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Sample records for styrene-maleic anhydride copolymer

  1. Feasibility of Using Foamed Styrene Maleic Anhydride (SMA) Co-polymer in Wood Based Composites

    OpenAIRE

    Mustafa Zor; Nurgul Tankut; Alper Kiziltas; Douglas Gardner; Hikmet Yazici

    2017-01-01

    Wood plastic composites (WPCs) have often been used in consumer applications, automotive industry and exterior construction. WPCs consist mostly of wood and thermoplastic polymer. WPCs can have superior outdoor durability and much lower maintenance costs than regular wood. WPCs can be used instead of wood. Styrene maleic anhydride (SMA) is used in plastic composites for the automotive industry and also in engineering applications. SMA wood composites, as one of the WPCs using wood fibers as r...

  2. Grafting of copolymer styrene maleic anhydride on poly(ethylene terephthalate) film by chemical reaction and by plasma method

    Energy Technology Data Exchange (ETDEWEB)

    Bigan, Muriel; Bigot, Julien [Laboratoire de Chimie Organique et Macromoleculaire (UMR 8009), Universite des Sciences et Technologies de Lille, 59655 Villeneuve d' Ascq Cedex (France); Mutel, Brigitte [Laboratoire de Genie des Procedes d' Interactions Fluides reactifs-Materiaux (UPRES-EA 3751), Batiment C5, Universite des Sciences et Technologies de Lille, 59655 Villeneuve d' Ascq Cedex (France)], E-mail: Brigitte.mutel@univ-lille1.fr; Coqueret, Xavier [Laboratoire Reactions Selectives et Applications (UMR-CNRS 6519) Universite de Reims Champagne-Ardennes, B.P. 1039, 51687 Reims Cedex 2 (France)

    2008-02-15

    This work deals with the chemical grafting of a styrene maleic anhydride copolymer on the surface of a previously hydrolyzed polyethylene terephthalate (PET) film 12 {mu}m thick via covalent bond. Two different ways are studied. The first one involves an activation of the hydrolyzed PET by the triethylamine before the grafting step. In the second one, the copolymer reacts with the 4-dimethylaminopyridine in order to form maleinyl pyridinium salt which reacts with alcohol function of the hydrolyzed PET. Characterization and quantification of the grafting are performed by Fourier transform infrared spectroscopy. Factorial experiment designs are used to optimize the process and to estimate experimental parameters effects. The opportunity to associate the chemical process to a cold remote nitrogen plasma one is also examined.

  3. Reactive blending of poly(styrene-maleic) anhydride with poly(phenylene oxide) by addition of `-amino-polystyrene

    NARCIS (Netherlands)

    Koning, Cor; Ikker, Andreas; Ikker, A.; Borggreve, Rein; Leemans, Luc; Möller, Martin; Moller, M.

    1993-01-01

    -(3-Aminopropyl-l-amino)polystyrene (-amino-PS) was melt-blended with styrene/maleic anhydride copolymers (SMA) containing 28 wt% maleic anhydride groups. The terminal primary amino group can react with the maleic anhydride monomer units in SMA, forming imides. The resulting product turned out to be

  4. Nanocomposites of PA6/ABS blends compatibilized with styrene-maleic anhydride copolymer;Nanocompositos de blendas de PA6/ABS compatibilizadas com copolimero estireno-anidrido maleico

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Amanda D. de, E-mail: amandaengmat@yahoo.com.b [Universidade Federal de Sao Carlos (PPG-CEM/UFSCar), SP (Brazil). Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais; Araujo, Edcleide M. [Universidade Federal de Campina Grande (UFCG), PB (Brazil); Pessan, Luiz A. [Universidade Federal de Sao Carlos (DEMa/UFSCar), SP (Brazil). Dept. de Engenharia de Materiais

    2009-07-01

    To achieve a balance between stiffness and toughness, ternary nanocomposites based on blends of polyamide 6 (PA6) and acrylonitrile-butadiene-styrene (ABS) were prepared by the melt intercalation using the organoclay Cloisite{sup R} 30B (OMMT) and the styrene-maleic anhydride copolymer (SMA) as compatibilizer. Four blending sequences were used to prepare studied systems and their mechanical properties studied through the Young's modulus and notched Izod impact. It was observed that the materials prepared by all blending sequences studied showed an increase in the Young's modulus compared to the neat PA6. However, a decrease in the toughness was observed for the systems with the addition of the organoclay. The DRX results showed an intercalated structure for the some systems that used ABS in their compositions. HDT measurements of the nanocomposites showed an increase in this property compared to the neat PA6. The use of nanoclay lead to a reinforcement of the polymeric matrix. (author)

  5. Preparation, characterization and thermal properties of styrene maleic anhydride copolymer (SMA)/fatty acid composites as form stable phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Sari, Ahmet; Alkan, Cemil; Karaipekli, Ali; Oenal, Adem [Department of Chemistry, Gaziosmanpasa University, 60240, Tokat (Turkey)

    2008-02-15

    Fatty acids such as stearic acid (SA), palmitic acid (PA), myristic acid (MA) and lauric acid (LA) are promising phase change materials (PCMs) for latent heat thermal energy storage (LHTES) applications, but high cost is the major drawback of them, limiting their utility area in thermal energy storage. The use of fatty acids as form stable PCMs will increase their feasibilities in practical applications due to the reduced cost of the LHTES system. In this regard, a series of styrene maleic anhydride copolymer (SMA)/fatty acid composites, SMA/SA, SMA/PA, SMA/MA, and SMA/LA, were prepared as form stable PCMs by encapsulation of fatty acids into the SMA, which acts as a supporting material. The encapsulation ratio of fatty acids was as much as 85 wt.% and no leakage of fatty acid was observed even when the temperature of the form stable PCM was over the melting point of the fatty acid in the composite. The prepared form stable composite PCMs were characterized using optic microscopy (OM), viscosimetry and Fourier transform infrared (FT-IR) spectroscopy methods, and the results showed that the SMA was physically and chemically compatible with the fatty acids. In addition, the thermal characteristics such as melting and freezing temperatures and latent heats of the form stable composite PCMs were measured by using the differential scanning calorimetry (DSC) technique, which indicated they had good thermal properties. On the basis of all the results, it was concluded that form stable SMA/fatty acid composite PCMs had important potential for practical LHTES applications such as under floor space heating of buildings and passive solar space heating of buildings by using wallboard, plasterboard or floors impregnated with a form stable PCM due to their satisfying thermal properties, easy preparation in desired dimensions, direct usability without needing additional encapsulation thereby eliminating the thermal resistance caused by the shell and, thus, reducing the cost of

  6. Thermotropic properties of phosphatidylcholine nanodiscs bounded by styrene-maleic acid copolymers.

    Science.gov (United States)

    Dominguez Pardo, J J; Dörr, J M; Renne, M F; Ould-Braham, T; Koorengevel, M C; van Steenbergen, M J; Killian, J A

    2017-11-01

    Styrene-maleic acid copolymers (SMA) have been gaining interest in the field of membrane research due to their ability to solubilize membranes into nanodics. The SMA molecules act as an amphipathic belt that surrounds the nanodiscs, whereby the hydrophobic styrene moieties can insert in between the lipid acyl chains. Here we used SMA variants with different styrene-to-maleic acid ratio (i.e. 2:1, 3:1 and 4:1) to investigate how lipid packing in the nanodiscs is affected by the presence of the polymers and how it depends on polymer composition. This was done by analyzing the thermotropic properties of a series of saturated phosphatidylcholines in nanodiscs using laurdan fluorescence and differential scanning calorimetry. In all cases it was found that the temperature of the main phase transition (Tm) of the lipids in the nanodiscs is downshifted and that its cooperativity is strongly reduced as compared to the situation in vesicles. These effects were least pronounced for lipids in nanodiscs bounded by SMA 2:1. Unexpected trends were observed for the calorimetric enthalpy of the transition, suggesting that the polymer itself contributes, possibly by rearranging around the nanodiscs when the lipids adopt the fluid phase. Finally, distinct differences in morphology were observed for nanodiscs at relatively high polymer concentrations, depending on the SMA variant used. Overall, the results suggest that the extent of preservation of native thermodynamic properties of the lipids as well as the stability of the nanodiscs at high polymer concentrations is better for SMA 2:1 than for the other SMA variants. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  7. The effectiveness of styrene-maleic acid (SMA) copolymers for solubilisation of integral membrane proteins from SMA-accessible and SMA-resistant membranes

    NARCIS (Netherlands)

    Swainsbury, David J. K.; Scheidelaar, Stefan; Foster, Nicholas; van Grondelle, Rienk; Killian, J. Antoinette; Jones, Michael R.

    2017-01-01

    Solubilisation of biological lipid bilayer membranes for analysis of their protein complement has traditionally been carried out using detergents, but there is increasing interest in the use of amphiphilic copolymers such as styrene maleic acid (SMA) for the solubilisation, purification and

  8. The effectiveness of styrene-maleic acid (SMA) copolymers for solubilisation of integral membrane proteins from SMA-accessible and SMA-resistant membranes.

    Science.gov (United States)

    Swainsbury, David J K; Scheidelaar, Stefan; Foster, Nicholas; van Grondelle, Rienk; Killian, J Antoinette; Jones, Michael R

    2017-10-01

    Solubilisation of biological lipid bilayer membranes for analysis of their protein complement has traditionally been carried out using detergents, but there is increasing interest in the use of amphiphilic copolymers such as styrene maleic acid (SMA) for the solubilisation, purification and characterisation of integral membrane proteins in the form of protein/lipid nanodiscs. Here we survey the effectiveness of various commercially-available formulations of the SMA copolymer in solubilising Rhodobacter sphaeroides reaction centres (RCs) from photosynthetic membranes. We find that formulations of SMA with a 2:1 or 3:1 ratio of styrene to maleic acid are almost as effective as detergent in solubilising RCs, with the best solubilisation by short chain variants (membranes was uniformly low, but could be increased through a variety of treatments to increase the lipid:protein ratio. However, proteins isolated from such membranes comprised clusters of complexes in small membrane patches rather than individual proteins. We conclude that short-chain 2:1 and 3:1 formulations of SMA are the most effective in solubilising integral membrane proteins, but that solubilisation efficiencies are strongly influenced by the size of the target protein and the density of packing of proteins in the membrane. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  9. The effectiveness of styrene-maleic acid (SMA) copolymers for solubilisation of integral membrane proteins from SMA-accessible and SMA-resistant membranes.

    NARCIS (Netherlands)

    Swainsbury, David J K; Scheidelaar, S.|info:eu-repo/dai/nl/413333418; Foster, Nicolas; Van Grondelle, Rienk; Killian, J.A.|info:eu-repo/dai/nl/071792317; Jones, Michael R.

    2017-01-01

    Solubilisation of biological lipid bilayer membranes for analysis of their protein complement has traditionally been carried out using detergents, but there is increasing interest in the use of amphiphilic copolymers such asstyrene maleic acid (SMA) for the solubilisation, purification and

  10. Non-woven fibrous materials with antibacterial properties prepared by tailored attachment of quaternized chitosan to electrospun mats from maleic anhydride copolymer.

    Science.gov (United States)

    Ignatova, Milena; Petkova, Zhanina; Manolova, Nevena; Markova, Nadya; Rashkov, Iliya

    2012-01-01

    In order to impart antibacterial properties to microfibrous electrospun materials from styrene/maleic anhydride copolymers, quaternized chitosan derivatives (QCh) containing alkyl substituents of different chain lengths are covalently attached to the mats. A complete inhibition of the growth of bacteria, S. aureus (Gram-positive) and E. coli (Gram-negative), for a contact time of 30–120 min or a decrease of the bacterial titer by 2–3 log units is observed depending on the quaternization degree, the chain length of the alkyl substituent, and the molar mass of QCh. The modified mats are also effective in suppressing the adhesion of pathogenic S. aureus bacteria. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. 21 CFR 872.3500 - Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium...

    Science.gov (United States)

    2010-04-01

    ...), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. 872.3500 Section 872.3500...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3500 Polyvinylmethylether maleic anhydride (PVM-MA), acid copolymer, and carboxymethylcellulose sodium (NACMC) denture adhesive. (a) Identification...

  12. Retardation of the dewetting process due to the addition of functional copolymers at polymer-polymer interfaces

    CERN Document Server

    Wunnicke, O; Lorenz-Haas, C; Leiner, V

    2002-01-01

    We studied the retardation of the dewetting process due to the addition of a functional copolymer in a polymer bilayer film. The model system consists of fully deuterated polystyrene (PS-d) on top of an amorphous polyamide (PA) sublayer on silicon substrates. Bilayer films were prepared with different content (0, 5, 10 and 30 vol. %) of a statistical copolymer (protonated styrene maleic anhydride acid (SMA2) containing 2% MA groups along the chain) being capable of forming hydrogen bonds with PA. The as-prepared as well as the annealed samples were investigated by neutron-reflectivity (NR) experiments, scanning force microscopy and optical microscopy. A significant retardation of dewetting is observed with the addition of SMA2. From model fits of NR curves the scattering length density profiles perpendicular to the sample surface were determined and an enrichment layer of SMA2 is detected. Retardation is explained by the intermixing of SMA2 and PS-d at the interface. (orig.)

  13. SMA-SH: Modified styrene maleic acid copolymer for functionalization of lipid nanodiscs

    NARCIS (Netherlands)

    Lindhoud, S.; Dias Ribeiro De Carvalho, V.I.; Pronk, J.W.; Aubin-Tam, M.E.

    2016-01-01

    Challenges in purification and subsequent functionalization of membrane proteins often complicate their biochemical and biophysical characterization. Purification of membrane proteins generally involves replacing the lipids surrounding the protein with detergent molecules, which can affect protein

  14. Styrene maleic acid encapsulated raloxifene micelles for management of inflammatory bowel disease.

    Science.gov (United States)

    Greish, Khaled; Taha, Safa; Jasim, Anfal; Elghany, Sara Abd; Sultan, Ameera; AlKhateeb, Ali; Othman, Manal; Jun, Fang; Taurin, Sebastien; Bakhiet, Moiz

    2017-12-01

    Inflammatory bowel disease (IBD) comprises a group of disorders that manifest through chronic inflammation of the colon and small intestine. Although the exact cause of IBD is still unclear, dysfunctional immunoregulation involving overproduction of inflammatory cytokines such as TNF-α, and IL-6 have been implicated in pathogenesis. Current therapy relies on immunosuppression, cytotoxic drugs, and monoclonal antibodies against TNF-α. These classes of drugs have severe side-effects, especially when used for long duration. Our previous work with raloxifene, a selective estrogen receptor modulator, has shown that the drug, and to a greater extent its micellar formulation, has a significant suppressive effect on NF-κB, an essential immune-regulator. This finding directed the current work towards testing the anti-inflammatory and immunomodulatory effects of raloxifene using cell lines, as well as testing the potential use of the styrene maleic acid (SMA) micelles loaded with raloxifene (SMA-Ral) against dextran sulfate sodium (DSS) induced colitis in an in vivo model of IBD. Treatment of MCF-7 cells with TNF-α was shown to protect the cells from the cytotoxic effect of raloxifene (42 vs. 10% cell death, with TNF-α. Treating CaCo-2 cells with both free and SMA-Ral improved cell survival after exposure to 2% DDS with significantly higher protection with SMA-Ral. Treatment of U-937 with SMA-Ral and free-Ral resulted in down-regulation of TNF-α, IL-1β, IL-6, and MIP1α, with greater inhibition of the SMA-Ral, compared to free Ral. Balb/c mice treated with raloxifene and SMA-Ral showed weight gain at 14 days, compared to the control group (122, and 115% respectively). Treatment with raloxifene prevented DSS-induced diarrhea in 6/6 of free raloxifene treated mice and in 5/6 mice treated with SMA-Ral. Control group of DSS-treated mice showed average colon length of 7.4 cm compared to 13 cm in the control group. The average colon length was 12.3 and 11.5 cm for

  15. Cycloolefin/maleic anhydride copolymers for 193-nm resist compositions

    Science.gov (United States)

    Rahman, M. D.; Dammel, Ralph R.; Cook, Michelle M.; Ficner, Stanley A.; Padmanaban, Munirathna; Oberlander, Joseph E.; Durham, Dana L.; Klauck-Jacobs, Axel

    1999-06-01

    Several novel norbornene carboxylate monomers consisting of isobornyl and alkyl ether chains on the ester groups were synthesized and polymerized with maleic anhydride (MA), t- butylnorbornene carboxylate (BNC), hydroxyethylnorbornene carboxylate (HNC) and norbornene carboxylic acid (NC). These polymers were compared with BNC/HNC/NC/MA tetra-polymers with respect to glass transition temperature (Tg) as well as photoresist performance using a 193 nm exposure tool. It was observed that introduction of these groups decreases the Tg but not to the extent where the polymers can be used as an annealing type resist. The synthesis of these polymers, their characterization, and their lithographic evaluation as 193 resists will be discussed in this paper. Further optimization in terms of final polymer composition as well as resist formulation is on-going in order to fully exploit these monomers for photoresist application.

  16. Stereocomplexes of enantiomeric lactic acid and sebacic acid ester-anhydride triblock copolymers.

    Science.gov (United States)

    Slivniak, Raia; Domb, Abraham J

    2002-01-01

    A systematic study on the synthesis, characterization, degradation, and drug release of d-, l-, and dl-poly(lactic acid) (PLA)-terminated poly(sebacic acid) (PSA) and their stereocomplexes is reported. PLA-terminated sebacic acid polymers were synthesized by melt condensation of the acetate anhydride derivatives of PLA oligomers and sebacic anhydride oligomers to yield ABA triblock copolymers of molecular weights between 3000 and 9000 that melt at temperatures between 35 and 80 degrees C. Pairs of the corresponding enantiomeric ABA copolymers composed of l-PLA-PSA-l-PLA and d-PLA-PSA-d-PLA were solvent mixed to form stereocomplexes. The formed stereocomplexes exhibited higher crystalline melting temperature than the enantiomeric polymers, which indicate stereocomplex formulation. The PLA terminals had a significant effect on the polymer degradation and drug release rate. PSA with up to 20% w/w of PLA terminals degraded and released the incorporated drug for more than 3 weeks as compared with 10 days for PSA homopolymer.

  17. Synthesis of ethylene maleic anhydride copolymer containing fungicides and evaluation of their effect for wood decay resistance

    Science.gov (United States)

    George C. Chen

    2008-01-01

    The aim of the present study was to combat wood decay based on the approach controlled-release biocides from polymers. The possibility of introducing polymer-bonded fungicides into the cell lumens was investigated. The synthesis of ethylene maleic anhydride copolymer containing pentachlorophenol (penta) and 8-hydroxy quinoline (8HQ) in N, N dimethyl formamide is...

  18. Short-chain grafting of tetrahydrofuran and 1,4-dioxane cycles on vinylchloride-maleic anhydride copolymer

    Directory of Open Access Journals (Sweden)

    2009-01-01

    Full Text Available Mass increase of vinylchloride-maleic anhydride (VC-MA copolymer samples aged in tetrahydrofuran (THF or in 1,4-dioxane results from chemical interaction of VC-MA macromolecules with 1,4-dioxane or THF. Microstructure of the products of such modification was proved by infrared spectroscopy (IR- and nuclear magnetic resonance spectroscopy (13C NMR and 1H NMR. Mechanism of modification has been proposed. The results of microstructure research of VC-MA samples aged in THF and in 1,4-dioxane coincide with already known data on the reactions of opening of these and other oxygen-containing cycles under mild conditions.

  19. Styrene maleic acid-encapsulated RL71 micelles suppress tumor growth in a murine xenograft model of triple negative breast cancer.

    Science.gov (United States)

    Martey, Orleans; Nimick, Mhairi; Taurin, Sebastien; Sundararajan, Vignesh; Greish, Khaled; Rosengren, Rhonda J

    2017-01-01

    Patients with triple negative breast cancer have a poor prognosis due in part to the lack of targeted therapies. In the search for novel drugs, our laboratory has developed a second-generation curcumin derivative, 3,5-bis(3,4,5-trimethoxybenzylidene)-1-methylpiperidine-4-one (RL71), that exhibits potent in vitro cytotoxicity. To improve the clinical potential of this drug, we have encapsulated it in styrene maleic acid (SMA) micelles. SMA-RL71 showed improved biodistribution, and drug accumulation in the tumor increased 16-fold compared to control. SMA-RL71 (10 mg/kg, intravenously, two times a week for 2 weeks) also significantly suppressed tumor growth compared to control in a xenograft model of triple negative breast cancer. Free RL71 was unable to alter tumor growth. Tumors from SMA-RL71-treated mice showed a decrease in angiogenesis and an increase in apoptosis. The drug treatment also modulated various cell signaling proteins including the epidermal growth factor receptor, with the mechanisms for tumor suppression consistent with previous work with RL71 in vitro. The nanoformulation was also nontoxic as shown by normal levels of plasma markers for liver and kidney injury following weekly administration of SMA-RL71 (10 mg/kg) for 90 days. Thus, we report clinical potential following encapsulation of a novel curcumin derivative, RL71, in SMA micelles.

  20. Styrene maleic acid micelles as a nanocarrier system for oral anticancer drug delivery – dual uptake through enterocytes and M-cells

    Science.gov (United States)

    Parayath, Neha N; Nehoff, Hayley; Müller, Philipp; Taurin, Sebastien; Greish, Khaled

    2015-01-01

    Drug delivery systems could potentially overcome low bioavailability and gastrointestinal toxicity, which are the major challenges for the development of oral anticancer drugs. Herein, we demonstrate the ability of styrene maleic acid (SMA) nanomicelles encapsulating epirubicin to traverse in vitro and ex vivo models of the intestinal epithelium without affecting the tissue integrity. Further, SMA micelles encapsulating a fluorescent dye dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI) showed twofold higher accumulation in the liver and spleen, 15-fold higher accumulation in the tumor, and sixfold higher accumulation in the lung as compared with the free DiI, following oral administration in a mice xenograft breast cancer model. Additionally, SMA micelles showed colocalization with microfold (M)-cells and accumulation in Peyer’s patches, which together confirms the M-cell mediated uptake and transport of SMA micelles. Our results indicate that SMA micelles, showing dual uptake by enterocytes and M-cells, are a potential tool for safe oral anticancer drug delivery. PMID:26229468

  1. Styrene maleic acid micelles as a nanocarrier system for oral anticancer drug delivery - dual uptake through enterocytes and M-cells.

    Science.gov (United States)

    Parayath, Neha N; Nehoff, Hayley; Müller, Philipp; Taurin, Sebastien; Greish, Khaled

    2015-01-01

    Drug delivery systems could potentially overcome low bioavailability and gastrointestinal toxicity, which are the major challenges for the development of oral anticancer drugs. Herein, we demonstrate the ability of styrene maleic acid (SMA) nanomicelles encapsulating epirubicin to traverse in vitro and ex vivo models of the intestinal epithelium without affecting the tissue integrity. Further, SMA micelles encapsulating a fluorescent dye dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) showed twofold higher accumulation in the liver and spleen, 15-fold higher accumulation in the tumor, and sixfold higher accumulation in the lung as compared with the free DiI, following oral administration in a mice xenograft breast cancer model. Additionally, SMA micelles showed colocalization with microfold (M)-cells and accumulation in Peyer's patches, which together confirms the M-cell mediated uptake and transport of SMA micelles. Our results indicate that SMA micelles, showing dual uptake by enterocytes and M-cells, are a potential tool for safe oral anticancer drug delivery.

  2. The Use of Styrene Maleic Acid Nanomicelles Encapsulating the Synthetic Cannabinoid Analog WIN55,212-2 for the Treatment of Cancer.

    Science.gov (United States)

    Xian, Susan; Parayath, Neha N; Nehoff, Hayley; Giles, Niroshini M; Greish, Khaled

    2015-09-01

    Synthetic cannabinoid WIN55,212-2 (WIN) has shown a promise as an anticancer agent but causes psychoactive side-effects. In the present study, nano-micelles of styrene maleic acid (SMA)-conjugated WIN were synthesized to reduce side-effects and increase drug efficacy. SMA-WIN micelles were characterised and their in vitro cytotoxic effect was compared to that of free WIN against triple-negative breast cancer (MDA-MB-231), hormone receptor-positive breast cancer (MCF-7) and castration-resistant prostate cancer (PC3) cell lines. SMA-WIN micelles were synthesised with a ~15% loading, 132.7 nm average diameter, -0.0388 mV charge, and pH-dependent release rate. A dose-dependent inhibition of cell growth was observed in all three cell lines treated with both free and micellar WIN, with both formulations demonstrating equal cytotoxicity. SMA-WIN demonstrated characteristics theorized to improve in vivo drug biodistribution. Potent cytotoxicity was found against breast and prostate cancer cells in vitro, showing promise as a novel treatment against breast and prostate cancer. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  3. Aggregate structure and effect of phthalic anhydride modified soy protein on the mechanical properties of styrene-butadiene copolymer

    Science.gov (United States)

    The aggregate structure of phthalic anhydride (PA) modified soy protein isolate (SPI) was investigated by estimating its fractal dimension from the equilibrated dynamic strain sweep experiments. The estimated fractal dimensions of the filler aggregates were less than 2, indicating that these partic...

  4. Influência da estrutura de diferentes copolímeros de etileno e a-olefinas na funcionalização com anidrido maleico Influence of structure of ethylene a-olefins copolymers in functionalization with maleic anhydride

    Directory of Open Access Journals (Sweden)

    Carlota H. F. Maurano

    1998-01-01

    Full Text Available A funcionalização de copolímeros de etileno e a-olefinas com anidrido maleico (AM foi realizada em solução de xileno com peróxido de dibenzoíla (DBP como iniciador. Foi estudado o efeito das diferentes estruturas dos copolímeros, como número e comprimento de ramificação, na incorporação do AM. A funcionalização também foi realizada em estado fundido utilizando-se um misturador Rheomix 600 e uma extrusora Rheocord 9000 da Haake. A funcionalidade foi determinada por titulometria de neutralização e os produtos foram caracterizados por espectroscopia na região do infravermelho (FT-IR e por cromatografia de permeação em gel (GPC. A funcionalidade dos copolímeros de etileno com 1-hexeno aumentou com o aumento do teor de comonômero e dos copolímeros com 1-octeno e 1-deceno aumentou com o aumento do teor de a-olefina até um máximo, decrescendo e mantendo-se constante.Chemical modification of ethylene a-olefins copolymers with maleic anhydride was studied by radical reaction in solution, melt mixing and extrusion. The effect of copolymer structure, as the amount and length of the branches, was evaluated on the MA incorporation. The reactions were also achieved in Rheomix 600 (Haake mixer and Rheocord 9000 (Haake extruder. Functionalization was determinated by titration and modified ethylene a-olefins copolymers were characterized by Infrared Spectroscopy and Gel Permeation Chromatography. The maleic anhydride incorporation in the ethylene-hexene copolymers increases with the amount of a-olefin. Functionalization of ethylene-octene and ethylene-decene comonomers increases with increasing peroxide concentration until a maximum and then decreases up to a constant value.

  5. Efeito da sequência de mistura nas propriedades de blendas PA6/ABS compatibilizadas com o copolímero SMA Effect from the blending sequence on the properties of PA6/ABS blends compatibilized with SMA copolymer

    Directory of Open Access Journals (Sweden)

    Amanda D. de Oliveira

    2011-01-01

    Full Text Available Blendas de poliamida 6 (PA6 com acrilonitrila-butadieno-estireno (ABS foram preparadas em uma extrusora de rosca dupla, utilizando-se o copolímero estireno-anidrido maleico (SMA, com 7% de anidrido maleico, como compatibilizante. O efeito de três sequências de mistura na microestrutura e propriedades das blendas foi estudado. A morfologia e as propriedades mecânicas dos materiais foram caracterizadas por microscopia eletrônica de transmissão (MET e testes de resistência ao impacto e módulo de elasticidade, respectivamente. Os resultados mostraram que a morfologia e propriedades mecânicas das blendas ternárias foram bastante diferentes e dependem da sequência de mistura. A blenda preparada pela mistura simultânea de todos os componentes, em uma única extrusão, apresentou melhor tenacidade. Por outro lado, quando o ABS e o SMA foram misturados juntos em uma primeira extrusão, antes da incorporação da PA6 em uma segunda extrusão, o valor da resistência ao impacto encontrado foi menor que o da matriz PA6 e da blenda sem compatibilizante PA6/ABS. Evidências de reações químicas entre o compatibilizante SMA e a matriz PA6 também foram investigadas através de reometria de torque.Blends of polyamide 6 (PA6 with acrylonitrile-butadiene-estyrene (ABS were prepared in a twin-screw extruder, using the styrene-maleic anhydride (SMA copolymer containing 7% of maleic anhydride as compatibilizer. The effects from three blending sequences on the microstructure and properties of the blends were investigated. The morphology and mechanical properties of the materials were characterized by transmission electron microscopy and tensile and impact tests. The results showed that the morphology and mechanical properties of ternary blends depend on the sequence of blend preparation. The blend prepared using the mixture of all components in a single-pass extrusion showed the more significant improvement in the material toughness. However, when the

  6. Dissolution of paracetamol crystallized in the presence of poly(vinyl acetate-co-maleic anhydride)

    OpenAIRE

    Raval D; Parikh D; Patel V

    2006-01-01

    Copolymer of vinyl acetate and maleic anhydride, poly (vinyl acetate-co-maleic anhydride) was prepared by precipitation polymerization and characterized. Paracetamol was crystallized in presence of different concentrations of poly (vinyl acetate-co-maleic anhydride). Crystals were characterized by sieve analysis, solubility and dissolution study. Crystallization of paracetamol in presence of poly (vinyl acetate-co-maleic anhydride) caused a marked enhancement in its dissolution rate with incr...

  7. Poly(ester-anhydride):poly(beta-amino ester) micro- and nanospheres: DNA encapsulation and cellular transfection.

    Science.gov (United States)

    Pfeifer, Blaine A; Burdick, Jason A; Little, Steve R; Langer, Robert

    2005-11-04

    Poly(ester-anhydride) delivery devices allow flexibility regarding carrier dimensions (micro- versus nanospheres), degradation rate (anhydride versus ester hydrolysis), and surface labeling (through the anhydride functional unit), and were therefore tested for DNA encapsulation and transfection of a macrophage P388D1 cell line. Poly(l-lactic acid-co-sebacic anhydride) and poly(l-lactic acid-co-adipic anhydride) were synthesized through melt condensation, mixed with 25 wt.% poly(beta-amino ester), and formulated with plasmid DNA (encoding firefly luciferase) into micro- and nanospheres using a double emulsion/solvent evaporation technique. The micro- and nanospheres were then characterized (size, morphology, zeta potential, DNA release) and assayed for DNA encapsulation and cellular transfection over a range of poly(ester-anhydride) copolymer ratios. Poly(ester-anhydride):poly(beta-amino ester) composite microspheres (6-12 microm) and nanospheres (449-1031 nm), generated with copolymers containing between 0 and 25% total polyanhydride content, encapsulated plasmid DNA (>or=20% encapsulation efficiency). Within this polyanhydride range, poly(adipic anhydride) copolymers provided DNA encapsulation at an increased anhydride content (10%, microspheres; 10-25%, nanospheres) compared to poly(sebacic anhydride) copolymers (1%, microspheres and nanospheres) with cellular transfection correlating with the observed DNA encapsulation.

  8. Dynamic mechanical analysis of binary and ternary polymer blends based on nylon copolymer/EPDM rubber and EPM grafted maleic anhydride compatibilizer

    Directory of Open Access Journals (Sweden)

    2007-10-01

    Full Text Available The dynamic mechanical properties such as storage modulus, loss modulus and damping properties of blends of nylon copolymer (PA6,66 with ethylene propylene diene (EPDM rubber was investigated with special reference to the effect of blend ratio and compatibilisation over a temperature range –100°C to 150°C at different frequencies. The effect of change in the composition of the polymer blends on tanδ was studied to understand the extent of polymer miscibility and damping characteristics. The loss tangent curve of the blends exhibited two transition peaks, corresponding to the glass transition temperature (Tg of individual components indicating incompatibility of the blend systems. The morphology of the blends has been examined by using scanning electron microscopy. The Arrhenius relationship was used to calculate the activation energy for the glass transition of the blends. Finally, attempts have been made to compare the experimental data with theoretical models.

  9. Phenylethynyl Phthalic Anhydride

    Science.gov (United States)

    Hergenrother, Paul M. (Inventor); Smith, Joseph G., Jr. (Inventor)

    1997-01-01

    Controlled molecular weight PhenylEthynyl Terminated Imide oligomers (PETIs) have been prepared by the cyclodehydration of precursor phenylethynyl terminated amic acid oligomers. Amino terminated amic acid oligomers are prepared from the reaction of dianhydride(s) with an excess of diamine(s) and subsequently endcapped with PhenylEthynyl Phthalic Anhydride(s) (PEPA). The polymerizations are carried out in polar aprotic solvents such as N-methyl-2pyrrolidinone or N N-dimethylacetamide under nitrogen at room temperature. The amic acid oligomers are subsequently cyclodehydrated either thermally or chemically to the corresponding imide oligomers. Direct preparation of PETIs from the reaction of dianhydride(s) with an excess of diamine(s) and endcapped with phenylethynyl phthalic anhydride(s) has been performed in m-cresol. Phenylethynyl phthalic anhydrides are synthesized by the palladium catalyzed reaction of phenylacetylene with bromo substituted phthalic anhydrides in triethylamine. These new materials exhibit excellent properties and are potentially useful as adhesives, coatings, films, moldings and composite matrices.

  10. Ferrocenecarboxylic anhydride: a redetermination

    Directory of Open Access Journals (Sweden)

    C. John McAdam

    2016-11-01

    Full Text Available The title molecule, [Fe2(C5H52(C12H8O3], briefly reported previously [Zhang (2015. Private Communication (CCDC reference 1056736. CCDC, Cambridge, England], comprises two ferrocenyl units connected by an acid anhydride bridge. Both ferrocene units have near coplanar [dihedral angles between the ring planes = 2.84 (4 and 1.74 (13°] and eclipsed [pseudo torsion angles = 6.3 (2 and 5.1 (2°] cyclopentadienyl (Cp rings. A twist through the anhydride linkage results in a dihedral angle of 73.81 (8° between the two substituted Cp rings planes. An intramolecular C—H...O hydrogen bond is also found. In the crystal, C—H...O hydrogen bonds link the molecules into a three-dimensional network.

  11. complexes of poly(methyl vinyl ether-alt-maleic anhydride).

    Indian Academy of Sciences (India)

    chelates changes due to the polymeric effect.8–12 Jiang and Zhu reported that poly(ester-anhydrides) exhibit better degradation ability as anti-infective polymeric prodrugs or matrices for drug delivery.13. Copolymers have available carboxylic acid func- tional groups, which can be used in further incorpo- ration of drugs or ...

  12. RAFT copolymerization of itaconic anhydride and 2-methoxyethyl acrylate: a multifunctional scaffold for preparation of “clickable” gold nanoparticles

    DEFF Research Database (Denmark)

    Javakhishvili, Irakli; Kasama, Takeshi; Jankova, Katja Atanasova

    2013-01-01

    RAFT copolymerization of 2-methoxyethyl acrylate and itaconic anhydride – a monomer derived from renewable resources – is carried out in a controlled fashion. The copolymer allows preparation of gold nanoparticles with abundant surficial carboxyl and alkyne functional groups that are dendronized...

  13. Oil recovery with sulfomethylated poly (lower alkyl vinyl ether/maleic anhydride)

    Energy Technology Data Exchange (ETDEWEB)

    Norton, C.J.; Falk, D.O.

    1973-05-22

    Lower alkyl vinyl ether e.g., methyl vinyl ether, propyl vinyl ether, isopropyl vinyl ether, hexyl vinyl ether, is copolymerized conventionally with maleic anhydride, the resulting copolymer is treated with ammonia or ammonium hydroxide to form the partial amide-ammonium salt, and this salt is in turn treated with formaldehyde and thereafter or simultaneously with ammonium or alkali metal salt sulfite (including bisulfites, etc.) to form an at least partially sulfomethylated copolymer. Aqueous solutions of the sulfomethylated copolymer are useful in increasing the viscosity of drive fluids used in the supplemented recovery of petroleum from subterranean formations. In general, enhancing the polyionic character of mobility control agents used in supplemented recovery of petroleum provides enhanced recovery. Achieving this enhancement of polyionic character through use of sulfonate groups provides a mobility control agent with good ability to sustain viscosity in the presence of brine and lime, usually present in the connate waters of petroleum-bearing formations. (7 claims)

  14. Anhydric maleic functionalization and polyethylene glycol grafting of lactide-co-trimethylene carbonate copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Díaz, A.; Valle, L.; Franco, L. del [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Sarasua, J.R. [Department of Mining-Metallurgy Engineering and Materials Science, University of the Basque Country (UPV/EHU), Bilbao (Spain); Estrany, F. [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Puiggalí, J., E-mail: Jordi.Puiggali@upc.es [Department of Mining-Metallurgy Engineering and Materials Science, University of the Basque Country (UPV/EHU), Bilbao (Spain)

    2014-09-01

    Lactide and trimethylene carbonate copolymers were successfully grafted with polyethylene glycol via previous functionalization with maleic anhydride and using N,N′-diisopropylcarbodiimide as condensing agent. Maleinization led to moderate polymer degradation. Specifically, the weight average molecular weight decreased from 36,200 to 30,200 g/mol for the copolymer having 20 mol% of trimethylene carbonate units. Copolymers were characterized by differential scanning calorimetry, thermogravimetry and X-ray diffraction. Morphology of spherulites and lamellar crystals was evaluated with optical and atomic force microscopies, respectively. The studied copolymers were able to crystallize despite the randomness caused by the trimethylene carbonate units and the lateral groups. Contact angle measurements indicated that PEG grafted copolymers were more hydrophilic than parent copolymers. This feature justified that enzymatic degradation in lipase medium and proliferation of both epithelial-like and fibroblast-like cells were enhanced. Grafted copolymers were appropriate to prepare regular drug loaded microspheres by the oil-in-water emulsion method. Triclosan release from loaded microspheres was evaluated in two media. - Highlights: • Pegylated copolymers of lactide and trimethylene carbonate have been synthesized. • Grafting with polyethylene glycol was able via maleic anhydride functionalization. • Drug-loaded microspheres could be prepared from new pegylated copolymers. • Hydrophilicity of lactide/trimethylene carbonate copolymers increased by pegylation. • New pegylated copolymers supported cell adhesion and proliferation.

