Synthesis and light‐emitting properties of a novel π‐conjugated poly[di(p‐phenyleneethynylene)‐alt‐ (p‐phenylenecyanovinylene)] containing n‐octyloxy side branches

A novel π‐conjugated poly[di(p‐phenyleneethynylene)‐alt‐(p‐phenylenecyanovinylene)] having n‐octyloxy side chains (PPE‐C₈PPE‐PPV) was prepared by polymerization of the monomer DEDB with BCN. Chemical structure of the polymer obtained was confirmed by ¹H NMR, FTIR, and EA. PPE‐C₈PPE‐PPV had a molecular weight enough to fabricate the electroluminescent (EL) device, and showed a good organosolubility, excellent thermal stability, and film‐forming property. In UV absorption and PL spectra in film it showed a maximum at 430 and 543 nm, respectively, which appeared 5 and 41 nm longer wavelengths than that of the solution, respectively. HOMO, LUMO energy levels and band gap were determined to be ?5.70, ?3.29, and 2.41 eV, respectively. Two EL devices with low‐work function cathodes were fabricated with the structures of ITO/PEDOT/PPE‐C₈PPE‐PPV/cathodes (LiF/Al and Mg:Ag/Ag). The both devices exhibited a bright green light emission at 545 nm and the maximum luminescence of 197 cd/cm² (LiF/Al) and 158 cd/cm² (Mg:Ag/Ag). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis and characterizations of poly(4‐alkylthiazole vinylene)

Two poly(thiazole vinylene) derivatives, poly(4‐hexylthiazole vinylene) (P4HTzV) and poly(4‐nonylthiazole vinylene) (P4NTzV), were synthesized by Pd‐catalyzed Stille coupling method. The polymers are soluble in common organic solvents such as o‐dichlorobenzene and chloroform, and possess good thermal stability. P4HTzV and P4NTzV films exhibit broad absorption bands at 400–720 nm with an optical bandgap of 1.77 eV and 1.74 eV, respectively. The HOMO (the highest occupied molecular orbital) energy levels of P4HTzV and P4NTzV are ?5.11 and ?5.12 eV, respectively, measured by cyclic voltammetry. Preliminary results of the polymer solar cells based on P4HTzV : PC₆₁BM ([6,6]‐phenyl‐C‐61‐butyric acid methyl ester) (1 : 1, w/w) show a power conversion efficiency of 0.21% with an open‐circuit voltage of 0.55 V and a short circuit current density of 1.11 mA cm^?2, under the illumination of AM1.5G, 100 mW cm^?2. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Part 7. Effects of poly(L‐lactide‐co‐ϵ‐caprolactone) on morphology,structure, crystallization,and physical properties of blends of poly(L‐lactide) and poly(ϵ‐caprolactone)

Blended films of poly(L ‐lactide) [ie poly(L ‐lactic acid)] (PLLA) and poly(?‐caprolactone) (PCL) without or mixed with 10 wt% poly(L ‐lactide‐co‐?‐caprolactone) (PLLA‐CL) were prepared by solution‐casting. The effects of PLLA‐CL on the morphology, phase structure, crystallization, and mechanical properties of films have been investigated using polarization optical microscopy, scanning electron microscopy, differential scanning calorimetry and tensile testing. Addition of PLLA‐CL decreased number densities of spherulites in PLLA and PCL films, and improved the observability of spherulites and the smoothness of cross‐section of the PLLA/PCL blend film. The melting temperatures (T_m) of PLLA and PCL in the films remained unchanged upon addition of PLLA‐CL, while the crystallinities of PLLA and PCL increased at PLLA contents [X_PLLA = weight of PLLA/(weight of PLLA and PCL)] of 0.4–0.7 and at most of the X_PLLA values, respectively. The addition of PLLA‐CL improved the tensile strength and the Young modulus of the films at X_PLLA of 0.5–0.8 and of 0–0.1 and 0.5–0.8, respectively, and the elongation at break of the films at all the X_PLLA values. These findings strongly suggest that PLLA‐CL was miscible with PLLA and PCL, and that the dissolved PLLA‐CL in PLLA‐rich and PCL‐rich phases increased the compatibility between these two phases. © 2003 Society of Chemical Industry     

