Multipurpose selenophene containing conjugated polymers for optoelectronic applications

In this study, two new conjugated polymers were synthesized including benzotriazole (BTz) as the acceptor unit and selenophene as the π bridge donor segment. These acceptors were coupled with fluorene and carbazole via Suzuki condensation reactions. Electrochemical band gaps were calculated as 2.45 eV for P1 and 2.40 eV for P2. Electrochemical and optical studies of polymers indicate that both polymers are promising candidates for organic solar cell (OSC) and polymer organic light emitting diode (PLED) applications since they have suitable HOMO-LUMO energy levels and appropriate absorption and emission band ranges. Light emitting properties of synthesized polymers were investigated and the highest luminance value was found as 6608cd/m² for P1 at 8 V. Photovoltaic properties of polymers were investigated and the optimized device based on P2 showed 1.75% power conversion efficiency for P2 under AM 1.5 G illumination at 100 mW/cm².     

Ab initio calculations on urea

Multiconfiguration wave functions constructed from contracted Gaussian-lobe functions have been found for the ground and valence-excited states of urea. ICSCF molecular orbitals of the excited states were used as the parent configurations for the CI calculations except for the ¹A₁(π → π*) state. The ¹A₁(π → π*) state used as its parent configuration an orthogonal linear combination of natural orbitals obtained from the second root of a three-configuration SCF calculation. The lowest excited states are predicted to be the n π → π* and π → π* triplet states. The lowest singlet state is predicted to be the n π → π* state with an energy in good agreement with the one known UV band at 7.2 eV. The π → π* singlet state is predicted to be about 1.9 eV higher, contrary to several previous assignments which assumed the lowest band was a π → π* amide resonance band. The predicted ionization energy of 9.0 eV makes this and higher states autoionizing.     

Preparation and characterization of PVC/PANI conductive composite with extremely low percolation threshold

Aniline was polymerized in the presence of poly(vinyl chloride) (PVC) powders in hydrochloric acid to in situ prepare poly(vinyl chloride)/polyaniline (PVC/PANI) composite particles. UV‐vis spectra and FT‐IR spectra indicate PANI in PVC/PANI composite particles possessed a higher oxidation state with decreased aniline content in reactants. Both conductivity and impact strength of the dodecylbenzenesulfonic acid (DBSA) doped PANI composites (PVC/PANI‐DBSA), which were compression molded from the in situ prepared PVC/PANI particles, increase with the pressing temperature and decrease with the increase of DBSA doped PANI (PANI‐DBSA) loading. An excellent electric conductivity of 5.06 × 10^?2 S/cm and impact strength of 0.518 KJ/m² could be achieved for the in situ synthesized and subsequently compression molded composite. Copyright © 2004 John Wiley & Sons, Ltd.     

Chemical and electrochemical grafting of polyaniline onto poly(vinyl chloride): synthesis,characterization, and materials properties

We have designed and developed a new strategy for the chemical and electrochemical graft copolymerization of aniline onto poly(vinyl chloride). For this purpose, first phenylamine groups were incorporated into poly(vinyl chloride) via a nucleophilic substitution reaction in the presence of a solvent composed of 4‐aminophenol, potassium carbonate, and dry N,N‐dimethylformamide at room temperature, in order to avoid cross‐linking. The macromonomer obtained was used in chemical and electrochemical oxidation copolymerization with aniline monomer to yield a poly(vinyl chloride)‐g‐polyaniline (PVC‐g‐PANI) graft copolymer. The chemical structures of samples as representatives were characterized by means of Fourier transform infrared and ¹H nuclear magnetic resonance spectroscopies. The electroactivity behaviors of the synthesized samples were verified under cyclic voltammetric conditions. The electrical conductivity and electroactivity measurements showed that the PVC‐g‐PANI graft copolymer has lower electrical conductivity as well as electroactivity than those of the pure PANI. However, the lower electrical conductivity and electroactivity levels in this material can be improved at the price of solubility and processability. Moreover, the thermal behavior and chemical composition of the synthesized graft copolymer were investigated. Copyright © 2016 John Wiley & Sons, Ltd.     