  15. GPCR-styrene maleic acid lipid particles (GPCR-SMALPs): their nature and potential.

    Science.gov (United States)

    Wheatley, Mark; Charlton, Jack; Jamshad, Mohammed; Routledge, Sarah J; Bailey, Sian; La-Borde, Penelope J; Azam, Maria T; Logan, Richard T; Bill, Roslyn M; Dafforn, Tim R; Poyner, David R

    2016-04-15

    G-protein-coupled receptors (GPCRs) form the largest class of membrane proteins and are an important target for therapeutic drugs. These receptors are highly dynamic proteins sampling a range of conformational states in order to fulfil their complex signalling roles. In order to fully understand GPCR signalling mechanisms it is necessary to extract the receptor protein out of the plasma membrane. Historically this has universally required detergents which inadvertently strip away the annulus of lipid in close association with the receptor and disrupt lateral pressure exerted by the bilayer. Detergent-solubilized GPCRs are very unstable which presents a serious hurdle to characterization by biophysical methods. A range of strategies have been developed to ameliorate the detrimental effect of removing the receptor from the membrane including amphipols and reconstitution into nanodics stabilized by membrane scaffolding proteins (MSPs) but they all require exposure to detergent. Poly(styrene-co-maleic acid) (SMA) incorporates into membranes and spontaneously forms nanoscale poly(styrene-co-maleic acid) lipid particles (SMALPs), effectively acting like a 'molecular pastry cutter' to 'solubilize' GPCRs in the complete absence of detergent at any stage and with preservation of the native annular lipid throughout the process. GPCR-SMALPs have similar pharmacological properties to membrane-bound receptor, exhibit enhanced stability compared with detergent-solubilized receptors and being non-proteinaceous in nature, are fully compatible with downstream biophysical analysis of the encapsulated GPCR. © 2016 Authors; published by Portland Press Limited.

  16. Compatibility of Functionalized Graphene with Polyethylene and Its Copolymers

    Directory of Open Access Journals (Sweden)

    Hyeon Myeong Seo

    2013-01-01

    Full Text Available The compatibility of polyethylene (PE with a functionalized graphene sheet (FGS, which was prepared by the thermal reduction of graphite oxide, was examined in this study. The dispersion of the FGS in the PE was improved as the molecular weight of the PE was decreased. The PE copolymers containing polar comonomers such as maleic anhydride or acrylic acid exhibited better compatibility with FGS than the PE homopolymers. The compatibility of the FGS with PE copolymers containing small amounts of comonomers, which have a solubility parameter slightly larger [up to approximately 0.5 (J/cm31/2] than that of PE itself, was better than the compatibility of both the PE and PE copolymers containing larger amounts of comonomers. The morphology, electric conductivity, and tensile properties of FGS/PE copolymer/PE nanocomposites showed that the copolymers with a solubility parameter slightly larger than that of PE effectively served as a compatibilizer in FGS/PE nanocomposites.

  17. Decarbonylative cycloaddition of phthalic anhydrides with allenes.

    Science.gov (United States)

    Ochi, Yosuke; Kurahashi, Takuya; Matsubara, Seijiro

    2011-03-18

    The decarbonylative cycloadditions of phthalic anhydrides with allenes were performed by using nickel catalyst. The asymmetric variant of the cycloaddition was also achieved by using chiral phosphine ligands to provide δ-lactones enantioselectively.

  18. Quantification of anhydride groups in anhydride-based epoxy hardeners by reaction headspace gas chromatography.

    Science.gov (United States)

    Xie, Wei-Qi; Gong, Yi-Xian; Yu, Kong-Xian

    2017-06-01

    We demonstrate a reaction headspace gas chromatographic method for quantifying anhydride groups in anhydride-based epoxy hardeners. In this method, the conversion process of anhydride groups can be realized by two steps. In the first step, anhydride groups in anhydride-based epoxy hardeners completely reacted with water to form carboxyl groups. In the second step, the carboxyl groups reacted with sodium bicarbonate solution in a closed sample vial. After the complete reaction between the carboxyl groups and sodium bicarbonate, the CO2 formed from this reaction was then measured by headspace gas chromatography. The data showed that the reaction in the closed headspace vial can be completed in 15 min at 55°C, the relative standard deviation of the reaction headspace gas chromatography method in the precision test was less than 3.94%, the relative differences between the new method and a reference method were no more than 9.38%. The present reaction method is automated, efficient and can be a reliable tool for quantifying the anhydride groups in anhydride-based epoxy hardeners and related research. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Synthesis and properties of starch-g-poly(maleic anhydride-co-vinyl acetate

    Directory of Open Access Journals (Sweden)

    2010-01-01

    Full Text Available Starch-g-poly(maleic anhydride-co-vinyl acetate (SMV was synthesized via the esterification reaction of starch with the copolymer of maleic anhydride and vinyl acetate. The carboxylic unit percentage (CUP of SMV was tailored with reaction conditions, and it ranged from 29.8 to 46.9%. The structure and the morphology of the copolymers were characterized with Fourier Transform Infrared spectroscopy and X-ray diffraction analysis. It was found that SMV could form complex with some metal cations such as Ca2+, Pb2+ and Hg2+ or cationic polyelectrolyte chitosan, and precipitate from the solution. The weight of precipitation increases with an increase of the CUP of SMV. In addition, a physically cross-linked hydrogel of SMV/poly(vinyl alcohol (PVA was obtained by freeze/thaw technique. Scanning electron microscopy exhibited the hydrogel was uniform. The gel exhibited pH-responsive re-swelling. The maximum swelling-ratio values of SMV/PVA (9:1, wt/wt gel were 3.29 and 5.34 in HCl (pH 1.0 and phosphate-buffer saline (PBS (pH 12 respectively.

  20. Preparation of poly(glycidylmethacrylate-divinylbenzene) weak acid cation exchange stationary phases with succinic anhydride, phthalic anhydride, and maleic anhydride for ion chromatography.

    Science.gov (United States)

    Liu, Junwei; Wang, Yong; Wu, Shuchao; Zhang, Peimin; Zhu, Yan

    2016-08-01

    In this work, poly(glycidylmethacrylate-divinylbenzene) microspheres were prepared and applied for the preparation of weak acid cation exchange stationary phases. Succinic anhydride, phthalic anhydride, and maleic anhydride were selected as carboxylation reagents to prepare three weak acid cation exchangers by direct chemical derivatization reaction without solvent or catalyst. The diameters and dispersity of the microspheres were characterized by scanning electron microscopy; the amount of accessible epoxy groups and mechanical stability were also measured. The weak acid cation exchangers were characterized by Fourier transform infrared spectroscopy; the content of carboxyl groups was measured by traditional acid base titration method. The chromatographic properties were characterized and compared by separating alkali, alkaline earth metal ions and ammonium and polar amines. The separation properties enhanced in the order of succinic anhydride, phthalic anhydride, and maleic anhydride modified poly(glycidylmethacrylate-divinylbenzene) cation exchangers. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Adsorption and kinetic studies on the removal of chromium and copper onto Chitosan-g-maliec anhydride-g-ethylene dimethacrylate.

    Science.gov (United States)

    Gopal Reddi, M R; Gomathi, T; Saranya, M; Sudha, P N

    2017-11-01

    The present work was designed to remove toxic metals chromium and copper using the double grafted copolymer Chitosan-g-Maleic anhydride-g-ethylene dimethacrylate. The graft copolymer was synthesized through chain polymerization reaction using ceric ammonium nitrate as the initiator. Prepared Chitosan-g-Maleic anhydride-g-ethylene dimethacrylate was used in order to remove the heavy metals chromium and copper from aqueous solutions of 200ppm/L concentration proceeding batch adsorption process by varying the parameters such as adsorbent dose, contact time, pH and initial concentration of the metal solution. The experimental data were equipped with isotherm models such as Langmuir and Freundlich and pseudo-first order and pseudo-second order kinetics. The calculated results revealed that the adsorption favours Freundlich isotherm and follows pseudo-second order kinetics. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Condensation of anhydrides or dicarboxylic acids with compounds containing active methylene groups. Part 19: Condensation of phthalic and substituted phthalic anhydrides with benzoylacetic ester

    Science.gov (United States)

    Rotberg, Y. T.; Oshkaya, V. P.

    1985-01-01

    Phthalylbenzoylacetic ester and its nitro and halogen derivatives were prepared through condensation of phthalic anhydride, nitrophthalic anhydride, and phthalic halide anhydride with benzoylacetic ester in a solution of acetic anhydride and triethylamine. The condensation of hemipinic acid anhydride proceeds similarly, but under more drastic conditions. Derivatives of indan-1,3-dione are also formed, with a small yield, in the reaction of nitrophthalic anhydrides with benzoylacetic ester in the presence of increased quantities of triethylamine.

  3. Influence of Maleic Anhydride/Glycidyl Methacrylate Cografted Polylactic Acid on Properties of Wood Flour/PLA Composites

    Directory of Open Access Journals (Sweden)

    DU Jun

    2017-12-01

    Full Text Available Graft copolymers of PLA-g-MAH, PLA-g-GMA and PLA-co-MAH/GMA were prepared by means of melt grafting. The structure of the graft copolymers were characterized by FTIR.Wood flour/PLA composites were prepared by injection molding with three kinds of graft copolymers as compatibilizers, and the fractured morphology of composites was investigated by scanning electron microscope (SEM. Results show that there is no obvious phase interface between wood flour and PLA,which indicating the interfacial compatibility of wood flour/PLA composites is improved after adding different graft copolymers. The determination results of mechanical properties, processing flowability and dynamic rheological property of composites prepared with different graft copolymers reveal that, compared to the composite without compatibilizer, the tensile strength and impact strength of wood flour/PLA composites are increased by 9.54% and 7.23% respectively, and the equilibrium torque, shear heat, storage modulus and complex viscosity are all increased after adding maleic anhydride/glycidyl methacrylate cografted polylactic acid.

  4. Responsive copolymers for enhanced petroleum recovery. Second annual report

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, C.; Hester, R.

    1995-05-01

    The authors describe second year efforts in synthesis, characterization, and rheology to develop polymers with significantly improved efficiency in mobility control and conformance. These advanced polymer systems would maintain high viscosities or behave as virtual gels under low shear conditions and at elevated electrolyte concentrations. At high fluid shear rates, associates would deaggregate yielding low viscosity solutions, reducing problems of shear degradation or face plugging during injection. Polymeric surfactants were also developed with potential for use in higher salt, higher temperature reservoirs for mobilization of entrapped oil. Chapters include: Ampholytic terpolymers of acrylamide with sodium 3-acrylamido-3-methylbutanoate and 2-acrylamido-2-methylpropanetrimethylammonium chloride; Hydrophilic sulfobetaine copolymers of acrylamide and 3-(2-acrylamido-methylpropane-dimethylammonio)-1-propanesulfonate; Copolymerization of maleic anhydride and N-vinylformamide; Reactivity ratio of N-vinylformamide with acrylamide, sodium acrylate, and n-butyl acrylate; Effect of the distribution of the hydrophobic cationic monomer dimethyldodecyl(2-acrylamidoethyl)ammonium bromide on the solution behavior of associating acrylamide copolymers; Effect of surfactants on the solution properties of amphipathic copolymers of acrylamide and N,N-dimethyl-N-dodecyl-N-(2-acrylamidoethyl)ammonium bromide; Associative interactions and photophysical behavior of amphiphilic terpolymers prepared by modification of maleic anhydride/ethyl vinyl ether copolymers; Copolymer compositions of high-molecular-weight functional acrylamido water-soluble polymers using direct-polarization magic-angle spinning {sup 13}C NMR; Use of factorial experimental design in static and dynamic light scattering characterization of water soluble polymers; and Porous medium elongational rheometer studies of NaAMB/AM copolymer solutions.

  5. Paclitaxel Release from Polyether-Anhydrides Prepared with UV-Curing Process

    Directory of Open Access Journals (Sweden)

    Anxin Dong

    2013-01-01

    Full Text Available Polyanhydrides have been used as drug delivery systems to achieve a long-term delivery due to its hydrophobicity and surface erosion degradation behavior. In order to develop a simple, economical, and rapid approach to synthesize polyanhydrides, we prepared a series of polyether-anhydride membranes composed of different mass fractions of sebacic acid, polyethylene glycol dimethacrylate, and poly(tetramethylene oxide dimethacrylate by ultraviolet curing process. The chemical structure and thermal properties of target polyanhydrides were characterized, while the paclitaxel releases from the polymer matrix were evaluated by HPLC. The results demonstrated that the UV-curing process is a good method to synthesize the target polymers in a short time, and the paclitaxel release procedure can be controlled by changing the component in the copolymers.

  6. Maleic anhydride grafting on EPDM rubber in the melt

    NARCIS (Netherlands)

    Oostenbrink, A.J.; Oostenbrink, A.J.; Gaymans, R.J.

    1992-01-01

    The grafting of maleic anhydride on a EPDM rubber was studied with a twin screw extruder. The effect of barrel temperatures, throughput, maleic anhydride concentration and peroxide concentration [bis(t-butyl peroxy isopropyl)benzene] on the degree of grafting and melt viscosity was studied. The

  7. Electrochemical, Antifungal, Antibacterial and DNA Cleavage Studies of Some Co(II), Ni(II), Cu(II) and Zn(II)-Copolymer Complexes

    OpenAIRE

    Dhanaraj, C. Justin; Nair, M. Sivasankaran

    2008-01-01

    Cyclic voltammetric measurements were performed for Co(II), Ni(II), Cu(II) and Zn(II) complexes of 1 : 1 alternating copolymer, poly(3-nitrobenzylidene-1-naphthylamine-co-succinic anhydride) (L) and Ni(II) and Cu(II) complexes of 1 : 1 alternating copolymer, poly(3-nitrobenzylidene-1-naphthylamine-co-methacrylic acid) (L1). The in vitro biological screening effects of the investigated compounds were tested against the fungal species including Aspergillus niger, Rhizopus stolonifer, Aspergillu...

  8. Synthesis and Characterization of Poly(maleic Anhydride)s Cross-linked Polyimide Aerogels

    Science.gov (United States)

    Guo, Haiquan; Meador, Mary Ann B.

    2015-01-01

    With the development of technology for aerospace applications, new thermal insulation materials are required to be flexible and capable of surviving high heat flux. For instance, flexible insulation is needed for inflatable aerodynamic decelerators which are used to slow spacecraft for entry, descent and landing (EDL) operations. Polyimide aerogels have low density, high porosity, high surface area, and better mechanical properties than silica aerogels and can be made into flexible thin films, thus they are potential candidates for aerospace needs. The previously reported cross-linkers such as octa(aminophenyl)silsesquioxane (OAPS) and 1,3,5-triaminophenoxybenzene (TAB) are either expensive or not commercially available. Here, we report the synthesis of a series of polyimide aerogels cross-linked using various commercially available poly(maleic anhydride)s, as seen in Figure 1. The amine end capped polyimide oligomers were made with 3,3,4,4-biphenyltetracarboxylic dianhydride (BPDA) and diamine combinations of dimethylbenzidine (DMBZ) and 4, 4-oxydianiline (ODA). The resulting aerogels have low density (0.12 gcm3 to 0.16 gcm3), high porosity (90) and high surface area (380-554 m2g). The effect of the different poly(maleic anhydride) cross-linkers and polyimide backbone structures on density, shrinkage, porosity, surface area, mechanical properties, moisture resistance and thermal properties will be discussed.

  9. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2013. Scientific Opinion on the safety of ―Methyl Vinyl Ether-Maleic Anhydride Copolymer‖ (chewing gum base ingredient) as a Novel Food ingredient

    DEFF Research Database (Denmark)

    Tetens, Inge; Poulsen, Morten

    Following a request from the European Commission, the EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA) was asked to deliver a scientific opinion on the safety of “methyl vinyl ether-maleic anhydride copolymer (Gantrez SF)” as a novel food ingredient in the context of Regulation (EC......) No 258/97. The novel food ingredient Gantrez SF is an anhydrous copolymer formed by the reaction of methyl vinyl ether (MVE) and maleic anhydride (MAN) under appropriate conditions. The Panel considers that the information provided on the specifications, stability and production process do not raise...... estimate of 280 mg Gantrez SF per day was derived. The Panel notes that the NOAEL of 1.8 and 2.1 g/kg bw per day Gantrez SF for male and female rats, respectively, which was derived from a 90-day subchronic toxicity study, is about 500-fold above this conservative intake estimate. The Panel has no safety...

  10. Alternating copolymerization of epoxides with anhydrides initiated by organic bases

    Czech Academy of Sciences Publication Activity Database

    Hošťálek, Z.; Trhlíková, Olga; Walterová, Zuzana; Martinez, T.; Peruch, F.; Cramail, H.; Merna, J.

    2017-01-01

    Roč. 88, March (2017), s. 433-447 ISSN 0014-3057 Institutional support: RVO:61389013 Keywords : copolymerization * epoxides * anhydrides Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 3.531, year: 2016

  11. Thermal Study of Anhydrides Cured Tetrafunctional Cardo Epoxy Resin

    Directory of Open Access Journals (Sweden)

    Jignesh P. Patel

    2013-01-01

    Full Text Available Tetrafunctional cardo epoxy resin (EBCF was cured by using 10 wt% maleic anhydride (MA, pyromellitic dianhydride (PMDA, phthalic anhydride (PA, tetrahydrophthalic anhydride (THPA, tetrabromophthalic anhydride (TBPA, and tetrachlorophthalic anhydride (TCPA as hardeners at 120°C for 40–105 min (gel time and then postcured 1 h at 130°C. Gel time is found to depend on the structure of the anhydrides used. Cured samples were found insoluble in common solvents. Cured and uncured EBCF were characterized by FTIR, DSC, and TGA techniques. Cured and uncured resins followed multistep degradation reactions. Kinetic parameters, namely, order of degradation, energy of activation, frequency factor, and entropy change, were determined according to the Anderson-Freeman method and interpreted in light of the nature of hardeners used for curing purpose. The resins followed integral or fractional order degradation kinetics. Complex degradation reactions are due to different types of linkages in cured resins. Both nature and structure of resin and hardeners affected the curing behavior and the resultant thermal properties of the cured resins.

  12. Imide Oligomers Endcapped with Phenylethynl Phthalic Anhydrides and Polymers Therefrom

    Science.gov (United States)

    Hergenrother, Paul M. (Inventor); Smith, Joseph G., Jr. (Inventor)

    1998-01-01

    Controlled molecular weight phenylethynyl terminated imide oligomers (PETIs) have been prepared by the cyclodehydration of precursor phenylethynyl terminated amic acid oligomers. Amino terminated amic acid oligomers are prepared from the reaction of dianhydride(s) with an excess of diamine(s) and subsequently endcapped with phenylethynyl phthalic anhydride(s) (PEPA). The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N.N-dimethylacetamide under nitrogen at room temperature. The amic acid oligomers are subsequently cyclodehydrated either thermally or cheznicauy to the corresponding imide oligomers. Direct preparation of PETIs from the reaction of dianhydxide(s) with an excess of diamine(s) and endcapped with phenylethynyl phthalic anhydride(s) has been performed in m-cresol. Phenylethynyl phthalic anhydrides are synthesized by the palladium catalyzed reaction of phenylacetylene with bromo substituted phthalic anhydrides in triethylamine. These new materials exhibit excellent properties and are potentially useful as adhesives, coatings, films, moldings and composite matrices.

  13. Imide oligomers endcapped with phenylethynyl phthalic anhydrides and polymers therefrom

    Science.gov (United States)

    Hergenrother, Paul M. (Inventor); Smith, Jr., Joseph G. (Inventor)

    1996-01-01

    Controlled molecular weight phenylethynyl terminated imide oligomers (PETIs) have been prepared by the cyclodehydration of precursor phenylethynyl terminated amic acid oligomers. Amino terminated amic acid oligomers are prepared from the reaction of dianhydride(s) with an excess of diamine(s) and subsequently endcapped with phenylethynyl phthalic anhydride(s) (PEPA). The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide under nitrogen at room temperature. The amic acid oligomers are subsequently cyclodehydrated either thermally or chemically to the corresponding imide oligomers. Direct preparation of PETIs from the reaction of dianhydride(s) with an excess of diamine(s) and endcapped with phenylethynyl phthalic anhydride(s) has been performed in m-cresol. Phenylethynyl phthalic anhydrides are synthesized by the palladium catalyzed reaction of phenylacetylene with bromo substituted phthalic anhydrides in triethylamine. These new materials exhibit excellent properties and are potentially useful as adhesives, coatings, films, moldings and composite matrices.

  14. PDMS-modified poly(styrene-alt-maleic anhydride)s as water-borne coatings based on surfactant-free latexes

    NARCIS (Netherlands)

    Gunbas, I.D.; Wouters, M.E.L.; Benthem, R.A.T.M. van; Koning, C.E.; Noordover, B.A.J.

    2013-01-01

    In this work, two series of PDMS-modified poly(styrene-alt-maleic anhydride)s (PSMA) were prepared by the partial imidization of their anhydride groups with mono-functional, amine-terminated polydimethyl siloxanes (PDMS-NH2) with two different molecular weights. Subsequently, surfactant-free

  15. Charge-Reversible Multifunctional HPMA Copolymers for Mitochondrial Targeting.

    Science.gov (United States)

    Wang, Fengling; Sun, Wei; Li, Lian; Li, Lijia; Liu, Yuanyuan; Zhang, Zhi-Rong; Huang, Yuan

    2017-08-23

    Mitochondrial-oriented delivery of anticancer drugs has been considered as a promising strategy to improve the antitumor efficiency of chemotherapeutics. However, the physiological and biological barriers from the injection site to the final mitochondrial action site remain great challenges. Herein, a novel mitochondrial-targeted multifunctional nanocomplex based on N-(2-hydroxypropyl) methacrylamide (HPMA) copolymers (MPC) is designed to enhance drug accumulation in mitochondria. MPC possesses various functions such as extracellular pH response, superior cellular uptake, lysosomal escape, and mitochondrial targeting. In detail, MPC was formed by two oppositely charged HPMA copolymers, that is, positively charged mitochondrial-targeting guanidine group-modified copolymers and charge-reversible 2,3-dimethylmaleic anhydride (DMA)-modified copolymers (P-DMA). It was validated that MPC could remain stable in the blood circulation (pH 7.4) but could be cleaved to expose the positive charge of the guanidine group immediately in response to the mild acidity of tumor tissues (pH 6.5). The gradual exposure of positively charged guanidine will simultaneously facilitate endocytosis, endosomal/lysosomal escape, and mitochondrial targeting. The in vitro experiments showed that compared with copolymers without guanidine modification, the cellular uptake and mitochondrial-targeting ability of MPC in the simulated tumor environment (MPC@pH6.5) separately increased 4.3- and 23.8-fold, respectively. The in vivo experiments were processed on B16F10 tumor-bearing C57 mice, and MPC showed the highest accumulation in the tumor site and a peak tumor inhibition rate of 82.9%. In conclusion, multifunctional mitochondrial-targeting HPMA copolymers provide a novel and versatile approach for cancer therapy.

  16. Phthalic anhydride: Illustrating a conundrum in chemical allergy.

    Science.gov (United States)

    Basketter, David A; Kimber, Ian

    2016-11-01

    Although a substantial number of chemicals has the ability to bind covalently to proteins and thereby, given sufficient exposure, induce a state of sensitization, only a small minority appear to be able to cause allergic hypersensitivity of the respiratory tract; the great majority being exclusively skin sensitizers. The key mechanistic drivers for the differentiation between skin and respiratory sensitization are already well characterized at the cellular/cytokine level. However, at both the chemical level and in terms of predictive toxicology, matters are much less clear. In the present article, phthalic anhydride is used as an exemplar, since it displays a particularly differentiated profile as a chemical allergen. Whereas most respiratory sensitizers are known also to give rise to delayed skin reactions, evidence for phthalic anhydride suggests that it only causes immediate type allergy. Chemically, phthalic anhydride can be presumed to react similar to other respiratory sensitizing anhydrides; in predictive tests for skin sensitization, phthalic anhydride is clearly positive, a property it has in common with all other chemical respiratory allergens. Thus, in the context of interpreting predictive toxicology tests for skin sensitization, the inference is that negative results demonstrate an absence of both skin- and respiratory-sensitizing capacity.

  17. Silicone/Acrylate Copolymers

    Science.gov (United States)

    Dennis, W. E.

    1982-01-01

    Two-step process forms silicone/acrylate copolymers. Resulting acrylate functional fluid is reacted with other ingredients to produce copolymer. Films of polymer were formed by simply pouring or spraying mixture and allowing solvent to evaporate. Films showed good weatherability. Durable, clear polymer films protect photovoltaic cells.

  18. Silicon containing copolymers

    CERN Document Server

    Amiri, Sahar; Amiri, Sanam

    2014-01-01

    Silicones have unique properties including thermal oxidative stability, low temperature flow, high compressibility, low surface tension, hydrophobicity and electric properties. These special properties have encouraged the exploration of alternative synthetic routes of well defined controlled microstructures of silicone copolymers, the subject of this Springer Brief. The authors explore the synthesis and characterization of notable block copolymers. Recent advances in controlled radical polymerization techniques leading to the facile synthesis of well-defined silicon based thermo reversible block copolymers?are described along with atom transfer radical polymerization (ATRP), a technique utilized to develop well-defined functional thermo reversible block copolymers. The brief also focuses on Polyrotaxanes and their great potential as stimulus-responsive materials which produce poly (dimethyl siloxane) (PDMS) based thermo reversible block copolymers.

  19. Method for epoxy foam production using a liquid anhydride

    Science.gov (United States)

    Celina, Mathias [Albuquerque, NM

    2012-06-05

    An epoxy resin mixture with at least one epoxy resin of between approximately 50 wt % and 100 wt %, an anhydride cure agent of between approximately 0 wt % and approximately 50 wt %, a tert-butoxycarbonyl anhydride foaming agent of between proximately 0.1-20 wt %, a surfactant and an imidazole or similar catalyst of less than approximately 2 wt %, where the resin mixture is formed from at least one epoxy resin with a 1-10 wt % tert-butoxycarbonyl anhydride compound and an imidazole catalyst at a temperature sufficient to keep the resin in a suitable viscosity range, the resin mixture reacting to form a foaming resin which in the presence of an epoxy curative can then be cured at a temperature greater than 50.degree. C. to form an epoxy foam.

  20. Hydration of AN Acid Anhydride: the Water Complex of Acetic Sulfuric Anhydride

    Science.gov (United States)

    Smith, CJ; Huff, Anna; Mackenzie, Becca; Leopold, Ken

    2017-06-01

    The water complex of acetic sulfuric anhydride (ASA, CH_{3}COOSO_{2}OH) has been observed by pulsed nozzle Fourier transform microwave spectroscopy. ASA is formed in situ in the supersonic jet via the reaction of SO_{3} and acetic acid and subsequently forms a complex with water during the expansion. Spectra of the parent and fully deuterated form, as well as those of the species derived from CH_{3}^{13}COOH, have been observed. The fitted internal rotation barrier of the methyl group is 219.599(21), \\wn indicating the complexation with water lowers the internal rotation barrier of the methyl group by 9% relative to that of free ASA. The observed species is one of several isomers identified theoretically in which the water inserts into the intramolecular hydrogen bond of the ASA. Aspects of the intermolecular potential energy surface are discussed.

  1. Carboxylic Terminated Thermo-Responsive Copolymer Hydrogel and Improvement in Peptide Release Profile

    Directory of Open Access Journals (Sweden)

    Zi-Kun Rao

    2018-02-01

    Full Text Available To improve the release profile of peptide drugs, thermos-responsive triblock copolymer poly (ε-caprolactone-co-p-dioxanone-b-poly (ethylene glycol-b-poly (ε-caprolactone-co-p-dioxanone (PECP was prepared and end capped by succinic anhydride to give its carboxylic terminated derivative. Both PCEP block copolymer and its end group modified derivative showed temperature-dependent reversible sol-gel transition in water. The carboxylic end group could significantly decrease the sol-gel transition temperature by nearly 10 °C and strengthen the gel due to enhanced intermolecular force among triblock copolymer chains. Furthermore, compared with the original PECP triblock copolymer, HOOC–PECP–COOH copolymer displayed a retarded and sustained release profile for leuprorelin acetate over one month while effectively avoiding the initial burst. The controlled release was believed to be related to the formation of conjugated copolymer-peptide pair by ionic interaction and enhanced solubility of drug molecules into the hydrophobic domains of the hydrogel. Therefore, carboxyl terminated HOOC–PECP–COOH hydrogel was a promising and well-exhibited sustained release carrier for peptide drugs with the advantage of being able to develop injectable formulation by simple mixing.

  2. Radical coupling of maleic anhydride onto graphite to fabricate ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 39; Issue 1. Radical coupling of maleic anhydride onto graphite to fabricate oxidized graphene nanolayers ... After modification with MAH, lamella flake structure of graphite was retained whereas the edges of sheets became distinguishable as depicted by scanning ...

  3. Triflic Anhydride-Mediated Beckmann Rearrangement Reaction of Β ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 128; Issue 6. Triflic Anhydride-Mediated Beckmann Rearrangement Reaction of Β-Oximyl Amides: Access to 5-Iminooxazolines. MANGFEI YU QIAN ZHANG JIA WANG PENG HUANG PENGFEI YAN RUI ZHANG DEWEN DONG. Regular Article Volume 128 Issue 6 ...

  4. Condensation of anhydrides or dicarboxylic acids with compounds containing active methylene groups. Part 1: Condensation of phthalic anhydride with acetoacetic and malonic ester

    Science.gov (United States)

    Oshkaya, V. P.; Vanag, G. Y.

    1985-01-01

    Phthalic anhydride was condensed with acetoacetic ester in acetic anhydride and triethylamine solution, and when phthalyl chloride was reacted with sodium acetoacetic ester compounds were formed of the phthalide and indandione series: phthalylacetoacetic ester and a derivative of indan-1,3-dione which after boiling with hydrochloric acid yielded indan-1,3-dione. Phthalylmalonic ester was obtained from phthalic anhydride and malonic ester in the presence of triethylamine.

  5. Synthesis and characterization of functional copolymer/organo-silicate nanoarchitectures through interlamellar complex-radical (coterpolymerization

    Directory of Open Access Journals (Sweden)

    2008-09-01

    Full Text Available The functional copolymers, having a combination of rigid/flexible linkages and an ability of complex-formation with interlayered surface of organo-silicate, and their nanocomposites have been synthesized by interlamellar complex-radical (coterpolymerization of intercalated monomer complexes of maleic anhydride (MA and itaconic acid (IA with dimethyl dodecylamine surface modified montmorillonite (organo-MMT (MA…DMDA-MMT and IA…DMDA-MMT n-butyl methacrylate (BMA and/or BMA/styrene monomer mixtures. The results of nanocomposite structure–composition– property relationship studies indicate that interlamellar complex-formation between anhydride/acid units and surface alkyl amine and rigid/flexible linkage balance in polymer chains are important factors providing the effective intercalation/ exfoliation of the polymer chains into the silicate galleries, the formation of nanostructural hybrids with higher thermal stability, dynamic mechanical behaviour and well dispersed morphology.

  6. Effect of gamma-dose rate and total dose interrelation on the polymeric hydrogel: A novel injectable male contraceptive

    Energy Technology Data Exchange (ETDEWEB)

    Jha, Pradeep K. [School of Medical Science and Technology, Indian Institute of Technology, Kharagpur 721302 (India); Department of Management Science, U.P. Technical University, Lucknow 226021 (India); Jha, Rakhi [School of Medical Science and Technology, Indian Institute of Technology, Kharagpur 721302 (India); Toxicology Laboratory, Department of Zoology, Ch. C.S. University, Meerut 200005 (India); Gupta, B.L. [CH3/56 Kendriya Vihar, Kharghar, Sector-11, Navi Mumbai-410 210 (India); Guha, Sujoy K., E-mail: guha_sk@yahoo.co [School of Medical Science and Technology, Indian Institute of Technology, Kharagpur 721302 (India)

    2010-05-15

    Functional necessity to use a particular range of dose rate and total dose of gamma-initiated polymerization to manufacture a novel polymeric hydrogel RISUG (reversible inhibition of sperm under guidance) made of styrene maleic anhydride (SMA) dissolved in dimethyl sulphoxide (DMSO), for its broad biomedical application explores new dimension of research. The present work involves 16 irradiated samples. They were tested by fourier transform infrared spectroscopy, matrix assisted laser desorption/ionization-TOF, field emission scanning electron microscopy, high resolution transmission electron microscopy, etc. to see the interrelation effect of gamma dose rates (8.25, 17.29, 20.01 and 25.00 Gy/min) and four sets of doses (1.8, 2.0, 2.2 and 2.4 kGy) on the molecular weight, molecular weight distribution and porosity analysis of the biopolymeric drug RISUG. The results of randomized experiment indicated that a range of 18-24 Gy/min gamma-dose rate and 2.0-2.4 kGy gamma-total doses is suitable for the desirable in vivo performance of the contraceptive copolymer.

  7. Effect of γ-dose rate and total dose interrelation on the polymeric hydrogel: A novel injectable male contraceptive

    Science.gov (United States)

    Jha, Pradeep K.; Jha, Rakhi; Gupta, B. L.; Guha, Sujoy K.

    2010-05-01

    Functional necessity to use a particular range of dose rate and total dose of γ-initiated polymerization to manufacture a novel polymeric hydrogel RISUG ® (reversible inhibition of sperm under guidance) made of styrene maleic anhydride (SMA) dissolved in dimethyl sulphoxide (DMSO), for its broad biomedical application explores new dimension of research. The present work involves 16 irradiated samples. They were tested by fourier transform infrared spectroscopy, matrix assisted laser desorption/ionization-TOF, field emission scanning electron microscopy, high resolution transmission electron microscopy, etc. to see the interrelation effect of gamma dose rates (8.25, 17.29, 20.01 and 25.00 Gy/min) and four sets of doses (1.8, 2.0, 2.2 and 2.4 kGy) on the molecular weight, molecular weight distribution and porosity analysis of the biopolymeric drug RISUG ®. The results of randomized experiment indicated that a range of 18-24 Gy/min γ-dose rate and 2.0-2.4 kGy γ-total doses is suitable for the desirable in vivo performance of the contraceptive copolymer.

  8. SMA chemical modification for application as diesel oil additive; Modificacao quimica do SMA visando aplicacao como aditivo para oleo diesel

    Energy Technology Data Exchange (ETDEWEB)

    Soldi, Rafael A.; Oliveira, Angelo R.S.; Zawadzki, Sonia F.; Cesar-Oliveira, Maria Aparecida F. [Parana Univ., Curitiba, PR (Brazil). Dept. de Quimica. Lab. de Polimeros Sinteticos]. E-mails: rafaelsoldi@hotmail.com, mafco@quimica.ufpr.br

    2003-07-01

    The deposition of paraffinic material during the crude oil and their derivatives production and transportation is one of the principal problems in the petroleum industry. Polymer derivatives obtained from styrene-maleic anhydride copolymers (SMA), containing long pendant hydrocarbon segments in the polymeric backbone, are known as efficient polymeric additives to prevent the wax deposition and to reduce the oil pour point. Nevertheless, this application for this class of polymer is not much evaluated in Brazil. In this work, a new procedure was developed for SMA synthesis and chemical modification using stearyl alcohol. The performance of these polymeric materials as pour point depressants were evaluated using a Brazilian diesel oil from REPAR/PETROBRAS. The best results were obtained for the polymeric additives with small amounts of octadecyl ester groups. When it was used only 25 ppm of one of these additives, the oil presented a pour point value of -17 deg C and the diesel oil containing 100 ppm of this same additive presented a pour point value of -30 deg C. This last result indicates a 24 deg C pour point decreasing. (author)

  9. Experimental and Computational Thermochemistry of 3- and 4-Nitrophthalic Anhydride.

    Science.gov (United States)

    García-Castro, Miguel A; Amador, Patricia; Hernández-Pérez, Julio M; Medina-Favela, Adrián E; Flores, Henoc

    2014-05-29

    In order to understand the influence that the position of the nitro group on the aromatic ring has on the relative stability of two isomers, the standard enthalpies of formation of 3- and 4-nitrophthalic anhydride in the gaseous phase, at T = 298.15 K, were obtained by experimental thermochemistry and theoretical studies. The standard enthalpies of formation in the crystalline phase, at T = 298.15 K, were obtained by combustion calorimetry and the enthalpies of sublimation by the Knudsen method. For the theoretical calculations, a standard ab initio molecular orbital method at the G3 level was used. The enthalpies of formation in the gaseous phase were obtained from atomization and isodesmic reactions. A theoretical study of the molecular and electronic structures of these compounds was also performed. Differences of -9.7 kJ·mol(-1), for 3-nitrophthalic anhydride, and -2.6 kJ·mol(-1) for 4-nitrophthalic anhydride, were found from a comparison between our theoretical and experimental results.

  10. Stereoselective direct glycosylation with anomeric hydroxy sugars by activation with phthalic anhydride and trifluoromethanesulfonic anhydride involving glycosyl phthalate intermediates.