Synthesis and characterization of photoluminescent conjugated polymer containing N‐(α‐naphthyl)‐carbazole unit

A novel luminescent conjugated polymer, poly[{9‐(α‐naphthyl)‐3,6‐divinylenecarbazolylene}‐alt‐co‐(1,4‐phenylene)] (PNVCP), bearing alternated 9‐(α‐naphthyl)‐carbazole and benzene units, was synthesized via a Wittig–Horner reaction. The solubility, thermal, and optical properties were investigated. It was soluble in common organic solvents, such as tetrahydrofuran and 1,2‐dichlororoethane. Thermogravimetric analysis and differential scanning calorimetry showed that the conjugated polymer exhibited good thermal stability up to 496°C with a glass‐transition temperature higher than 110°C. The photoluminescence properties were studied. The polymer emits blue light and the quantum yield is 93% in solution. The emission spectra exhibited an obvious solvent effect. With the increase of the polarity of the solvents, the fluorescence spectra changed obviously and appeared to be redshifted at room temperature. The redshift was more obvious in aromatic solvents than in aliphatic solvents. When N,N‐dimethylaniline was gradually added into the solution of the conjugated polymer, the emission intensity of the fluorescence decreased. In comparison, the emission intensity of the polymer showed invariability when 1,4‐dicyanobenzene was added into the polymer solution. Moreover, the fluorescence of the polymer could be effectively quenched by fullerene. Overall, the synthesized polymer is a potential candidate material for fabrication of polymeric light‐emitting devices. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 923–927, 2006     

New,organo‐soluble,thermally stable aromatic polyimides and poly(amide‐imide) based on 2‐[5‐(3,5‐dinitrophenyl)‐1,3, 4‐oxadiazole‐2‐yl]pyridine

New, thermally stable polyimides and a poly(amide‐imide) containing a 1,3,4‐oxadiazole‐2‐pyridyl pendant group based on 2‐[5‐(3,5‐diaminophenyl)‐1,3,4‐oxadiazole‐2‐yl]pyridine were synthesized. The synthesis and characterization of the model compound 2‐{5‐[(3,5‐bistrimellitimido)phenyl]‐1,3,4‐oxadiazole‐2‐yl}pyridine (DIDA) were also investigated, and DIDA was used in the preparation of the poly(amide‐imide) in an ionic liquid, 1‐butyl‐3‐methylimidazolium bromide, as a polymerization solvent. The polymers were characterized by separating and characterizing the poly(amic acid) intermediates using infrared and elemental analyses. The prepared polymers were soluble in polar and aprotic solvents, such as dimethylformamide, dimethylsulfoxide, N‐methyl‐2‐pyrrolidone and dimethylacetamide. Thermal behaviour of the polymers was studied using thermogravimetric analysis and differential scanning calorimetry. The inherent viscosities of the polyimide and poly(amide‐imide) solutions were in the range 0.34–0.85 dL g^?1 (in concentrated sulfuric acid with a concentration of 0.125 g dL^?1 at 25 ± 0.5 °C). The removal of Co(II) from aqueous solutions was performed using one of the polyimides. It was found that this polymer had a maximum adsorption capacity and efficiency at pH = 10.0. Copyright © 2012 Society of Chemical Industry     

Blue fluorescent conductive poly(9,10‐di(1‐naphthalenyl)‐2‐vinylanthracene) homopolymer and its highly soluble copolymers with styrene or 9‐vinylcarbazole