Kinetics of thermal degradation of poly(vinyl chloride)

Extensively studied thermal degradation of polyvinyl chloride (PVC) occurs with formation of free hydrogen chloride and conjugated double bonds absorbing light in visible region. Thermogravimetric monitoring of PVC blends degradation kinetics by the loss of HCl is often complicated by evaporation and degradation of plasticizers and additives. Spectroscopic PVC degradation kinetics monitoring by absorbance of forming conjugated polyenes is specific and should not be affected by plasticizers loss. The kinetics of isothermal degradation monitored by thermal gravimetric analysis in real time was compared with batch data obtained by UV/Visible absorption spectroscopy. Effects of plasticizer on kinetics of polyene formation were examined. Thermal degradation of PVC films plasticized with di-(2-ethylhexyl) phthalate (DEHP) and 1,2,4-benzenedicarboxylic acid, tri-(3-ethylhexyl) ester (TOTM) was monitored by conjugated double bonds light absorption at 350 nm at 160, 180, and 200 °C. Plasticizer-free PVC powder degradation kinetics and that of plasticized films were also obtained thermogravimetrically at temperatures ranging from 160 to 220 °C. Plasticizer-free PVC powder degradation and spectroscopically monitored degradation of plasticized PVC films occurred with the same apparent activation energy of ≈150 kJ mol⁻¹. No difference in degradation kinetics of films plasticized with DEHP and TOTM was detected.     

Polyethylenimine—Poly(vinyl Chloride) Crosslinked Polymers and Their Use in Adsorption of Mercuric and Cupric Salts

The alkylation reaction of polyethylenimine (PEI) by polyvinyl chloride) (PVC) was investigated. PEI-PVC cross-linked polymers with high PEI content were obtained in good yields. Study of the adsorption by complexation of mercuric chloride and cupric sulfate from aqueous solution by these polymers showed that they can be used effectively to remove mercuric and cupric salts from aqueous solutions.     

氯化聚氯乙烯热稳定性研究 Ⅰ.氯含量对热稳定性影响

本文用红外光谱分析了聚氯乙烯(PVC)和氯化聚氯乙烯(CPVC)的分子结构,用电导法评价了它们的热稳定性. 试料 PVC系天津化工厂生产,XS-7型;CPVC系前者的氯化产品,由安徽化工研究所提供,含氯量64％,日本产CPVC,牌号H827,含氯量68.5％.     

Synthesis of functionalized conducting polymer “polyanthranilic acid” using various oxidizing agents and formation of composites with PVC

Synthesis of carboxyl functionalized polyaniline (PANI) (polyanthranilic acid PANA) is reported based on our recent studies using various oxidizing agents. PANA was synthesized in acidic medium using ammonium peroxodisulfate, hydrogen peroxide, and potassium permanganate as oxidizing agents and their structural, electrochemical, and electrical properties are studied. A comparative study among the polymers formed by various oxidizing agents and also with PANI is made. Various possible oxidation states of PANA are discussed, with the help of electrochemical data. A composite of PANA and polyvinyl chloride (PVC) containing 20% PVC by weight is synthesized and used for the development of solid state pH electrode. The composite was synthesized to improve mechanical strength, stability, and restrict solubility. The pH sensor response is found to be reversible and linear in the pH range 1–7. PANA and PVC (20 wt%) based pH sensors show potential applications in development of pH transducers based sensors/biosensors. Copyright © 2010 John Wiley & Sons, Ltd.     

Spectroscopic and Morphological Study of Irradiated PVC Films Doped with Polyphosphates Containing 4,4'-Methylenedianiline

Russian Journal of Applied Chemistry - Polyphosphates containing 4,4'-methylenedianiline moiety were synthesized and their use as polyvinyl chloride (PVC) additives to enhance PVC...     