    Science.gov (United States)

    Kim, Kwan Soo; Fulse, Dinanath Baburao; Baek, Ju Yuel; Lee, Bo-Young; Jeon, Heung Bae

    2008-07-02

    An efficient direct one-pot glycosylation method with anomeric hydroxy sugars as glycosyl donors employing phthalic anhydride and triflic anhydride as activating agents has been developed. Thus, highly stereoselective beta-mannopyranosylations were achieved by the reaction of 2,3-di-O-benzyl-4,6-O-benzylidene-D-mannopyranose (2) with phthalic anhydride in the presence of DBU at room temperature followed by sequential addition of DTBMP and Tf2O and glycosyl acceptors to the reaction mixture at -78 degrees C in one-pot. Stereoselective alpha-glucopyranosylations with 2,3-di-O-benzyl-4,6-O-benzylidene-D-glucopyranose (25) and other glycosylations with glucopyranoses and mannopyranoses having tetra-O-benzyl- and tetra-O-benzoyl protecting groups were also possible by utilizing the present one-pot glycosylation protocol. The possible mechanism for the beta-mannosylation with 2 was proposed based on the NMR study, in which alpha-mannosyl phthalate 55alpha and alpha-mannosyl triflate 59 were detected as intermediates. The versatility and efficiency of the present glycosylation methodology, especially those of the beta-mannopyranosylation protocol, were readily demonstrated by the efficient synthesis of protected beta-(1-->4)-D-mannotriose 62 and beta-(1-->4)-D-mannotetraose 67 with perfect beta-stereoselectivity.

  11. 78 FR 76567 - Tall Oil, Polymer With Polyethylene Glycol and Succinic Anhydride Monopolyisobutylene Derivs...

    Science.gov (United States)

    2013-12-18

    ...,000, and the polymer does not contain any reactive functional groups. Thus, tall oil, polymer with... AGENCY 40 CFR Part 180 Tall Oil, Polymer With Polyethylene Glycol and Succinic Anhydride... oil, polymer with polyethylene glycol and succinic anhydride monopolyisobutylene derivs. (CAS Reg. No...

  12. Investigations on organolead compounds III. The reaction of organolead compounds with ketene. (Triphenylplumbyl)acetic anhydride

    NARCIS (Netherlands)

    Willemsens, L.C.; Kerk, G.J.M. van der

    The reaction of ketene with triphenyllead hydroxide in diethyl ether gave (triphenylplumbyl)acetic anhydride, (Ph3PbCH2CO)2O, the first anhydride-substituted organolead compound known. The reaction of ketene with triphenyllead acetate in absolute ethanol gave ethyl (triphenylplumbyl)acetate,

  13. Block copolymer investigations

    Science.gov (United States)

    Yufa, Nataliya A.

    The research presented in this thesis deals with various aspects of block copolymers on the nanoscale: their behavior at a range of temperatures, their use as scaffolds, or for creation of chemically striped surfaces, as well as the behavior of metals on block copolymers under the influence of UV light, and the healing behavior of copolymers. Invented around the time of World War II, copolymers have been used for decades due to their macroscopic properties, such as their ability to be molded without vulcanization, and the fact that, unlike rubber, they can be recycled. In recent years, block copolymers (BCPs) have been used for lithography, as scaffolds for nano-objects, to create a magnetic hard drive, as well as in photonic and other applications. In this work we used primarily atomic force microscopy (AFM) and transmission electron microscopy (TEM), described in Chapter II, to conduct our studies. In Chapter III we demonstrate a new and general method for positioning nanoparticles within nanoscale grooves. This technique is suitable for nanodots, nanocrystals, as well as DNA. We use AFM and TEM to demonstrate selective decoration. In Chapters IV and V we use AFM and TEM to study the structure of polymer surfaces coated with metals and self-assembled monolayers. We describe how the surfaces were created, exhibit their structure on the nanoscale, and prove that their macroscopic wetting properties have been altered compared to the original polymer structures. Finally, Chapters VI and VII report out in-situ AFM studies of BCP at high temperatures, made possible only recently with the invention of air-tight high-temperature AFM imaging cells. We locate the transition between disordered films and cylinders during initial ordering. Fluctuations of existing domains leading to domain coarsening are also described, and are shown to be consistent with reptation and curvature minimization. Chapter VII deals with the healing of PS-b-PMMA following AFM-tip lithography or

  14. Modification of wheat starch with succinic acid/acetic anhydride and azelaic acid/acetic anhydride mixtures I. Thermophysical and pasting properties.

    Science.gov (United States)

    Subarić, Drago; Ačkar, Durđica; Babić, Jurislav; Sakač, Nikola; Jozinović, Antun

    2014-10-01

    The aim of this research was to investigate the influence of modification with succinic acid/acetic anhydride and azelaic acid/acetic anhydride mixtures on thermophysical and pasting properties of wheat starch. Starch was isolated from two wheat varieties and modified with mixtures of succinic acid and acetic anhydride, and azelaic acid and acetic anhydride in 4, 6 and 8 % (w/w). Thermophysical, pasting properties, swelling power, solubility and amylose content of modified starches were determined. The results showed that modifications with mixtures of afore mentioned dicarboxylic acids with acetic anhydride decreased gelatinisation and pasting temperatures. Gelatinisation enthalpy of Golubica starch increased, while of Srpanjka starch decreased by modifications. Retrogradation after 7 and 14 day-storage at 4 °C decreased after modifications of both starches. Maximum, hot and cold paste viscosity of both starches increased, while stability during shearing at high temperatures decreased. % setback of starches modified with azelaic acid/acetic anhydride mixture decreased. Swelling power and solubility of both starches increased by both modifications.

  15. Synthesis and Alcoholysis of α-Alkylated Cyclopentane and Cyclohexane Fused Succinic Racemic Anhydrides in the Presence of Chiral Bases

    Directory of Open Access Journals (Sweden)

    Lidija Lerman

    2015-12-01

    Full Text Available Bicyclic succinic anhydrides alkylated at the α-position have been prepared and submitted to alcoholysis in the presence of alkaloid bases. Anhydrides with a cyclopentane fused ring, open only from the less hindered side, generating monoesters of >80 % ee, whereas cyclohexane fused anhydrides undergo parallel kinetic resolution, producing both regioisomeric monoesters.

  16. Adsorption of heavy metal ions and azo dyes by crosslinked nanochelating resins based on poly(methylmethacrylate-co-maleic anhydride

    Directory of Open Access Journals (Sweden)

    M. Ghaemy

    2014-03-01

    Full Text Available Chelating resins are suitable materials for the removal of heavy metals in water treatments. A copolymer, Poly(MMA-co-MA, was synthesized by radical polymerization of maleic anhydride (MA and methyl methacrylate (MMA, characterized and transformed into multifunctional nanochelating resin beads (80–150 nm via hydrolysis, grafting and crosslink reactions. The resin beads were characterized by swelling studies, field emission scanning electron microscopy (FESEM and Fourier transform infrared spectroscopy (FTIR. The main purpose of this work was to determine the adsorption capacity of the prepared resins (swelling ratio ~55% towards metal ions such as Hg2+, Cd2+, Cu2+ from water at three different pH values (3, 6 and 9. Variations in pH and types of metal ions have not significantly affected the chelation capacity of these resins. The maximum chelation capacity of one of the prepared resin beads (Co-g-AP3 for Hg2+ was 63, 85.8 and 71.14 mg/g at pH 3, 6 and 9, respectively. Approximately 96% of the metal ions could be desorbed from the resin. Adsorption capacity of these resins towards three commercial synthetic azo dyes was also investigated. The maximum adsorption of dye AY42 was 91% for the resin Co-g-AP3 at room temperature. This insures the applicability of the synthesized resins for industrial applications.

  17. Chemical Modification of Butyl Rubber with Maleic Anhydride via Nitroxide Chemistry and Its Application in Polymer Blends

    Directory of Open Access Journals (Sweden)

    José Bonilla-Cruz

    2017-02-01

    Full Text Available Butyl rubber (isobutylene–isoprene–rubber, IIR was functionalized in solution with a nitroxide moiety taking advantage of the unsaturations present in the isoprene units of IIR, and was further grafted with maleic anhydride (MA or styrene–MA (SMA to produce IIR-g-MA and IIR-g-SMA. In one of the functionalization techniques used, the molecular structure of the IIR was preserved as the chain-breaking reactions are prevented from occurring. The resulting graft copolymers were tested as compatiblizers/impact modifiers blended with Nylon-6, and one of them was preliminarily tested as a coupling agent in the preparation of nanocomposites of IIR and an organo-clay. Blends of PA-6/IIR-g-MA exhibited a significant increase in impact resistance at increasing loads of the modified IIR, as well as a good rubber particle dispersion in the polyamide matrix. On the other hand, the performance of IIR-g-SMA as an impact modifier of PA, or as a coupling agent in the preparation of rubber-organoclay nanocomposites, is marginal.

  18. Styrene maleic acid-encapsulated paclitaxel micelles: antitumor activity and toxicity studies following oral administration in a murine orthotopic colon cancer model.

    Science.gov (United States)

    Parayath, Neha N; Nehoff, Hayley; Norton, Samuel E; Highton, Andrew J; Taurin, Sebastien; Kemp, Roslyn A; Greish, Khaled

    2016-01-01

    Oral administration of paclitaxel (PTX), a broad spectrum anticancer agent, is challenged by its low uptake due to its poor bioavailability, efflux through P-glycoprotein, and gastrointestinal toxicity. We synthesized PTX nanomicelles using poly(styrene-co-maleic acid) (SMA). Oral administration of SMA-PTX micelles doubled the maximum tolerated dose (60 mg/kg vs 30 mg/kg) compared to the commercially available PTX formulation (PTX [Ebewe]). In a murine orthotopic colon cancer model, oral administration of SMA-PTX micelles at doses 30 mg/kg and 60 mg/kg reduced tumor weight by 54% and 69%, respectively, as compared to the control group, while no significant reduction in tumor weight was observed with 30 mg/kg of PTX (Ebewe). In addition, toxicity of PTX was largely reduced by its encapsulation into SMA. Furthermore, examination of the tumors demonstrated a decrease in the number of blood vessels. Thus, oral delivery of SMA-PTX micelles may provide a safe and effective strategy for the treatment of colon cancer.

  19. Copolymères greffés et matériaux nanostructurés à base de polyméthacrylate de méthyle et de polyamide-6

    OpenAIRE

    Freluche, Mathilde

    2005-01-01

    This work focuses on the synthesis of nanostructured polymeric materials based on polymethylmethacrylate (PMMA) and polyamide-6 (PA-6). Blends are prepared by reactive blending, namely melt-mixing of polymers bearing mutually reactive groups. The grafting reaction occurs between the amino end-group of PA-6 and glutaric anhydride units distributed along PMMA backbones. The compositions of the extruded blend and of the graft copolymer can be estimated in most cases using a method based on size ...

  20. Low Viscosity Imides Based on Asymmetric Oxydiphthalic Anhydride

    Science.gov (United States)

    Chuang, Kathy C.; Criss, Jim M., Jr.; Mintz, Eric A.; Scheiman, Daniel A.; Nguyen, Baochau N.; McCorkle, Linda S.

    2008-01-01

    A series of low-melt viscosity imide resins were prepared from asymmetric oxydiphthalic dianhydride (a-ODPA) and 4-phenylethynylphthalic anhydride as the endcap, along with 3,4' - oxydianiline (3,4' -ODA), 3,4' -methylenedianiline (3,4' -MDA), 3,3' -methylenedianiline (3,3' - MDA) and 3,3'-diaminobenzophenone (3,3'-DABP), using a solvent-free melt process. These imide oligomers displays low-melt viscosities (2-15 poise) at 260-280 C, which made them amenable to low-cost resin transfer molding (RTM) process. The a-ODPA based RTM resins exhibits glass transition temperatures (Tg's) in the range of 265-330 C after postcure at 343 C. The mechanical properties of these polyimide/carbon fiber composites fabricated by RTM will be discussed.

  1. Copolymerization and terpolymerization of carbon dioxide/propylene oxide/phthalic anhydride using a (salen)Co(III) complex tethering four quaternary ammonium salts.

    Science.gov (United States)

    Jeon, Jong Yeob; Eo, Seong Chan; Varghese, Jobi Kodiyan; Lee, Bun Yeoul

    2014-01-01

    The (salen)Co(III) complex 1 tethering four quaternary ammonium salts, which is a highly active catalyst in CO2/epoxide copolymerizations, shows high activity for propylene oxide/phthalic anhydride (PO/PA) copolymerizations and PO/CO2/PA terpolymerizations. In the PO/PA copolymerizations, full conversion of PA was achieved within 5 h, and strictly alternating copolymers of poly(1,2-propylene phthalate)s were afforded without any formation of ether linkages. In the PO/CO2/PA terpolymerizations, full conversion of PA was also achieved within 4 h. The resulting polymers were gradient poly(1,2-propylene carbonate-co-phthalate)s because of the drift in the PA concentration during the terpolymerization. Both polymerizations showed immortal polymerization character; therefore, the molecular weights were determined by the activity (g/mol-1) and the number of chain-growing sites per 1 [anions in 1 (5) + water (present as impurity) + ethanol (deliberately fed)], and the molecular weight distributions were narrow (M w/M n, 1.05-1.5). Because of the extremely high activity of 1, high-molecular-weight polymers were generated (M n up to 170,000 and 350,000 for the PO/PA copolymerization and PO/CO2/PA terpolymerization, respectively). The terpolymers bearing a substantial number of PA units (f PA, 0.23) showed a higher glass-transition temperature (48 °C) than the CO2/PO alternating copolymer (40 °C).

  2. Copolymerization and terpolymerization of carbon dioxide/propylene oxide/phthalic anhydride using a (salenCo(III complex tethering four quaternary ammonium salts

    Directory of Open Access Journals (Sweden)

    Jong Yeob Jeon

    2014-08-01

    Full Text Available The (salenCo(III complex 1 tethering four quaternary ammonium salts, which is a highly active catalyst in CO2/epoxide copolymerizations, shows high activity for propylene oxide/phthalic anhydride (PO/PA copolymerizations and PO/CO2/PA terpolymerizations. In the PO/PA copolymerizations, full conversion of PA was achieved within 5 h, and strictly alternating copolymers of poly(1,2-propylene phthalates were afforded without any formation of ether linkages. In the PO/CO2/PA terpolymerizations, full conversion of PA was also achieved within 4 h. The resulting polymers were gradient poly(1,2-propylene carbonate-co-phthalates because of the drift in the PA concentration during the terpolymerization. Both polymerizations showed immortal polymerization character; therefore, the molecular weights were determined by the activity (g/mol-1 and the number of chain-growing sites per 1 [anions in 1 (5 + water (present as impurity + ethanol (deliberately fed], and the molecular weight distributions were narrow (Mw/Mn, 1.05–1.5. Because of the extremely high activity of 1, high-molecular-weight polymers were generated (Mn up to 170,000 and 350,000 for the PO/PA copolymerization and PO/CO2/PA terpolymerization, respectively. The terpolymers bearing a substantial number of PA units (fPA, 0.23 showed a higher glass-transition temperature (48 °C than the CO2/PO alternating copolymer (40 °C.

  3. Synthesis of polyaspartic acid-aminobenzenesulfonic acid grafted copolymer and its scale inhibition performance and dispersion capacity.

    Science.gov (United States)

    Xu, Ying; Wang, Lina; Zhao, Linlin; Cui, Yuanchen

    2011-01-01

    Polysuccinimide (abridged as PSI) was synthesized by urea and maleic anhydride. Aminobenzenesulfonic acid (ABSA) was introduced at different mole ratio to PSI to generate polyaspartic acid (abridged as PASP)/ABSA graft copolymer. The scale inhibition behavior of resultant PASP/ABSA copolymer was evaluated by using static scale inhibition method. The transmittance of the supernatant of the copolymer solution was measured to evaluate its dispersion ability for ferric oxide. The corrosion inhibition performance of the copolymer for iron plates immersed in the refined testing water (including 0.555 g of CaCl2 2H2O, 0.493 g of MgSO4 7H2O, 50 mg PASP/ABSA graft copolymer and 0.168 g of NaCl) was tested. It was found that PASP/ABSA copolymer was able to efficiently inhibit CaCO3 and Ca3(PO4)2 scales and had good corrosion inhibition ability as well, and it also had good dispersion ability for Fe2O3. Besides, the inhibition efficiency of PASP/ABSA against CaCO3 and Ca3(PO4)2 scales and its dispersion capacity for Fe2O3 was highly dependent on dosage. The reason may lie in that PASP/ABSA copolymer simultaneously possesses carboxylic ion and sulfonic group which can chelate Ca2+ to form stabilized and dissoluble chelates, resulting in increase of solubility of calcium salts in water. Also it may lie in that the introduction of acidic hydrophilic sulfonic group with a strong electrolytic capacity into PASP molecule simultaneously enhances the dispersion of the inhibitor molecules and hinders the formation of Ca3(PO4)2 scale.

  4. Development of chitosan derivatives with anhydride maleic; Desenvolvimento de derivados de quitosana com anidrido maleico

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Solranny C.C.C.; Braz, Elton Marks de A.; Brito, Carla Adriana R. de S.; Silva, Durcilene A. da; Junior, Luiz de S.S.; Silva Filho, Edson C. da, E-mail: solbiologa@hotmail.com [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil)

    2015-07-01

    Chitosan was chemically modified with maleic anhydride in ratios of 1/2, 1/5 and 1/10 in the absence of solvents. The obtained derivatives were characterized by elemental analysis, FTIR, thermal analysis (TGA / DTG) and XRD where it was possible to prove the chemical modification. Elemental analysis showed an increase of the relation C / N with the increasing of the proportion of anhydrides. The FTIR showed the incorporation of the anhydride in the biopolymer structure. The thermal stability of the derivatives was lower in comparison to the polysaccharide and by XRD the modified materials were less crystalline. (author)

  5. Effects of concentration of maleic anhydride of compatibilizer on morphology and mechanical properties of PA6/AES blend-based nanocomposites; Efeito da concentracao do grupo anidrido maleico do compatibilizante na morfologia e propriedades mecanicas de nanocompositos de blendas PA6/AES

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, A.D. de; Castro, L.D.C.; Jung, M.K.; Pessan, L.A., E-mail: amandaoliveira82@gmail.com [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil)

    2014-07-01

    The effects of functionality and concentration of the maleic anhydride (MA) group of the copolymer methyl methacrylate-maleic anhydride (MMA-MA) on the morphology and mechanical properties of nanocomposites based on polyamide 6 (PA6)/acrylonitrile-EPDM-styrene (AES) were studied. The nanocomposites were prepared in a twin screw extruder and characterized by transmission electron microscopy (MET), wide angle X-ray diffraction (WAXD) and tensile and impact tests. The impact strength results showed that the addition of 5wt% of MMA-MA with 1.4wt% of MA is sufficient to increase the toughness of the nanocomposites. A significant increase of elastic modulus was observed for the nanocomposites with respect to the pure blend (PA6/AES). TEM micrographs showed that the clay layers exhibited exfoliated structure and are preferably located in the matrix phase. (author)

  6. Highly efficient peptide formation from N-acetylaminoacyl-AMP anhydride and free amino acid

    Science.gov (United States)

    Mullins, D. W., Jr.; Lacey, J. C., Jr.

    1983-01-01

    The kinetics of formation of the N-blocked dipeptide, N-acetylglycylglycine, from N-acetylglycyl adenylate anhydride and glycine in aqueous solution at 25 C, and at various PH's are reported. The reaction is of interest in that over a physiologically relevant pH range (6-8), peptide synthesis proceeds more rapidly than hydrolysis, even at those pH's at which this compound becomes increasingly susceptible to base-catalyzed hydrolysis. Under similar conditions, the corresponding unblocked aminoacyl adenylate anhydrides are considerably more unstable, and undergo appreciable hydrlysis in the presence of free amino acid. Because N-blocked aminoacyl adenylate anhydrides serve as model compounds of peptidyl adenylate anhydrides, these results suggest that primitive amino acid polymerization systems may have operated by cyclic reactivation of the peptidyl carboxyl group, rather than that of the incoming amino acid.

  7. Advantages of polycarboxylic over dicarboxylic anhydrides in the melt modification of PPC

    Directory of Open Access Journals (Sweden)

    C. Barreto

    2013-11-01

    Full Text Available We present an alternative polymer modification of poly (propylene carbonate (PPC. A conventional practice for PPC melt processing is the melt – modification with maleic anhydride (MAH – a di-carboxylic anhydride –. In our work, PPC is melt-modified with pyromellitic di-anhydride (PDAH – a tetra-carboxylic dianhydride –. Using MAH modified PPC as reference, the polymer degradation and the thermal and viscoelastic properties of the materials are studied. Both anhydrides after their melt compounding have similar efficiency in the conservation of the molecular weight. Strikingly, the use of PDAH is advantageous over MAH considering the improvement of the thermal stability, the decrease of the complex melt viscosity and higher storage modulus (stiffness of the modified PPC. It is speculated that the changes in the material performance arise from the occurrence of long chain branching and non-covalent interactions from the PDAH modifier.

  8. Respiratory allergy and pulmonary irritation to trimellitic anhydride in Brown Norway rats

    NARCIS (Netherlands)

    Arts, J.H.E.; Bloksma, N.; Leusink-Muis, T.; Kuper, C.F.

    2003-01-01

    Occupational exposure to low-molecular-weight (LMW) allergens such as acid anhydrides can result in occupational asthma, an allergic disease characterized by episodic airway obstruction, airways inflammation, and non specific airways hyperresponsiveness. Since LMW irritants can provoke rather

  9. New determination method for sulfonation degree of phthalic anhydride by RP-HPLC.

    Science.gov (United States)

    Zhu, Lijun; Song, Lechun; Liu, Bin; Zhou, Yulu; Xiang, Yuzhi; Xia, Daohong

    2014-01-01

    A novel method was developed to monitor the reaction process and evaluate the sulfonation level in the sulfonation of phthalic anhydride by reversed-phase high-performance liquid chromatography (RP-HPLC). The product peak was identified in chromatograms through product analysis and by comparing its retention time with that of standard compounds. By comparing the hydrolysis and alcoholysis methods, optimized pretreatment of the sample was found for RP-HPLC. Based on the determined percentages of phthalic anhydride and sulfonated phthalic anhydride in the mixture, the degree of sulfonation was calculated. When the sulfonation degree of phthalic anhydride was in the range of 2.8-71%, the recovery of 97-104% was achieved, and the procedure was rapid and accurate.

  10. Poly(butylene succinate-co-butylene adipate)/cellulose nanocrystal composites modified with phthalic anhydride.

    Science.gov (United States)

    Zhang, Xuzhen; Zhang, Yong

    2015-12-10

    As a kind of biomass nanofiller for polymers, cellulose nanocrystal (CNC) has good mechanical properties and reinforcing capability. To improve the compatibility of poly(butylene succinate-co-butylene adipate) (PBSA)/CNC composites, phthalic anhydride was used as a compatilizer during melt mixing, leading to the significant improvement of the mechanical properties and thermal stability of the composites, which is related to the better dispersion of CNC in the composites. The addition of phthalic anhydride could accelerate the crystallization of PBSA component as evidenced by the curves of isothermal crystallization of the composites, but had little effect on the crystalline polymorphs of PBSA component. The addition of phthalic anhydride could strongly improve the hydrophobicity of the composites. The good mechanical properties, fast crystallization and improved hydrophobicity of PBSA/CNC composites with phthalic anhydride are favor to their practical commercial utilization. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Room temperature (nπ∗) phosphorescence of indanetrione (anhydrous ninhydrine) in phthalic anhydride matrix

    Science.gov (United States)

    Roy, J.; Bhattacharya, S.; Mondal, S.; Ghosh, Sanjib

    1997-02-01

    Indanetrione, a cis vicinal cyclic triketone, is found to exhibit room temperature (nπ∗) phosphorescence (RTP) in a phthalic anhydride matrix in addition to (nπ∗) fluorescence. The compound does not show RTP in benzophenone mixed crystals or in any other solvent studied. A rigid binding of the cyclic triketone in the phthalic anhydride matrix, lowering the T 1 → S 0 nonradiative rate, has been proposed as the explanation for RTP.

  12. Réaction du polyisobutène chloré sur l'anhydride maléique : mécanisme. Catalyse par l'anhydride dichloromaléique Reaction of Chlorinated Polyisobutene on Maleic Anhydride. Mechanism. Catalysis by Dichloromaleic Anhydride

    Directory of Open Access Journals (Sweden)

    Sillion B.

    2006-11-01

    Full Text Available Dans cet article le mécanisme de la réaction de condensation du polyisobutène chloré sur l'anhydride maléique, qui sert dans la synthèse d'additif pour lubrifiant, est étudié par une cinétique globale et par un travail sur composés modèles. Il est montré que, dans cette réaction, l'anhydride maléique joue un double rôle : de catalyseur de déshydrochloration par une réactivité de type acide de Lewis organique, de réactif comme diénophile. Grâce à ces résultats, il est proposé une catalyse par l'anhydride dichloromaléique, qui permet une amélioration sensible du procédé. This article examines the mechanism of the chlorinated-polyisobutene condensation reaction on maleic anhydride. The overall kinetics and model compounds are investigated for this reaction which is used in the synthesis of lubricant additives. Maleic anhydride is shown to play the dual role of a dehydrochlorination catalyst by having a reactivity of the organic Lewis acid type and of a reactant like dienophile. These results are used to propose a catalysis by dichloromaleic anhydride which appreciably improves the process.

  13. The characteristics of specific IgG to phthalic anhydride (PA)-albumin conjugate.

    Science.gov (United States)

    Hatanaka, S; Imamura, I; Terazawa, Y; Kuroda, K; Endo, G

    1997-10-01

    Phthalic anhydride (PA), used in the chemical industry, binds to proteins and causes allergic reactions. It is important to study the characteristics of antibody to PA-protein. We produced specific IgG against PA-rabbit serum albumin (RSA) by administering subcutaneous injections of PA-RSA conjugate to two rabbits. Both rabbits' sera had high titers of IgG not only to PA-RSA but also to PA-human serum albumin (HSA) and HSA. In enzyme-linked immunosorbent assay (ELISA) and ELISA HSA inhibition, specific IgG to PA-HSA revealed cross-reactivity to three other phthalyl anhydride conjugates, hexahydrophthalic anhydride (HHPA)-HSA, methylhexahydrophthalic anhydride (MHHPA)-HSA, and methyltetrahydrophthalic anhydride (MTHPA)-HSA, in both sera. Titers of IgG to HHPA-HSA, MHHPA-HSA, and MTHPA-HSA were not significantly different. On affinity chromatography, highly specific IgG to PA hapten alone was purified. In the serum not binding to PA column, specific IgG to PA-HSA was significantly less than in original serum, but levels of specific IgG to other phthalyl anhydride-HSA were unchanged. Rabbits immunized with PA-RSA produced at least two types of IgG: one is to PA hapten alone and the other may be against new antigenic determinants (NADs) on HSA.

  14. [Determination of phthalic anhydride in ambient air by high performance liquid chromatography].

    Science.gov (United States)

    Zaĭtseva, N V; Ulanova, T S; Karnazhitskaia, T D; Antip'eva, M V; Kislitsina, A V

    2011-01-01

    The paper considers the measurement of phthalic anhydride in the ambient air samples by high performance liquid chromatography. It describes conditions for air sampling and analysis of phthalic anhydride levels in the presence of concomitant components of its production (phthalic and maleic acids, maleic anhydride, etc.) on a liquid chromatograph with an UV detector. The procedure was tested, by estimating the quality of ambient air at the border of a sanitary protection zone of phthalic anhydride production and when analyzing the air in the industrial area. Field studies detected the concentrations of phthalic anhydrate in the air of an enterprise area, which were equal to 0.017-0.115 mg/dm3. Phthalic anhydride was detectable at a concentration of 0.001-0.0021 mg/dm3 at the border of the existing sanitary protection zone in single cases. The procedure has been recommended to measure the mass concentrations of phthalic anhydride aerosol and vapors in ambient air at the reference concentration.

  15. Lignin poly(lactic acid) copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Johan Vilhelm; Chung, Yi-Lin; Li, Russell Jingxian; Waymouth, Robert; Sattely, Elizabeth; Billington, Sarah; Frank, Curtis W.

    2017-02-14

    Provided herein are graft co-polymers of lignin and poly(lactic acid) (lignin-g-PLA copolymer), thermoset and thermoplastic polymers including them, methods of preparing these polymers, and articles of manufacture including such polymers.

  16. Removal of Copper ions from aqueous solutions using polymer derivations of poly (styrene-alt-maleic anhydride

    Directory of Open Access Journals (Sweden)

    Naser Samadi

    2017-06-01

    Full Text Available In this study chelating resins have been considered to be suitable materials for the recovery of Copper (II ions in water treatments. Furthermore, these modified resins were reacted with 1,2-diaminoethane in the presence of ultrasonic irradiation for the preparation of a tridimensional chelating resin on the Nano scale for the recovery of Copper (II ions from aqueous solutions. This method which is used for removing and determining Copper (II ions using copolymers derived resins of poly (styrene-alternative-maleic anhydride (SMA and atomic absorption spectroscopy. The method is simple, sensitive, inexpensive and fast. The various parameters such as pH, contact time, concentrations of metal ions, mass of resin, and agitation speed were investigated on adsorption effect. The adsorption behavior of Copper (II ions were investigated by the synthesis of chelating resins at various pHs. The prepared resins showed a good tendency for removing the selected metal ions from aqueous solution, even at an acidic pH. Also, the prepared resins were examined for the removal of Copper (II ions from real samples such as industrial wastewater and were shown to be very efficient at adsorption in the cases of Copper (II ions. The pseudo-first-order, pseudo-second-order, and intra-particle diffusion kinetics equations were used for modeling of adsorption data and it was shown that pseudo-second-order kinetic equation could best describe the adsorption kinetics. The intra-particle diffusion study revealed that external diffusion might be involved in this case. The resins were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction analysis.

  17. Composites copolymer-nanoparticule : courbure

    Science.gov (United States)

    Hamdoun, B.; Ausserré, D.; Joly, S.

    1996-08-01

    The compression coefficient and the mean curvature coefficient of a composite of an A-B diblock copolymer charged with nanoparticles depend on the concentration of nanoparticles and on the dissymmetry of the copolymer chains. Concerning the curvature coefficient, a distinction must be done between an adiabatic and an isotherm coefficient when the copolymer chains are not symmetric or when Φ is not zero. Finally, the AB interfaces of the composite film present a spontaneous curvature that we calculate in the approximation of “small” nanoparticles. Les coefficients de compression et de courbure moyenne d'un composite de copolymères diblocs A-B et de nanoparticules dépendent de la concentration Φ en nanoparticules et de la dissymétrie du copolymères. Pour la courbure, on doit faire une distinction entre un coefficient adiabatique et un coefficient isotherme dès que le polymère n'est plus symétrique ou que Φ n'est plus nulle. Enfin, et surtout, les interfaces AB du composite présentent une courbure spontanée que nous calculons dans l'approximation des “petites” nanoparticules.

  18. Allergy to methyltetrahydrophthalic anhydride in epoxy resin workers.

    Science.gov (United States)

    Nielsen, J; Welinder, H; Horstmann, V; Skerfving, S

    1992-01-01

    One hundred and forty four current and 26 former workers in a plant producing barrels for rocket guns from an epoxy resin containing methyltetrahydrophthalic anhydride (MTHPA; time weighted average air concentration up to 150 micrograms/m3) were studied. They showed higher frequencies of work related symptoms from the eyes (31 v 0%; p < 0.001), nose (53 v 9%; p < 0.001), pharynx (26 v 6%; p < 0.01), and asthma (11 v 0%; p < 0.05) than 33 controls. Also they had higher rates of positive skin prick test to a conjugate of MTHPA and human serum albumin (16 v 0%; p < 0.01), and more had specific IgE and IgG serum antibodies (18 v 0%; p < 0.01 and 12 v 0%; p < 0.05 respectively). There were statistically significant exposure-response relations between exposure and symptoms from eyes and upper airways, dry cough, positive skin prick test, and specific IgE and IgG antibodies. There was a non-significant difference in reaction to metacholine between exposed workers and non-smoking controls. In workers with and without specific IgE antibodies, differences existed in frequency of nasal secretion (54 v 23%; p < 0.05) and dry cough (38 v 12%; p < 0.05). Workers with specific IgG had more dry cough (38 v 12%; p < 0.05), but less symptoms of non-specific bronchial hyperreactivity (0 v 26%; p < 0.05). Atopic workers sneezed more than non-atopic workers (65 v 30%; p < 0.01). In a prospective study five sensitised workers who left the factory became less reactive to metacholine, and became symptom free. In 41 workers who stayed, there was no improvement, despite a 10-fold reduction in exposure. The results show the extreme sensitising properties of MTHPA. PMID:1463677

  19. Kinetic study of the hydrolysis of phthalic anhydride and aryl hydrogen phthalates.

    Science.gov (United States)

    Andrés, G O; Granados, A M; de Rossi, R H

    2001-11-16

    The kinetics of the hydrolysis of phthalic anhydride and X-phenyl hydrogen phthalate (X = H, p-Me, m-Cl, and p-Cl) were studied. Several bases accelerate the reaction of phthalic anhydride: acetate, phosphate, N-methyl imidazole, 1,4-diazabicyclo[2,2,2]octane (DABCO), and carbonate. Phosphate, DABCO, and N-methyl imidazole react as nucleophiles, whereas the data do not allow the determination of whether the other bases react in the same way or as general bases catalyzing the water reaction. The rate constants for all of them including water and HO- define a Brönsted plot with beta = 0.46. The kinetics of the hydrolysis of the esters were studied below pH 6.20, and the mechanism involves the formation of phthalic anhydride, which then is hydrolyzed to the phthalic acid. Phenoxide ion has a very high rate constant for the reaction with phthalic anhydride, so above pH 6.20 it competes significantly with the hydrolysis of the anhydride. The reactions of the esters as a function of pH allow the determination of the kinetic pK(a) which are 3.06, 3.02, 2.95, and 2.93 for X = H, p-Me, m-Cl, and p-Cl, respectively. The data also show that the catalysis by the neighboring carboxy group takes place only when it is ionized (i.e., as carboxylate).

  20. Polyethylene-Based Tadpole Copolymers

    KAUST Repository

    Alkayal, Nazeeha

    2017-02-15

    Novel well-defined polyethylene-based tadpole copolymers ((c-PE)-b-PS, PE: polyethylene, PS: polystyrene) with ring PE head and linear PS tail are synthesized by combining polyhomologation, atom transfer radical polymerization (ATRP), and Glaser coupling reaction. The -OH groups of the 3-miktoarm star copolymers (PE-OH)-b-PS, synthesized by polyhomologation and ATRP, are transformed to alkyne groups by esterification with propiolic acid, followed by Glaser cyclization and removal of the unreacted linear with Merrifield\\'s resin-azide. The characterization results of intermediates and final products by high-temperature size exclusion chromatography, H NMR spectroscopy, and differential scanning calorimetry confirm the tadpole topology.

  1. Composites copolymer-nanoparticule : courbure

    OpenAIRE

    Hamdoun, B.; Ausserré, D.; Joly, S.

    1996-01-01

    Les coefficients de compression et de courbure moyenne d'un composite de copolymères diblocs A-B et de nanoparticules dépendent de la concentration Φ en nanoparticules et de la dissymétrie du copolymères. Pour la courbure, on doit faire une distinction entre un coefficient adiabatique et un coefficient isotherme dès que le polymère n'est plus symétrique ou que Φ n'est plus nulle. Enfin, et surtout, les interfaces AB du composite présentent une courbure spontanée que nous calculons dans l'appr...

  2. Main-chain supramolecular block copolymers.

    Science.gov (United States)

    Yang, Si Kyung; Ambade, Ashootosh V; Weck, Marcus

    2011-01-01

    Block copolymers are key building blocks for a variety of applications ranging from electronic devices to drug delivery. The material properties of block copolymers can be tuned and potentially improved by introducing noncovalent interactions in place of covalent linkages between polymeric blocks resulting in the formation of supramolecular block copolymers. Such materials combine the microphase separation behavior inherent to block copolymers with the responsiveness of supramolecular materials thereby affording dynamic and reversible materials. This tutorial review covers recent advances in main-chain supramolecular block copolymers and describes the design principles, synthetic approaches, advantages, and potential applications.

  3. Chemical modification of Posidonia with cyclic anhydrides: effect on thermal stability.

    Science.gov (United States)

    Chadlia, Aguir; Farouk, M'henni Mohamed

    2010-01-26

    In the present work, we studied the chemical modification of Posidonia with maleic (AM) and phthalic (AP) anhydrides, and in the absence of any solvent. We used tripropylamine (TPA) as a catalyst and the mixture underwent an ultrasonic pretreatment. The influence of ultrasonic pretreating time, reaction time, temperature, anhydride concentration, was investigated. The extent of maleation and phthalation was measured by the percent of ester groups (TE), which increased when there was a parallel increment of anhydride concentration, reaction time, and temperature. Evidence of maleation and phthalation of the waste Posidonia biomass was provided by FT-IR and CP/MAS(13)C NMR. Thermogravimetric investigation of chemically modified Posidonia indicated a better thermal stability in comparison with the untreated Posidonia. 2009 Elsevier Ltd. All rights reserved.

  4. Solubility and dissolution thermodynamics of phthalic anhydride in organic solvents at 283-313 K

    Science.gov (United States)

    Wang, Long; Zhang, Fang; Gao, Xiaoqiang; Luo, Tingliang; Xu, Li; Liu, Guoji

    2017-08-01

    The solubility of phthalic anhydride was measured at 283-313 K under atmospheric pressure in ethyl acetate, n-propyl acetate, methyl acetate, acetone, 1,4-dioxane, n-hexane, n-butyl acetate, cyclohexane, and dichloromethane. The solubility of phthalic anhydride in all solvents increased with the increasing temperature. The Van't Hoff equation, modified Apelblat equation, λ h equation, and Wilson model were used to correlate the experimental solubility data. The standard dissolution enthalpy, the standard entropy, and the standard Gibbs energy were evaluated based on the Van't Hoff analysis. The experimental data and model parameters would be useful for optimizing of the separation processes involving phthalic anhydride.