A new blue fluorescent monomer, 9,10‐di(1‐naphthalenyl)‐2‐vinylanthracene, was designed and synthesized in good yield. Its homopolymer poly(9,10‐di(1‐naphthalenyl)‐2‐vinylanthracene) (P(ADN)) and soluble conductive vinyl copolymers poly[(9,10‐di(1‐naphthalenyl)‐2‐vinylanthracene)‐co‐styrene] (P(ADN‐co‐S)) and poly[(9,10‐di(1‐naphthalenyl)‐2‐vinylanthracene)‐co‐(9‐vinylcarbazole)] (P(ADN‐co‐VK)) were synthesized using free radical solution polymerization. All the polymers showed high glass transition mid‐point temperatures (203 to 237 °C) and good thermal stabilities. The photoluminescence emission of the copolymers was similar to that of P(ADN) (with two maxima at 423 and 442 nm). The lifetimes of P(ADN‐co‐S) (6.82 to 7.91 ns) were all slightly less than that of P(ADN) (8.40 ns). The lifetime of P(ADN‐co‐VK) increased from 7.8 to 8.8 ns with an increase in VK content. The fluorescence quantum yields of P(ADN‐co‐S) showed an overall increasing tendency from 0.42 to 0.58. The quantum efficiencies of P(ADN‐co‐VK) decreased from 0.36 to 0.19 with an increase of VK fraction. With increasing S/VK content, the highest occupied molecular orbital of P(ADN‐co‐S)/P(ADN‐co‐VK) ranged from ?5.58 to ?5.73 eV, which was similar to that of P(ADN) (?5.71 eV). The band gaps of P(ADN‐co‐S) and P(ADN‐co‐VK) were about 2.97 eV, which were equal to that of P(ADN), and smaller than that of 2‐methyl‐9,10‐di(1‐naphthalenyl)anthracene (MADN) (3.04 eV) and poly(9‐vinylcarbazole) (3.54 eV). Preliminary electroluminescence results were obtained for a homojunction device with the configuration ITO/MoO₃ (20 nm)/P(ADN)/LiF (1 nm)/Al (100 nm), which achieved only 30–50 cd m^?2, due to P(ADN) having a low mobility of 4.7 × 10^?8 cm² V^?1 s^?1 compared to that of its model compound MADN of 6.5 × 10^?4 cm² V^?1 s^?1. © 2013 Society of Chemical Industry     

Synthesis, characterization and photovoltaic properties of random poly(arylene-vinylene)s containing benzothiadiazole

New random poly(arylene-vinylene)s obtained by combining different amounts of benzo[2,1,3]thiadiazole units with 9,9-dialkylfluorene and/or 1,4-dialkoxybenzene building blocks were synthesized by the Suzuki-Heck polymerization and characterized for use in bulk hetero-junction solar cells. Their optical, electrochemical, morphological and photovoltaic features were investigated. Notwithstanding the relatively low weight-average molecular weights of the obtained polymers (7000-13000 Da), they formed good quality films by spin-coating. UV-Vis measurements permitted the evaluation of their band gap (1.77-2.12 eV), enabling them to harvest a broad portion of the solar spectrum from 350 nm to 650-700 nm. An electrochemical study revealed that the copolymers are endowed with HOMO/LUMO energy levels suitable for both an efficient electron transfer and a high open circuit voltage (V_oc) for devices embodying the polymer/PCBM blends. This investigation pinpoints the important role of the copolymer composition (in terms of molar ratio of the monomeric units) on the performance of the donors in BHJs. In fact, in disagreement with the presumed V_oc and current densities, the terpolymer poly[1,4-bis(2-ethylhexyloxy)-2,5-phenylene-vinylene-co-9,9-bis(2-ethylhexyl)-2,7-fluorenylene-vinylene-co-4,7-benzo[2,1,3]thiadiazolylene-vinylene] showed the best performance of the copolymer series, with a PCE of 0.4% and a V_oc of 0.76 V, probably due to the favorable phase separation in the blend and consequently a better exciton dissociation.     