Designing anti-migration furan-based plasticizers and their plasticization properties in poly (vinyl chloride) blends

The use of bio-based plasticizers with low toxicity and good compatibility with polyvinyl chloride (PVC) has attracted more attention in the recent years. With bio-based 2, 5-furandicarboxylic acid (FDCA) and butyl oligo-glycol ethers as raw materials, three liquid furan-based plasticizers of di(butyl glycol) furan-2,5-dicarboxylate, di(butyldiglycol) furan-2,5-dicarboxylate and di(butyltriglycol) furan-2,5-dicarboxylate were synthesized by direct esterification. The chemical structure of three plasticizers was characterized with FTIR, ¹H NMR and ¹³C NMR. From DMA measurement, the glass transition temperature (T_g) of the plasticized PVC was decreased gradually when furan-based plasticizers were added to PVC formulation from 30 up to 50 phr. Due to lots of ether bonds in furan-based plasticizers, they expressed over two-fold lower migration in organic solvent compared with the traditional plasticizer diethylhexyl phthalate (DEHP). Through the characterization of elongation at break, hardness and thermal stability, furan-based plasticizers presented the same plasticization properties as DEHP, and had potential industrial application prospects.     

Preparation of conducting poly(vinyl chloride)/polyindole composites and freestanding films via chemical polymerization

This study covers the synthesis of conducting polyindole (PIN) homopolymer, poly(vinyl chloride)/polyindole (PVC/PIN) composites, and preparation of their freestanding films. PIN and composites were synthesized chemically by radicalic mechanism using FeCl₃ as an initiator. Films of PVC and PVC/PIN composites were prepared by casting on glass Petri dishes. Mechanical properties of films were examined by stress–strain experiments. From FTIR spectra of polymers, it was revealed that polymerization reaction occurred by 2–3 mechanism. The conductivities of polymers at different temperatures were also measured by four‐probe technique and found in the range 10^?4 to 10^?5 S cm^?1. Magnetic properties of the polymers were analyzed by Gouy scale measurements and were found that their conducting mechanisms are of polaron and bipolaron natures. Thermal properties of polymers were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) and found that they had shown adequate thermal stability. X‐ray diffraction (XRD) spectra showed the amorphous nature of the polymers. Scanning electron microscopy (SEM) was used for microstructural analysis. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1290–1298, 2010     

Synthesis and characterization of photosensitive liquid crystalline poly(benzylidene‐ether)s with alkanones and methylene spacers in the main chain

Photosensitive main chain liquid crystalline poly (benzylidene‐ether)s were synthesized by Claisen‐Schmidt polycondensation reaction of 4,4′‐Diformyl‐α,ω‐diphenoxyalkanes with acetone, cyclopentanone and cyclohexanone. The diformyl precursors were synthesized from 4‐hydroxybenzaldehyde and dibromoalkanes of varying spacer lengths. The structure of the monomers and polymers was confirmed by ELEM ANAL , Fourier transform infrared, ¹H NMR and ¹³C NMR spectral analyses. Molecular weight of the polymers was determined by gel permeation chromatography and was found to be moderate. The thermogravimetric analysis data revealed that the polymers were stable up to 280 °C and start degrading thereafter. Cyclopentanone containing polymers are more stable than acetone and cyclohexanone containing polymers. The self‐extinguishing properties of the synthesized polymers were studied by the determination of the limiting oxygen index values with Van Krevelen's equation. The influence of the length of methylene spacer on phase transition was investigated with differential scanning calorimetry and proved that the isotropic temperature decreases as the spacer length increases. Polarized optical microscopic study showed that cyclohexanone containing polymer IIIb exhibit nematic schlieren texture. Crystallinity of the polymers was studied with X‐ray diffractograms. The photolysis of liquid crystalline poly(benzylidene‐ether)s revealed that the entgegen, zusammen (EZ) photoisomerization proceeds in the system. Fluorescence spectra showed violet and green emission maxima. The band gap energy is calculated from absorption spectra are in the range of 3.17–3.40 eV. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Production of Polymers from the Seed Oil of Crambe Abyssinica. II. PVC Plasticizers Based on Tridecanedioic (Brassylic) Acid