  5. Modification of cellulose with succinic anhydride in TBAA/DMSO mixed solvent under catalyst-free conditions

    Science.gov (United States)

    Ping-Ping Xin; Yao-Bing Huang; Chung-Yun Hse; Huai N. Cheng; Chaobo Huang; Hui. Pan

    2017-01-01

    Homogeneous modification of cellulose with succinic anhydride was performed using tetrabutylammonium acetate (TBAA)/dimethyl sulfoxide (DMSO) mixed solvent. The molar ratio of succinic anhydride (SA) to free hydroxyl groups in the anhydroglucose units (AGU), TBAA dosage, reaction temperature, and reaction time were investigated. The highest degree of substitution (DS)...

  6. Modification of cellulose with succinic anhydride in TBAA/DMSO mixed solvent under catalyst-free conditions

    Science.gov (United States)

    Homogeneous modification of cellulose with succinic anhydride was performed in tetrabutylammonium acetate (TBAA)/dimethyl sulfoxide (DMSO) mixed solvent. The molar ratio of succinic anhydride (SA) to free hydroxyl groups in the anhydroglucose units (AGU) and TBAA dosage were investigated as paramete...

  7. Influence of the degree of hydrolysis of poly(styrene-alt-maleic anhydride) on miscibility with poly(vinyl acetate)

    NARCIS (Netherlands)

    Bosma, M.; Vorenkamp, E.J.; Brinke, G. ten; Challa, G.

    1988-01-01

    The influence of the hydrolysis of anhydride groups in poly(styrene-alt-maleic anhydride) (PSMA) on its miscibility with poly(vinyl acetate) (PVAc) is investigated. The cloudpoint curves of these blends are determined as a function of the degree of hydrolysis. The miscibility is shown to improve

  8. Micelles based on HPMA copolymers

    NARCIS (Netherlands)

    Talelli, M.; Rijcken, C.J.F.; Nostrum, C.F. van; Storm, G.; Hennink, W.E.

    Polymeric micelles have been under extensive investigation during the past years as drug delivery systems, particularly for anticancer drugs. They are formed by the self-assembly of amphiphilic block copolymers in aqueous solutions and have a spherical shape and a size in the nano-range (<200 nm).

  9. Electroluminescence and impedance analyses of organic light emitting diodes using anhydride materials as cathode interfacial layers

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Eunkyoung [Department of Physics, Brain Korea 21 Physics Research Division, Institute of Basic Science, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Park, Hyungjun [School of Information and Communication Engineering, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Park, Keunhee; Moon, Mi Ran [Department of Physics, Brain Korea 21 Physics Research Division, Institute of Basic Science, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Sohn, Sunyoung [Korea Basic Science Institute, Dukjin Dong 664-14, Jeonju 561-756 (Korea, Republic of); Jung, Donggeun [Department of Physics, Brain Korea 21 Physics Research Division, Institute of Basic Science, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Yi, Junsin [School of Information and Communication Engineering, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Chae, Heeyeop [Department of Chemical Engineering, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Kim, Hyoungsub, E-mail: hsubkim@skku.ed [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of)

    2009-05-29

    Pyromellitic dianhydride (PMDA) and trimellitic anhydride (TMA) were tried as cathode interfacial layers between tris-(8-hydroxyquinoline) aluminum (Alq{sub 3}) and Al in organic light emitting diodes (OLEDs). Both ultra-thin anhydride cathode interfacial layers improved the electroluminescence characteristics of OLEDs compared to those without any interfacial layer, and the PMDA interfacial layer showed the most significant enhancement of the device performance. According to impedance measurements and equivalent circuit analysis, the PMDA interfacial layer decreased the impedance, probably due to the increase in the injection efficiency of electrons from the Al cathode.

  10. Impacts of Repeat Unit Structure and Copolymer Architecture on Thermal and Solution Properties in Homopolymers, Copolymers, and Copolymer Blends

    Science.gov (United States)

    Marrou, Stephen Raye

    Gradient copolymers are a relatively new type of copolymer architecture in which the distribution of comonomers gradually varies over the length of the copolymer chain, resulting in a number of unusual properties derived from the arrangement of repeat units. For example, nanophase-segregated gradient copolymers exhibit extremely broad glass transition temperatures (Tgs) resulting from the wide range of compositions present in the nanostructure. This dissertation presents a number of studies on how repeat unit structure and copolymer architecture dictate bulk and solution properties, specifically taking inspiration from the gradient copolymer architecture and comparing the response from this compositionally heterogeneous material to other more conventional materials. The glass transition behavior of a range of common homopolymers was studied to determine the effects of subunit structure on Tg breadth, observing a significant increase in T g breadth with increasing side chain length in methacrylate-based homopolymers and random copolymers. Additionally, increasing the composition distribution of copolymers, either by blending individual random copolymers of different overall composition or synthesizing random copolymers to high conversion, resulted in significant increases to Tg breadth. Plasticization of homopolymers and random copolymers with low molecular weight additives also served to increase the Tg breadth; the most dramatic effect was observed in the selective plasticization of a styrene/4-vinylpyridine gradient copolymer with increases in T g breadth to values above 100 °C. In addition, the effects of repeat unit structure and copolymer architecture on other polymer properties besides Tg were also investigated. The intrinsic fluorescence of styrene units in styrene-containing copolymers was studied, noting the impact of repeat unit structure and copolymer architecture on the resulting fluorescence spectra in solution. The impact of repeat unit structure on

  11. Synthetic studies with Pinus elliottiis rosin derivatives. Oxidation of maleopimaric anhydride methyl ester and trimethyl fumaropimarate

    Directory of Open Access Journals (Sweden)

    Hess Sonia C.

    2000-01-01

    Full Text Available Ozonolysis of maleopimaric anhydride methyl ester in the presence of tetracyanoethylene led to an epoxide and an ozonide. Ozonolysis of the trimethyl fumaropimarate, followed by treatment with Me2S, led to an epoxide, a diene, a keto-acid and an allylic oxidation product. Some of the compounds obtained were active against Staphylococcus aureus, Bacillus subtilis and Micrococcus luteus.

  12. Respiratory irritation by trimellitic anhydride in Brown Norway and Wistar rats

    NARCIS (Netherlands)

    Arts, J.H.E.; Koning, M.W.de; Bloksma, N.; Kuper, C.F.

    2001-01-01

    Several acid anhydrides are known for their sensitizing and irritative properties. Since both irritation and respiratory allergy can cause changes of lung function, proper testing of allergen-dependent effects on the respiratory tract requires knowledge of the respiratory irritant effects. To study

  13. Charge-Transfer Complex of p-Aminodiphenylamine with Maleic Anhydride: Spectroscopic, Electrochemical, and Physical Properties.

    Science.gov (United States)

    Karaca, Erhan; Kaplan Can, Hatice; Bozkaya, Uğur; Özçiçek Pekmez, Nuran

    2016-07-04

    A new charge-transfer complex and the amide formed by the interaction between the electron donor of the p-aminodiphenylamine and the electron acceptor of maleic anhydride are investigated by spectroscopic methods. The amidation reaction is caused by proton and charge transfer between the maleic anhydride and p-aminodiphenylamine molecules. The Benesi-Hildebrand equation is used to determine the formation constant, the molar extinction coefficient and the standard Gibbs free energy of the complex by using UV/Vis spectroscopy. To reveal the electronic and spectroscopic properties of these molecules, theoretical computations are performed on the structures of maleic anhydride, p-aminodiphenylamine and the conformers of their charge-transfer complex. The charge-transfer complex and amidation reaction mechanism are also confirmed by IR and NMR spectroscopy and HRMS. The nature of the maleic anhydride-p-aminodiphenylamine complex is characterized by cyclic voltammetry, thermogravimetric analysis, XRD and SEM. Solid microribbons of this complex show higher thermal stability than p-aminodiphenylamine. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. SYNTHESIS AND HYDROLYSIS OF NEW ASPIRIN-DERIVED AND TRIFLUSAL-DERIVED ORTHO ESTERS AND ANHYDRIDES

    DEFF Research Database (Denmark)

    FALBORG, L; SENNING, A

    1993-01-01

    Ten new 2-substituted 2-methyl-2-oxy-4H-1,3-benzodioxin-4-ones, 4a-i and 6, have been synthesized and their rate constants of pseudo-first-order non-enzymatic hydrolysis determined. One of the compounds, 2-(2-acetoxybenzoyloxy)-2-methyl-4H-1,3-benzodioxin-4-one, 6, is a new anhydride of aspirin...

  15. Controlled release from aspirin based linear biodegradable poly(anhydride esters) for anti-inflammatory activity.

    Science.gov (United States)

    Dasgupta, Queeny; Movva, Sahitya; Chatterjee, Kaushik; Madras, Giridhar

    2017-08-07

    This work reports the synthesis of a novel, aspirin-loaded, linear poly (anhydride ester) and provides mechanistic insights into the release of aspirin from this polymer for anti-inflammatory activity. As compared to conventional drug delivery systems that rely on diffusion based release, incorporation of bioactives in the polymer backbone is challenging and high loading is difficult to achieve. In the present study, we exploit the pentafunctional sugar alcohol (xylitol) to provide sites for drug (aspirin) attachment at its non-terminal OH groups. The terminal OH groups are polymerized with a diacid anhydride. The hydrolysis of the anhydride and ester bonds under physiological conditions release aspirin from the matrix. The resulting poly(anhydride ester) has high drug loading (53%) and displays controlled release kinetics of aspirin. The polymer releases 8.5 % and 20%, of the loaded drug in one and four weeks, respectively and has a release rate constant of 0.0035h -0.61 . The release rate is suitable for its use as an anti-inflammatory agent without being cytotoxic. The polymer exhibits good cytocompatibility and anti-inflammatory properties and may find applications as injectable or as an implantable bioactive material. The physical insights into the release mechanism can provide development of other drug loaded polymers. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Reaction of acetylenes with acetyl fluoroborate in the presence of acetic anhydride

    Energy Technology Data Exchange (ETDEWEB)

    Shastin, A.V.; Balenkova, E.S.; Luzikov, Yu.N.; Gusev, A.I.; Gurkova, S.N.

    1986-01-10

    The reaction of phenyl-, dimethyl-, and diphenylacetylene with acetyl fluoroborate in the presence of acetic anhydride at 20-50/sup 0/C leads to boron-containing heterocyclic compounds having dipolar structures (substituted 2,2-difluoro-1,2-dihydro-1,3,2-dioxaborins) and can serve as a convenient single-stage method for their synthesis.

  17. Nano-encapsulation of coenzyme Q10 using octenyl succinic anhydride modified starch

    Science.gov (United States)

    Octenyl succinic anhydride modified starch (OSA-ST) was used to encapsulate Coenzyme Q10 (CoQ10). CoQ10 was dissolved in rice bran oil (RBO), and incorporated into an aqueous OSA-ST solution. High pressure homogenization (HPH) of the mixture was conducted at 170 MPa for 5-6 cycles. The resulting ...

  18. Coal-based monomers for thermostable polymers anhydrides of pyromellitic and mellitic acids

    Energy Technology Data Exchange (ETDEWEB)

    Sapunov, V.A.; Saranchuk, V.I.; Kucherenko, V.A. [National Academy of Sciences, Donetsk (Ukraine). L.M. Litvinenko Institute of Physical Organic and Coal Chemistry

    1999-07-01

    Coal conversion to organic acids, to mellitic acid and to anhydrides is discussed. The study of thermolysis of mellitic acid into dianhydride, mellitic acid trianhydride and pyromellitic dianhydride is presented. These products are useful in the preparation polymers. 10 refs., 3 figs.

  19. Molecular characterization of trimellitic anhydride-induced respiratory allergy in Brown Norway rats

    NARCIS (Netherlands)

    Kuper, C.F.; Heijne, W.H.; Dansen, M.; Verhoeckx, K.C.; Boorsma, A.; Radonjic, M.; Bruijntjes, J.; Stierum, R.; Muijser, H.; Arts, J.H.

    2008-01-01

    To contribute to the hazard identification of low molecular weight (LMW) respiratory allergens, respiratory allergy induced by trimellitic anhydride (TMA) was characterized by whole genome analysis of lung tissue and blood proteomics in Brown Norway rats. Dermal sensitization (50% and 25% w/v) with

  20. Formation and stability of Vitamin E enriched nanoemulsions stabilized by Octenyl Succinic Anhydride modified starch

    Science.gov (United States)

    Vitamin E (VE) is highly susceptible to autoxidation; therefore, it requires systems to encapsulate and protect it from autoxidation.In this study,we developed VE delivery systems, which were stabilized by Capsul® (MS), a starch modified with octenyl succinic anhydride. Influences of interfacial ten...

  1. Respiratory Allergy to Trimellitic Anhydride in Rats: Concentration-Response Relationships during Elicitation

    NARCIS (Netherlands)

    Arts, J.H.E.; Koning, M.W. de; Bloksma, N.; Kuper, C.F.

    2004-01-01

    The present study investigated whether airway responses of sensitized rats to trimellitic anhydride (TMA) were concentration dependent and whether these were related to irritation by TMA. Groups of BN and Wistar rats were sensitized by two dermal applications of TMA (50% w/v, followed by 25% w/v in

  2. Spectroscopic study of phthalic anhydride and its thia, selena, and tellura analogues

    Science.gov (United States)

    Bigotto, A.; Galasso, V.; Pellizer, G.; Distefano, G.; Pappalardo, G. C.; Bergman, J.; Engman, L.

    The He(I) photoelectron, u.v.-visible absorption, 1H and 13C NMR, i.r. and Raman-laser spectra of selenophthalic and tellurophthalic anhydride have been obtained and compared to those of phthalic and thiophthalic anhydride. The main features of the spectra of these four compounds (the ordering and splitting of the n CO and π x ionizations, the location and nature of the π → π* transitions, the trend and spread of the chemical shifts, and the symmetry assignments of the fundamental vibrations) have been surveyed and discussed in terms of qualitative and correlative arguments, related to the ability of the chalcogen atoms to transmit electronic effects, and also with the aid of semi-empirical MO calculations. A fair correlation between the average ionization energy of the CO lone pair orbitals, the average of the CO stretching frequencies and the 13C carbonyl chemical shift has been found. The electric dipole moment, measured in benzene at 25°C, is 3.30D for selenophthalic anhydride and 2.71 D for tellurophthalic anhydride.

  3. Effect of Phthalic Anhydride Modified Soy Protein on Viscoelastic Properties of Polymer Composites

    Science.gov (United States)

    Phthalic anhydride (PA) modified soy protein isolates (SPI), both hydrolyzed and un-hydrolyzed, are investigated as reinforcement fillers in styrene-butadiene (SB) composites. The modification of SPI by PA increases the number of carboxylic acid functional groups on the protein surface and therefor...

  4. Synthesis of N-sugar-substituted phthalimides and their derivatives from sugar azides and phthalic anhydride.

    Science.gov (United States)

    Zhang, Su-Na; Li, Zhong-Jun; Cai, Meng-Shen

    2004-06-01

    N-Sugar-substituted phthalimides and tetrachlorophthalimide derivatives can be prepared in good yields under essentially neutral conditions. Mixing a sugar azide, NaI, Me3SiCl, phthalic or substituted phthalic anhydride and tetrabutylammonium iodide as catalyst in acetonitrile at rt or 60 degrees C, afforded 12 imides in 83-95% yields. Copyright 2004 Elsevier Ltd.

  5. MODIFICATION OLIGOMER DERIVED FROM BY-PRODUCTS OF POLYBUTADIENE USING WASTE OF PRODUCTION OF PHTHALIC ANHYDRIDE

    Directory of Open Access Journals (Sweden)

    N. S. Nikulina

    2013-01-01

    Full Text Available The modification of the oligomer synthesized from polybutadiene waste byproducts formed during the production of phthalic anhydride comprising as a main component maleic acid was studied. The influence of temperature, duration of the process and content of the waste on the properties of the resulting product was considered.

  6. Substituted Phthalic Anhydrides from Biobased Furanics : A New Approach to Renewable Aromatics

    NARCIS (Netherlands)

    Thiyagarajan, Shanmugam; Genuino, Homer C.; Sliwa, Michal; van der Waal, Jan C.; de Jong, Ed; van Haveren, Jacco; Weckhuysen, Bert M.; Bruijnincx, Pieter C. A.; van Es, Daan S.

    2015-01-01

    A novel route for the production of renewable aromatic chemicals, particularly substituted phthalic acid anhydrides, is presented. The classical two-step approach to furanics-derived aromatics via Diels-Alder (DA) aromatization has been modified into a three-step procedure to address the general

  7. Synergistic enhancement of anticancer therapeutic efficacy of HPMA copolymer doxorubicin conjugates via combination of ligand modification and stimuli-response srategies.

    Science.gov (United States)

    Li, Lian; Zhou, Minglu; Huang, Yuan

    2017-12-10

    N-(2-Hydroxypropyl) methacrylamide (HPMA) copolymer has been extensively studied as drug carrier for tumor therapy. Due to the Enhanced Permeability and Retention (EPR) effect, HPMA copolymer drug conjugates are able to be passively accumulated in the tumor site. Currently, efficient uptake of this polymeric system by the cancer cells remains a big challenge, as HPMA polymer is highly hydrophilic, neutrally charged, and has low affinity towards cell membrane. In this study, selective and enhanced intracellular internalization of the copolymer-drug conjugates was achieved by utilizing a hybrid strategy including ligand modification and stimuli response. This hybrid approach was rationally designed to comprise cationic HPMA copolymer backbone as drug carrier, doxorubicin (Dox) as model drug, hydrazone bond as drug spacer, FQSIYPpIK (FQS) peptide as αvβ3 targeting ligand and 2, 3-Dimethylmaleic Anhydride (DMA) as a shielded/deshielded cationic group. We demonstrated our system exhibited the "seek-and-destroy" tumor tropic behavior by sequentially undergoing the following steps: (i) tumor passive targeting mediated by EPR effect; (ii) charge reversal at tumor extracellular pH of 6.5; (iii) synergistically enhanced cell uptake via electrostatic interaction with cell membrane and FQS ligand-mediated bio-recognition; (iv) drug released in the lysosome; and v) anticancer effect exerted by the targeted delivery of the Dox. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Doxorubicin-loaded, charge reversible, folate modified HPMA copolymer conjugates for active cancer cell targeting.

    Science.gov (United States)

    Li, Lian; Yang, Qingqing; Zhou, Zhou; Zhong, Jiaju; Huang, Yuan

    2014-06-01

    Although folate exhibits many advantages over other targeting ligands, it has one major defect: poor water solubility. Once it was conjugated to hydrophilic drug carrier such as N-(2-hydroxypropyl) methacrylamide (HPMA) copolymer, the hydrophobic folate may be buried inside the random polymer coil and not exposed to be accessible to its receptor on the cell surface, thus losing its active targeting ability. To address this folate dilemma, the positive charge was introduced in the present study. The obtained cationic folate-functionalized HPMA copolymers exhibited a synergistic enhancing effect on cellular uptake by folate receptor (FR) positive Hela cells via electrostatic absorptive endocytosis and folate receptor-mediated endocytosis, with the involvement of multiple internalization pathways including clathrin-mediated endocytosis, caveolae-mediated endocytosis, macropinocytosis and energy-dependent endocytosis. As demonstrated in binding efficiency study, the FR antibody bound to 71.2% of tested cells in the competition with neutral folate modified HPMA copolymers, while the FR antibody-bounded cells decreased to only 34.0% in competition with cationic folate modified HPMA copolymers, indicating that the positively charge could probably amplify the binding efficiency of folate to its receptor due to close proximity of the conjugates to the cell surface by the electronic adhesion. In addition, the cell uptake study on FR negative A549 cells also confirmed the specific role of folate as targeting ligand. Then, to avoid non-specific binding by positive charge in the circulation, the charge shielding/deshielding approach was further employed. With selective hydrolysis of the charge shielding groups 2,3-dimethylmaleic anhydride (DMA) at tumor extracellular pH 6.8, the conjugates underwent a quick charge-reversible process with more than 80% DMA cleavage within 2 h and endocytosed into the endo/lysosomes much more rapidly than at physiological pH 7.4. And then the

  9. Poly-L-Lysine-Poly[HPMA] Block Copolymers Obtained by RAFT Polymerization as Polyplex-Transfection Reagents with Minimal Toxicity.

    Science.gov (United States)

    Tappertzhofen, Kristof; Weiser, Franziska; Montermann, Evelyn; Reske-Kunz, Angelika; Bros, Matthias; Zentel, Rudolf

    2015-08-01

    Herein we describe the synthesis of poly-L-lysine-b-poly[N-(2-hydroxypropyl)-metha-crylamide)] (poly[HPMA]) block copolymers by combination of solid phase peptide synthesis or polymerization of α-amino acid-N-carboxy-anhydrides (NCA-polymerization) with the reversible addition-fragmentation chain transfer polymerization (RAFT). In the presence of p-DNA, these polymers form polyplex micelles with a size of 100-200 nm in diameter (monitored by SDS-PAGE and FCS). Primary in vitro studies with HEK-293T cells reveal their cellular uptake (FACS studies and CLSM) and proof successful transfection with efficiencies depending on the length of polylysine. Moreover, these polyplexes display minimal toxicity (MTT-assay and FACS-measurements) featuring a p[HPMA] corona for efficient extracellular shielding and the potential ligation with antibodies. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Drug targeting to tumors using HPMA copolymers

    NARCIS (Netherlands)

    Lammers, T.G.G.M.

    2009-01-01

    Copolymers based on N-(2-hydroxypropyl)methacrylamide (HPMA) are prototypic and well-characterized polymeric drug carriers that have been broadly implemented in the delivery of anticancer agents. HPMA copolymers circulate for prolonged periods of time, and by means of the Enhance Permeability and

  11. On the reactivity of triphenylphosphoranylidenesuccinic anhydride with nitrogen nucleophiles: a new synthetic route to nitrogen-containing phosphonium salts

    Directory of Open Access Journals (Sweden)

    Cunha Silvio

    2000-01-01

    Full Text Available The reactions of triphenylphosphoranylidenesuccinic anhydride with amines, hydrazines and dipolar nitrogen nucleophiles were investigated, and a new method of synthesis of phosphonioum salts containing the fragment RNHC(C=OCH2CH2PPh3 is described.

  12. A new process for the valorisation of a bio-alcohol. The oxidehydration of 1-butanol into maleic anhydride

    Energy Technology Data Exchange (ETDEWEB)

    Caldarelli, A.; Cavani, F.; Garone, O.; Pavarelli, G. [Bologna Univ. (Italy). Dipt. di Chimica Industriale e dei Materiali; Bologna Univ. (Italy). CIRCC, Research Unit; Dubois, J.L. [ARKEMA, Colombes (France); Mitsova, I.; Simeonova, L. [JSC, Russe (Bulgaria). Orgachim

    2012-07-01

    This paper deals with a study on the gas-phase transformation of 1-butanol into maleic anhydride, using different types of catalysts. Indeed, catalytic acid properties are needed to dehydrate 1-butanol into 1-butene, whereas redox-type properties are required for the oxidation of the olefin into maleic anhydride. The two types of active sites can be combined in bifunctional systems, showing both acid and redox-type properties. We found that vanadyl pyrophosphate catalyzes the one-pot reaction, giving a maximum selectivity to maleic anhydride of 28%. In fact, various side reactions contributed to the formation of by-products, eg, 1-butanol (oxidative) dehydrogenation into butyraldehyde, formation of light carboxylic acids and carbon oxides, and condensation of unsaturated C{sub 4} intermediates (butenes and butadiene) with the formed maleic anhydride to yield heavier compounds. (orig.)

  13. Preparation and Physical Properties of Chitosan Benzoic Acid Derivatives Using a Phosphoryl Mixed Anhydride System

    Directory of Open Access Journals (Sweden)

    Kyu Yun Chai

    2012-02-01

    Full Text Available Direct benzoylation of the two hydroxyl groups on chitosan was achieved using a phosphoryl mixed anhydride system, derived from trifluoroacetic anhydride (TFAA, benzoic acids (BAs, and phosphoric acid (PA. The reaction is operated as a one pot process under mild conditions that does not require neither an inert atmosphere nor dry solvents. The structures of the synthesized compounds were confirmed by NMR and IR spectroscopy. Solubility tests on the products revealed that they were soluble in organic solvents such as N,N-dimethylformamide (DMF, dimethylsulfoxide (DMSO, and acetone. In the meantime, a morphological study by scanning electron microscopy (SEM evidently indicated that the chitosan benzoates underwent significant structural changes after the benzoylation.

  14. Perylene anhydride fused porphyrins as near-infrared sensitizers for dye-sensitized solar cells

    KAUST Repository

    Jiao, Chongjun

    2011-07-15

    Two perylene anhydride fused porphyrins 1 and 2 have been synthesized and employed successfully in dye-sensitized solar cells (DSCs). Both compounds showed broad incident monochromatic photon-to-current conversion efficiency spectra covering the entire visible spectral region and even extending into the near-infrared (NIR) region up to 1000 nm, which is impressive for ruthenium-free dyes in DSCs. © 2011 American Chemical Society.

  15. Selective hydrogenation of maleic anhydride over Pd/Al2O3 ...

    Indian Academy of Sciences (India)

    Jilin University, Qianjin Road 2699, Changchun 130012, PR China. bShanghai Huayi ... majority of its reaction products, including succinic anhydride ... The product was dried at 373 K for 6 h and was reduced with H2/Ar at 573 K for 2 h prior to use. The obtained catalyst was labelled as CD-Pd/Al2O3.21,22. To compare, 1 ...

  16. Emulsion stabilizing capacity of intact starch granules modified by heat treatment or octenyl succinic anhydride

    OpenAIRE

    Timgren, Anna; Rayner, Marilyn; Dejmek, Petr; Marku, Diana; Sjöö, Malin

    2013-01-01

    Starch granules are an interesting stabilizer candidate for food-grade Pickering emulsions. The stabilizing capacity of seven different intact starch granules for making oil-in-water emulsions has been the topic of this screening study. The starches were from quinoa; rice; maize; waxy varieties of rice, maize, and barley; and high-amylose maize. The starches were studied in their native state, heat treated, and modified by octenyl succinic anhydride (OSA). The effect of varying the continuous...

  17. Retrospective exposure assessment for a cohort study into respiratory effects of acid anhydrides

    OpenAIRE

    van Tongeren, M. J.; Barker, R. D.; GARDINER, K; Harris, J.M.; Venables, K. M.; Harrington, J M; Newman, T

    1998-01-01

    OBJECTIVES: To estimate past exposure to phthalic (PA), trimellitic (TMA) and maleic anhydride (MA) in three alkyd resin and one cushioned flooring factory to estimate exposure-response relations in a retrospective cohort study. METHODS: Personal exposure measurements were carried out in 1992 and quantitative and qualitative information on past exposure and production processes were collected. Job titles were ranked by decreasing exposure and amalgamated into job categories and exposure...

  18. Phthalic anhydride production from hemicellulose solutions: Technoeconomic analysis and life cycle assessment

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Zhaojia [Dept. of Chemical and Biochemical Engineering, Rutgers-The State University of New Jersey, Piscataway NJ; Ierapetritou, Marianthi [Dept. of Chemical and Biochemical Engineering, Rutgers-The State University of New Jersey, Piscataway NJ; Nikolakis, Vladimiros [Catalysis Center for Energy Innovation and Dept. of Chemical & Biomolecular Engineering, University of Delaware, Newark, DE

    2015-07-14

    The process synthesis, technoeconomic analysis, and life cycle assessment (LCA) of a novel route for phthalic anhydride (PAN) production from hemicellulose solutions are presented. The production contains six steps including dehydration of xylose to furfural, reductive decarbonylation of furfural to furan, oxidation of furfural to maleic anhydride (MA), Diels-Alder cycloaddition of furan, and MA to exo-4,10-dioxa-tricyclo[5.2.1.0]dec-8-ene-3,5-dione followed by dehydration to PAN in the presence of mixture of methanesulfonic acid and acetic anhydride (AAN) which is converted to acetyl methanesulfonate and acetic acid (AAD), and dehydration of AAD to AAN. The minimum selling price of PAN is determined to be $810/metric ton about half of oil-based PAN. The coproduction of high-value products is essential to improve the economics. Biomass feedstock contributes to the majority of cost. LCA results shows that biomass-based PAN has advantages over oil-based PAN to reduce climate change and fossil depletion however requires more water usage.

  19. Block copolymer membranes for aqueous solution applications

    KAUST Repository

    Nunes, Suzana Pereira

    2016-03-22

    Block copolymers are known for their intricate morphology. We review the state of the art of block copolymer membranes and discuss perspectives in this field. The main focus is on pore morphology tuning with a short introduction on non-porous membranes. The two main strategies for pore formation in block copolymer membranes are (i) film casting and selective block sacrifice and (ii) self-assembly and non-solvent induced phase separation (SNIPS). Different fundamental aspects involved in the manufacture of block copolymer membranes are considered, including factors affecting the equilibrium morphology in solid films, self-assembly of copolymer in solutions and macrophase separation by solvent-non-solvent exchange. Different mechanisms are proposed for different depths of the SNIPS membrane. Block copolymer membranes can be prepared with much narrower pore size distribution than homopolymer membranes. Open questions and indications of what we consider the next development steps are finally discussed. They include the synthesis and application of new copolymers and specific functionalization, adding characteristics to respond to stimuli and chemical environment, polymerization-induced phase separation, and the manufacture of organic-inorganic hybrids.

  20. Orientation and bonding of benzoic acid, phthalic anhydride and pyromellitic dianhydride on Cu(110)

    Science.gov (United States)

    Frederick, B. G.; Ashton, M. R.; Richardson, N. V.; Jones, T. S.

    1993-07-01

    The interaction of the polyimide precursor pyromellitic dianhydride (PMDA), and the related compounds benzoic acid and phthalic anhydride, with Cu(110) has been studied by high resolution electron energy loss spectroscopy (HREELS). For benzoic acid, deprotonation of the carboxylic acid group occurs on adsorption leading to the formation of a surface benzoate species (C 6H 5COO-). Bonding to the surface occurs through a carboxylate linkage via two equivalent oxygen atoms. The HREEL spectrum is characterised by an intense dipole active band, the symmetric OCO stretching vibration, at ˜ 1420 cm -1. The plane of the carboxylate group is aligned perpendicular to the surface as is the plane of the benzene ring. A similar species is found following exposure of Cu(110) to phthalic anhydride. The carboxylate linkage results from disruption of the anhydride ring with loss of the CO character (C 6H 4COO-). In the case of the dianhydride species PMDA, only one of the anhydride units is used in bonding to the surface; the second unit points away from the surface and is characterised by the symmetric anhydride stretch at 1255 cm -1 and weak OO stretching vibrations at ˜ 1850 cm -1. In both cases, changes in the intensity of some of the bands compared with benzoic acid suggest that the carboxylate group is tilted away from the surface normal due to an interaction between one of the carbons of the aromatic ring and the copper surface. This implies that the plane of the aromatic ring is now twisted out of the plane of the carboxylate group and, although still perpendicular to the surface, the axis is tilted to allow one of the β-carbon atoms to interact with the surface. In all cases, off-specular measurements at a primary electron energy of ˜ 8 eV are dominated by the intense CH stretching vibration. Measurements of the intensity of this mode, in the surface benzoate species, as a function of incident electron energy suggest that excitation of this mode occurs via

  1. Injectible bodily prosthetics employing methacrylic copolymer gels

    Energy Technology Data Exchange (ETDEWEB)

    Mallapragada, Surya K.; Anderson, Brian C.

    2007-02-27

    The present invention provides novel block copolymers as structural supplements for injectible bodily prosthetics employed in medical or cosmetic procedures. The invention also includes the use of such block copolymers as nucleus pulposus replacement materials for the treatment of degenerative disc disorders and spinal injuries. The copolymers are constructed by polymerization of a tertiary amine methacrylate with either a (poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) polymer, such as the commercially available Pluronic.RTM. polymers, or a poly(ethylene glycol) methyl ether polymer.

  2. Phthalic Anhydride-Mediated Direct Glycosylation of Anomeric Hydroxy Arabinofuranose: Synthesis of Repeating Oligoarabinofuranoside and Tetradecasaccharide Arabinan Motif of Mycobacterial Cell Wall.

    Science.gov (United States)

    Lee, Bo-Young; Oh, Jung Woo; Baek, Ju Yuel; Jeon, Heung Bae; Kim, Kwan Soo

    2016-11-18

    An efficient direct phthalic anhydride-mediated one-pot glycosylation method employing anomeric hydroxy arabinofuranose as glycosyl donor and triflic anhydride as activating agent has been developed. This method afforded the desired di- and oligoarabinofuranosides in good yields even in gram scale glycosylation when t-butylphthalic anhydride was used. Moreover, our new method can be further extended to the syntheses of repeating oligoarabinofuranoside and tetradecasaccharide arabinan motif found in mycobacterial cell wall.

  3. XRD study of intercalation in statically annealed composites of ethylene copolymers and organically modified montmorillonites. 2. One-tailed organoclays

    Directory of Open Access Journals (Sweden)

    Sara Filippi

    2014-01-01

    Full Text Available Ethylene copolymers with different polar comonomers, such as vinyl acetate, methyl acrylate, glycidyl methacrylate, and maleic anhydride, were used for the preparation of polymer/clay nanocomposites by statically annealing their mechanical mixtures with different commercial or home-made organically modified montmorillonites containing only one long alkyl tail. The nanostructure of the products was monitored by X-ray diffraction, and the dispersion of the silicate particles within the polymer matrix was qualitatively evaluated through microscopic analyses. The effect of the preparation conditions on the structure and the morphology of the composites was also addressed through the characterization of selected samples with similar composition prepared by melt compounding. In agreement with the findings reported in a previous paper for the composites filled with two-tailed organoclays, intercalation of the copolymer chains within the tighter galleries of the one-tailed clays occurs easily, independent of the application of a mechanical stress. However, the shear-driven break-up of the intercalated clay particles into smaller platelets (exfoliation seems more hindered. A collapse of the organoclay interlayer spacing was only observed clearly for a commercial one-tailed organoclay – Cloisite® 30B – whereas the same effect was almost negligible for a home-made organoclay with similar structure.

  4. Micellization and Dynamics of a Block Copolymer

    DEFF Research Database (Denmark)

    Hvidt, Søren

    2006-01-01

    ratios and temperature. The micellization process with increasing temperature has been followed by a number of techniques including differential scanning calorimetry, liquid chromatography, and surface tension measurements. Different micellization models have been tested for purified copolymers...

  5. Electrostatic control of block copolymer morphology

    Science.gov (United States)

    Sing, Charles E.; Zwanikken, Jos W.; Olvera de La Cruz, Monica

    2014-07-01

    Energy storage is at present one of the foremost issues society faces. However, material challenges now serve as bottlenecks in technological progress. Lithium-ion batteries are the current gold standard to meet energy storage needs; however, they are limited owing to the inherent instability of liquid electrolytes. Block copolymers can self-assemble into nanostructures that simultaneously facilitate ion transport and provide mechanical stability. The ions themselves have a profound, yet previously unpredictable, effect on how these nanostructures assemble and thus the efficiency of ion transport. Here we demonstrate that varying the charge of a block copolymer is a powerful mechanism to predictably tune nanostructures. In particular, we demonstrate that highly asymmetric charge cohesion effects can induce the formation of nanostructures that are inaccessible to conventional uncharged block copolymers, including percolated phases desired for ion transport. This vastly expands the design space for block copolymer materials and is informative for the versatile design of battery electrolyte materials.

  6. Block copolymer structures in nano-pores

    Science.gov (United States)

    Pinna, Marco; Guo, Xiaohu; Zvelindovsky, Andrei

    2010-03-01

    We present results of coarse-grained computer modelling of block copolymer systems in cylindrical and spherical nanopores on Cell Dynamics Simulation. We study both cylindrical and spherical pores and systematically investigate structures formed by lamellar, cylinders and spherical block copolymer systems for various pore radii and affinity of block copolymer blocks to the pore walls. The obtained structures include: standing lamellae and cylinders, ``onions,'' cylinder ``knitting balls,'' ``golf-ball,'' layered spherical, ``virus''-like and mixed morphologies with T-junctions and U-type defects [1]. Kinetics of the structure formation and the differences with planar films are discussed. Our simulations suggest that novel porous nano-containers can be formed by confining block copolymers in pores of different geometries [1,2]. [4pt] [1] M. Pinna, X. Guo, A.V. Zvelindovsky, Polymer 49, 2797 (2008).[0pt] [2] M. Pinna, X. Guo, A.V. Zvelindovsky, J. Chem. Phys. 131, 214902 (2009).

  7. Gyroid Membranes made from Nanoporous Blck Copolymers

    DEFF Research Database (Denmark)

    Szewczykowski, Piotr Plzemystaw; Vigild, Martin Etchells; Ndoni, Sokol

    2007-01-01

    Nanoporous materials are interesting and exciting materials in view of their many potential applications, especially as ultrafiltration membranes. One way of preparing nanoporous polymeric materials is to use block copolymers. Block copolymers have the great advantage that they organize them......-selves into different morphologies on the nano scale. Block copolymer synthesis controls the molecular weight and volume fraction of blocks, which determine the resulting nano-structures. From a membrane application point of view one very suitable morphology is the bicontinuous gyroid. Mechanical stability...... of the membrane and its nanoporosity is e.g. obtained by cross-linking the majority blocks and selectively etching the minority blocks. Here we report on ultrafiltration membranes prepared from a 1,2-polybutadiene-b-polydimethylsiloxane diblock copolymer with gyroid structure. Different experimental methods...

  8. Silica reinforced triblock copolymer gels

    DEFF Research Database (Denmark)

    Theunissen, E.; Overbergh, N.; Reynaers, H.