Electrochemical synthesis of poly(N‐vinyl carbazole) doped with HSO4− and NO3− anions

In this study, the conducting forms of poly(N‐vinyl carbazole) (PNVC) doped with HSO₄⁻ and NO₃⁻ anions were synthesized electrochemically in dioxane and ethanol. It was observed that the acid concentration was an important factor in the synthesis of the conducting PNVC in dioxane–H₂SO₄ media. No conducting PNVC film was formed on the electrode surface in the electrolyses carried out with acid concentrations below 2.0 M H₂SO₄ in dioxane. However, a conducting PNVC film was obtained at lower acid concentrations (i.e., 0.5 M H₂SO₄) when the solvent was switched from dioxane to ethanol. The use of HCl and acetic acid at different concentrations in ethanol or dioxane media failed to yield conducting PNVC. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1792–1796, 1999     

Synthesis and properties of a soluble conjugated polymer,poly(2‐methoxy‐5‐N‐butoxy‐p‐phenylene vinylene)

The synthesis of poly(2‐methoxy‐5‐n‐butoxy‐p‐phenylene vinylene) (MBPPV) via a dehydrochlorination of 2‐methoxy‐5‐n‐butoxy‐α,α′‐dichloro‐p‐xylene is described. The soluble polymer was characterized by elemental analysis, Fourier transform infrared (FTIR), ¹H nuclear magnetic resonance (NMR), and UV‐visible spectroscopy. The energy gap (Eg) of the polymer was 2.53 eV determined by cyclic voltammogram. Light‐emitting diode (LED) and light‐emitting electrochemical cell (LEC) with the polymer were fabricated. The LED displayed unipolar I‐V dependence with the turn‐on voltage at 4.2 V. I‐V curve of the LEC with poly(ethylene oxide) (PEO, Mw 2 × 10⁴) displayed mirror symmetry with the turn‐on voltage at 2.7 V, but to the device with PEO (Mw 5 × 10⁶) no mirror symmetry was observed, the turn‐on voltages at +2.7 V, −11.5 V. The emission maximum of the polymer in chloroform was at λ = 550 nm, whereas the emission maxima of the LED at 5.2 V and the LEC at 4.8 V were at λ = 566, 569 nm, respectively. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 2180–2185, 2000     

Synthesis and characterization of novel aromatic poly(amide‐imide)s derived from 2,2′‐bis(4‐trimellitimidophenoxy)biphenyl or 2,2′‐bis(4‐trimellitimidophenoxy)‐1,1′‐binaphthyl and various aromatic diamines

New aromatic diimide‐dicarboxylic acids having kinked and cranked structures, 2,2′‐bis(4‐trimellitimidophenoxy)biphenyl (2a) and 2,2′‐bis(4‐trimellitimidophenoxy)‐1,1′‐binaphthyl (2b), were synthesized by the reaction of trimellitic anhydride with 2,2′‐bis(4‐aminophenoxy)biphenyl (1a) and 2,2′‐bis(4‐aminophenoxy)‐1,1′‐binaphthyl (1b), respectively. Compounds 2a and 2b were characterized by FT‐IR and NMR spectroscopy and elemental analyses. Then, a series of novel aromatic poly(amide‐imide)s were prepared by the phosphorylation polycondensation of the synthesized monomers with various aromatic diamines. Owing to structural similarity, and a comparison of the characterization data, a model compound was synthesized by the reaction of 2b with aniline. The resulting polymers with inherent viscosities of 0.58–0.97 dl g^?1 were obtained in high yield. The polymers were fully characterized by FT‐IR and NMR spectroscopy. The ultraviolet λ_max values of the poly(amide‐imide)s were also determined. The polymers were readily soluble in polar aprotic solvents. They exhibited excellent thermal stabilities and had 10% weight loss at temperatures above 500 °C under a nitrogen atmosphere. Copyright © 2003 Society of Chemical Industry     

Proton conducting polymer blends from poly(2,5‐benzimidazole) and poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid)