Brassylic acid obtained from crambe oil has been used to make linear polyesters by condensation with 1, 3-butandiol; other polyesters were synthesized for comparison purposes. Number-average molecular weights were determined from the saponification equivalent and by vapor-phase osmometry; viscosity measurements are also reported. These polymers, together with comparison materials, have been evaluated as plasticizers for polyvinyl chloride). The poly(butan brassylates) give plasticized PVC having good mechanical properties at room temperature and, except for extraction with hydrocarbon, with low migration of plasticizer and which are particularly good in retaining flexibility at low temperatures.     

Synthesis and properties of polyamides of p-phenylenedioxydiacetic acid

Several polyamides of p-phenylenedioxydiacetic acid (PDDA) were synthesized by the low-temperature solution polycondensation techniques. Six different diamines were condensed independently with p-phenylenedioxydiacetyl chloride (PDC) in a mixture of N-methyl pyrolidone (NMP) and hexamethyl phosphoramide (HMPA). The polymers were obtained in 80–95% yield and possessed inherent viscosities in the range 0.32–0.81 dL/g. The polymers were characterized by infrared (IR) and H¹-NMR spectra. The solubility, density, crystallinity, and thermal stability of the polyamides were also determined. A model diamide (MDA-1) was also synthesized from aniline and PDC to confirm the formation of polyamides from diamines.     

Solid contact PVC membrane electrodes based on neutral or charged carriers for the selective reading of anionic sulfamethoxazole and their application to the analysis of aquaculture water

Sulfamethoxazole (SMX) is among the antibiotics employed in aquaculture for prophylactic and therapeutic reasons. Environmental and food spread may be prevented by controlling its levels in several stages of fish farming. The present work proposes for this purpose new SMX selective electrodes for the potentiometric determination of this sulphonamide in water. The selective membranes were made of polyvinyl chloride (PVC) with tetraphenylporphyrin manganese (III) chloride or cyclodextrin-based acting as ionophores. 2-nitrophenyl octyl ether was employed as plasticizer and tetraoctylammonium, dimethyldioctadecylammonium bromide or potassium tetrakis (4-chlorophenyl) borate was used as anionic or cationic additive. The best analytical performance was reported for ISEs of tetraphenylporphyrin manganese (III) chloride with 50% mol of potassium tetrakis (4-chlorophenyl) borate compared to ionophore. Nersntian behaviour was observed from 4.0?×?10^?5 to 1.0?×?10^?2?mol/L (10.0 to 2500?µg/mL), and the limit of detection was 1.2?×?10^?5?mol/L (3.0?µg/mL). In general, the electrodes displayed steady potentials in the pH range of 6 to 9. Emf equilibrium was reached before 15?s in all concentration levels. The electrodes revealed good discriminating ability in environmental samples. The analytical application to contaminated waters showed recoveries from 96 to 106%.     

Narrow band gap D–A copolymer of indacenodithiophene and diketopyrrolopyrrole with deep HOMO level: Synthesis and application in field‐effect transistors and polymer solar cells

A novel fused ladder alternating D–A copolymer, PIDT–DPP, with alkyl substituted indacenodithiophene (IDT) as donor unit and diketopyrrolopyrrole (DPP) as acceptor unit, was designed and synthesized by Pd‐catalyzed Stille‐coupling method. The copolymer showed good solubility and film‐forming ability combining with good thermal stability. PIDT–DPP exhibited a broad absorption band from 350 to 900 nm with an absorption peak centered at 735 nm. The optical band gap determined from the onset of absorption of the polymer film was 1.37 eV. The highest occupied molecular orbital level of the polymer is as deep as ?5.32 eV. The solution‐processed organic field‐effect transistor (OFETs) was fabricated with bottom gate/top contact geometry. The highest FET hole mobility of PIDT–DPP reached 0.065 cm² V^?1 s^?1 with an on/off ratio of 4.6 × 10⁵. This mobility is one of the highest values for narrow band gap conjugated polymers. The power conversion efficiency of the polymer solar cell based on the polymer as donor was 1.76% with a high open circuit voltage of 0.88 V. To the best of our knowledge, this is the first report on the photovoltaic properties of alkyl substituted IDT‐based polymers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Organometallic polymers. IV. Organometallic modifications of halogen-containing polymers