    2004-01-01

    The effect of silica and polymer coated silica particles as reinforcing agents on the structural and mechanical properties of polystyrene-poly(ethylene/butylene)-polystyrene (PS-PEB-PS) triblock gel has been investigated. Different types of chemically modified silica have been compared in order...... to evaluate the influence of the compatibility between gel and filler. Time-resolved SANS and small-angle X-ray scattering (SAXS) shows that the presence of silica particles affects the ordering of the polystyrene domains during gelsetting. The scattering pattern of silica-reinforced gels reveals strong...... scattering at very low q, but no structure and formfactor information. However, on heating above the viscoelastic to plastic transition, the 'typical' scattering pattern of the copolymer gel builds-up. All reinforced gels are strengthened by the addition of the reinforcing agent. The transitions from...

  9. Responsive Copolymers for Enhanced Petroleum Recovery

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, C.; Hester, R.

    2001-02-27

    The objectives of this work was to: synthesize responsive copolymer systems; characterize molecular structure and solution behavior; measure rheological properties of aqueous fluids in fixed geometry flow profiles; and to tailor final polymer compositions for in situ rheology control under simulated conditions. This report focuses on the synthesis and characterization of novel stimuli responsive copolymers, the investigation of dilute polymer solutions in extensional flow and the design of a rheometer capable of measuring very dilute aqueous polymer solutions at low torque.

  10. Drawbacks in the use of unconventional hydrophobic anhydrides for histone derivatization in bottom-up proteomics PTM analysis.

    Science.gov (United States)

    Sidoli, Simone; Yuan, Zuo-Fei; Lin, Shu; Karch, Kelly; Wang, Xiaoshi; Bhanu, Natarajan; Arnaudo, Anna M; Britton, Laura-Mae; Cao, Xing-Jun; Gonzales-Cope, Michelle; Han, Yumiao; Liu, Shichong; Molden, Rosalynn C; Wein, Samuel; Afjehi-Sadat, Leila; Garcia, Benjamin A

    2015-05-01

    MS-based proteomics has become the most utilized tool to characterize histone PTMs. Since histones are highly enriched in lysine and arginine residues, lysine derivatization has been developed to prevent the generation of short peptides (<6 residues) during trypsin digestion. One of the most adopted protocols applies propionic anhydride for derivatization. However, the propionyl group is not sufficiently hydrophobic to fully retain the shortest histone peptides in RP LC, and such procedure also hampers the discovery of natural propionylation events. In this work we tested 12 commercially available anhydrides, selected based on their safety and hydrophobicity. Performance was evaluated in terms of yield of the reaction, MS/MS fragmentation efficiency, and drift in retention time using the following samples: (i) a synthetic unmodified histone H3 tail, (ii) synthetic modified histone peptides, and (iii) a histone extract from cell lysate. Results highlighted that seven of the selected anhydrides increased peptide retention time as compared to propionic, and several anhydrides such as benzoic and valeric led to high MS/MS spectra quality. However, propionic anhydride derivatization still resulted, in our opinion, as the best protocol to achieve high MS sensitivity and even ionization efficiency among the analyzed peptides. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. The influence of chain stretching on the phase behavior of multiblock copolymer and comb copolymer melts

    NARCIS (Netherlands)

    Angerman, HJ; ten Brinke, G

    The subject of this paper is inspired by microphase-separated copolymer melts in which a small-scale structure is present inside one of the phases of a large-scale structure. Such a situation can arise in a diblock copolymer melt, if one of the blocks of the diblock is in itself a multiblock

  12. A sulfonic anhydride derivative from dibenzyl trisulphide with agro-chemical activities.

    Science.gov (United States)

    Williams, L A D; Vasquez, E; Klaiber, I; Kraus, W; Rosner, H

    2003-06-01

    In the present study, the biologically active natural product dibenzyl trisulphide (DTS) which was previously isolated from the sub-tropical shrub Petiveria alliacea was transformed to methyl benzyl sulphonic anhydride (MBSA) using a "one pot" transformation method. The anhydride was evaluated for anti-microbial activities on the bacteria, Bacillus subtilis and Pseudomonas fluorescens and found to be 2.5 fold more effective than the commercial agents isoniazid and ampicillin in inhibiting the growth of B. subtilis, while on P. fluorescens it was 2.5, 5.0 and 10.0 fold more inhibitory than isoniazid, ampicillin and dibenzyl trisulphide, respectively. DTS was inactive on B. subtillis. The MIC value (microgram/spot) found for DTS on the plant pathogenic fungus, Cladosporium cucumerinum was 5.0 microgram/spot, while MBSA gave a value of 0.1 microgram/spot, compared with 1.25 and 0.16 microgram/spot for the commercial agents ketoconazole and nystatin, respectively. On the larval nematode (Meloidogyne incognita) MBSA inflicted 97.72% and 57.47% Abbotts nematicidal activities at 125.0 and 62.5 ppm, respectively, while DTS had no effect at 125.0 ppm. Nematodes which were immobilized by the low concentrations of MBSA were unable to re-activate when exposed to 10.0 ppm picrotoxin, thus suggesting that the anhydride nematicidal activity is independent of the GABA-ergic neurophysiological pathway.MBSA demonstrated a strong dose dependent radicular suppression effect (r=0.984), on the radicles of Latuca sativa germinating seeds. DTS was weakly active.

  13. MECHANICAL, ELECTRICAL, AND THERMAL PROPERTIES OF MALEIC ANHYDRIDE MODIFIED RICE HUSK FILLED PVC COMPOSITES

    OpenAIRE

    Navin Chand; Bhajan Das Jhod

    2008-01-01

    Unmodified and modified rice husk powder filled PVC composites were prepared having different amounts of rice husk powder. Mechanical, thermal, and electrical properties of these composites were determined. The tensile strength of rice husk powder PVC composites having 0, 10, 20, 30, and 40 weight percent of rice husk powder was found to be 33.9, 19.4, 18.1, 14.6, and 9.5 MPa, respectively. Adding of maleic anhydride- modified rice husk powder improved the tensile strength of rice husk powder...

  14. Synthesis and paste properties of octenyl succinic anhydride modified early Indica rice starch*

    OpenAIRE

    Song, Xiao-Yan; Chen, Qi-He; Ruan, Hui; He, Guo-qing; Xu, Qiong

    2006-01-01

    Octenyl succinic anhydride (OSA) modified early Indica rice starch was prepared in aqueous slurry systems using response surface methodology. The paste properties of the OSA starch were also investigated. Results indicated that the suitable parameters for the preparation of OSA starch from early Indica rice starch were as follows: reaction period 4 h, reaction temperature 33.4 °C, pH of reaction system 8.4, concentration of starch slurry 36.8% (in proportion to water, w/w), amount of OSA 3% (...

  15. Adsorption of alkenyl succinic anhydride from solutions in carbon tetrachloride on a fine magnetite surface

    Science.gov (United States)

    Balmasova, O. V.; Ramazanova, A. G.; Korolev, V. V.

    2016-06-01

    The adsorption of alkenyl succinic anhydride from a solution in carbon tetrachloride on a fine magnetite surface at a temperature of 298.15 K is studied using fine magnetite, which forms the basis of magnetic fluids, as the adsorbent. An adsorption isotherm is recorded and interpreted in terms of the theory of the volume filling of micropores (TVFM). Adsorption process parameters are calculated on the basis of the isotherm. It is shown that at low equilibrium concentrations, the experimental adsorption isotherm is linear in the TVFM equation coordinates.

  16. Highly photoluminescent polysilsesquioxane hybrids based on weakly fluorescent 1,8-naphthalic anhydride derivatives

    Science.gov (United States)

    Pan, Fei; Huang, Miao; Song, Jianhui; Wu, Meng; Xu, Min

    2016-07-01

    A series of highly fluorescent polysilsesquioxane materials based on 1,8-naphthalic anhydride derivatives(XNA) have been prepared. The XNAs were chemically bonded with the polysiloxane. Though the fluorescent intensities of the solution of XNAs with different substitutes make a great difference, some of them are even very weakly emissive, the fluorescent intensities of the corresponding solid polysilsesquioxane materials are strong. In this case, the electronic effect of the substitute became non-important. With restricted molecular motion and J-aggregation, some traditionally weakly fluorescent or non-fluorescent chromophoric organics due to the substituent effect may be used to prepare highly fluorescent materials.

  17. Lead tetraacetate oxidation of the Diels-Alder adduct of 7-dehydrocholestryl acetate with maleic anhydride

    Directory of Open Access Journals (Sweden)

    MIHAILO LJ. MIHAILOVIC

    2000-03-01

    Full Text Available The Diels-Alder adduct (3, obtained by cycloaddition of 7-dehydrocholesteryl acetate (1 and maleic anhydride (2, was heated at ca. 90°C with a large excess of lead tetraacetate in pyridine solution for 5 h. Under these conditions, compound 3 underwent lactonization with the participation of the olefinic D6-double bond to give two isomeric monolactone derivatives, 9 and 10 (in a total yield of ca. 6%, and the bislactone product 11 (in 11.5% yield. The starting material was recovered in 36% yield.

  18. Recent advances on the difructose anhydride IV preparation from levan conversion.

    Science.gov (United States)

    Hang, Hua

    2017-09-13

    Difructose anhydride IV (DFA IV) is a cyclic disaccharide consisting of two fructose residues, which is obtained from levan conversion with levan fructotransferase (LFTase) and rarely found in nature as a low-calorie sugar substitute. Some beneficial effects of DFA IV connected with its consumption have been described. The article reviews the properties and physiological functions of DFA IV, levan conversion, resources and properties of LFTase and the produced methods of DFA IV. LFTase as a relatively novel enzyme and its molecular evolution are discussed as well. The aim is to better understand a novel sugar-substituting sweetener of DFA IV as a food additive.

  19. Facile Synthesis of (R,R and of (R,S Tricarballylic Acid Anhydride and Imide Derivatives

    Directory of Open Access Journals (Sweden)

    Abdel-Sattar S. Hamad Elgazwy

    2000-04-01

    Full Text Available The diastereomeric mixture of (R-2-(methoxycarbonylmethyl-N-(R-1-(1-phenylethyl succinimide 11s and (S-2-(methoxycarbonylmethyl-N-(R-1-(1-phenylethyl succinimide 11a was synthesized by reaction of 2-(carboxymethylsuccinic anhydride 6 with (R-(α-methylbenzylamine in dry THF/room temperature/24 hrs. The diastereomeric mixture of 1-[(R-(α-Methylbenzylamideformyl]propane-2,3-dicarboxylic acid anhydride 9s and 1-[(R-(α-methylbenzylamideformyl]propane-2,3-dicarboxylic acid anhydride 9a was isolated as an intermediate under the reaction conditions. This diastereomeric mixture 9s/9a was also prepared by a different route via reaction of 1-(chloroformylpropane-2,3-dicarboxylic acid anydride 12 with (R-(α-methylbenzylamine in the presence of DMA at 0oC for 24 hrs.

  20. Polyamide copolymers having 2,5-furan dicarboxamide units

    Energy Technology Data Exchange (ETDEWEB)

    Chisholm, Bret Ja; Samanta, Satyabrata

    2017-09-19

    Polyamide copolymers, and methods of making and using polyamide copolymers, having 2,5-furan dicarboxamide units are disclosed herein. Such polymers can be useful for engineering thermoplastics having advantageous physical and/or chemical properties.

  1. A self-crosslinking thermosetting monomer with both epoxy and anhydride groups derived from Tung oil fatty acids: Synthesis and properties

    Science.gov (United States)

    A self-crosslinking compound with epoxy groups and anhydride groups (GEMA) has been successfully synthesized from Tung oil fatty acid by reacting with maleic anhydride via the Diels-Alder reaction. GEMA has very good storage stability and can be cured with trace amounts of tertiary amine. This advan...

  2. Selective oxidation of n-butane to maleic anhydride under oxygen-deficient conditions over V-P-O mixed oxides

    NARCIS (Netherlands)

    Bosch, H.; Bruggink, A.A.; Ross, J.R.H.

    1987-01-01

    The selective oxidation of n-butane to maleic anhydride over V-P-O mixed oxides was studied under oxygen deficient conditions. The mixed oxides were prepared with P/V atomic ratios ranging from 0.7 to 1.0. Catalysts with P/V <1.0 did not show any selectivity to maleic anhydride formation, regardless

  3. XPS depth profiling of derivatized amine and anhydride plasma polymers: Evidence of limitations of the derivatization approach

    Energy Technology Data Exchange (ETDEWEB)

    Manakhov, Anton, E-mail: ant-manahov@ya.ru [National University of Science and Technology “MISiS”, Leninsky pr. 4, Moscow 119049 (Russian Federation); RG Plasma Technologies, CEITEC – Masaryk University, Purkyňova 123, Brno 61200 (Czech Republic); Michlíček, Miroslav [RG Plasma Technologies, CEITEC – Masaryk University, Purkyňova 123, Brno 61200 (Czech Republic); Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářská, 2, Brno 61137 (Czech Republic); Felten, Alexandre; Pireaux, Jean-Jacques [LISE, Department of Physics, University of Namur, Rue de Bruxelles, 61, Namur B5000 (Belgium); Nečas, David [RG Plasma Technologies, CEITEC – Masaryk University, Purkyňova 123, Brno 61200 (Czech Republic); Zajíčková, Lenka [RG Plasma Technologies, CEITEC – Masaryk University, Purkyňova 123, Brno 61200 (Czech Republic); Department of Physical Electronics, Faculty of Science, Masaryk University, Kotlářská, 2, Brno 61137 (Czech Republic)

    2017-02-01

    Highlights: • TFBA derivatizatized amine plasma layers exhibited heterogeneous profile of [F] due to low diffusion (permeability) of TFBA • Anhydride layers derivatized by trifluoroethylamine exhibited relatively homogenous profile as this molecule is smaller • The results of TFBA derivatization will depend on XPS take-off angle, polymer crosslinking and density - Abstract: The quantitative analysis of the chemistry at the surface of functional plasma polymers is highly important for the optimization of their deposition conditions and, therefore, for their subsequent applications. The chemical derivatization of amine and carboxyl-anhydride layers is a well-known technique already applied by many researchers, notwithstanding the known drawback of the derivatization procedures like side or uncomplete reactions that could lead to “unreliable” results. In this work, X-ray photoelectron spectroscopy (XPS) combined with depth profiling with argon clusters is applied for the first time to study derivatized amine and carboxyl-anhydride plasma polymer layers. It revealed an additional important parameter affecting the derivatization reliability, namely the permeation of the derivatizing molecule through the target analysed layer, i.e. the composite effect of the probe molecule size and the layer porosity. Amine-rich films prepared by RF low pressure plasma polymerization of cyclopropylamine were derivatized with trifluoromethyl benzaldehide (TFBA) and it was observed by that the XPS-determined NH{sub 2} concentration depth profile is rapidly decreasing over top ten nanometers of the layer. The anhydride-rich films prepared by atmospheric plasma co-polymerization of maleic anhydride and C{sub 2}H{sub 2} have been reacted with, parafluoroaniline and trifluoroethyl amine. The decrease of the F signal in top surface layer of the anhydride films derivatized by the “large” parafluoroaniline was observed similarly as for the amine films but the derivatization with

  4. Zinc versus Magnesium: Orthogonal Catalyst Reactivity in Selective Polymerizations of Epoxides, Bio-derived Anhydrides and Carbon Dioxide.

    Science.gov (United States)

    Saini, Prabhjot K; Fiorani, Giulia; Mathers, Robert T; Williams, Charlotte K

    2017-03-28

    Developing selective polymerizations from complex monomer mixtures is an important challenge. Here, dinuclear catalysts allow selective polymerization from mixtures of sterically hindered tricyclic anhydrides, carbon dioxide and epoxides to yield well-controlled copoly(ester-carbonates). Surprisingly, two very similar homogeneous catalysts differing only in the central metal, zinc versus magnesium, show very high but diametrically opposite monomer selectivity. The selectivity is attributed to different polymerization kinetics and to steric factors associated with the anhydrides. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Anhydrides-Cured Bimodal Rubber-Like Epoxy Asphalt Composites: From Thermosetting to Quasi-Thermosetting

    Directory of Open Access Journals (Sweden)

    Yang Kang

    2016-03-01

    Full Text Available The present engineering practices show the potential that epoxy asphalt composites (EACs would be a better choice to obtain long life for busy roads. To understand the service performance–related thermorheological properties of prepared bimodal anhydrides-cured rubber-like EACs (REACs, a direct tensile tester, dynamic shear rheometer and mathematical model were used. Tensile tests demonstrate that all the REACs reported here are more flexible than previously reported anhydrides-cured REACs at both 20 and 0 °C. The better flexibility is attributed to the change of bimodal networks, in which cross-linked short chains decreased and cross-linked long chains increased, relatively. Strain sweeps show that all the REACs have linear viscoelastic (LVE properties when their strains are smaller than 1.0% from −35 to 120 °C. Temperature sweeps illustrate that the thermorheological properties of REACs evolve from thermosetting to quasi-thermosetting with asphalt content, and all the REACs retain solid state and show elastic properties in the experimental temperature range. A Cole–Cole plot and Black diagram indicate that all the REACs are thermorheologically simple materials, and the master curves were constructed and well-fitted by the Generalized Logistic Sigmoidal models. This research provides a facile approach to tune the thermorheological properties of the REACs, and the cheaper quasi-thermosetting REAC facilitates their advanced applications.

  6. High biobased content epoxy-anhydride thermosets from epoxidized sucrose esters of Fatty acids.

    Science.gov (United States)

    Pan, Xiao; Sengupta, Partha; Webster, Dean C

    2011-06-13

    Novel highly functional biobased epoxy compounds, epoxidized sucrose esters of fatty acids (ESEFAs), were cross-linked with a liquid cycloaliphatic anhydride to prepare polyester thermosets. The degree of cure or conversion was studied using differential scanning calorimetry (DSC), and the sol content of the thermosets was determined using solvent extraction. The mechanical properties were studied using tensile testing to determine Young's modulus, tensile stress, and elongation at break. Dynamic mechanical analysis (DMA) was used to determine glass-transition temperature, storage modulus, and cross-link density. The nanomechanical properties of the surfaces were studied using nanoindentation to determine reduced modulus and indentation hardness. The properties of coatings on steel substrates were studied to determine coating hardness, adhesion, solvent resistance, and mechanical durability. Compared with the control, epoxidized soybean oil, the anhydride-cured ESEFAs have high modulus and are hard and ductile, high-performance thermoset materials while maintaining a high biobased content (71-77% in theory). The exceptional performance of the ESEFAs is attributed to the unique structure of these macromolecules: well-defined compact structures with high epoxide functionality. These biobased thermosets have potential uses in applications such as composites, adhesives, and coatings.

  7. Effects of Different Types of Clays and Maleic Anhydride Modified Polystyrene on Polystyrene/Clay Nanocomposites

    Directory of Open Access Journals (Sweden)

    M. Mehrabzadeh

    2013-01-01

    Full Text Available Polymer/clay nanocomposites are considered as a new subject of research in Iran and the world. Addition of a minimum amount of clay (2-5wt% can improve the mechanical properties, enhance barrier properties and reduce flammability dramatically. Polystyrene (PS exhibits high strength, high modulus and excellent dimensional stability, but it has poor ductility, elongation, and flexural modulus. By incorporating clay into polystyrene these properties can be improved. In this study preparation of polystyrene/clay nanocomposite, effects of different types of clays (Cloisite 10A andNanomer I.30TC and maleic anhydride modified polystyrene on mechanical properties of the prepared polystyrene/clay nanocomposites were evaluated. Samples were prepared by a twin screw extruder. Transmission electron microscopy (TEM and X-ray diffraction (XRD techniques were employed to evaluate the extent of intercalation and exfoliation of silicate layers in the nanocomposites. Mechanical tests show that by addition of clay and maleic anhydride modified polystyrene the flexural modulus (~30% and elongation-at-break (~40% of prepared nanocomposites have been improved. XRD and TEM results show that nanocomposite have an intercalated structure with ability to change to further exfoliation structure.

  8. Flexible Polyimide Aerogel Cross-linked by Poly(maleic Anhydride-alt-alkylene)

    Science.gov (United States)

    Guo, Haiquan; Meador, Mary Ann B.; Wilkewitz, Brittany Marie

    2014-01-01

    Aerogels are potential materials for aerospace applications due to their lower thermal conductivity, lighter weight, and low dielectric constant. However, silica aerogels are restricted due to their inherent fragility, hygroscopic nature, and poor mechanical properties, especially in extreme aerospace environments. In order to fit the needs of aerospace applications, developing new thermal insulation materials that are flexible, and moisture resistant is needed. To this end, we fabricated a series of polyimide aerogels crosslinked with different poly(maleic anhydride-alt-alkylene)s as seen in Scheme 1. The polyimide oligomers were made with 3,3,4,4-biphenyltetracarboxylic dianhydride (BPDA), and different diamines or diamine combinations. The resulting aerogels have low density (0.06 gcm3 to 0.16 gcm3) and high surface area (240-440 m2g). The effect of the different backbone structures on density, shrinkage, porosity, surface area, mechanical properties, moisture resistance and thermal properties will be discussed. These novel polyalkylene-imide aerogels may be potential candidates for applications such as space suit insulation for planetary surface missions, insulation for inflatable structures for habitats, inflatable aerodynamic decelerators for entry, descent and landing (EDL) operations, and cryotank insulation for advance space propulsion systems. Scheme 1. Network of polyimide aerogels crosslinked with deifferent poly(maleic anhydride).

  9. Preparation, characterization and antibacterial activity of octenyl succinic anhydride modified inulin.

    Science.gov (United States)

    Zhang, Xiaoyun; Zhang, Ye-Wang; Zhang, Hongyin; Yang, Qiya; Wang, Haiying; Zhang, Guochao

    2015-01-01

    Octenyl succinic anhydride modified inulin (In-OSA) was synthesized via chemical modification of inulin with octenyl succinic anhydride (OSA). The esterification of inulin with OSA was confirmed by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and degree of substitution (DS) calculation. Antibacterial activity of In-OSA against Staphylococcus aureus and Escherichia coli was investigated by minimum inhibitory concentration (MIC) and inhibition rate determination. The results showed that inhibition rates against both E.coli and S. aureus increased with the increase of the In-OSA concentration. And the MICs against E. coli and S. aureus were 1% and 0.5% (w/v), respectively. The antibacterial mechanism was analyzed with the results of the proteins and nucleic acids leakage, SEM and negative staining transmission electron microscopy (TEM). Both the leakages of proteins and nucleic acids increased with the increase of the In-OSA concentration. The leakage occurred mainly in the early stage which indicated that cell membrane and wall were destroyed by In-OSA quickly. The images of SEM and negative staining TEM suggested that the cell membranes and cell walls of S. aureus were damaged more severely and even destroyed completely; but only pores appeared on the surface of E. coli. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Identification of covalent binding sites of phthalic anhydride in human hemoglobin.

    Science.gov (United States)

    Jeppsson, Marina C; Jönsson, Bo A G; Kristiansson, Monica; Lindh, Christian H

    2008-11-01

    Phthalic anhydride (PA) is a reactive low molecular weight compound used in the chemical industry. The exposure of PA may lead to work-related airway diseases such as rhinitis, chronic bronchitis, and asthma. The exposure gives rise to an increase in hapten-specific IgG antibodies in workers but with a low presence of specific IgE antibodies. In this study, the binding of PA to human hemoglobin (Hb) in vitro was investigated. Trypsin and Pronase E digestion, LC, LC/MS/MS, GC/MS analysis, and nanoelectrospray hybrid quadrupole time-of-flight MS were used to identify the adducted amino acids of the synthesized PA-Hb conjugates. In the conjugate with the molar ratio 1:0.1, a total of six adducted amino acids were identified. N-Terminal valine was found adducted in both the alpha- and the beta-chains as well as a total of four lysines, Val 1, Lys 16, and Lys 61 on the alpha-chain and Val 1, Lys 66, and Lys 144 on the beta-chain. Two types of lysine adducts were found, a phthalamide and a phthalimide. It was also found that PA differs in its binding site as compared to hexahydrophthalic anhydride. The result of this study suggests several interesting applications of biological monitoring.

  11. Polycondensation of Tetrahydrofuran with Phthalic Anhydride Induced By a Proton Exchanged Montmorillonite Clay

    Directory of Open Access Journals (Sweden)

    Mohammed Belbachir

    2003-05-01

    Full Text Available Abstract: “Maghnite” a montmorillonite sheet silicate clay, exchanged with protons to produce “H-Maghnite” is an efficient catalyst for polymerization of many vinylic and heterocyclic monomers (Belbachir, M. U.S. Patent. 066969.0101 –2001. The structure compositions of both “Maghnite” and “H-Maghnite” have been developed. This catalyst was used for the polycondensation of the tetrahydrofuran with phthalic anhydride. The polymerization was performed under suitable conditions at temperature (40°C, in presence of acetic anhydride. Experiments revealed that polymerization induced by “H-Maghnite”, proceed in bulk and the conversion increases with increasing “H-Maghnite” proportion.

  12. Oil recovery with vinyl sulfonic acid-acrylamide copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Norton, C.J.; Falk, D.O.

    1973-12-18

    An aqueous polymer flood containing sulfomethylated alkali metal vinyl sulfonate-acrylamide copolymers was proposed for use in secondary or tertiary enhanced oil recovery. The sulfonate groups on the copolymers sustain the viscosity of the flood in the presence of brine and lime. Injection of the copolymer solution into a waterflooded Berea core, produced 30.5 percent of the residual oil. It is preferred that the copolymers are partially hydrolyzed.

  13. Charge Transport in Conjugated Block Copolymers

    Science.gov (United States)

    Smith, Brandon; Le, Thinh; Lee, Youngmin; Gomez, Enrique

    Interest in conjugated block copolymers for high performance organic photovoltaic applications has increased considerably in recent years. Polymer/fullerene mixtures for conventional bulk heterojunction devices, such as P3HT:PCBM, are severely limited in control over interfaces and domain length scales. In contrast, microphase separated block copolymers self-assemble to form lamellar morphologies with alternating electron donor and acceptor domains, thereby maximizing electronic coupling and local order at interfaces. Efficiencies as high as 3% have been reported in solar cells for one block copolymer, P3HT-PFTBT, but the details concerning charge transport within copolymers have not been explored. To fill this gap, we probed the transport characteristics with thin-film transistors. Excellent charge mobility values for electron transport have been observed on aluminum source and drain contacts in a bottom gate, bottom contact transistor configuration. Evidence of high mobility in ordered PFTBT phases has also been obtained following thermal annealing. The insights gleaned from our investigation serve as useful guideposts, revealing the significance of the interplay between charge mobility, interfacial order, and optimal domain size in organic block copolymer semiconductors.

  14. Photo-Induced Micellization of Block Copolymers

    Directory of Open Access Journals (Sweden)

    Satoshi Kuwayama

    2010-11-01

    Full Text Available We found novel photo-induced micellizations through photolysis, photoelectron transfer, and photo-Claisen rearrangement. The photolysis-induced micellization was attained using poly(4-tert-butoxystyrene-block-polystyrene diblock copolymer (PBSt-b-PSt. BSt-b-PSt showed no self-assembly in dichloromethane and existed as isolated copolymers. Dynamic light scattering demonstrated that the copolymer produced spherical micelles in this solvent due to irradiation with a high-pressure mercury lamp in the presence of photo-acid generators, such as bis(alkylphenyliodonium hexafluorophosphate, diphenyliodonium hexafluorophosphate, and triphenylsulfonium triflate. The 1H NMR analysis confirmed that PBSt-b-PSt was converted into poly(4-vinylphenol-block-PSt by the irradiation, resulting in self-assembly into micelles. The irradiation in the presence of the photo-acid generator also induced the micellization of poly(4-pyridinemethoxymethylstyrene-block-polystyrene diblock copolymer (PPySt-b-PSt. Micellization occurred by electron transfer from the pyridine to the photo-acid generator in their excited states and provided monodispersed spherical micelles with cores of PPySt blocks. Further, the photo-Claisen rearrangement caused the micellization of poly(4-allyloxystyrene-block-polystyrene diblock copolymer (PASt-b-PSt. Micellization was promoted in cyclohexane at room temperature without a catalyst. During micellization, the elimination of the allyl groups competitively occurred along with the photorearrangement of the 4-allyloxystyrene units into the 3-allyl-4-hydroxystyrene units.

  15. PEO-related block copolymer surfactants

    DEFF Research Database (Denmark)

    Mortensen, K.

    2001-01-01

    Non-ionic block copolymer systems based on hydrophilic poly(ethylene oxide) and more hydrophobic co-polymer blocks are used intensively in a variety of industrial and personal applications. A brief description on the applications is presented. The physical properties of more simple model systems ...... or lamellar nature. Shear has major effect on the crystalline texture, but seems not to change the thermodynamic stable phases significantly. (C) 2001 Elsevier Science B.V. All rights reserved.......Non-ionic block copolymer systems based on hydrophilic poly(ethylene oxide) and more hydrophobic co-polymer blocks are used intensively in a variety of industrial and personal applications. A brief description on the applications is presented. The physical properties of more simple model systems...... of such PEG-based block copolymers in aqueous suspensions are reviewed. Based on scattering experiments using either X-ray or neutrons, the phase behavior is characterized, showing that the thermo-reversible gelation is a result of micellar ordering into mesoscopic crystalline phases of cubic, hexagonal...

  16. Chain exchange in block copolymer micelles

    Science.gov (United States)

    Lu, Jie; Bates, Frank; Lodge, Timothy

    2014-03-01

    Block copolymer micelles are aggregates formed by self-assembly of amphiphilic copolymers dispersed in a selective solvent, driven by unfavorable interactions between the solvent and the core-forming block. Due to the relatively long chains being subject to additional thermodynamic and dynamic constraints (e.g., entanglements, crystallinity, vitrification), block copolymer micelles exhibit significantly slower equilibration kinetics than small molecule surfactants. As a result, details of the mechanism(s) of equilibration in block copolymer micelles remain unclear. This present works focuses on the chain exchange kinetics of poly(styrene-b-ethylenepropylene) block copolymers in squalane (C30H62) using time-resolved small angle neutron scattering (TR-SANS). A mixture of h-squalane and d-squalane is chosen so that it contrast matches a mixed 50/50 h/d polystyrene micelle core. When the temperature is appropriate and isotopically labeled chains undergo mixing, the mean core contrast with respect to the solvent decreases, and the scattering intensity is therefore reduced. This strategy allows direct probing of chain exchange rate from the time dependent scattering intensity I(q, t).

  17. 21 CFR 177.1980 - Vinyl chloride-propylene copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Vinyl chloride-propylene copolymers. 177.1980... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1980 Vinyl chloride-propylene copolymers. The vinyl chloride-propylene copolymers identified in paragraph (a) of this section may be safely...

  18. 78 FR 6213 - Styrene-2-Ethylhexyl Acrylate Copolymer; Tolerance Exemption

    Science.gov (United States)

    2013-01-30

    ... AGENCY 40 CFR Part 180 Styrene-2-Ethylhexyl Acrylate Copolymer; Tolerance Exemption AGENCY: Environmental...; also known as styrene-2-ethylhexyl acrylate copolymer when used as an inert ingredient in a pesticide...-risk polymers are described in 40 CFR 723.250(d). Styrene-2-ethylhexyl acrylate copolymer conforms to...

  19. 21 CFR 177.1312 - Ethylene-carbon monoxide copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-carbon monoxide copolymers. 177.1312... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1312 Ethylene-carbon monoxide copolymers. The ethylene-carbon monoxide copolymers identified in paragraph (a) of this section may be safely...

  20. 21 CFR 177.1320 - Ethylene-ethyl acrylate copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-ethyl acrylate copolymers. 177.1320... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1320 Ethylene-ethyl acrylate copolymers. Ethylene-ethyl acrylate copolymers may be safely used to produce packaging materials, containers...

  1. 21 CFR 177.1350 - Ethylene-vinyl acetate copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-vinyl acetate copolymers. 177.1350 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1350 Ethylene-vinyl acetate copolymers. Ethylene-vinyl acetate copolymers may be safely used as articles or components of articles...

  2. 21 CFR 177.1950 - Vinyl chloride-ethylene copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Vinyl chloride-ethylene copolymers. 177.1950... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1950 Vinyl chloride-ethylene copolymers. The vinyl chloride-ethylene copolymers identified in paragraph (a) of this section may be safely...

  3. 21 CFR 177.1310 - Ethylene-acrylic acid copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-acrylic acid copolymers. 177.1310 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1310 Ethylene-acrylic acid copolymers. The ethylene-acrylic acid copolymers identified in paragraph (a) of this section may be safely...

  4. 21 CFR 177.1211 - Cross-linked polyacrylate copolymers.

    Science.gov (United States)

    2010-04-01

    ... polyacrylate copolymers consist of: (1) The grafted copolymer of cross-linked sodium polyacrylate identified as... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Cross-linked polyacrylate copolymers. 177.1211... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1211 Cross-linked polyacrylate...

  5. 21 CFR 181.32 - Acrylonitrile copolymers and resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylonitrile copolymers and resins. 181.32 Section... Ingredients § 181.32 Acrylonitrile copolymers and resins. (a) Acrylonitrile copolymers and resins listed in this section, containing less than 30 percent acrylonitrile and complying with the requirements of...

  6. Functional Nanoporous Polymers from Block Copolymer Precursors

    DEFF Research Database (Denmark)

    Guo, Fengxiao

    applications as, e.g., membranes for separation and purification, templates for nanostructured materials, sensors, substrates for catalysis, low dielectric constant materials, photonic materials, and depots for controlled drug delivery. The development of nanoporous polymers with well controlled pore wall......Abstract Self-assembly of block copolymers provides well-defined morphologies with characteristic length scales in the nanometer range. Nanoporous polymers prepared by selective removal of one block from self-assembled block copolymers offer great technological promise due to their many potential...... functionalities remains a great challenge due to the limitation of available polymer synthesis and the nanoscale confinement of the porous cavities. The main topic of this thesis is to develop methods for fabrication of functional nanoporous polymers from block copolymer precursors. A method has been developed...

  7. Functionalization of Block Copolymer Vesicle Surfaces

    Directory of Open Access Journals (Sweden)

    Wolfgang Meier

    2011-01-01

    Full Text Available In dilute aqueous solutions certain amphiphilic block copolymers self-assemble into vesicles that enclose a small pool of water with a membrane. Such polymersomes have promising applications ranging from targeted drug-delivery devices, to biosensors, and nanoreactors. Interactions between block copolymer membranes and their surroundings are important factors that determine their potential biomedical applications. Such interactions are influenced predominantly by the membrane surface. We review methods to functionalize block copolymer vesicle surfaces by chemical means with ligands such as antibodies, adhesion moieties, enzymes, carbohydrates and fluorophores. Furthermore, surface-functionalization can be achieved by self-assembly of polymers that carry ligands at their chain ends or in their hydrophilic blocks. While this review focuses on the strategies to functionalize vesicle surfaces, the applications realized by, and envisioned for, such functional polymersomes are also highlighted.

  8. Separation and recovery of lead from a low concentration solution of lead(II) and zinc(II) using the hydrolysis production of poly styrene-co-maleic anhydride.

    Science.gov (United States)

    Liang, Xing; Su, Yibing; Yang, Ying; Qin, Wenwu

    2012-02-15

    The PbZn separation/preconcentration technique, based on the complex formation reaction of Pb(II) and Zn(II), using a copolymer poly(styrene-co-maleic anhydride) (PSMA), without adding any carrier element was developed. The effects of several experimental parameters such as solution pH, temperature and adsorption time were studied. The experimental results show that the PSMA resin-Pb equilibrium was achieved in 2 min and the Pb(II) loading capacity is up to 641.62 mg g(-1) in aqueous solution under optimum conditions, which is much higher than the Zn(II) loading capacity within 80 min. The adsorption test for Pb(II) indicates that PSMA can recover Pb(II) from a mixed solution of Pb(II), Zn(II) and light metals such as Ca(II) and Mg(II) with higher adsorption rate and larger selective coefficient. A further study indicates that PSMA as chelating resins recovering Pb(II) can be regenerated via mineral acid (6M H(2)SO(4)). PSMA was synthesized by radical polymerization and tested as an adsorbent for the selective recovery of Pb(II). In addition, the formation procedure and structure of Pb-PSMA complex were also studied. Both the PSMA and the Pb-PSMA complex were characterized by means of FTIR spectroscopy, elemental analysis, gel permeation chromatography (GPC) and atomic absorption spectrometry (AAS). Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Dynamics of Block Copolymer Nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Mochrie, Simon G. J.

    2014-09-09

    A detailed study of the dynamics of cadmium sulfide nanoparticles suspended in polystyrene homopolymer matrices was carried out using X-ray photon correlation spectroscopy for temperatures between 120 and 180 °C. For low molecular weight polystyrene homopolymers, the observed dynamics show a crossover from diffusive to hyper-diffusive behavior with decreasing temperatures. For higher molecular weight polystyrene, the nanoparticle dynamics appear hyper-diffusive at all temperatures studied. The relaxation time and characteristic velocity determined from the measured hyper-diffusive dynamics reveal that the activation energy and underlying forces determined are on the order of 2.14 × 10-19 J and 87 pN, respectively. We also carried out a detailed X-ray scattering study of the static and dynamic behavior of a styrene– isoprene diblock copolymer melt with a styrene volume fraction of 0.3468. At 115 and 120 °C, we observe splitting of the principal Bragg peak, which we attribute to phase coexistence of hexagonal cylindrical and cubic double- gyroid structure. In the disordered phase, above 130 °C, we have characterized the dynamics of composition fluctuations via X-ray photon correlation spectroscopy. Near the peak of the static structure factor, these fluctuations show stretched-exponential relaxations, characterized by a stretching exponent of about 0.36 for a range of temperatures immediately above the MST. The corresponding characteristic relaxation times vary exponentially with temperature, changing by a factor of 2 for each 2 °C change in temperature. At low wavevectors, the measured relaxations are diffusive with relaxation times that change by a factor of 2 for each 8 °C change in temperature.

