assembling amphiphilic architecture containing hydrophilic ammonium salt and hydrophobic alkyl ester group were obtained via ring-opening metathesis polymerization (ROMP) of 5-(octanoate methyl)bicyclo[2.2.1]hept-2-ene (NBMO) and 5-(phthalimide methyl)bicyclo[2.2.1]hept-2-ene (NBMPI), hydrogenation, hydrazinolysis, and subsequent quaternization. Polymeric micelles of such amphiphilic random and block polynorbornenes formed in solvents by varying the content of ammonium salts were investigated. Amphiphilic block copolymers exhibited perfect spherical morphology. Nanoscale polymeric micelles of random copolymers with 50–75 mol% of ammonium salts were roughly spherical in shape, while the morphologies of micelles transferred into network-like aggregates as hydrophilic contents of the random copolymers are higher than 80 mol%. The formation and fine structures of micelles were investigated by dynamic light scattering (DLS), TEM, and fluorescence technique using pyrene as fluorescence probe.

A new diamine containing a pyridine heterocyclic group and a pyrene substituent, 4-(1-pyrene)-2,6-bis(4-aminophenyl)pyridine (PBAPP), was synthesized and used in a preparation of poly(pyridine−imide) by direct polycondensation with 4,4‘-hexafluoroisopropylidenediphathalic anhydride (6FDA) in N-methyl-2-pyrrolidinone (NMP). The poly(pyridine−imide) derived from diamine (PBAPP) was highly soluble in several solvents such as THF, NMP, DMAc, DMF, pyridine, DMSO, and cyclohexanone at room temperature or upon heating at 70 °C and exhibited good thermal stability both in nitrogen and air (Td10>520 °C) and a high dielectric constant of 4.32 at 1 kHz. The poly(pyridine−imide) could be cast into a flexible and tough film from DMAc solution. The poly(pyridine−imide) film had a tensile strength of 118 MPa and a tensile modulus of 2.2 GPa. The optical properties exhibited the UV−vis absorption bands at the region of 200−400 nm and possessed strong orange fluorescent (560 nm) after protonated with protic acid.

A new diamine containing a pyridine heterocyclic group and a naphthalene substituent, 4-(2-naphthyl)-2,6-bis(4-aminophenyl) pyridine (NBAPP), was synthesized with the Chichibabin reaction and used in the preparation of poly(pyridine imide) by direct polycondensation with 4,4′-hexafluoroisopropylidenediphathalic anhydride in N-methyl-2-pyrrolidinone (NMP). The poly(pyridine imide) derived from diamine NBAPP with naphthalene substituents was highly organosoluble: it was soluble in tetrahydrofuran, NMP, N,N-dimethylacetamide (DMAc), N,N-dimethylformamide, and γ-butyrolactone at room temperature and in pyridine, dimethyl sulfoxide, and cyclohexanone upon heating at 70 °C. The poly(pyridine imide) was converted into lightly colored, optically transparent, flexible, and tough polyimide films via casting onto glass from a DMAc solution. This polymer exhibited good thermal stability (temperature of 10% weight loss = 527 °C) in air and high dielectric constants (as high as 4.20 at 1 kHz). The polyimide films had a tensile strength of 102 MPa and a tensile modulus of 1.8 GPa. As for the optical properties, the polymer exhibited UV–vis absorption bands in the region of 223–450 nm and possessed strong green-yellow fluorescence (500 nm) after being protonated with acid. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2367–2374, 2007

Pure exo-functional norbornene monomers containing various chromophores such as fluorene, pyrene, and carbazole were successfully prepared via the Diels–Alder reaction and condensation reaction. The living ring-opening metathesis polymerization (ROMP) of a fluorene-containing monomer, exo-2-(fluorene-9-ylcarboxymethyl)norborn-5-ene (exo-1), was observed and confirmed by the formation of a diblock copolymer and a linear relationship between the number-average molecular weight and [M]/[I] ratios ([M] = monomer concentration; [I] = initiator concentration). The synthesis and characteristics of novel fluorene-containing polymers based on pure exo-1 are reported with Grubbs catalyst I {RuCl2(CHPh)[P(C6H11)3]2} with a high molecular weight of 3.18 × 104 in 90 s ([M]/[I] = 100). However, the ROMP of pyrene- and carbazole-containing monomers [exo-5-(pyrene methoxy carbonyl)bicyclo[2.2.1]hept-2-ene and exo-5-(carbazole ethoxy carbonyl)bicyclo[2.2.1]hept-2-ene, respectively] were carried out in a nonliving fashion. All the chromophore-containing polymers showed excellent solubility in various organic solvents, particularly in chloroform, N-methyl-2-pyrrolidinone, and 1,2-dichlorobenzene. The glass transition temperatures of polynorbornenes containing various chromophores were determined to be 80–109 °C (by differential scanning calorimetry) higher than that of ring-opened polynorbornene (glass transition temperature = 35 °C), indicating that the incorporation of the pendant aromatic moieties (e.g., fluorene, pyrene, and carbazole) could enhance the transition temperature for segmental motions of polymer chains. The photoluminescence spectra of all polymer solutions showed a strong emission in the blue region of the visible spectra. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3022–3031, 2007

Ring opening metathesis is an important class of controlled polymerization techniques. Synthesis of novel polynorbornene derivatives with functional groups designed for application in crosslikable and self assembling materials, and the polymerizations via ROMP and/or free radical polymerization are introduced. Novel monomers and/or macroinitiators for combination of two polymerization techniques are useful for controlling molecular architecture. The sequence of using controlled polymerization techniques affects the molecular structure and the properties of resulting polymers.