Proton conducting polymer electrolyte membranes were produced by blending of poly(2,5‐benzimidazole) (ABPBI) and poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) (PAMPS) at several stoichiometric ratios with respect to polymer repeating units. The membranes were characterized by using Fourier transform infrared spectroscopy for interpolymer interactions and scanning electron microscope for surface morphology. Thermal stability of the materials was investigated by thermogravimetric analysis. Glass transition temperatures of the samples were measured via differential scanning calorimetry. The spectroscopic measurements and water uptake studies indicate a complexation between ABPBI and PAMPS that inhibited polymer exclusion up on swelling in excess water. Proton conductivities of the anhydrous and humidified samples were measured using impedance spectroscopy. The proton conductivity of the humidified ABPBI:PAMPS (1 : 2) blend showed a proton conductivity of 0.1 S/cm, which is very close to Nafion 117, at 20°C at 50% relative humidity. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis of poly(ester‐anhydride)s based on poly(ϵ‐caprolactone) prepolymer

The objective of this study was to prepare high molecular weight poly(ester‐anhydride)s by melt polycondensation. The polymerization procedure consisted of the preparation of carboxylic acid terminated poly(?‐caprolactone) prepolymers that were melt polymerized to poly(?‐caprolactone)s containing anhydride functions along the polymer backbone. Poly(?‐caprolactone) prepolymers were prepared using either 1,4‐butanediol or 4‐(hydroxymethyl)benzoic acid as initiators, yielding hydroxyl‐terminated intermediates that were then converted to carboxylic acid‐terminated prepolymers by reaction with succinic anhydride. Prepolymers were then allowed to react with an excess of acetic anhydride, followed by subsequent polycondensation to resulting high molecular weight poly(ester‐anhydride)s. Upon coupling of prepolymers, size exclusion chromatography analyses showed an increase from 3600 to 70,000 g/mol in number‐average molecular weight (M_n) for the 1,4‐butanediol initiated polymer, and an increase from 7200 to 68,000 g/mol for the 4‐(hydroxymethyl)benzoic acid‐initiated polymer. 4‐Hydroxybenzoic acid and adipic acid were also used as initiators in the preparation of poly(?‐caprolactone) prepolymers. However, with these initiators, the results were not satisfactory. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 176–185, 2001     

Porous biodegradable polyester blends of poly(L‐lactic acid) and poly(ε‐caprolactone): physical properties,morphology, and biodegradation

Poly(L ‐lactic acid) (PLLA), poly(ε‐caprolactone) (PCL), and their films without or blended with 50 wt% poly(ethylene glycol) (PEG) were prepared by solution casting. Porous films were obtained by water‐extraction of PEG from solution‐cast phase‐separated PLLA‐blend‐PCL‐blend‐PEG films. The effects of PLLA/PCL ratio on the morphology of the porous films and the effects of PLLA/PCL ratio and pores on the physical properties and biodegradability of the films were investigated. The pore size of the blend films decreased with increasing PLLA/PCL ratio. Polymer blending and pore formation gave biodegradable PLLA‐blend‐PCL materials with a wide variety of tensile properties with Young's modulus in the range of 0.07–1.4 GPa and elongation at break in the range 3–380%. Pore formation markedly increased the PLLA crystallinity of porous films, except for low PLLA/PCL ratio. Polymer blending as well as pore formation enhanced the enzymatic degradation of biodegradable polyester blends. Copyright © 2006 Society of Chemical Industry     

Alternating phenylenevinylene copolymers with dithienbenzothiadiazole moieties: Synthesis,photophysical, and photovoltaic properties

Two new soluble alternating phenylenevinylene copolymers S and L which contained dithienbenzothiadiazole moieties were synthesized by Heck coupling. The repeating unit of L was longer than that of S and contained two additional phenylene rings and two cyano‐vinylene bonds. Both copolymers were stable up to about 350°C and afforded char yield of 52–66% at 800°C in N₂. Their absorption spectra were broad and extended up to about 600 nm with a longer wavelength maximum at 447–502 nm and optical band gap of ～ 2.0 eV. These copolymers emitted yellow light in solution with PL maximum at 551–580 nm and orange‐red light in thin film with PL maximum at 588–661 nm. The emission maximum of L was considerably red‐shifted relative to S . Photovoltaic cells based on S (or L ) as donor and [6,6]‐phenyl C61‐butyric acid methyl ester as acceptor were investigated. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Miscibility,morphology and tensile properties of vinyl chloride polymer and poly(ε‐caprolactone) blends