  10. Co-polymer Films for Sensors

    Science.gov (United States)

    Ryan, Margaret A. (Inventor); Homer, Margie L. (Inventor); Yen, Shiao-Pin S. (Inventor); Kisor, Adam (Inventor); Jewell, April D. (Inventor); Shevade, Abhijit V. (Inventor); Manatt, Kenneth S. (Inventor); Taylor, Charles (Inventor); Blanco, Mario (Inventor); Goddard, William A. (Inventor)

    2012-01-01

    Embodiments include a sensor comprising a co-polymer, the co-polymer comprising a first monomer and a second monomer. For some embodiments, the first monomer is poly-4-vinyl pyridine, and the second monomer is poly-4-vinyl pyridinium propylamine chloride. For some embodiments, the first monomer is polystyrene and the second monomer is poly-2-vinyl pyridinium propylamine chloride. For some embodiments, the first monomer is poly-4-vinyl pyridine, and the second monomer is poly-4-vinyl pyridinium benzylamine chloride. Other embodiments are described and claimed.

  11. Electrochemical and spectroscopic characterization of poly (bithiophene + 2-methylfuran) copolymer

    Science.gov (United States)

    Lamiri, Leila; Nessark, Belkacem; Habelhames, Farid; Sibous, Lakhdar

    2017-09-01

    In this work, Poly(bithiophene + 2-methylfuran) copolymer was successfully synthetized by an electrochemical polymerization of two monomers, bithiophene and 2-methylfuran in acetonitrile containing lithium perchlorate. The obtained copolymer was characterized via cyclic voltammetry, impedance spectroscopy, UV-visible, scanning electron microscope, conductivity and photocurrent measurements. The cyclic voltammetry study showed two redox couples characteristic of Poly (bithiophene + 2-methylfuran) copolymer. The impedance spectroscopy study revealed that the resistance of the copolymer film increases with the addition of 2-methylfuran. The photocurrent measurement showed good photoelectrochemical properties, making this copolymer an ideal candidate for photovoltaic cell applications.

  12. Preexposure to amorphous silica particles attenuates but also enhances allergic reactions in trimellitic anhydride-sensitized brown Norway rats

    NARCIS (Netherlands)

    Arts, J.H.E.; Schijf, M.A.; Kuper, C.F.

    2008-01-01

    Irritant-induced inflammation of the airways may aggravate respiratory allergy induced by chemical respiratory allergens. Therefore, the effect of airway irritation by synthetic amorphous silica (SAS) on respiratory allergy to trimellitic anhydride (TMA) was studied. Brown Norway (BN) rats were

  13. Anhydride formation is not a valid mechanism for peptide cleavage by carboxypeptidase-A: a semiempirical reaction pathway study

    Science.gov (United States)

    Vardi-Kilshtain, Alexandra; Shoham, Gil; Goldblum, Amiram

    The mechanism of action of zinc metalloproteinases has been studied by following the direct nucleophilic pathway, which has been frequently suggested but not yet examined by computational methods, and comparing it to other pathways. We computed the reaction enthalpies for the direct nucleophilic attack by Glu270 in the active site model of carboxypeptidase-A on a model substrate's peptide carbonyl and followed this pathway through mixed anhydride formation and subsequent anhydride cleavage by water. The starting molecular coordinates originate in our own high-resolution crystal structure and the computations have been conducted with the minimal neglect of differential overlap (MNDO) Hamiltonian, modified to include the d-orbitals of zinc and the effects of multiple hydrogen bonding, thus labelled MNDO/d/H. Compared to our recent results for two other candidate pathways for this mechanism, both of the General-Acid-General-Base type, we conclude that the direct nucleophilic or 'anhydride' pathway has a much higher energy barrier at the rate determining step, which is a proton transfer, than previously calculated paths. We argue that the 'anhydride' pathway is thus not a valid one for the cleavage of peptides by carboxypeptidase-A.

  14. Alveolar macrophages have a dual role in a rat model for trimellitic anhydride-induced occupational asthma

    NARCIS (Netherlands)

    Valstar, D.L.; Schijf, M.A.; Nijkamp, F.P.; Storm, G.; Arts, J.H.E.; Kuper, C.F.; Bloksma, N.; Henricks, P.A.J.

    2006-01-01

    Occupational exposure to low molecular weight chemicals, like trimellitic anhydride (TMA), can result in occupational asthma. Alveolar macrophages (AMs) are among the first cells to encounter inhaled compounds. These cells can produce many different mediators that have a putative role in asthma. In

  15. 40 CFR 721.6183 - Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated tallow alkyl amines...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amides, from ammonium hydroxide... Substances § 721.6183 Amides, from ammonium hydroxide - maleic anhydride polymer and hydrogenated tallow... subject to reporting. (1) The chemical substance identified as amides, from ammonium hydroxide - maleic...

  16. Pre-exposure to sulfur dioxide attenuates most allergic reactions upon trimellitic anhydride challenge in sensitized Brown Norway rats

    NARCIS (Netherlands)

    Arts, J.H.E.; Jacobs, E.J.; Kuper, C.F.

    2010-01-01

    Irritant-induced inflammation of the airways may aggravate respiratory allergy induced by chemical respiratory allergens. Therefore, it was studied whether airway irritation by sulfur dioxide (SO2) would enhance respiratory allergic reactions to trimellitic anhydride (TMA), using a rat

  17. Acetyl substitution patterns of amylose and amylopectin populations in cowpea starch modified with acetic anhydride and vinyl acetate

    NARCIS (Netherlands)

    Huang, J.; Schols, H.A.; Klaver, R.; Jin, Z.; Voragen, A.G.J.

    2007-01-01

    To study the effect of reagent type on the distribution pattern of acetyl groups in acetylated cowpea starch, amylose and amylopectin populations were isolated from the starch granules after modification to a low degree of substitution (DS <0.1) with acetic anhydride and vinyl acetate,

  18. Alveolar macrophages suppress non-specific inflammation caused by inhalation challenge with trimellitic anhydride conjugated to albumin

    NARCIS (Netherlands)

    Valstar, D.L.; Schijf, M.A.; Arts, J.H.E.; Kuper, C.F.; Nijkamp, F.P.; Storm, G.; Bloksma, N.; Henricks, P.A.J.

    2006-01-01

    Occupational exposure to low molecular weight chemicals, like trimellitic anhydride (TMA), can result in occupational asthma. Alveolar macrophages (AMs) are among the first cells to encounter these inhaled compounds and were previously shown to affect TMA-induced asthma-like symptoms in the Brown

  19. Preventing false-negatives in the in vitro skin sensitization testing of acid anhydrides using interleukin-8 release assays.

    Science.gov (United States)

    Narita, Kazuto; Vo, Phuc Thi Hong; Yamamoto, Kenta; Kojima, Hajime; Itagaki, Hiroshi

    2017-08-01

    In vitro safety tests may be used as replacements for animal tests owing to their accuracy and high-throughput performance. However, several in vitro skin sensitization tests produce false-negative results such as acid anhydride. Here, we investigated the relationship between false-negative results of acid anhydride and its hydrolysis by aqueous vehicle. Differences in the pattern of hydrolysis for phthalic anhydride (PAH) due to addition of 1 drop of stock solution of PAH in liquid paraffin (LP) dispersion medium and PAH in DMSO were analyzed in a cell-free system. The results showed that use of LP dispersion medium stabilized the concentration of PAH in water over 5min by sustained-release, although almost all PAH converted to phthalic acid in water within 5min using DMSO. Additionally, treatment of THP-1 cells with PAH and phthalic acid using LP dispersion medium for 5min resulted in a 32-fold increase in IL-8 release for PAH as compared with that in the vehicle control. In contrast, for PAH using aqueous vehicle and phthalic acid using LP dispersion medium, there were no significant increases in IL-8 release. Similarly, using LP dispersion medium, trimellitic anhydride significantly increased IL-8 release was observed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. POLIELECTROLITI PE BAZA DE COPOLIMERI MALEICI
    (Polyélectrolytes à base de copolymères de l'anhydride maléique)

    OpenAIRE

    Aldea, Gabriela

    2005-01-01

    Travail expérimental réalisé à Angers dans le cadre du programme d'échanges Brancusi.; Polyelectrolytes are an important class of polymers which were studied over 3 decades. The field of polyelectrolytes is currently undergoing an amazing explosion of activity in several science domains: chemistry, biology, medicine, physics, nanomaterials, nanotechnologies... The peculiar interest manifested for the polyelectrolytes is due not only to the need for better understanding of their behavior but a...

  1. Synthesis of amphiphilic diblock copolymer for surface modification of Ethylene-Norbornene copolymers

    DEFF Research Database (Denmark)

    Levinsen, Simon; Svendsen, Winnie Edith; Horsewell, Andy

    2014-01-01

    consisting of a bulk material compatible block and a hydrophilic block. To utilize the possibility of incorporating diblock copolymers into ethylenenorbornene copolymers, we have in this work developed a model poly(ethylene-1-butene) polymer compatible with the commercial available ethylene......-norbornene copolymer TOPAS. Through matching of the radius of gyration for the model polymer and TOPAS the miscibility was achieved. The poly(ethylene-1-butene) polymer was synthesized from a hydrogenated anionic polymerized polybutadiene polymer. As hydrophilic block poly(ethylene oxide) was subsequently added also......The aim of this work is to produce polymer modifiers in order to develop hydrophilic polymeric surfaces for use in microfluidics. The use of hydrophilic polymers in microfluidics will have many advantages e.g. preventing protein absorbance. Here we present an amphiphilic diblock copolymer...

  2. Molecular Interaction Control in Diblock Copolymer Blends and Multiblock Copolymers with Opposite Phase Behaviors

    Science.gov (United States)

    Cho, Junhan

    2014-03-01

    Here we show how to control molecular interactions via mixing AB and AC diblock copolymers, where one copolymer exhibits upper order-disorder transition and the other does lower disorder-order transition. Linear ABC triblock copolymers possessing both barotropic and baroplastic pairs are also taken into account. A recently developed random-phase approximation (RPA) theory and the self-consistent field theory (SCFT) for general compressible mixtures are used to analyze stability criteria and morphologies for the given systems. It is demonstrated that the copolymer systems can yield a variety of phase behaviors in their temperature and pressure dependence upon proper mixing conditions and compositions, which is caused by the delicate force fields generated in the systems. We acknowledge the financial support from National Research Foundation of Korea and Center for Photofunctional Energy Materials.

  3. Surface Functionalization of WO3 Thin Films with (3-Aminopropyl)triethoxysilane and Succinic Anhydride

    Science.gov (United States)

    Ta, Thi Kieu Hanh; Tran, Thi Nhu Hoa; Tran, Quang Minh Nhat; Pham, Duy Phong; Pham, Kim Ngoc; Cao, Thi Thanh; Kim, Yong Soo; Tran, Dai Lam; Ju, Heongkyu; Phan, Bach Thang

    2017-06-01

    We report effects of oxygen plasma treatment on the surface functionalization of WO3 thin films with (3-aminopropyl)triethoxysilane (APTES) and succinic anhydride (SA). X-ray diffraction and x-ray photoelectron spectroscopy results indicate the existence of the WO3 phase. Fourier transform infrared spectroscopy measurement shows clear bands at 1040 cm-1 (Si-O-Si), 1556 cm-1 (N-H), 1655 cm-1 (C=O), 2937 cm-1 (C-H) and 3298 cm-1 (N-H), confirming the surface functionalization efficiency enhanced by prior treatment of oxygen plasma. It thus follows that the prior oxygen plasma treatment activates hydroxylation with more -OH groups on the WO3 surface, which can pave a highly efficient way to the surface functionalization by APTES and SA.

  4. Asymmetric Alternating Copolymerization of Meso-epoxides and Cyclic Anhydrides: Efficient Access to Enantiopure Polyesters.

    Science.gov (United States)

    Li, Jie; Liu, Ye; Ren, Wei-Min; Lu, Xiao-Bing

    2016-09-14

    Synthesis of stereoregular polyesters with main-chain chirality was achieved for the first time by the asymmetric copolymerization of meso-epoxides and cyclic anhydrides using catalyst systems based on enantiopure bimetallic complexes. The combination of the biphenol-linked dinuclear aluminum complex with tert-butyl groups in the phenolate ortho-positions and a nucleophilic co-catalyst was found to be more efficient in catalyzing this asymmetric copolymerization, affording enantiomerically enriched polyesters (up to 91% ee) with completely alternating structure and narrow molecular weight distribution. It was discovered that the isotactic-enriched poly(cyclopentene phthalate) is a typical semicrystalline material with a melting endothermic peak at 221 °C. This study is expected to provide a promising route to prepare various stereoregular polyesters having a wide variety of physical properties and degradability.

  5. Ionic liquids as novel solvents for biosynthesis of octenyl succinic anhydride-modified waxy maize starch.

    Science.gov (United States)

    Li, Dandan; Zhang, Xiwen; Tian, Yaoqi

    2016-05-01

    Biosynthesis of octenyl succinic anhydride (OSA) starch was investigated using ionic liquids (ILs) as reaction media. Waxy maize starch was pretreated in 1-butyl-3-methylimidazolium chlorine and then esterified with OSA in 1-octyl-3-methylimidazolium nitrate by using Novozyme 435 as catalyst. The degree of substitution of OSA starch reached 0.0130 with 5 wt% starch concentration and 1 wt% lipase dosage based on ILs weight at 50 °C for 3h. The formation of OSA starch was confirmed by fourier transform infrared spectroscopy. Scanning electron microscopy and X-ray diffraction revealed that the morphology and crystal structure of starch were significantly destroyed. Thermogravimetric analysis showed that esterification decreased the thermal stability of starch. The successful lipase-catalyzed synthesis of OSA starch in ILs suggests that ILs are potential replacement of traditional organic solvents for starch ester biosynthesis. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Preparation and Characterization of Octenyl Succinic Anhydride Modified Taro Starch Nanoparticles.

    Science.gov (United States)

    Jiang, Suisui; Dai, Lei; Qin, Yang; Xiong, Liu; Sun, Qingjie

    2016-01-01

    The polar surface and hydrophilicity of starch nanoparticles (SNPs) result in their poor dispersibility in nonpolar solvent and poor compatibility with hydrophobic polymers, which limited the application in hydrophobic system. To improve their hydrophobicity, SNPs prepared through self-assembly of short chain amylose debranched from cooked taro starch, were modified by octenyl succinic anhydride (OSA). Size via dynamic light scattering of OSA-SNPs increased compared with SNPs. Fourier transform infrared spectroscopy data indicated the OSA-SNPs had a new absorption peak at 1727 cm-1, which was the characteristic peak of carbonyl, indicating the formation of the ester bond. The dispersibility of the modified SNPs in the mixture of water with nonpolar solvent increased with increasing of degree of substitution (DS). OSA-SNPs appear to be a potential agent to stabilize the oil-water systems.

  7. Dual-Functional Hydrazide-Reactive and Anhydride-Containing Oligomeric Hydrogel Building Blocks.

    Science.gov (United States)

    Kascholke, Christian; Loth, Tina; Kohn-Polster, Caroline; Möller, Stephanie; Bellstedt, Peter; Schulz-Siegmund, Michaela; Schnabelrauch, Matthias; Hacker, Michael C

    2017-03-13

    Biomimetic hydrogels are advanced biomaterials that have been developed following different synthetic routes. Covalent postfabrication functionalization is a promising strategy to achieve efficient matrix modification decoupled of general material properties. To this end, dual-functional macromers were synthesized by free radical polymerization of maleic anhydride with diacetone acrylamide (N-(1,1-dimethyl-3-oxobutyl)acrylamide) and pentaerythritol diacrylate monostearate. Amphiphilic oligomers (M n 40%). Efficient hydrazide/hydrazine immobilization depending on solution pH, hydrogel ketone content as well as ligand concentration for bioconjugation was shown and reversibility of hydrazone formation was indicated by physiologically relevant hydrazide release over 7 days. Proof-of-concept experiments with hydrazido-functionalized hyaluronan demonstrated potential for covalent aECM immobilization. The presented dual-functional macromers have perspective as reactive hydrogel building blocks for various biomedical applications.

  8. One-pot synthesis of thermoplastic mixed paramylon esters using trifluoroacetic anhydride.

    Science.gov (United States)

    Shibakami, Motonari; Tsubouchi, Gen; Sohma, Mitsugu; Hayashi, Masahiro

    2015-03-30

    Mixed paramylon esters prepared from paramylon (a storage polysaccharide of Euglena), acetic acid, and a long-chain fatty acid by one-pot synthesis using trifluoroacetic anhydride as a promoter and solvent were shown to have thermoplasticity. Size exclusion chromatography indicated that the mixed paramylon esters had a weight average molecular weight of approximately 4.9-6.7×10(5). Thermal analysis showed that these esters were stable in terms of the glass transition temperature (>90°C) and 5% weight loss temperature (>320°C). The degree of substitution of the long alkyl chain group, a dominant factor determining thermoplasticity, was controlled by tuning the feed molar ratio of acetic acid and long-chain fatty acid to paramylon. These results implied that the one-pot synthesis is useful for preparing structurally-well defined thermoplastic mixed paramylon esters with high molecular weight. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Versatile colorant syntheses by multiple condensations of acetyl anilines with perylene anhydrides.

    Science.gov (United States)

    Jänsch, Daniel; Li, Chen; Chen, Long; Wagner, Manfred; Müllen, Klaus

    2015-02-09

    We report a key step forward in rylene chemistry: the transformation of rylenes into novel chromophore families. The imidization of rylene anhydrides with 2-acetyl anilines could be controlled by the choice of the solvent, thus causing a transformation into either a 4-hydroxyquinoline (4-HQ) or a 4-oxoquinoline (4-OQ) unit. The 4-OQ motif contains an aminoenone group formed by intramolecular aldol condensation and is the first vinylogous rylene imide. The concept of vinylogy was further developed by utilizing 2,6-diacetyl aniline leading to an 3a-aza-1,6-phenalenedione-extended rylene skeleton fully embracing the nitrogen atom. By functionalization of the aminoenone motifs, for example, malononitrile addition at the carbonyl groups, the optical and electronic properties could be further tuned. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Enzymatic Kinetic Resolution of Secondary Alcohols Using an Ionic Anhydride Generated In Situ.

    Science.gov (United States)

    Rocha, Ângelo; Teixeira, Raquel; Lourenço, Nuno M T; Afonso, Carlos A M

    2017-01-10

    We developed a method for the resolution of secondary alcohols using an ionic anhydride acylating agent prepared directly in the reaction medium containing the biocatalyst Candida antarctica lipase B (CALB). NMR studies showed that mixing all components at the same time does not interfere with the coupling reaction or the enzymatic activity. After optimization of the reaction conditions, the method allowed the resolution of a number of substrates in very high conversions (46-48 %) and enantiomeric ratios (E>170) along with an easy recovery of both enantiomers without the need for preparative chromatographic separation. Additionally, both the starting ionic acid and the biocatalyst could be recovered and reused up to nine cycles without significant loss of enantioselectivity. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Heterogeneous catalyst for the production of acetic anhydride from methyl acetate

    Science.gov (United States)

    Ramprasad, Dorai; Waller, Francis Joseph

    1999-01-01

    This invention relates to a process for producing acetic anhydride by the reaction of methyl acetate, carbon monoxide, and hydrogen at elevated temperatures and pressures in the presence of an alkyl halide and a heterogeneous, bifunctional catalyst that contains an insoluble polymer having pendant quaternized phosphine groups, some of which phosphine groups are ionically bonded to anionic Group VIII metal complexes, the remainder of the phosphine groups being bonded to iodide. In contrast to prior art processes, no accelerator (promoter) is necessary to achieve the catalytic reaction and the products are easily separated from the catalyst by filtration. The catalyst can be recycled for consecutive runs without loss in activity. Bifunctional catalysts for use in carbonylating dimethyl ether are also provided.

  12. Effects of phthalic anhydride modification on horseradish peroxidase stability and activity.

    Science.gov (United States)

    O'Brien, Anne Marie; Smith, Andrew T; O'Fágáin, Ciarán

    2003-01-20

    Phthalic anhydride (PA) modification stabilizes horseradish peroxidase (HRP) by reversal of the positive charge on two of HRP's six lysine residues. Native and PA-HRP had half-inactivation temperatures of 51 and 65 degrees C and half-lives at 65 degrees C of 4 and 17 min, respectively. PA-HRP was more resistant to dimethylformamide at room temperature and tetrahydrofuran at 60 degrees C and to unfolding by heat, guanidine chloride, EDTA, and the reducing agent tris(2-carboxyethyl)phosphine hydrochloride. Binding of the hydrophobic probe Nile Red to the native enzyme and to PA-HRP was similar. The kinetics of both HRPs with the substrates ABTS, ferrocyanide, ferulic acid, and indole-3-propionic acid were measured, as was binding of the inhibitor benzhydroxamic acid. Small improvements in the catalytic properties were detected. Copyright 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 81: 233-240, 2003.

  13. Substituted Phthalic Anhydrides from Biobased Furanics: A New Approach to Renewable Aromatics.

    Science.gov (United States)

    Thiyagarajan, Shanmugam; Genuino, Homer C; Śliwa, Michał; van der Waal, Jan C; de Jong, Ed; van Haveren, Jacco; Weckhuysen, Bert M; Bruijnincx, Pieter C A; van Es, Daan S

    2015-09-21

    A novel route for the production of renewable aromatic chemicals, particularly substituted phthalic acid anhydrides, is presented. The classical two-step approach to furanics-derived aromatics via Diels-Alder (DA) aromatization has been modified into a three-step procedure to address the general issue of the reversible nature of the intermediate DA addition step. The new sequence involves DA addition, followed by a mild hydrogenation step to obtain a stable oxanorbornane intermediate in high yield and purity. Subsequent one-pot, liquid-phase dehydration and dehydrogenation of the hydrogenated adduct using a physical mixture of acidic zeolites or resins in combination with metal on a carbon support then allows aromatization with yields as high as 84 % of total aromatics under relatively mild conditions. The mechanism of the final aromatization reaction step unexpectedly involves a lactone as primary intermediate. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Phenolic Acid-based Poly(anhydride-esters) as Antioxidant Biomaterials.

    Science.gov (United States)

    Prudencio, Almudena; Faig, Jonathan J; Song, MinJung; Uhrich, Kathryn E

    2016-02-01

    Poly(anhydride-esters) comprised of naturally occurring, non-toxic phenolic acids, namely syringic and vanillic acid, with antioxidant properties were prepared via solution polymerization methods. Polymer and polymer precursor physiochemical properties were characterized, including polymer molecular weight and thermal properties. In vitro release studies illustrated that polymer hydrolytic degradation was influenced by relative hydrophobicity and degree of methoxy substitution of the phenolic acids. Further, the released phenolic acids were found to maintain antioxidant potency relative to free phenolic acid controls as determined by a 2,2-diphenyl-1-picrylhydrazyl assay. Polymer cytotoxicity was assessed with L929 fibroblasts in polymer-containing media; appropriate cell morphology and high fibroblast proliferation were obtained for the polymers at the lower concentrations. These polymers deliver non-cytotoxic levels of naturally occurring antioxidants, which could be efficacious in topical delivery of antioxidant therapies. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Physico-mechanical properties of silanized-montmorillonite reinforced chitosan-co-poly(maleic anhydride) composites

    Science.gov (United States)

    Saputra, O. A.; Fajrin, A.; Nauqinida, M.; Suryanti, V.; Pramono, E.

    2017-07-01

    To solve the problems of dependence on petroleum as starting material in the manufacturing of plastics in Indonesia, green plastic from biopolymer like chitosan to be one of promising options and alternative to replace the conventional plastics. However, to overcome the mechanical and physical properties of chitosan, the addition of reinforcement agent was introduced. In this study, silanized-montmorillonite (sMMt) has been prepared as a reinforcement agent in the chitosan-co-poly(maleic anhydride) (referred as Cs-MAH) matrix. Silanizing of montmorillonite is one of strategy to improve the interaction between montmorillonite and chitosan, consequently, the mechanical properties, tensile strength of composites contained 6 phr of sMMt improved 56.5% to chitosan. Moreover, the presence both MAH and sMMt on the comosites also reduced swelling degree and swelling area by 20.6% and 26.7%.

  16. The influence of tertiary amine accelerators on the curing behaviors of epoxy/anhydride systems

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Tao; Zhang, Chongfeng; Zhang, Junying, E-mail: zjybuct@gmail.com; Cheng, Jue

    2014-02-10

    Highlights: • The influences of two types of accelerators (BDMA and DMP-30) on curing reaction of DGEBF/MeHHPA systems were studied comparatively. • The activation energy and kinetic parameters of DGEBF/MeHHPA systems with accelerator content of 0.2 phr and 0.5 phr were calculated, respectively. • The dependence of autocatalytic and non-autocatalytic curing reaction on the loading of accelerators was discussed. • The non-catalytic curing reaction dominated absolutely in the curing process of DGEBF/MeHHPA systems when the accelerator contents were 0.2 phr. - Abstract: Accelerators have significant effects on the curing behaviors of epoxy/anhydride (diglycidyl ether of bisphenol-F/methylhexahydrophthalic anhydride, DGEBF/MeHHPA) systems. Non-isothermal DSC was used to investigate the influence of dimethyl benzylamine (BDMA, 0.2 phr/0.5 phr) and Tris-(dimethyl aminomethyl) phenol (DMP-30, 0.2 phr/0.5 phr) on the curing behaviors of DGEBF/MeHHPA systems, respectively. When the amount of accelerators was kept constant, the activation energy calculated by Kissinger method changed slightly in the presence of either BDMA or DMP-30. And, with increasing the accelerator content from 0.2 phr to 0.5 phr, the value of activation energy decreased from 115 kJ/mol to 85 kJ/mol. Furthermore, the calculation results of Málek method identified that all systems in this study fitted Sesták–Berggren (SB) model and the corresponding model parameters, m and n, were obtained. It was found that the contribution of autocatalytic reaction with low accelerator content (0.2 phr) was far less than that with high accelerator content (0.5 phr)

  17. Glycine/Glycolic acid based copolymers

    NARCIS (Netherlands)

    in 't Veld, P.J.A.; in 't Veld, Peter J.A.; Shen, Zheng-Rong; Shen, Z.; Takens, Gijsbert A.J.; Takens, G.A.J.; Dijkstra, Pieter J.; Feijen, Jan

    1994-01-01

    Glycine/glycolic acid based biodegradable copolymers have been prepared by ring-opening homopolymerization of morpholine-2,5-dione, and ring-opening copolymerization of morpholine-2,5-dione and glycolide. The homopolymerization of morpholine-2,5-dione was carried out in the melt at 200°C for 3 min

  18. Restructuring in block copolymer thin films

    DEFF Research Database (Denmark)

    Posselt, Dorthe; Zhang, Jianqi; Smilgies, Detlef-M.

    2017-01-01

    Block copolymer (BCP) thin films have been proposed for a number of nanotechnology applications, such as nanolithography and as nanotemplates, nanoporous membranes and sensors. Solvent vapor annealing (SVA) has emerged as a powerful technique for manipulating and controlling the structure of BCP ...

  19. Synthesis of fluorescent diblock copolymer nanoparticle supported ...

    Indian Academy of Sciences (India)

    2017-06-09

    Jun 9, 2017 ... using different techniques. The diblock copolymer (DBC) of. PCL is reviewed in this paper. In 2005, PCL-based liquid crys- talline DBC was synthesized and characterized thoroughly. [3]. A RAFT technique was adopted for the synthesis of PCL- based DBC [4]. A DBC between PCL and MMA was prepared.

  20. Nylon 46-polytetramethylene oxide segmented block copolymers

    NARCIS (Netherlands)

    Gaymans, R.J.; Schwering, P.; de Haan, J.L.

    1989-01-01

    Block copolymers were synthesized from amine-terminated polytetramethylene oxide (PMTO) (Mw 800 and 1130) and polyamide 4,6 salt. First prepolymers were prepared at 200–210°C in the presence of a solvent (pyrrolidone). The prepolymers were postcondensed at 255°C (where possible in the solid state)

  1. CONJUGATED BLOCK-COPOLYMERS FOR ELECTROLUMINESCENT DIODES

    NARCIS (Netherlands)

    Hilberer, A; Gill, R.E; Herrema, J.K; Malliaras, G.G; Wildeman, J.; Hadziioannou, G

    In this article we review results obtained in our laboratory on the design and study of new light-emitting polymers. We are interested in the synthesis and characterisation of block copolymers with regularly alternating conjugated and non conjugated sequences. The blocks giving rise to luminescence

  2. Preparation of amphiphilic block copolymer containing triazene ...

    Indian Academy of Sciences (India)

    The lower rate constant in film state (film = 1.3 × 10−3 s-1), shows that the higher mobility of polymeric chains in solution allow a more rapid orientation, favourable to the triazene bond cleavage. The capability of block copolymer to form micelles in aqueous environment and implicitly, its critical micelle concentration (CMC) ...

  3. 21 CFR 177.1970 - Vinyl chloride-lauryl vinyl ether copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Vinyl chloride-lauryl vinyl ether copolymers. 177...-lauryl vinyl ether copolymers. The vinyl chloride-lauryl vinyl ether copolymers identified in paragraph... section vinyl chloride-lauryl vinyl ether copolymers consist of basic copolymers produced by the...

  4. Water-soluble metal working fluids additives derived from the esters of acid anhydrides with higher alcohols for aluminum alloy materials.

    Science.gov (United States)

    Yamamoto, Syutaro; Tomoda, Hideyuki; Watanabe, Shoji

    2007-01-01

    Water-soluble metal working fluids are used for processing of aluminum alloy materials. This short article describes properties of new additives in water-soluble metal working fluids for aluminum alloy materials. Many half esters or diesters were prepared from the reactions of higher alcohols with acid anhydrides. Interestingly, diesters of PTMG (tetrahydrofuran oligomer, MW = 650 and 1000) and polybutylene oxide (MW = 650) with maleic anhydride and succinic anhydride showed both of an excellent anti-corrosion property for aluminum alloy and a good hard water tolerance. The industrial soluble type processing oils including these additives also showed anti-corrosion property and hard water tolerance.

  5. Effect of maleic anhydride-aniline derivative buffer layer on the properties of flexible substrate heterostructures: Indium tin oxide/nucleic acid base/metal

    Energy Technology Data Exchange (ETDEWEB)

    Stanculescu, A., E-mail: sanca@infim.ro [National Institute of Materials Physics, 105 bis Atomistilor Street, P.O. Box MG-7, 077125, Bucharest-Magurele (Romania); Socol, M. [National Institute of Materials Physics, 105 bis Atomistilor Street, P.O. Box MG-7, 077125, Bucharest-Magurele (Romania); Socol, G.; Mihailescu, I.N. [National Institute for Laser, Plasma and Radiation Physics, P.O. Box MG-36, 077125, Bucharest-Magurele (Romania); Girtan, M. [Laboratoire de Photonique d' Angers, Universite d' Angers, 2, Bd. Lavoisier, 49045, Angers (France); Preda, N. [National Institute of Materials Physics, 105 bis Atomistilor Street, P.O. Box MG-7, 077125, Bucharest-Magurele (Romania); Albu, A.-M. [Department of Polymer Science, University ' Politehnica' of Bucharest, Bucharest (Romania); Stanculescu, F. [University of Bucharest, Faculty of Physics, Str. Atomistilor nr.405, P.O. Box MG-11, Bucharest-Magurele, 077125 (Romania)

    2011-12-01

    This paper presents some investigations on the properties of guanine (G) and cytosine (C) based heterostructures deposited on flexible substrates. The effects of two types of maleic anhydride-aniline derivatives (maleic anhydride-cyano aniline or maleic anhydride-2,4 dinitroaniline) buffer layer, deposited between indium tin oxide and (G) or (C) layer, on the optical and electrical properties of the heterostructures have been identified. The heterostructures containing a film of maleic anhydride-2,4 dinitroaniline have shown a good transparency and low photoluminescence in visible range. This buffer layer has determined an increase in the conductance only in the heterostructures based on (G) and (C) deposited on biaxially-oriented polyethylene terephthalate substrate.

  6. Copolymerization and terpolymerization of carbon dioxide/propylene oxide/phthalic anhydride using a (salen)Co(III) complex tethering four quaternary ammonium salts

    National Research Council Canada - National Science Library

    Jeon, Jong Yeob; Eo, Seong Chan; Varghese, Jobi Kodiyan; Lee, Bun Yeoul

    2014-01-01

    The (salen)Co(III) complex 1 tethering four quaternary ammonium salts, which is a highly active catalyst in CO2/epoxide copolymerizations, shows high activity for propylene oxide/phthalic anhydride (PO/PA...

  7. Renewable Pentablock Copolymers Containing Bulky Natural Rosin for Tough Bioplastics

    Science.gov (United States)

    Rahman, Md Anisur; Ganewatta, Mitra S.; Lokupitiya, Hasala N.; Liang, Yuan; Stefik, Morgan; Tang, Chuanbing

    Renewable polymers have received significant attention due to environmental concerns on petrochemical counterparts. One of the most abundant natural biomass is resin acids. However, most polymers derived from resin acids are low molecular weight and brittle because of the high chain entanglement molecular weight resulted from the bulky hydrophenanthrene pendant group. It is well established that the brittleness can be overcome by synthesizing multi-block copolymers with low entanglement molecular weight components. We investigated the effects of chain architecture and microdomain orientation on mechanical properties of both tri and pentablock copolymers. We synthesized rosin-containing A-B-A-B-A type pentablock and A-B-A type triblock copolymers to improve their mechanical properties. Pentablock copolymers showed higher strength and better toughness as compared to triblock copolymers, both superior to homopolymers. The greater toughness of pentablock copolymers is due to the presence of the rosin based midblock chains that act as bridging chains between two polynorbornene blocks.

  8. Optical nanoimaging for block copolymer self-assembly.

    Science.gov (United States)

    Yan, Jie; Zhao, Ling-Xi; Li, Chong; Hu, Zhe; Zhang, Guo-Feng; Chen, Ze-Qiang; Chen, Tao; Huang, Zhen-Li; Zhu, Jintao; Zhu, Ming-Qiang

    2015-02-25

    One approach toward optical nanoimaging involves sequential molecular localization of photoswitchable fluorophores to achieve high resolution beyond optical limit of diffraction. Block copolymer micelles assembled from polystryrene-block-poly(ethylene oxide) block copolymers (PSt-b-PEO) are visualized in optical nanoimaging by staining the polystyrene blocks with spiropyrans (SPs). SPs localized in hydrophobic phase of block copolymer micelles exhibit reversible fluorescence on-off switching at alternating irradiation of UV and visible light. Phase-selective distribution of SPs in block copolymer micelles enables optical nanoimaging of microphase structures of block copolymer self-assembly at 50-nm resolution. To date, this is the sturdiest realization of optical nanoimaging with subdiffraction resolution for solution self-assembly of block copolymers.

  9. Characterization of the Structure-Processing-Performance Relations of Phenylethynyl Phthalic Anhydride Crosslinked Fluorinated Polyimides (AFR-PEPA-N) and Their Carbon Fiber Composites

    Science.gov (United States)

    2007-04-12

    FA9550-04-1-0137 Relations of Phenylethynyl Phthalic Anhydride Crosslinked Fluorinated Polyimides (AFR-PEPA-N) and Their Carbon Fiber Composites 5b. GRANT...structure-processing-performance relations of phenylethynyl phthatic anhydride crosslinked fluorinated polyimides (AFR-PEPA-N) and their carbon fiber...Prescribed by ANSI Std. Z39.18 FINAL REPORT CHARACTERIZATION OF THE STRUCTURE - PROCESSING - PERFORMANCE RELATIONS OF PHENYLETHYNYL PHTHALIC

  10. Grafting amino drugs to poly(styrene-alt-maleic anhydride) as a potential method for drug release

    Energy Technology Data Exchange (ETDEWEB)

    Khazaei, Ardeshir; Saednia, Shahnaz; Saien, Javad; Abbasi, Fatemeh, E-mail: Khazaei_1326@yahoo.com, E-mail: ssaednia@gmail.com [Faculty of Chemistry, Bu-Ali Sina University, Hamedan (Iran, Islamic Republic of); Kazem-Rostami, Masoud [Young Researchers Club and Elite, Takestan Branch, Islamic Azad University, Takestan (Iran, Islamic Republic of); Sadeghpour, Mahdieh [Department of Chemistry, Takestan Branch, Islamic Azad University, Takestan (Iran, Islamic Republic of); Borazjani, Maryam Kiani [Faculty of Science, Department of Chemistry, Bushehr Payame Noor University (PNU), Bushehr (Iran, Islamic Republic of)

    2013-07-15

    Drug delivery systems based on polymer-drug conjugates give an improved treatment with lower toxicity or side effects and be used for the treatment of different diseases. Conjugates of biodegradable poly(styrene-alt-maleic anhydride) (PSMA), with a therapeutic agents such as amantadine hydrochloride, amlodipine, gabapentin, zonisamide and mesalamine, were afforded by the formation of the amide bonds of the amino drugs that reacted with the PSMA anhydride groups. The amounts of covalently conjugated drugs were determined by a {sup 1}H NMR spectroscopic method, and the in vitro release rate in buffer solution (pH 1.3) was studied at body temperature 37 Degree-Sign C. In kinetic studies, different dissolution models were examined to obtain drug release data and the collected data were well-fitted to the Korsmeyer-Peppas equation, revealing a dominant Fickian diffusion mechanism for drug release under the in vitro conditions. (author)

  11. A facile synthesis of deuterium labeled 2,2-dimethyl-[2H6]-succinic acid and its anhydride.

    Science.gov (United States)

    Srinivas, G; Unny, V K P; Mukkanti, K; Choudary, B M

    2013-05-30

    Deuterium labeled 2,2-dimethyl-[(2)H(6)]-succinic anhydride by a sequence of reactions involving Knoevenagel condensation of [(2)H(6)]-acetone with ethyl cyanoacetate in the presence of piperidine, Michael addition of cyanide, HCl hydrolysis, simultaneous decarboxylation, and subsequent dehydration using acetic anhydride in an overall yield of 34.23% based on [(2)H(6)]-acetone utilized in the reaction is reported. The title compounds were characterized and confirmed spectroscopically by Fourier transform infrared, (1) H-NMR, and Mass. The chemical purity as determined by HPLC was 99%. To the best of our knowledge, the synthesis of these specifically deuterium labeled compounds has not been reported so far. Copyright © 2013 John Wiley & Sons, Ltd.