The synthesis of ferrocene-containing polymers by chemical modification of chlorinated polyethylenes, polyvinyl chloride (PVC), and other halogenated polymers, under Friedel-Crafts conditions, is described. The effect of reaction conditions on the structure and composition of the products obtained with various substrates was investigated. Soluble polymers of up to 62% ferrocene content were obtained. In most cases, substitution was accompanied by dehydrohalogenation. The ferrocene-to-vinylene ratio was higher in the reaction products of chlorinated polyethylenes than in those of PVC.     

Structures and properties of Sm(III) coordination polymers based on 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylate

Two novel 1D and 3D Sm(III) coordination polymers involving the 2-pyridin-4-yl-4,5-imidazoledicarboxylic acid (H₃PIDC) ligand have been characterized by infrared spectroscopy, elemental analysis and single-crystal X-ray diffraction. The coordination polymers were synthesized under hydrothermal conditions. Coordination polymer 1 gave a 1D zigzag chain, then forming 3D supramolecular structure through π?π stacking interactions and hydrogen bonds. Coordination polymer 2, in which oxalate was introduced as the second ligand gave a 3D framework with a 3,3-connected (4.8⁵)(4.8²) topology structure. But the luminescence of the coordination polymers has significant quenching.     

Ion-selective sensors for determining Au(CN)<Stack><Subscript>2</Subscript><Superscript>−</Superscript></Stack> with membranes based on the ionic liquid tetradecylphosphonium dicyanoaurate

A polymeric membrane for an ion-selective electrode is proposed on the basis of supramolecular systems including a polymeric compound (polyvinyl chloride, PVC) and an ionophore (ionic liquid tetradecylphosphonium dicyanoaurate) in which ionic liquid is simultaneously used as a PVC plasticizer. The selectivity, linear response range, and potential stability of ion-selective electrodes with the optimum membrane composition are measured. The detection limit for Au(I) with the developed electrode is 4.5 × 10^?7 M.     

Laccase‐Catalyzed Synthesis of Low‐Molecular‐Weight Lignin‐Like Oligomers and their Application as UV‐Blocking Materials

The laccase‐catalyzed oxidative polymerization of monomeric and dimeric lignin model compounds was carried out with oxygen as the oxidant in aqueous medium. The oligomers were characterized by using gel permeation chromatography (GPC) and matrix‐assisted laser desorption ionization time‐of‐flight mass spectroscopy (MALDI‐TOF MS) analysis. Oxidative polymerization led to the formation of oligomeric species with a number‐average molecular weight (M_n) that ranged from 700 to 2300 Da with a low polydispersity index. Spectroscopic analysis provided insight into the possible modes of linkages present in the oligomers, and the oligomerization is likely to proceed through the formation of C?C linkages between phenolic aromatic rings. The oligomers were found to show good UV light absorption characteristics with high molar extinction coefficient (5000–38 000 m ^?1 cm^?1) in the UV spectral region. The oligomers were blended independently with polyvinyl chloride (PVC) by using solution blending to evaluate the compatibility and UV protection ability of the oligomers. The UV/Vis transmittance spectra of the oligomer‐embedded PVC films indicated that these lignin‐like oligomers possessed a notable ability to block UV light. In particular, oligomers obtained from vanillyl alcohol and the dimeric lignin model were found to show good photostability in accelerated UV weathering experiments. The UV‐blocking characteristics and photostability were finally compared with the commercial low‐molecular‐weight UV stabilizer 2,4‐dihydroxybenzophenone.