The miscibility, morphology and tensile properties of three blend systems of poly(ε‐caprolactone) (PCL) with poly(vinyl chloride) (PVC) and with two chlorinated PVCs (CPVCs) with different chlorine contents (63 wt% and 67 wt% of Cl) have been studied. Based on the shifts of single glass transition temperature, the Gordon–Taylor K parameter is calculated as a measurement of interaction strength between PCL and (C)PVCs. Higher K values are found for blends of (C)PVCs with higher chlorine content, together with the interaction χ parameters estimated from the melting point depression results. The morphology observed with polarized light microscopy shows that spherulites exist in blends rich in PCL (≥50 wt%) only. Wide angle X‐ray diffraction studies indicate that the crystal structure of PCL is independent of the Cl content of (C)PVCs. The tensile properties of various blends exhibit a minimum as the PCL content increases. The elongation at break increases with increasing PCL content. © 2000 Society of Chemical Industry     

Synthesis and properties of new poly(amide‐imide)s based on 2,5‐bis(trimellitimido)chlorobenzene

A series of new aromatic poly(amide‐imide)s were synthesized by the triphenyl phosphite‐activated polycondensation of the diimide‐diacid, 2,5‐bis(trimellitimido)chlorobenzene (I) with various aromatic diamines in a medium consisting of N‐methyl‐2‐pyrrolidone (NMP), pyridine, and calcium chloride. The poly(amide‐imide)s had inherent viscosities of 0.76–1.42 dL g⁻¹. The diimide‐diacid monomer (I) was prepared from 2‐chloro‐p‐phenylenediamine with trimellitic anhydride. Most of the resulting polymers showed an amorphous nature and were readily soluble in a variety of organic solvents, including NMP and N,N‐dimethylacetamide. Transparent, flexible, and tough films of these polymers could be cast from N,N‐dimethylacetamide or NMP solutions. Their cast films had tensile strengths ranging from 74 to 95 MPa, elongations at break from 7 to 11%, and initial moduli from 1.38 to 3.25 GPa. The glass transition temperatures of these polymers were in the range of 233°–260°C, and the 10% weight loss temperatures were above 450°C in nitrogen. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1691–1701, 1999     

Synthesis,characterization, and thermal behavior study of methyl methacrylate polymers containing 4‐carbazole substitutes

A new polymerizable monomer, [4‐(9‐ethyl)carbazolyl]methyl methacrylate ( 2 ), was synthesized by reacting of methacrylic acid and 4‐hydroxymethyl‐9‐ethyl carbazole ( 1 ) by esterification procedure in the presence of N,N′‐dicyclohexylcarbodiimide. The resulting monomer was then polymerized free‐radically to form the poly(methyl methacrylate) containing 4‐(9‐ethyl)carbazolyl pend ent groups. Also, copolymerization of monomer 2 with various acrylic monomers such as methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, and n‐butyl acrylate by azobisisobutyronitrile as a free radical polymerization initiator gave the related copolymers in high yields. The structure of all the resulted compounds was characterized and confirmed by FTIR and ¹H NMR spectroscopic techniques. The average molecular weight of the obtained polymers was determined by gel permeation chromatography using tetrahydrofurane as the solvent. The thermal gravimetric analysis and differential scanning calorimeter instruments were used for studying of thermal properties of polymers. It was found that, with the incorporation of bulky 4‐(9‐ethyl)carbazolyl substitutes in side chains of methyl methacrylate polymers, thermal stability and glass transition temperature of polymers are increased. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4989–4995, 2006     

Synthesis and properties of new aromatic poly(ester‐imide)s derived from 4‐p‐biphenyl‐2,6‐bis(4‐trimellitimidophenyl) pyridine and various dihydroxy compounds