  12. Preparation of Proteoglycan Mimetic Graft Copolymers.

    Science.gov (United States)

    Kipper, Matt J; Place, Laura W

    2016-01-01

    Proteoglycans are proteins with pendant glycosaminoglycan polysaccharide side chains. The method described here enables the preparation of graft copolymers with glycosaminoglycan side chains, which mimic the structure and composition of proteoglycans. By controlling the stoichiometry, graft copolymers can be obtained with a wide range of glycosaminoglycan side-chain densities. The method presented here uses a three-step reaction mechanism to first functionalize a hyaluronic acid backbone, followed by reductive amination to couple the glycosaminoglycan side chain to the backbone, by the reducing end. Proteoglycan mimics like the ones proposed here could be used to study the structure-property relationships of proteoglycans and to introduce the biochemical and biomechanical properties of proteoglycans into biomaterials and therapeutic formulations.

  13. Hybrid, Nanoscale Phospholipid/Block Copolymer Vesicles

    Directory of Open Access Journals (Sweden)

    Bo Liedberg

    2013-09-01

    Full Text Available Hybrid phospholipid/block copolymer vesicles, in which the polymeric membrane is blended with phospholipids, display interesting self-assembly behavior, incorporating the robustness and chemical versatility of polymersomes with the softness and biocompatibility of liposomes. Such structures can be conveniently characterized by preparing giant unilamellar vesicles (GUVs via electroformation. Here, we are interested in exploring the self-assembly and properties of the analogous nanoscale hybrid vesicles (ca. 100 nm in diameter of the same composition prepared by film-hydration and extrusion. We show that the self-assembly and content-release behavior of nanoscale polybutadiene-b-poly(ethylene oxide (PB-PEO/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC hybrid phospholipid/block copolymer vesicles can be tuned by the mixing ratio of the amphiphiles. In brief, these hybrids may provide alternative tools for drug delivery purposes and molecular imaging/sensing applications and clearly open up new avenues for further investigation.

  14. Phase-Segregated Dendrigraft Copolymer Architectures

    Directory of Open Access Journals (Sweden)

    Lorena-Eugenia Sanchez Cadena

    2010-11-01

    Full Text Available Dendrigraft polymers have a multi-level branched architecture resulting from the covalent assembly of macromolecular building blocks. Most of these materials are obtained in divergent (core-first synthetic procedures whereby the molecule grows outwards in successive grafting reactions or generations. Two main types of dendrigraft polymers can be identified depending on the distribution of reactive sites over the grafting substrate: Arborescent polymers have a large and variable number of more or less uniformly distributed sites, while dendrimer-like star polymers have a lower but well-defined number of grafting sites strictly located at the ends of the substrate chains. An overview of the synthesis and the characterization of dendrigraft copolymers with phase-segregated morphologies is provided in this review for both dendrigraft polymer families. The tethering of side-chains with a different composition onto branched substrates confers unusual physical properties to these copolymers, which are highlighted through selected examples.

  15. Nanostructured Polysulfone-Based Block Copolymer Membranes

    KAUST Repository

    Xie, Yihui

    2016-05-01

    The aim of this work is to fabricate nanostructured membranes from polysulfone-based block copolymers through self-assembly and non-solvent induced phase separation. Block copolymers containing polysulfone are novel materials for this purpose providing better mechanical and thermal stability to membranes than polystyrene-based copolymers, which have been exclusively used now. Firstly, we synthesized a triblock copolymer, poly(tert-butyl acrylate)-b-polsulfone-b-poly(tert-butyl acrylate) through polycondensation and reversible addition-fragmentation chain-transfer polymerization. The obtained membrane has a highly porous interconnected skin layer composed of elongated micelles with a flower-like arrangement, on top of the graded finger-like macrovoids. Membrane surface hydrolysis was carried out in a combination with metal complexation to obtain metal-chelated membranes. The copper-containing membrane showed improved antibacterial capability. Secondly, a poly(acrylic acid)-b-polysulfone-b-poly(acrylic acid) triblock copolymer obtained by hydrolyzing poly(tert-butyl acrylate)-b-polsulfone-b-poly(tert-butyl acrylate) formed a thin film with cylindrical poly(acrylic acid) microdomains in polysulfone matrix through thermal annealing. A phase inversion membrane was prepared from the same polymer via self-assembly and chelation-assisted non-solvent induced phase separation. The spherical micelles pre-formed in a selective solvent mixture packed into an ordered lattice in aid of metal-poly(acrylic acid) complexation. The space between micelles was filled with poly(acrylic acid)-metal complexes acting as potential water channels. The silver0 nanoparticle-decorated membrane was obtained by surface reduction, having three distinct layers with different particle sizes. Other amphiphilic copolymers containing polysulfone and water-soluble segments such as poly(ethylene glycol) and poly(N-isopropylacrylamide) were also synthesized through coupling reaction and copper0-mediated

  16. Rapid ordering of block copolymer thin films.

    Science.gov (United States)

    Majewski, Pawel W; Yager, Kevin G

    2016-10-12

    Block-copolymers self-assemble into diverse morphologies, where nanoscale order can be finely tuned via block architecture and processing conditions. However, the ultimate usage of these materials in real-world applications may be hampered by the extremely long thermal annealing times-hours or days-required to achieve good order. Here, we provide an overview of the fundamentals of block-copolymer self-assembly kinetics, and review the techniques that have been demonstrated to influence, and enhance, these ordering kinetics. We discuss the inherent tradeoffs between oven annealing, solvent annealing, microwave annealing, zone annealing, and other directed self-assembly methods; including an assessment of spatial and temporal characteristics. We also review both real-space and reciprocal-space analysis techniques for quantifying order in these systems.

  17. Ordering phenomena in ABA triblock copolymer gels

    DEFF Research Database (Denmark)

    Reynders, K.; Mischenko, N.; Kleppinger, R.

    1997-01-01

    Temperature and concentration dependencies of the degree of order in ABA triblock copolymer gels are discussed. Two factors can influence the ordering phenomena: the conformation of the midblocks (links of the network) and the polydispersity of the endblock domains (nodes of the network). The lat......Temperature and concentration dependencies of the degree of order in ABA triblock copolymer gels are discussed. Two factors can influence the ordering phenomena: the conformation of the midblocks (links of the network) and the polydispersity of the endblock domains (nodes of the network...... crystalline lattice with close-packed spheres or with cubic (presumably BCC) equilibrium morphology. The appearance of the latter is never detected in the gels with a stretched conformation of the midblock....

  18. A Cationic Smart Copolymer for DNA Binding

    Directory of Open Access Journals (Sweden)

    Tânia Ribeiro

    2017-11-01

    Full Text Available A new block copolymer with a temperature-responsive block and a cationic block was prepared by reversible addition-fragmentation chain transfer (RAFT polymerization, with good control of its size and composition. The first block is composed by di(ethylene glycol methyl ether methacrylate (DEGMA and oligo(ethylene glycol methyl ether methacrylate (OEGMA, with the ratio DEGMA/OEGMA being used to choose the volume phase transition temperature of the polymer in water, tunable from ca. 25 to above 90 °C. The second block, of trimethyl-2-methacroyloxyethylammonium chloride (TMEC, is positively charged at physiological pH values and is used for DNA binding. The coacervate complexes between the block copolymer and a model single strand DNA are characterized by fluorescence correlation spectroscopy and fluorescence spectroscopy. The new materials offer good prospects for biomedical application, for example in controlled gene delivery.

  19. Mechanism of Molecular Exchange in Copolymer Micelles

    Science.gov (United States)

    Choi, Soo-Hyung; Lodge, Timothy; Bates, Frank

    2010-03-01

    Compared to thermodynamic structure, much less has been known about the kinetics of block copolymer micelles which should underlay the attainment of thermodynamic equilibrium. In this presentation, molecular exchange between spherical micelles formed by isotopically labeled diblock copolymers was investigated using time-resolved small-angle neutron scattering. Two pairs of structurally matched poly(styrene-b-ethylene-alt-propylene) (PS-PEP) were synthesized and dispersed in isotopic mixture of squalane, highly selective to PEP block. Each pair includes polymers with fully deuterated (dPS-PEP) and a normal (hPS-PEP) PS blocks. Temperature dependence of the micelle exchange rate R(t) is consistent with melt dynamics for the core polymer. Furthermore, R(t) is significantly sensitive to the core block length N due to the thermodynamic penalty associated with ejecting a core block into the solvent. This hypersensitivity, combined with modest polydispersity in N, leads to an approximately logarithmic decay in R(t).

  20. Short communication: Difructose anhydride III promotes calcium absorption from the duodenum in cattle.

    Science.gov (United States)

    Teramura, M; Nakai, T; Itoh, M; Sato, T; Ohtani, M; Kawashima, C; Hanada, M

    2015-04-01

    Difructose anhydride (DFA) III promotes the intestinal absorption of calcium via a paracellular pathway in rats. In dairy cows, DFA III reaches the duodenum without being degraded by ruminal bacteria and hence could be used to control hypocalcemia. The aims of the present study were to investigate the percentage of DFA III that appears in the duodenum of cows and to determine the effect of DFA III on calcium absorption from duodenal fluid. The first experiment was performed in 3 ruminally and duodenally cannulated dry Holstein cows in a 3 × 3 Latin square design. Each experimental period lasted 7 d. On the first day, the cows were ruminally fed one of the following treatments: 0 (DFA0), 50 (DFA50), or 100 (DFA100) g/d of DFA III, using cobalt-EDTA as a liquid phase marker. Difructose anhydride III was detected in duodenal fluid 1 h after feeding, and its concentration peaked 4 h after feeding, in a dose-dependent manner. The percentages of DFA III that appeared in the duodenum after the DFA50 and DFA100 treatments were 69.1 ± 7.0% and 67.9 ± 5.6%, respectively. The second experiment used the everted duodenal sacs of cattle (n = 7 in each group). Sacs were incubated in artificial mucosal fluid containing 1 mM DFA III or no DFA III (control) for 60 min with 100% O2 in a water bath at 37 °C. After incubation, the calcium concentration of the artificial serosal fluid in the everted sacs was measured. Calcium absorption was higher in the DFA III-treated group than in the control group (803 ± 161 and 456 ± 74 nmol/cm of sac, respectively). The above results demonstrate that approximately 70% of administered DFA III reached the duodenum of cows intact. Moreover, similar to its effects on calcium absorption in rats, DFA III promoted calcium absorption via a paracellular pathway in the duodenum of cows. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  1. Effect of Linear Chain Carboxylic Acid Anhydrides on Physical and Mechanical Properties of Rubber (Hevea brasiliensis, Acacia, (Acacia spp., and Oil Palm (Tinnera spp. Woods

    Directory of Open Access Journals (Sweden)

    Mohd Afiq Mohtar

    2014-01-01

    Full Text Available The physical and mechanical properties of Rubber wood, Acacia wood, and Oil palm wood that reacted with acetic, propionic, and butyric anhydrides using a microwave heating for 4 minutes were investigated. A sample dimension of 300 mm × 100 mm × 25 mm (L×W×T was used for modification and they were cut into smaller specimens for different testing method. This study found that the density increment and void volume changes were not significantly different from anhydrides. The modification of wood with anhydrides was not significantly affected by the static bending properties, except for the Oil palm. The compression strength for any anhydrides shows an improvement for the Rubber wood and Acacia spp. but not Oil palm. The hardness was also not significantly different from anhydrides for all wood species. The impact strength of Rubber wood and Oil palm significantly increased compared to the untreated wood, but this was not the case for Acacia spp. Generally, the highest improvement in mechanical properties was obtained by modification of Rubber and Acacia woods with butyric anhydride.

  2. The oxidation of n-butane to maleic anhydride under hydrocarbon-rich conditions: The role of homogeneous and of mixed homogeneous-heterogeneous reactions

    Energy Technology Data Exchange (ETDEWEB)

    Ballarini, N.; Cortelli, C.; Pierelli, F.; Trifiro, F. [Dipt. di Chimica Industriale e dei Materiali, Bologna (Italy); Cavani, F. [INSTM, Research Unit of Bologna (Italy); Fumagalli, C.; Mazzoni, G. [Lonzagroup, Scanzorosciate (Italy)

    2004-07-01

    The reactivity of vanadyl pyrophosphate, catalyst for the selective oxidation of n-butane to maleic anhydride, was examined under n-butane-rich conditions. A lower selectivity to maleic anhydride was found with respect to the hydrocarbon-lean conditions, due to (i) the higher selectivity to carbon oxides and (ii) the formation of C{sub 8} by-products: tetrahydrophthalic and phthalic anhydrides. The latter compounds formed under conditions of total oxygen conversion by a consecutive reaction of maleic anhydride with butadiene, intermediate in n-butane transformation, due to the decreased oxidizing property of the vanadyl pyrophosphate. A relevant contribution of radicalic, homogeneous reactions was also observed, which led to the formation of carbon oxides and olefins. This contribution decreased in the presence of the catalyst, which acted as a radical scavenger, but nevertheless remained important at temperatures higher than 400 C even in the presence of the catalyst. When conditions were used under which the conversion of oxygen was not total, olefins generated in the gas phase reacted at the catalyst surface yielding maleic anhydride. This homogeneously-initiated, heterogeneous process led to an unusual effect, of a relevant increase of maleic anhydride yield over 400 C. (orig.)

  3. Critical adsorption of copolymer tethered on selective surfaces

    Science.gov (United States)

    Li, Hong; Qian, Chang-Ji; Luo, Meng-Bo

    2016-04-01

    Critical adsorption behaviors of flexible copolymer chains tethered to a flat homogeneous surface are studied by using Monte Carlo simulations. We have compared the critical adsorption temperature Tc, estimated by a finite-size scaling method, for different AB copolymer sequences with A the attractive monomer and B the inert monomer. We find that Tc increases with an increase in the fraction of monomers A, fA, in copolymers, and it increases with an increase in the length of block A for the same fA. In particular, Tc of copolymer (AnBn)r can be expressed as a function of the block length, n, and Tc of copolymer (AnB)r and (ABm)r can be expressed as a linear function of fA. Tc of random copolymer chains also can be expressed as a linear function of fA and it can be estimated by using weight-average of Tc of different diblocks in the random copolymer. However, the crossover exponent is roughly independent of AB sequence distributions either for block copolymers or for random copolymers.

  4. Zinc vs. magnesium: Orthogonal catalyst reactivity in selective polymerizations of epoxides, bio-derived anhydrides and carbon

    OpenAIRE

    Williams, C; Fiorani, G.; Saini, PJ; Mathers, RT

    2017-01-01

    Developing selective polymerizations from complex monomer mixtures is an important challenge. Here, dinuclear catalysts allow selective polymerization from mixtures of sterically hindered tricyclic anhydrides, carbon dioxide and epoxides to yield well-controlled co-poly(ester-carbonates). Surprisingly, two very similar homogeneous catalysts differing only in the central metal, zinc vs. magnesium, show very high but diametrically opposite monomer selectivity. The selectivity is attributed to d...

  5. Adsorption-like Collapse of Diblock Copolymers

    OpenAIRE

    Orlandini, E.; Seno, F.; Stella, A. L.

    1999-01-01

    A linear copolymer made of two reciprocally attracting N-monomer blocks collapses to a compact phase through a novel transition, whose exponents are determined with extensive MC simulations in two and three dimensions. In the former case, an identification with the statistical geometry of suitable percolation paths allows to predict that the number of contacts between the blocks grows like $N^{9/16}$. In the compact phase the blocks are mixed and, in two dimensions, also zipped, in such a way...

  6. Hydrogel networks based on ABA triblock copolymers.

    Science.gov (United States)

    Tartivel, Lucile; Behl, Marc; Schroeter, Michael; Lendlein, Andreas

    2012-01-01

    Triblock copolymers from hydrophilic oligo(ethylene glycol) segment A and oligo(propylene glycol) segment B, providing an ABA structure (OEG-OPG-OEG triblock), are known to be biocompatible and are used as self-solidifying gels in drug depots. A complete removal of these depots would be helpful in cases of undesired side effects of a drug, but this remains a challenge as they liquefy below their transition temperature. Therefore we describe the synthesis of covalently cross-linked hydrogel networks. Triblock copolymer-based hydrogels were created by irradiating aqueous solutions of the corresponding macro-dimethacrylates with UV light. The degree of swelling, swelling kinetics, mechanical properties and morphology of the networks were investigated. Depending on precursor concentration, equilibrium degree of swelling of the films ranged between 500% and 880% and was reached in 1 hour. In addition, values for storage and loss moduli of the hydrogel networks were in the 100 Pa to 10 kPa range. Although OEG-OPG-OEG triblocks are known for their micellization, which could hamper polymer network formation, reactive OEG-OPG-OEG triblock oligomers could be successfully polymerized into hydrogel networks. The degree of swelling of these hydrogels depends on their molecular weight and on the oligomer concentration used for hydrogel preparation. In combination with the temperature sensitivity of the ABA triblock copolymers, it is assumed that such hydrogels might be beneficial for future medical applications - e.g., removable drug release systems.

  7. A maleic anhydride grafted sugarcane bagasse adsorbent and its performance on the removal of methylene blue from related wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Mingliang; Du, Mingyi; Zheng, Luoyun [Key Laboratory of Polymer Processing Engineering of Ministry of Education, National Engineering Research Center of Novel Equipment for Polymer Processing, School of Mechanical & Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); Wang, Bingying; Zhou, Xiangyang [College of Chemistry and Chemical Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou 510225 (China); Jia, Zhixin [College of Material Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Hu, Guoqing [Key Laboratory of Polymer Processing Engineering of Ministry of Education, National Engineering Research Center of Novel Equipment for Polymer Processing, School of Mechanical & Automotive Engineering, South China University of Technology, Guangzhou 510640 (China); Jahangir Alam, S.M., E-mail: mejahangir@scut.edu.cn [Key Laboratory of Polymer Processing Engineering of Ministry of Education, National Engineering Research Center of Novel Equipment for Polymer Processing, School of Mechanical & Automotive Engineering, South China University of Technology, Guangzhou 510640 (China)

    2017-05-01

    Sugarcane bagasse (SCB) was selected as the supporting material for grafting maleic anhydride (MA) to obtain sugarcane-bagasse-grafting-maleic-anhydride (SCB-g-MA), which was used as an adsorbent for the removal of methylene blue (MB) in the dye-containing wastewater. The granular morphology and functional groups of the material were characterized by the scanning electron microscope (SEM), Fourier transforms infrared spectroscopy (FTIR), and solid-state analysis (13C NMR) methods. The effect(s) of the adsorbent dosage, adsorption time, initial concentration of MB, and the pH of solution on the MB adsorption performance of the material have been also investigated. The results showed that the adsorption capacity and removal rate of MB were found to be 82 mg/g and 98%, respectively. It has also showed that the adsorption behavior on the MB could be well described by the pseudo-second-order model integrated with Langmuir model. - Highlights: • Using solid phase grafting method to graft the maleic anhydride (MA) onto the Sugarcane bagasse (SCB) and get the SCB-g-MA. • SEM, FTIR and 13C NMR analysis were used to characterize the grafting of MA on to the SCB by the solid phase grafting method. • The adsorption capacity and removal rate of MB were to be 82 mg/g and 98% respectively, to show an excellent adsorption effect. • Pseudo-second-order model and Langmuir model are better fitted the adsorption kinetics and isotherms in this research.

  8. Organic linkers on oxide surfaces: Adsorption and chemical bonding of phthalic anhydride on MgO(100)

    Science.gov (United States)

    Mohr, Susanne; Doepper, Tibor; Xu, Tao; Tariq, Quratulain; Lytken, Ole; Laurin, Mathias; Steinrueck, Hans-Peter; Goerling, Andreas; Libuda, Joerg

    2016-04-01

    To elucidate the adsorption behavior and interaction mechanisms of organic linker units on oxide surfaces, we have performed a model study under ultrahigh vacuum (UHV) conditions. We apply infrared reflection absorption spectroscopy (IRAS) in combination with density-functional theory (DFT), temperature programmed desorption (TPD), and X-ray photoelectron spectroscopy (XPS). Phthalic anhydride (PAA) was deposited at temperatures between 100 and 300 K by physical vapor deposition (PVD) onto an ordered MgO(100) film grown on Ag(100). At 100 K, the first monolayer adsorbs molecularly with the molecular plane aligned parallel to the surface. Subsequent growth of a multilayer film at low temperature also occurs with preferential molecular alignment parallel to the surface. At 240 K, the multilayer desorbs without decomposition. At 300 K, a mixed monolayer of chemically modified ring-opened and intact phthalic anhydride exists on the surface. The chemically modified species binds in a strongly tilted geometry via opening of the anhydride ring to form a bis-carboxylate species. This species additionally stabilizes the coadsorbed molecular PAA via intermolecular interactions. Finally, surface defects and hydroxyl groups are found to increase the amount of surface bis-carboxylate at 300 K, whereas the relative amount of coadsorbed molecular PAA decreases.

  9. Fractographic and rheological characterizations of CF/PP-PE-copolymer composites tested in tensile

    Directory of Open Access Journals (Sweden)

    Paula Helena da Silva Cirilo

    Full Text Available Abstract This work shows the fractographic study of fractured surfaces resulted from tensile tests of thermoplastic composites based on poly(propylene-co-ethylene (PP-PE and modified PP-PE copolymers reinforced with continuous carbon fibers (CF. The PP-PE matrix was modified with two agents called AM1 (based on maleic anhydride and AM2 (containing an elastomeric agent, respectively. Three different laminates - CF/PP-PE, CF/PP-PE(AM1 and CF/PP-PE(AM2 - were manufactured. The best tensile strength and elastic modulus results were determined for the CF/PP-PE(AM1 laminate (507.6 ± 11.8 MPa and 54.7 ± 2.4 GPa, respectively. These results show that the AM1 agent contributed to increase the physicochemical interaction between the CF and the PP-PE matrix. This condition provided a better loading transfer from matrix to the reinforcement. Scanning electron microscopy analyses of the fracture surfaces show the fractographic aspects of the samples and allow evaluating the fiber/matrix-interfacial adhesion. Poor adhesion is observed for the CF/PP-PE and CF/PP-PE(AM2 laminates with the presence of fiber impressions on the polymer rich regions and fiber surfaces totally unprotected of polymer matrix. On the other side, a more consistent adhesion is observed for the CF/PP-PE(AM1 laminate. This result is in agreement with the tensile test data and show the presence of a good interaction between the laminate constituents. The correlation of the mechanical and fractographic results with the curves of complex viscosity versus temperature of the studied polymer matrices shows that the matrix viscosity did not affect the wettability of the reinforcement.

  10. Effect of the degree of substitution of octenyl succinic anhydride-banana starch on emulsion stability.

    Science.gov (United States)

    Bello-Pérez, Luis A; Bello-Flores, Christopher A; Nuñez-Santiago, María del Carmen; Coronel-Aguilera, Claudia P; Alvarez-Ramirez, J

    2015-11-05

    Banana starch was esterified with octenylsuccinic anhydride (OSA) at different degree substitution (DS) and used to stabilize emulsions. Morphology, emulsion stability, emulsification index, rheological properties and particle size distribution of the emulsions were tested. Emulsions dyed with Solvent Red 26 showed affinity for the oil phase. Backscattering light showed three regions in the emulsion where the emulsified region was present. Starch concentration had higher effect in the emulsification index (EI) than the DS used in the study because similar values were found with OSA-banana and native starches. However, OSA-banana presented greater stability of the emulsified region. Rheological tests in emulsions with OSA-banana showed G'>G" values and low dependence of G' with the frequency, indicating a dominant elastic response to shear. When emulsions were prepared under high-pressure conditions, the emulsions with OSA-banana starch with different DS showed a bimodal distribution of particle size. The emulsion with OSA-banana starch and the low DS showed similar mean droplet diameter than its native counterpart. In contrast, the highest DS led to the highest mean droplet diameter. It is concluded that OSA-banana starch with DS can be used to stabilize specific emulsion types. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Development of emulsifying property in Persian gum using octenyl succinic anhydride (OSA).

    Science.gov (United States)

    Mohammadi, S; Abbasi, S; Scanlon, M G

    2016-08-01

    In the present study, the influence of octenyle succinic anhydride (OSA),gum concentration, pH, temperature and reaction time on esterification of Persian gum (PG), and its soluble (SFPG) and insoluble (IFPG) fractions, were investigated by response surface methodology (RSM) in order to optimize the reaction conditions based on the degree of substitution (DS). The individual effect of all independent variables as well as the interactive effects of temperature-OSA concentration, and OSA-PG concentrations on DS was significant. However, the latter interactive effect (OSA-SFPG) was not significant in case of SFPG. The IFPG did not have any esterification reaction with OSA. The highest DS for PG and SFPG were 0.0285 and 0.0303 at the optimal conditions, respectively. The FTIR spectrums also confirmed the carbonyl group attachment in OSA-PG and OSA-SFPG. The enhancement of emulsifying capability was also confirmed by ECI and EAI values, microscopic images as well as rheological measurements. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. An efficient acetylation of dextran using in situ activated acetic anhydride with iodine

    Directory of Open Access Journals (Sweden)

    MUHAMMAD A. HUSSAIN

    2010-02-01

    Full Text Available A facile, efficient, cost-effective and solvent-free acetylation method has been developed for the acetylation of dextran. Dextran acetates were successfully synthesized using different molar ratios of acetic anhydride in the presence of iodine as a catalyst without the use of any solvent. The reactions were realized at 50 °C for 3 h under stirring and nitrogen. This efficient method yielded highly pure and organosoluble dextran esters. The reaction appears highly effective for obtaining higher degrees of substitution (DS with great efficiency. Under solvent-free conditions, dextran triacetates were efficiently synthesized. It was also observed that the molar ratio can easily control the DS of pendant groups onto the polymer backbone. Hence, a range of products with varying DS were successfully designed, purified and characterized. Covalent attachment of the pendant groups onto the polymer backbone was verified by spectroscopic techniques. Thermogravimetric analysis indicated that the obtained dextran esters were thermally as stable as dextran. The DS of the pendant groups onto the polymer backbone was calculated using standard acid base titration after saponification. Furthermore, all products were thoroughly characterized by thermal analysis (TG and DTG, and FTIR and 1H-NMR spectroscopic analysis.

  13. Nano-encapsulation of coenzyme Q10 using octenyl succinic anhydride modified starch.

    Science.gov (United States)

    Cheuk, Sherwin Y; Shih, Frederick F; Champagne, Elaine T; Daigle, Kim W; Patindol, James A; Mattison, Christopher P; Boue, Stephen M

    2015-05-01

    Octenyl succinic anhydride modified starch (OSA-ST) was used to encapsulate coenzyme Q10 (CoQ10). CoQ10 was dissolved in rice bran oil and incorporated into an aqueous OSA-ST solution. High pressure homogenisation of the mixture was conducted at 170 MPa for 56 cycles. The resulting emulsion had a particle size range of 200-300 nm and the absolute zeta potential varied between 8.4 and 10.6 mV. CoQ10 retention of the emulsion and freeze dried products, determined by a hexane rinse, was 98.2%. Reconstitution of the freeze dried product in Mcllvaine citrate-phosphate buffers with pH values of 3-5 and temperatures at 4 and 25 °C had very little effect on the range and distribution of the nanoparticles' size. The inflection point of the zeta potential and pH plot occurred at the first pKa of succinic acid (pH 4.2), indicating succinate as the main influence over zeta potential. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Position of modifying groups on starch chains of octenylsuccinic anhydride-modified waxy maize starch.

    Science.gov (United States)

    Bai, Yanjie; Kaufman, Rhett C; Wilson, Jeff D; Shi, Yong-Cheng

    2014-06-15

    Octenylsuccinic anhydride (OSA)-modified starches with a low (0.018) and high (0.092) degree of substitution (DS) were prepared from granular native waxy maize starch in aqueous slurry. The position of OS substituents along the starch chains was investigated by enzyme hydrolysis followed by chromatographic analysis. Native starch and two OS starches with a low and high DS had β-limit values of 55.9%, 52.8%, and 34.4%, respectively. The weight-average molecular weight of the β-limit dextrin from the OS starch with a low DS was close to that of the β-limit dextrin from native starch but lower than that of the β-limit dextrin from the OS starch with a high DS. Debranching of OS starches was incomplete compared with native starch. OS groups in the OS starch with a low DS were located on the repeat units near the branching points, whereas the OS substituents in the OS starch with a high DS occurred both near the branching points and the non-reducing ends. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Formulation and characterization of O/W emulsions stabilized using octenyl succinic anhydride modified kudzu starch.

    Science.gov (United States)

    Zhao, Yiguo; Khalid, Nauman; Shu, Gaofeng; Neves, Marcos A; Kobayashi, Isao; Nakajima, Mitsutoshi

    2017-11-15

    Kudzu starch esterified with octenyl succinic anhydride (OSA) was used as a food-grade emulsifier to formulate O/W emulsions. In addition, the difference between the physicochemical properties and emulsifying ability of native kudzu starch and those of OSA-modified kudzu starch was investigated. Granules of the OSA-modified kudzu starches increased in size after gelatinization. The interfacial tension between soybean oil and gelatinized OSA-modified kudzu starch was lower than that of kudzu starch. The droplet size of O/W emulsions decreased to 186nm at 100MPa after three passes. The emulsions stabilized using gelatinized OSA-modified kudzu starch were less stable when exposed to different ionic strengths (100mM to 500mM NaCl), than when exposed to different pH levels (2-8). The results of oil droplet size and confocal laser scanning microscopy analysis indicated that emulsions containing 2-5% OSA-modified kudzu starch remained stable at room temperature for 30 days. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Effect of maleic anhydride treatment on the mechanical properties of sansevieria fiber/vinyl ester composites

    Science.gov (United States)

    Pradipta, Rangga; Mardiyati, Steven, Purnomo, Ikhsan

    2017-03-01

    Sanseviera trifasciata commonly called mother-in-law tongue also known as snake plant is native to Indonesia, India and Africa. Sansevieria is a new fiber in composite research and has showed promising properties as reinforcement material in polymer matrix composites. Chemical treatment on reinforcing fiber is crucial to reduce hydrophilic tendency and thus improve compatibility with the matrix. In this study, effect of maleic anhydride as chemical treatment on the mechanical properties of Sansevieria fiber/vinyl ester composite was investigated. Sansevieria fibers were immersed by using NaOH 3% for two hours at 100°C and then treated by using maleic anhydrate for two hours at 120°C. Composites were prepared by solution casting with various volume fractions of fiber; 0%, 2.5%, 5%, 7.5% and 10%. Actual density, volume fraction of void and mechanical properties of composite were conducted according to ASTM standard testing methods D792, D3171 and D3039. It was found that mechanical properties of composites increased as volume fractions of fiber was increased. The highest tensile strength and modulus of elasticity of composites were 57.45 MPa and 3.47 GPa respectively, obtained from composites with volume fraction of fiber 10%.

  17. Acetylation of Wood Flour from Four Wood Species Grown in Nigeria Using Vinegar and Acetic Anhydride

    Directory of Open Access Journals (Sweden)

    Yakubu Azeh

    2013-01-01

    Full Text Available Effect of acetylation on pretreated wood flour of four different wood species, Boabab (Adansonia digitata, Mahoganny (Daniella oliveri, African locust bean (Parkia biglobosa and Beech wood (Gmelina arborea, had been investigated. The first batch of wood species were acetylated using acetic anhydride while the second batch were acetylated with commercial vinegar. Both experiments were conducted in the presence of varying amount of CaCl2 as catalyst and at temperature of 120°C for 3 h. The success of acetylation was determined based on Weight Percent Gain for each sample treated with either chemicals used. FT-IR, a veritable tool was used for the analysis of both treated and untreated samples to further investigate the success of acetylation. The results showed the presence of important band such as carbonyl absorptions at 1743, 1744, 1746, 1731, 1718 and 1696 cm−1 as appeared separately in the spectra of acetylated samples, confirming esterification occurred. The purpose of this work was to investigate the applicability of vinegar for acetylation of lignocellulosic fibers. Blends/composites were prepared by solution casting and their kinetics investigated in distilled water. The results indicated they could be used in outdoor applications such as, decking and packaging.

  18. Phthalic anhydride allergy: development and characterization of optimized hapten-carrier conjugates for improved diagnosis.

    Science.gov (United States)

    Pakarinen, M; Koivuluhta, M; Kalkkinen, N; Keskinen, H; Nordman, H; Estlander, T; Tupasela, O; Jolanki, R; Lauerma, A I; Pfäffli, P; Alenius, H

    2002-10-01

    At present the diagnosis of IgE-mediated hypersensitivity to phthalic anhydride (PA) is based on conjugates that are not characterized or standardized. The aim of this study was to develop optimized and molecularly characterized PA conjugates that can be used to improve the diagnosis of PA-allergy. The PA conjugates were synthesized and the number of haptens bound on a carrier protein was estimated by matrix-assisted laser desorption/ionization time of light (MALDI-TOF) mass spectrometry. The ability of conjugates to bind IgE and IgG antibodies was measured by enzyme-linked immunosorbent assay (ELISA). Reactivity of the conjugates in vivo was evaluated by skin prick testing. The most active IgE-binding conjugates had a PA : HSA molar ratio of 80 : 1. In the optimal conjugates the average numbers of PA haptens per carrier molecule of human serum albumin (HSA) were 14-16. In ELISA, all 13 patients and none of the 20 controls had IgE antibodies to optimized PA conjugate. The sensitivity and specificity of the ELISA was comparable to commercial CAP RAST. PA conjugates elicited positive test results in skin prick testing showing that conjugates are immunologically active also in vivo. These results indicate that optimized and molecularly characterized PA-HSA conjugates can be used both in vitro and in vivo assays to improve the diagnosis of PA allergy.

  19. Effect of Persimmon Leaf Extract on Phthalic Anhydride-induced Allergic Response in Mice.

    Science.gov (United States)

    Mok, Ji Ye; Jeon, In Hwa; Cho, Jung-Keun; Park, Ji Min; Kim, Hyeon Soo; Kang, Hyun Ju; Kim, Hyung Soon; Jang, Seon Il

    2012-03-01

    The purpose of this study was to investigate the anti-allergy activities of persimmon leaf extract (PLE) on a phthalic anhydride (PA)-induced allergic mouse model. A human leukemic mast cell line (HMC-1) was used to examine the inhibitory activity of PLE on the histamine release by human leukemic mast cells. PLE inhibited histamine release from HMC-1 cells in response to cross-linkage of high-affinity IgE receptor-α (FcεRIα). Additionally, a PA-induced allergic mouse model was used to investigate the effects of PLE in vivo. Mice were orally administrated with or without PLE of single dose (250 mg/kg/day) for 31 days. Oral intake of PLE significantly inhibited passive cutaneous reactions. Oral administration of PLE to PA-induced allergic mice also led to a striking suppression of the development of contact dermatitis, ear swelling and lymph node weight. In addition, PA-specific IL-4 production of draining lymph node cells was markedly diminished by PLE oral administration, but not IFN-γ. Furthermore, PLE treatment suppressed PA-induced thymus and activation-regulated chemokine (CCL17) and cutaneous T cell-attracting chemokine (CCL27) expressions in ear tissues. Based on these results, we suggest that PLE may have therapeutic potential as an effective material for management of irritant contact dermatitis or related inflammatory diseases.

  20. Catalyst optimization strategy: selective oxidation of o-xylene to phthalic anhydride.

    Science.gov (United States)

    Wöelk, Hans-Jörg; Mestl, Gerhard

    2012-02-01

    The oxidation of o-xylene and/or naphthalene to phthalic anhydride is one of the important industrial processes based on catalytic selective oxidation reactions. Vanadia--titania catalysts have been used in the industrial phthalic anyhdride process for the last 50 years. The operation parameters like the temperature range of operation, reactor inlet pressures, contact times, o-xylene loadings, etc. were constantly improved during this period of continuous process optimization so as to optimize catalyst performance and increase its life time. However, a fundamental understanding of the mutual interaction of the rather complex reaction network and the catalyst formulation is still missing. Recently, a detailed study of by-product formation as function of process conditions allowed us to develop a novel, improved reaction scheme for the catalytic oxidation of o-xylene. Based on this understanding, a detailed investigation was conducted for the first time of the by-product formation under varying operation conditions and as a function of the active mass variation exploiting high-throughput, as well as bench scales reactors. This high-throughput testing allowed us to relate reaction kinetics to novel catalyst formulations.

  1. Microwave measurements of the spectra and molecular structure for phthalic anhydride

    Science.gov (United States)

    Pejlovas, Aaron M.; Sun, Ming; Kukolich, Stephen G.