Aromatic polyamides with multi amino end groups were prepared from a novel triamine (II) (BB’B’’) and dicarboxylic acids (A2) in the presence of (2,3-dihydro-2-thioxo-3-benzoxazolyl) phosphonic acid diphenyl ester (DBOP) as a condensing agent. The corresponding polyamides were obtained in quantitative yields with inherent viscosities of 0.40–0.42 dL g-1. The structure of the polyamides with low degree of branching was confirmed by nuclear magnetic resonance and by infrared spectroscopy. The amino terminal groups of the polymers were modified by reacting with acetyl chloride, benzoyl chloride and phthalic anhydride to give terminally modified polyamides. Although the degree of branching was as small as 0.05, their solubility in amide solvents was clearly improved. The end group modification of the polyamides greatly affected the thermal properties. Strong but brittle films were prepared by casting from N, N–dimethylformamide (DMF) solution. The mechanical properties were comparable with those of corresponding linear polymers.

Hyperbranched polyamides with different degree of branchings (DBs) were prepared by different polycondensation conditions from an ABB′ type monomer, 4-(2,4-diaminophenoxy)benzoic acid. Polyamide (PA1) with multi-amino groups prepared in the presence of (2,3-dihydro-2-thioxo-3-benzoxazolyl) phosphonic acid diphenyl ester (DBOP) and triethylamine as condensing agents at room temperature had lower DB of 0.1. Polyamide (PA2) with multi-amino groups prepared in the presence of triphenylphosphite and pyridine as condensing agent at 100 °C had higher DB of 0.2. The free amino groups of both polyamides were modified by acetyl chloride, benzoyl chloride and phthalic anhydride, respectively, to give corresponding modified polyamides. The solubility and thermal properties were not influenced by the different DBs but were influenced by the end groups. Strong films were prepared from polyamides with lower DBs and polyamides with amino groups.

A novel ABB′ monomer, an isomeric mixture of 4-[4-(2,4-diaminophenoxy)phenoxy]phthalic acid 2-methyl ester, was successfully prepared. The direct polycondensation of the ABB′ monomer was carried out to form polyamic acid monomethyl ester as a precursor with an inherent viscosity of 0.30 dL/g and a number-average molecular weight of 12,000. The degree of branching of the precursor, determined by 1H NMR, was 0.07. The low degree of branching was caused by the differences in the reactivities of the amino groups. The shape factor was calculated to be 0.72. End-modified reactions with acetyl chloride, benzoyl chloride, and phthalic anhydride were carried out. After the chemical imidization of the end-modified precursors, end-modified polyimides were successfully prepared. The end-modified polyimides were soluble in dimethyl sulfoxide, dimethylformamide (DMF), and N-methyl-2-pyrrolidinone. On the basis of thermogravimetry and differential scanning calorimetry measurements of the polyimides, the 5 wt % thermal loss temperatures were determined to be 400–520 °C, and the glass-transition temperatures were determined to be 200–258 °C. According to the X-ray diffraction measurements, the end-modified polyimides were amorphous. A strong but brittle film was prepared from an acetamide end-modified polyimide solution, via casting from a DMF solution, with a tensile strength of 46 MPa, an elongation at break of 4%, and a modulus of 1.3 GPa. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3200–3211, 2004

A fluorine-containing diamine, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane (BAPPH) (II), was synthesized in two steps on condensation of 2,2-bis(4-hydroxyphenyl)hexafluoropropane with p-chloronitrobenzene in the presence of potassium carbonate, giving 2,2-bis[4-(4-nitrophenoxy)phenyl]hexafluoropropane (I), followed by reduction with hydrazine monohydrate/Pd—C. Fluorine-containing polyamides and copolyamides having inherent viscosities 0.41–0.88 dL g−1 were prepared by direct polycondensation of BAPPH with various aromatic diacids or with mixed diacids, by triphenyl phosphite and pyridine in N-methyl-2-pyrrolidinone (NMP). The polyamides were examined by elemental analysis, IR spectra, inherent viscosity, x-ray diffraction, solubility, DSC, and TGA. The diffractogram showed that the polyamides were crystalline except IVb, IVc, IVf, and Vc. Almost all polyamides were soluble in polar aprotic solvents. The polymers obtained from BAPPH lost no mass below 350°C, with 10% loss of mass being recorded above 467°C in nitrogen. These aromatic polyamides had glass transition temperatures in the 221–253°C range. © 1996 John Wiley & Sons, Inc.

A solution-processable functional polyimide (PYTPA-PI), containing triphenylamine-substituted diphenylpyridine moieties (PYTPA, electron donors) and phthalimide moieties (PI, electron acceptors), was synthesized. The copolymer exhibits a high glass transition temperature of 342 °C. A switching device, based on a solution-cast thin film of PYTPA-PI sandwiched between an indium-tin oxide (ITO) bottom electrode and an Al top electrode, exhibits two accessible conductivity states and can be switched from the low-conductivity (OFF) state to the high-conductivity (ON) state, with an ON/OFF current ratio of more than 103, at the threshold voltage of about 2.7 V. The ON state is volatile and relaxes readily to the OFF state. However, it can be electrically sustained by a refreshing voltage pulse of 2 V. The ON state can also be reset to the initial OFF state by a reverse bias of −0.9 V. The ability to write, erase, read, and refresh the electrical states fulfills the functionality of a dynamic random access memor...