A novel class of wholly aromatic poly(ester‐imide)s, having a biphenylene pendant group, with inherent viscosities of 0.32–0.49 dL g^?1 was prepared by the diphenylchlorophosphate‐activated direct polyesterification of the preformed imide‐ring‐containing diacid, 4‐p‐biphenyl‐2,6‐bis(4‐trimellitimidophenyl)pyridine (1) with various aromatic dihydroxy compounds in the presence of pyridine and lithium chloride. A reference diacid, 2,6‐bis(trimellitimido)pyridine (2) without a biphenylene pendant group and two phenylene rings in the backbone, was also synthesized for comparison purposes. At first, with due attention to structural similarity and to compare the characterization data, a model compound (3) was synthesized by the reaction of compound 1 with two mole equivalents of phenol. Moreover, the optimum condition of polymerization reactions was obtained via a study of the model compound synthesis. All of the resulting polymers were characterized by Fourier transform infrared and ¹H NMR spectroscopy and elemental analysis. The ultraviolet λ_max values of the poly(ester‐imide)s were also determined. All of the resulting polymers exhibited excellent solubility in common organic solvents, such as pyridine, chloroform, tetrahydrofuran, and m‐cresol, as well as in polar organic solvents, such as N‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, N,N‐dimethylformamide, and dimethyl sulfoxide. The crystalline nature of the polymers obtained was evaluated by means of wide‐angle X‐ray diffraction. The resulting poly(ester‐imide)s showed nearly an amorphous nature, except poly(ester‐imide) derived from 4,4′‐dihydroxy biphenyl. The glass transition temperatures (T_g) of the polymers determined by differential scanning calorimetry thermograms were in the range 298–342 °C. The 10% weight loss temperatures (T_10%) from thermogravimetric analysis curves were found to be in the range 433–471 °C in nitrogen. Films of the polymers were also prepared by casting the solutions. Copyright © 2006 Society of Chemical Industry     

Synthesis and characterization of poly(ester‐ether‐imide)s derived from 5‐(4‐trimellitimidophenoxy)‐1‐trimellitimido naphthalene

A series of novel aromatic poly(ester‐ether‐imide)s with inherent viscosity values of 0.44–0.74 dL g^?1 were prepared by the diphenylchlorophosphate‐activated direct polycondensation of an imide ring‐containing diacid namely 5‐(4‐trimellitimidophenoxy)‐1‐trimellitimido naphthalene ( 1 ) with various aromatic dihydroxy compounds in the presence of pyridine and lithium chloride. Owing to comparison of the characterization data, an ester‐containing model compound ( 2 ) was also synthesized by the reaction of 1 with phenol. The model compound 2 and the resulted polymers were fully characterized by FT‐IR and NMR spectroscopy. The ultraviolet λ_max values of the poly(ester‐ether‐imide)s were also determined. The resulting polymers exhibited an excellent organosolubility in a variety of high polar solvents such as N,N‐dimethylacetamide, N,N‐dimethylformamide, dimethyl sulfoxide, and N‐methyl‐2‐pyrrolidone. They were soluble even in common less polar organic solvents such as pyridine, m‐cresol, and tetrahydrofuran on heating. Crystallinity of the polymers was estimated by means of wide‐angle X‐ray diffraction. The resulted polymers exhibited nearly an amorphous nature. From differential scanning calorimetry thermograms, the polymers showed glass‐transition temperatures between 221 and 245°C. Thermal behaviors of the obtained polymers were characterized by thermogravimetric analysis, and the 10% weight loss temperatures of the poly(ester‐ether‐imide)s were found to be over 410°C in nitrogen. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Conducting properties of iodine‐doped low‐density polyethylene–poly(4‐vinylpyridine) blends

The conductivities of blends of low‐density polyethylene and poly(4‐vinyl pyridine) (P4VP) were studied. The blends were synthesized by in situ sorption and thermal polymerization of 4‐vinylpyridine in low‐density polyethylene. They showed, after iodine doping, conductivities of 1.7 to 5.0 × 10^?7 S cm^?1 at 298 K, depending on the P4VP mass increment into the matrix. Their conductivities were one order of magnitude higher for measurements at 338 K. The optimum ratio of iodine to pyridine (n) which gave the highest conductivity was 0.21. The thermal stability of doped blends was acceptable for their uses as electrochemical devices. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 939–944, 2003