    2014-05-01

    The microwave rotational spectrum for phthalic anhydride (PhA) has been measured in the 4-14 GHz microwave region using a pulsed-beam Fourier transform (PBFT) Flygare-Balle type microwave spectrometer. Initially, the molecular structure was calculated using Gaussian 09 suite with mp2/6-311++G** basis and the calculations were used in predicting spectra for the measured isotopologues. The experimental rotational transition frequencies were measured and used to calculate the rotational and centrifugal distortion constants. The rotational constants for the normal isotopologue, four unique 13C substituted isotopologues and two 18O isotologues, were used in a least squares fit to determine nearly all structural parameters for this molecule. Since no substitutions were made at hydrogen sites, the calculated positions of the hydrogen atoms relative to the bonded carbon atoms were used in the structure determination. The rotational constants for the parent isotopologue were determined to be A = 1801.7622(9) MHz, B = 1191.71816(26) MHz, C = 717.44614(28) MHz. Small values for the centrifugal distortion constants were obtained; DJ = 0.0127 kHz, DJK = 0.0652 kHz, and DK = -0.099 kHz, indicating a fairly rigid structure. The structure of PhA is planar with a negative inertial defect of Δ = -0.154 amu Å2. Structural parameters from the mp2 and DFT calculations are in quite good agreement with measured parameters.

  2. Tensile Behaviour and Morphology of Polypropylene/Polycar-bonate/Polypropylene-graft-maleic Anhydride Blends

    Directory of Open Access Journals (Sweden)

    Mat-Shayuti M.S.

    2017-01-01

    Full Text Available This work investigates the effect of blending polycarbonate (PC into polypropylene (PP matrix polymer on mechanical tensile properties and morphology. The blends, containing 5% to 35% of polycarbonate and 5% compatibilizer, were compounded using twin-screw extruder and fabricated into standard tests samples using injection molding. The compatibilizer used was polypropylene-graft-maleic anhydride (PP-g-MA. The values of tensile strengths and moduli for PP/PC/PP-g-MA blends were lower than that of pure PP. Tensile strength of pure PP was 37.74 MPa, whereas the highest tensile strength among the blends was 32.60 MPa at 70/25/5 composition. The pattern for the blends is non-linear, where the optimum amount of PC for tensile strength was 25%. Addition of PP-g-MA imparts positive effect towards the blends, shown by higher value for both tensile strength and tensile modulus compared to the noncompatibilized blend. Microscopy analysis showed PC reinforcement phase existed as particulates dispersed in PP matrix phase. PC particulates size depends on its fraction and compatibilizer content. As PC content in compatibilized blends increases, its particulate size also increases.

  3. Short communication: effect of difructose anhydride III on serum immunoglobulin G concentration in newborn calves.

    Science.gov (United States)

    Sato, T; Hanada, M; Ohtani, M; Nakai, T; Teramura, M; Sadoya, H; Takahashi, T; Hongo, A

    2012-09-01

    Difructose anhydride (DFA) III is an indigestible disaccharide that promotes paracellular absorption of calcium, magnesium, and other minerals in the intestine by acting on epithelial tight junctions. This study aimed to elucidate the effect of DFA III on serum IgG concentration. One hundred and twenty Holstein and Holstein/Japanese Black crossbred calves were randomly divided into 4 groups of 30 to receive untreated colostrum (DFA0) or colostrum containing 3, 6, or 18 g of DFA III (DFA3, DFA6, or DFA18, respectively). At 24 h after birth, both serum IgG (ranging from 16.4 to 21.2 mg/mL) and apparent efficiency of absorption (26.0 to 37.2%) showed increases with the amount of DFA III intake. By multiple regression analysis, the standardized partial regression coefficient for DFA III was 0.25, the second highest following that for the colostrum IgG concentration (0.80), indicating a positive effect of DFA III on serum IgG. A positive linear regression was found between colostrum IgG and serum IgG concentrations at 24h of age. These results indicate that IgG absorption occurred as a nonsaturable process, which might be characteristic of gradient-dependent paracellular transport. Thus, it was concluded that DFA III improves not only minerals but IgG absorption in calves. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  4. Effects of difructose anhydride III (DFA III) administration on rat intestinal microbiota.

    Science.gov (United States)

    Minamida, Kimiko; Shiga, Kazuki; Sujaya, I Nengah; Sone, Teruo; Yokota, Atsushi; Hara, Hiroshi; Asano, Kozo; Tomita, Fusao

    2005-03-01

    The effects of difructose anhydride III (di-D-fructofuranose-1,2':2,3'-dianhydride; DFA III) administration (3% DFA III for 4 weeks) on rat intestinal microbiota were examined using denaturing gradient gel electrophoresis (DGGE). According to DGGE profiles, the number of bacteria related to Bacteroides acidofaciens and uncultured bacteria within the Clostridium lituseburense group decreased, while that of bacteria related to Bacteroides vulgatus, Bacteroides uniformis and Ruminococcus productus increased in DFA III-fed rat cecum. In the cecal contents of DFA III-fed rats, a lowering of pH and an increase in short chain fatty acids (SCFAs), especially acetic acid, were observed. The DFA III-assimilating bacterium, Ruminococcus sp. M-1, was isolated from the cecal contents of DFA III-fed rats. The strain had 98% similarity with R. productus ATCC 27340T (L76595), and mainly produced acetic acid. These results confirmed that the bacteria harmful to host health were not increased by DFA III administration. Moreover, DFA III stimulated the growth of Ruminococcus sp. M-1 producing acetic acid, which may alter the intestinal microbiota towards a healthier composition. It is expected that DFA III would be a new candidate as a prebiotic.

  5. Granular size of potato starch affects structural properties, octenylsuccinic anhydride modification and flowability.

    Science.gov (United States)

    Wang, Chan; Tang, Chuan-He; Fu, Xiong; Huang, Qiang; Zhang, Bin

    2016-12-01

    Native potato starch (PS) granules were separated into three size fractions: larger than 30μm (P-L), 15-30μm (P-M), and smaller than 15μm (P-S). The morphological and crystalline structure of fractionated potato starches were investigated by light and scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The P-L fraction showed ellipsoidal shape and B-type X-ray pattern, whereas the P-S fraction had spherical shape and A-type pattern. The fluorophore-assisted capillary electrophoresis data showed that the P-L fraction had more B2 chains and less short A and B1 chains than the P-S counterparts. Smaller granules with larger specific surface area had higher degree of substitution when reacted with octenylsuccinic anhydride (OSA), and showed more uniform distribution of octenylsuccinate substituents. Both OSA modified and unmodified P-S samples showed higher flowability compared with the P-L counterparts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Convenient synthetic method of starch/lactic acid graft copolymer ...

    Indian Academy of Sciences (India)

    Copolymer of starch grafted with lactic acid (LA) could be directly prepared by reaction of cornstarch with lactic acid and with sodium hydroxide (NaOH) as the catalyst. The structure of starch/LA copolymer was characterized by IR, XRD, SEM and 1H-NMR. The effects of NaOH concentration, ratios of starch and LA, reaction ...

  7. Micellar structure of amphiphilic poly(2-oxazoline) diblock copolymers

    DEFF Research Database (Denmark)

    Papadakis, C.M.; Ivanova, R.; Lüdtke, K.

    2007-01-01

    Amphiphilic diblock copolymers from poly(2-oxazoline)s in aqueous solution can form micelles. By means of small-angle neutron scattering, we have found that poly[(n-nonyl-2-oxazoline)-b-(methyl-2-oxazoline)] {P[(NOx)-b-(MOx)]} diblock copolymers in aqueous solution form micelles of core-shell typ...

  8. Cryoelectron microscopy of block-copolymers in an organic solvent

    NARCIS (Netherlands)

    Oostergetel, G.T.; Esselink, F.J; Hadziioannou, G

    1995-01-01

    Solutions of the diblock copolymer polystyrene/poly-2-vinylpyridine (PS/P2VP) in toluene were studied by cryo-transmission electron microscopy following fast freezing of a thin film of the solution in liquid nitrogen. The block copolymer forms spherical micelles which can be visualized using phase

  9. Positively charged co-polymers for use as antimicrobial agents

    DEFF Research Database (Denmark)

    2016-01-01

    The present invention provides a positively charged co-polymer for use as an antimicrobial agent, wherein said positively charged co-polymer is composed of amino acids and/or derivatives thereof and wherein at least 75 molar percent of said amino acids are selected from the group consisting...

  10. Rheological Behavior of Entangled Polystyrene-Polyhedral Oligosilsesquioxane (POSS) Copolymer

    National Research Council Canada - National Science Library

    Wu, Jian; Mather, Patrick T; Haddad, Timothy S; Kim, Gyeong-Man

    2006-01-01

    ...: random copolymers of polystyrene (PS) and styryl-based polyhedral oligosilsesquioxane (POSS), R7(Si8O12)(C6H4CH=CH2), with R = isobutyl (iBu). A series of styrene-styryl POSS random copolymers with 0, 6, 15, 30, 50 wt...

  11. From Block Copolymers to Nano-porous Materials

    DEFF Research Database (Denmark)

    Vigild, Martin Etchells; Ndoni, Sokol; Berg, Rolf Henrik

    2003-01-01

    Quantitative etching of the polydimethylsiloxane block in a series of polystyrene-polydimethylsiloxane (PS-PDMS) block copolymers is reported. Reacting the block copolymer with anhydrous hydrogen fluoride (HF) renders a nanoporous material with the remaining PS maintaining the original morphology...

  12. Block Copolymer Directed Assembly for Nanomaterials and Nanodevices

    Science.gov (United States)

    Kim, Sang

    2013-03-01

    Block copolymer nanopatterning is a promising technology that can complement the inherent limitations of conventional photolithography. The spontaneous and parallel assembly of block copolymers may generate densely packed, periodic 10-nm-scale nanodomains in a scalable way. Furthermore, laterally ordered, device-oriented nanostructures are attainable by the directed self-assembly principles employing prepatterned substrates. In this presentation, the overview of my research achievements associated to block copolymer nanopatterning will be presented. My research group demonstrated the world-first successful integration of block copolymer nanopatterning with 193 nm ArF lithography. We also developed soft-graphoepitaxy, which generates highly aligned nanoscale metal and semiconductor nanostructures without any trace of structure-directing topographic pattern. Soft-graphoepitaxy could be further developed to ultralarge-area nanopatterning, where micrometer scale photoresist pattern can be completely transformed into large-area block copolymer nanopattern. My research group also developed various pattern transfer methods for block copolymer nanopatterning. Mussel-inspired block copolymer nanopatterning exploiting universal natural adhesive of mussel polydopamine enables the nanopatterning of low surface energy materials, such as gold, Teflon and graphene. Our recent transferrable and flexible nanopatterning employing chemically modified graphene films as pattern substrates makes it possible to apply block copolymer nanopatterning onto arbitrary nonplanar and flexible geometries and generates ideal three-dimensional assembly of carbon nanotubes and graphene.

  13. Sulfomethylated graft copolymers of xanthan gum and polyacrylamide

    Energy Technology Data Exchange (ETDEWEB)

    Cottrell, I.W.; Empey, R.A.; Racciato, J.S.

    1978-08-08

    A water-soluble anionic graft copolymer of xanthan gum and polyacrylamide is described in which at least part of the amide function of the acrylamide portion of the copolymer is sulfomethylated and the xanthan gum portion of the copolymer is unreacted with formaldehyde. The copolymer is sulfomethylated by reaction with formaldehyde and sodium metabisulfite. The formaldehyde does not cause any appreciable cross-linking between hydroxyl groups of the xanthan moieties. The sulfomethylation of the acrylamido group takes place at temperatures from 35 to 70 C. The pH is 10 or higher, typically from 12 to 13. The degree of anionic character may be varied by adjusting the molar ratio of formaldehyde and sodium metabisulfite with respect to the copolymer. 10 claims.

  14. 21 CFR 177.1990 - Vinylidene chloride/methyl acrylate copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Vinylidene chloride/methyl acrylate copolymers. 177... chloride/methyl acrylate copolymers. The vinylidene chloride/methyl acrylate copolymers (CAS Reg. No. 25038...) Identity. For the purposes of this section vinylidene chloride/methyl acrylate copolymers consist of basic...

  15. 21 CFR 177.1570 - Poly-1-butene resins and butene/ethylene copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Poly-1-butene resins and butene/ethylene copolymers... resins and butene/ethylene copolymers. The poly-1-butene resins and butene/ethylene copolymers identified... the catalytic polymerization of 1-butene liquid monomer. Butene/ethylene copolymers are produced by...

  16. Structural properties of pepsin-solubilized collagen acylated by lauroyl chloride along with succinic anhydride

    Energy Technology Data Exchange (ETDEWEB)

    Li, Conghu [The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu 610065 (China); College of Life Sciences, Anqing Normal University, Anqing 246011 (China); Tian, Zhenhua; Liu, Wentao [The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu 610065 (China); Li, Guoying, E-mail: liguoyings@163.com [The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu 610065 (China)

    2015-10-01

    The structural properties of pepsin-solubilized calf skin collagen acylated by lauroyl chloride along with succinic anhydride were investigated in this paper. Compared with native collagen, acylated collagen retained the unique triple helix conformation, as determined by amino acid analysis, circular dichroism and X-ray diffraction. Meanwhile, the thermostability of acylated collagen using thermogravimetric measurements was enhanced as the residual weight increased by 5%. With the temperature increased from 25 to 115 °C, the secondary structure of native and acylated collagens using Fourier transform infrared spectroscopy measurements was destroyed since the intensity of the major amide bands decreased and the positions of the major amide bands shifted to lower wavenumber, respectively. Meanwhile, two-dimensional correlation spectroscopy revealed that the most sensitive bands for acylated and native collagens were amide I and II bands, respectively. Additionally, the corresponding order of the groups between native and acylated collagens was different and the correlation degree for acylated collagen was weaker than that of native collagen, suggesting that temperature played a small influence on the conformation of acylated collagen, which might be concluded that the hydrophobic interaction improved the thermostability of collagen. - Highlights: • Acylated collagen retained the unique triple helix conformation. • Acylated collagen had stronger thermostability than native collagen. • Amide I was the most sensitive band to the temperature for acylated collagen. • Amide II was the most sensitive band to the temperature for native collagen. • Auto-peak at 1680 cm{sup −1} for acylated collagen disappeared at higher temperature.

  17. Elucidation of substituted ester group position in octenylsuccinic anhydride modified sugary maize soluble starch.

    Science.gov (United States)

    Ye, Fan; Miao, Ming; Huang, Chao; Lu, Keyu; Jiang, Bo; Zhang, Tao

    2014-12-03

    The octenylsuccinic groups in esterification-modified sugary maize soluble starches with a low (0.0191) or high (0.0504) degree of substitution (DS) were investigated by amyloglucosidase hydrolysis followed by a combination of chemical and physical analysis. The results showed the zeta-potential remained at approximately the same value regardless of excessive hydrolysis. The weight-average molecular weight decreased rapidly and reached 1.22 × 10(7) and 1.60 × 10(7) g/mol after 120 min for low-DS and high-DS octenylsuccinic anhydride (OSA) modified starch, respectively. The pattern of z-average radius of gyration as well as particle size change was similar to that of Mw, and z-average radius of gyration decreased much more slowly, especially for high-DS OSA starch. Compared to native starch, two characteristic absorption peaks at 1726.76 and 1571.83 cm(-1) were observed in FT-IR spectra, and the intensity of absorption peaks increased with increasing DS. The NMR results showed that OSA starch had several additional peaks at 0.8-3.0 ppm and a shoulder at 5.56 ppm for OSA substituents, which were grafted at O-2 and O-3 positions in soluble starch. The even distribution of OSA groups in the center area of soluble starch particle has been directly shown under CLSM. Most substitutions were located near branching points of soluble starch particles for a low-DS modified starch, whereas the substituted ester groups were located near branching points as well as at the nonreducing ends in OSA starch with a high DS.

  18. Inhibitory Effect of Carnosol on Phthalic Anhydride-Induced Atopic Dermatitis via Inhibition of STAT3.

    Science.gov (United States)

    Lee, Do Yeon; Hwang, Chul Ju; Choi, Ji Yeon; Park, Mi Hee; Song, Min Ji; Oh, Ki Wan; Son, Dong Ju; Lee, Seung Hwa; Han, Sang Bae; Hong, Jin Tae

    2017-09-01

    Carnosol is a phenolic antioxidant present in rosemary (Rosmarinus officinalis). It is known for anti-inflammatory effects, analgesic activity and anti-cancer effects. However, no study has been dedicated yet to its effect on atopic dermatitis (AD). Here, we show that carnosol effectively inhibited LPS-induced nitric oxide (NO) generation and expression of inflammatory marker proteins (iNOS and COX-2) in RAW 264.7 cells. In addition, carnosol effectively inhibits the phosphorylation of STAT3 and DNA binding activity in RAW 264.7 cells. Pull down assay and docking model analysis showed that carnosol directly binds to the DNA binding domain (DBD) of STAT3. We next examined the anti-atopic activity of carnosol (0.05 µg/cm(2)) using 5% Phthalic anhydride (PA)-induced AD model in HR1 mice. Carnosol treatment significantly reduced 5% PA-induced AD like skin inflammation in skin tissues compared with control mice. Moreover, carnosol treatment inhibits the expression of iNOS and COX-2 in skin tissue. In addition, the levels of TNF-α, IL-1β, and Immunoglobulin-E in blood serum was significantly decreased in carnosol treated mice compared with those of 5% PA treated group. Furthermore, the activation of STAT3 in skin tissue was decreased in carnosol treated mice compared with control mice. In conclusion, these findings suggest that carnosol exhibited a potential anti-AD activity by inhibiting pro-inflammatory mediators through suppression of STAT3 activation via direct binding to DBD of STAT3.

  19. Therapeutic effects of fermented soycrud on phenotypes of atopic dermatitis induced by phthalic anhydride.

    Science.gov (United States)

    Sung, Ji-Eun; Kwak, Moon-Hwa; Kim, Ji-Eun; Lee, Young-Ju; Kim, Ro-Ui; Kim, Eun-Ah; Lee, Ga-Young; Kim, Dong-Seob; Hwang, Dae-Youn

    2013-06-01

    Atopic dermatitis (AD), which is known as the most common pruritic skin disease, is caused by epidermal barrier dysfunction, allergies, microwave radiation, histamine intolerance, and genetic defects. To investigate the therapeutic effects of fermented soycrud (FSC) on AD pathology, alteration of AD phenotypes induced by phthalic anhydride (PA) treatment was assessed by ear thickness analysis, measurement of immune-related organ weights, ELISA, and histological and pathological analyses of ICR mice after FSC treatment for 2 weeks. Except for water content, the concentrations of most major components were lower in FSC compared to common tofu (CMT). Thymus and lymph node weights were significantly reduced in ICR mice treated with PA+CMT or PA+FSC, whereas spleen and body weights were maintained. Elevation of ear thickness induced by PA treatment was rapidly diminished in the CMT- and FSC-treated groups, although there was no significant difference between the two groups. Furthermore, significant reduction of epidermal thickness was detected in both the PA+CMT- and PA+FSC-treated groups. However, IgE concentration and dermal thickness were reduced only by PA+FSC treatment, whereas PA+CMT treatment maintained levels comparable to PA+vehicle treatment. The number of infiltrated mast cells was higher in the PA+vehicle-treated group compared to the untreated control. Following CMT or FSC treatment, mast cell infiltration was slightly reduced, although the CMT-treated group showed greater cell numbers. These results indicate that FSC may significantly relieve the phenotypes of AD induced by PA treatment and should be considered as a potential candidate for AD therapy.

  20. Therapeutic effect of ethyl acetate extract from Asparagus cochinchinensis on phthalic anhydride-induced skin inflammation.

    Science.gov (United States)

    Sung, Ji-Eun; Lee, Hyun-Ah; Kim, Ji-Eun; Go, Jun; Seo, Eun-Ji; Yun, Woo-Bin; Kim, Dong-Seob; Son, Hong-Joo; Lee, Chung-Yeoul; Lee, Hee-Seob; Hwang, Dae-Youn

    2016-03-01

    Asparagus cochinchinensis has been used to treat various diseases including fever, cough, kidney disease, breast cancer, inflammatory disease and brain disease, while IL-4 cytokine has been considered as key regulator on the skin homeostasis and the predisposition toward allergic skin inflammation. However, few studies have investigated its effects and IL-4 correlation on skin inflammation to date. To quantitatively evaluate the suppressive effects of ethyl acetate extracts of A. cochinchinensis (EaEAC) on phthalic anhydride (PA)-induced skin inflammation and investigate the role of IL-4 during their action mechanism, alterations in general phenotype biomarkers and luciferase-derived signals were measured in IL-4/Luc/CNS-1 transgenic (Tg) mice with PA-induced skin inflammation after treatment with EaEAC for 2 weeks. Key phenotype markers including lymph node weight, immunoglobulin E (IgE) concentration, epidermis thickness and number of infiltrated mast cells were significantly decreased in the PA+EaEAC treated group compared with the PA+Vehicle treated group. In addition, expression of IL-1β and TNF-α was also decreased in the PA+EaEAC cotreated group, compared to PA+Vehicle treated group. Furthermore, a significant decrease in the luciferase signal derived from IL-4 promoter was detected in the abdominal region, submandibular lymph node and mesenteric lymph node of the PA+EaEAC treated group, compared to PA+Vehicle treated group. Taken together, these results suggest that EaEAC treatment could successfully improve PA-induced skin inflammation of IL-4/Luc/CNS-1 Tg mice, and that IL-4 cytokine plays a key role in the therapeutic process of EaEAC.

  1. Anti-inflammatory effect of Astaxanthin in phthalic anhydride-induced atopic dermatitis animal model.

    Science.gov (United States)

    Park, Ju Ho; Yeo, In Jun; Han, Ji Hye; Suh, Jeong Won; Lee, Hee Pom; Hong, Jin Tae

    2017-09-08

    In this study, we investigated anti-dermatitic effects of Astaxanthin (AST) in phthalic anhydride (PA)-induced atopic dermatitis (AD) animal model as well as in vitro model. AD-like lesion was induced by the topical application of 5% PA to the dorsal skin or ear of Hos:HR-1 mouse. After AD induction, 100 μl of 1 mg/ml and 2 mg/ml of AST (10 μg or 20 μg/cm(2) ) was spread on the dorsum of ear or back skin three times a week for four weeks. We evaluated dermatitis severity, histopathological changes and changes in protein expression by Western blotting for inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and nuclear factor-κB (NF-κB) activity. We also measured tumor necrosis factor- α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and immunoglobulinE (IgE) concentration in the blood of AD mice by enzyme-linked immunosorbent assay (ELISA). AST treatment attenuated the development of PA-induced AD. Histological analysis showed that AST inhibited hyperkeratosis, mast cells and infiltration of inflammatory cells. AST treatment inhibited expression of iNOS and COX-2, and NF-κB activity as well as release of TNF-α, IL-1β, IL-6, and IgE. In addition, AST (5, 10, and 20μM) potently inhibited lipopolysaccharide (LPS) (1 μg/ml)-induced nitric oxide (NO) production, expression of iNOS and COX-2, and NF-κB DNA binding activities in RAW 264.7 macrophage cells. Our data demonstrated that AST could be a promising agent for AD by inhibition of NF-κB signaling. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  2. Emulsion stabilizing capacity of intact starch granules modified by heat treatment or octenyl succinic anhydride.

    Science.gov (United States)

    Timgren, Anna; Rayner, Marilyn; Dejmek, Petr; Marku, Diana; Sjöö, Malin

    2013-03-01

    Starch granules are an interesting stabilizer candidate for food-grade Pickering emulsions. The stabilizing capacity of seven different intact starch granules for making oil-in-water emulsions has been the topic of this screening study. The starches were from quinoa; rice; maize; waxy varieties of rice, maize, and barley; and high-amylose maize. The starches were studied in their native state, heat treated, and modified by octenyl succinic anhydride (OSA). The effect of varying the continuous phase, both with and without salt in a phosphate buffer, was also studied. Quinoa, which had the smallest granule size, had the best capacity to stabilize oil drops, especially when the granules had been hydrophobically modified by heat treatment or by OSA. The average drop diameter (d 32) in these emulsions varied from 270 to 50 μm, where decreasing drop size and less aggregation was promoted by high starch concentration and absence of salt in the system. Of all the starch varieties studied, quinoa had the best overall emulsifying capacity, and OSA modified quinoa starch in particular. Although the size of the drops was relatively large, the drops themselves were in many instances extremely stable. In the cases where the system could stabilize droplets, even when they were so large that they were visible to the naked eye, they remained stable and the measured droplet sizes after 2 years of storage were essentially unchanged from the initial droplet size. This somewhat surprising result has been attributed to the thickness of the adsorbed starch layer providing steric stabilization. The starch particle-stabilized Pickering emulsion systems studied in this work has potential practical application such as being suitable for encapsulation of ingredients in food and pharmaceutical products.

  3. Small domain-size multiblock copolymer electrolytes

    Science.gov (United States)

    Pistorino, Jonathan; Eitouni, Hany Basam

    2016-09-20

    New block polymer electrolytes have been developed which have higher conductivities than previously reported for other block copolymer electrolytes. The new materials are constructed of multiple blocks (>5) of relatively low domain size. The small domain size provides greater protection against formation of dendrites during cycling against lithium in an electrochemical cell, while the large total molecular weight insures poor long range alignment, which leads to higher conductivity. In addition to higher conductivity, these materials can be more easily synthesized because of reduced requirements on the purity level of the reagents.

  4. Nucleation of Ordered Phases in Block Copolymers

    Science.gov (United States)

    Cheng, Xiuyuan; Lin, Ling; E, Weinan; Zhang, Pingwen; Shi, An-Chang

    2010-04-01

    Nucleation of various ordered phases in block copolymers is studied by examining the free-energy landscape within the self-consistent field theory. The minimum energy path (MEP) connecting two ordered phases is computed using a recently developed string method. The shape, size, and free-energy barrier of critical nuclei are obtained from the MEP, providing information about the emergence of a stable ordered phase from a metastable phase. In particular, structural evolution of embryonic gyroid nucleus is predicted to follow two possible MEPs, revealing an interesting transition pathway with an intermediate perforated layered structure.

  5. Functional Nanoparticles Enabled by Block Copolymer Templates: from Precision Synthesis of Block Copolymers to Properties and Applications of Nanoparticles.

    Science.gov (United States)

    Li, Xiao; Iocozzia, James; Chen, Yihuang; Zhao, Shiqiang; Cui, Xun; Wang, Wei; Yu, Haifeng; Lin, Shaoliang; Lin, Zhiqun

    2017-08-07

    Inorganic nanoparticles have become a research focus in numerous fields because of their unique properties that distinguish them from their bulk counterparts. Controlling the size and shape of nanoparticles is an essential aspect of nanoparticle synthesis. Preparing inorganic nanoparticles via block copolymer templates is one of the most reliable routes for tuning the size and shape of nanoparticles with a high degree of precision. In this review, we discuss recent progress in block copolymer template design and implementation in the crafting of spherical inorganic nanoparticles including plain, hollow and core@shell varieties. The templates, also known as nanoreactors, are divided into two categories: micelles self-assembled from linear block copolymers and unimolecular star-like block copolymers. The precise control of size and morphology of nanoparticles is highlighted. The useful properties and applications of inorganic nanoparticles prepared from block copolymer templates are also addressed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. A New Process for Maleic Anhydride Synthesis from a Renewable Building Block: The Gas-Phase Oxidehydration of Bio-1-butanol.

    Science.gov (United States)

    Pavarelli, Giulia; Velasquez Ochoa, Juliana; Caldarelli, Aurora; Puzzo, Francesco; Cavani, Fabrizio; Dubois, Jean-Luc

    2015-07-08

    We investigated the synthesis of maleic anhydride by oxidehydration of a bio-alcohol, 1-butanol, as a possible alternative to the classical process of n-butane oxidation. A vanadyl pyrophosphate catalyst was used to explore the one-pot reaction, which involved two sequential steps: 1) 1-butanol dehydration to 1-butene, catalysed by acid sites, and 2) the oxidation of butenes to maleic anhydride, catalysed by redox sites. A non-negligible amount of phthalic anhydride was also formed. The effect of different experimental parameters was investigated with chemically sourced 1-butanol, and the results were then confirmed by using genuinely bio-sourced 1-butanol. In the case of bio-1-butanol, however, the purity of the product remarkably affected the yield of maleic anhydride. It was found that the reaction mechanism includes the oxidation of butenes to crotonaldehyde and the oxidation of the latter to either furan or maleic acid, both of which are transformed to produce maleic anhydride. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Chain exchange in triblock copolymer micelles

    Science.gov (United States)

    Lu, Jie; Lodge, Timothy; Bates, Frank

    2015-03-01

    Block polymer micelles offer a host of technological applications including drug delivery, viscosity modification, toughening of plastics, and colloidal stabilization. Molecular exchange between micelles directly influences the stability, structure and access to an equilibrium state in such systems and this property recently has been shown to be extraordinarily sensitive to the core block molecular weight in diblock copolymers. The dependence of micelle chain exchange dynamics on molecular architecture has not been reported. The present work conclusively addresses this issue using time-resolved small-angle neutron scattering (TR-SANS) applied to complimentary S-EP-S and EP-S-EP triblock copolymers dissolved in squalane, a selective solvent for the EP blocks, where S and EP refer to poly(styrene) and poly(ethylenepropylene), respectively. Following the overall SANS intensity as a function of time from judiciously deuterium labelled polymer and solvent mixtures directly probes the rate of molecular exchange. Remarkably, the two triblocks display exchange rates that differ by approximately ten orders of magnitude, even though the solvophobic S blocks are of comparable size. This discovery is considered in the context of a model that successfully explains S-EP diblock exchange dynamics.

  8. Preparation and structural characterisation of novel and versatile amphiphilic octenyl succinic anhydride-modified hyaluronic acid derivatives

    DEFF Research Database (Denmark)

    Eenschooten, Corinne Diane; Guillaumie, Fanny; Kontogeorgis, Georgios

    2010-01-01

    The purpose of the present study was to prepare amphiphilic hyaluronic acid (HA) derivatives and to study the influence of a selection of reaction parameters on the degree of substitution (DS) of the derivatives. Octenyl succinic anhydride (OSA)–modified HA (OSA–HA) derivatives were prepared...... and structurally characterised by Fourier transform-infrared spectroscopy and proton nuclear magnetic resonance spectroscopy (1H NMR). The influence of four reaction parameters on the DS of the derivatives was studied by means of an experimental design. The results showed that the OSA/HA molar ratio, the buffer...

  9. Benzodithiophene and Imide-Based Copolymers for Photovoltaic; Applications

    Energy Technology Data Exchange (ETDEWEB)

    Braunecker, W. A.; Owczarczyk, Z. R.; Garcia, A.; Kopidakis, N.; Larsen, R. E.; Hammond, S. R.; Ginley, D. S.; Olson, D. C.

    2012-04-10

    Conjugated alternating copolymers were designed with low optical band gaps for organic photovoltaic (OPV) applications by considering quinoid resonance stabilization. Copolymers of thienoisoindoledione (TID) and benzodithiophene (BDT) had appreciably lower band gaps (by {approx}0.4 eV) than copolymers of thienopyrroledione (TPD) and BDT. In addition to intramolecular charge transfer stabilization (i.e., the 'push-pull' effect), the former copolymer's quinoid resonance structure is stabilized by a gain in aromatic resonance energy in the isoindole unit. Additionally, the HOMO levels of the copolymers could be tuned with chemical modifications to the BDT monomer, resulting in open circuit voltages of greater than 1 V in photovoltaic devices. Despite the optimized band gap, TID containing polymers displayed lower photoconductance, as determined by time-resolved microwave conductivity, and decreased device efficiency (2.1% vs 4.8%) as compared with TPD analogues. These results were partially attributed to morphology, as computational modeling suggests TID copolymers have a twisted backbone, and X-ray diffraction data indicate the polymer films do not form ordered domains, whereas TPD copolymers are considerably more planar and are shown to form partially ordered domains.

  10. Synthesis and morphological characterization of block copolymers for improved biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Schricker, Scott, E-mail: Schricker.1@osu.edu [Restorative and Prosthetic Dentistry Section, College of Dentistry, The Ohio State University, Columbus, OH 43210 (United States); Palacio, Manuel [Nanoprobe Laboratory for Bio- and Nanotechnology and Biomimetics, The Ohio State University, Columbus, OH 43210 (United States); Thirumamagal, B.T.S. [Restorative and Prosthetic Dentistry Section, College of Dentistry, The Ohio State University, Columbus, OH 43210 (United States); Bhushan, Bharat [Nanoprobe Laboratory for Bio- and Nanotechnology and Biomimetics, The Ohio State University, Columbus, OH 43210 (United States)

    2010-05-15

    Biocompatible polymers are known to act as scaffolds for the regeneration and growth of bone. Block copolymers are of interest as scaffold materials because a number of the blocks are biocompatible, and their nanostructure is easily tunable with synthetic techniques. In this paper, we report the synthesis of a novel class of biomaterials from block copolymers containing a hydrophobic block of methyl methacrylate and a hydrophilic block of either acrylic acid, dimethyl acrylamide, or 2-hydroxyethyl methacrylate. The block copolymers were synthesized using a combination of reversible addition-fragmentation chain transfer (RAFT) polymerization and click chemistry. Since the surface morphology is critical for successful cell growth, atomic force microscopy (AFM) studies were conducted for selected block copolymers. The topography, phase angle and friction maps were obtained in dry and physiological buffer environments to study the morphology. Results of AFM imaging identified the presence of polymer domains corresponding to the copolymer components. The distribution of nanoscale features in these block copolymers is comparable to those found on other surfaces that exhibit favorable cell adhesion and growth. In physiological buffer medium, the hydrophilic component of the block copolymer (acrylic acid or hydroxyethyl methacrylate) appears to be present in greater amounts on the surface as a consequence of water absorption and swelling.

  11. Synthesis and characterization of diblock copolymer templated iron oxide nanoparticles

    Science.gov (United States)

    Akcora, Pinar

    2005-07-01

    Templating ordered assemblies of magnetic oxide nanoparticles within self-assembled diblock copolymers of varying morphologies is an important problem with a wide applicability such as in electromagnetics, optical devices, metal catalysts, medicine and biology. In this thesis, the effects of different polymer structures on particle ordering and resultant magnetic properties have been investigated using various microstructure and magnetic characterization tools. Ring-opening metathesis polymerization (ROMP) of norbornene and functionalized norbornene monomers has been used to synthesize diblock copolymers of narrow polydispersities using Grubbs' catalyst. These block copolymers can be used as templates to form inorganic nanoparticles. In this research, the structural and physical understanding of the inorganic-copolymer system was studied by small-angle neutron and x-ray scattering techniques and transmission electron microscopy. Synthesis of gamma-Fe2O3 nanoparticles has been achieved within novel block copolymers of (norbornene)-b-(deuterated norbornene dicarboxylic) acid and (norbornene methanol-(norbornene dicarboxylic acid). The polymer morphologies were controlled by varying the volume fractions of the constituent blocks. The pure norbornene based diblock copolymer morphologies were demonstrated by electron microscopy for the first tune. Spherical, cylindrical and lamellar morphologies of these novel diblock copolymers were reported. The block ratios of the synthesized polymers were determined using gel permeation chromatography-light scattering, elemental analysis and UV-VIS spectroscopy. Solution phase doping and submersion of thin films in metal salt solutions were employed as metal doping methods and the observed nanoparticle structures were compared to those of the undoped copolymer morphologies. This project reports on the types of templating structures and dispersion of the nanoparticles. The effects of particle, interactions on the microphase

  12. Nanoparticle Network Formation in Nanostructured and Disordered Block Copolymer Matrices

    Directory of Open Access Journals (Sweden)

    Khan Saad

    2010-01-01

    Full Text Available Abstract Incorporation of nanoparticles composed of surface-functionalized fumed silica (FS or native colloidal silica (CS into a nanostructured block copolymer yields hybrid nanocomposites whose mechanical properties can be tuned by nanoparticle concentration and surface chemistry. In this work, dynamic rheology is used to probe the frequency and thermal responses of nanocomposites composed of a symmetric poly(styrene-b-methyl methacrylate (SM diblock copolymer and varying in nanoparticle concentration and surface functionality. At sufficiently high loading levels, FS nanoparticle aggregates establish a load-bearing colloidal network within the copolymer matrix. Transmission electron microscopy images reveal the morphological characteristics of the nanocomposites under these conditions.

  13. Bicomponent Block Copolymers Derived from One or More Random Copolymers as an Alternative Route to Controllable Phase Behavior

    Energy Technology Data Exchange (ETDEWEB)

    Ashraf, Arman R. [Corporate Research and Development, The Procter and Gamble Company, Cincinnati OH 45224 USA; Ryan, Justin J. [Department of Materials Science and Engineering, North Carolina State University, Raleigh NC 27695 USA; Satkowski, Michael M. [Corporate Research and Development, The Procter and Gamble Company, Cincinnati OH 45224 USA; Lee, Byeongdu [Advanced Photon Source, Argonne National Laboratory, Argonne IL 60439 USA; Smith, Steven D. [Corporate Research and Development, The Procter and Gamble Company, Cincinnati OH 45224 USA; Spontak, Richard J. [Department of Materials Science and Engineering, North Carolina State University, Raleigh NC 27695 USA; Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh NC 27695 USA

    2017-06-29

    Block copolymers have been extensively studied due to their ability to spontaneously self-organize into a wide variety of morphologies that are valuable in energy-, medical- and conservation-related (nano)technologies. While the phase behavior of bicomponent diblock and triblock copolymers is conventionally governed by temperature and individual block masses, we demonstrate that their phase behavior can alternatively be controlled through the use of blocks with random monomer sequencing. Block random copolymers (BRCs), i.e., diblock copolymers wherein one or both blocks is a random copolymer comprised of A and B repeat units, have been synthesized, and their phase behavior, expressed in terms of the order-disorder transition (ODT), has been investigated. Our results establish that, depending on the block composition contrast and molecular weight, BRCs can microphase-separate. We also report that the predicted ODT can be generated at relatively constant molecular weight and temperature with these new soft materials. This sequence-controlled synthetic strategy is extended to thermoplastic elastomeric triblock copolymers differing in chemistry and possessing a random-copolymer midblock.

  14. Patchy micelles based on coassembly of block copolymer chains and block copolymer brushes on silica particles.

    Science.gov (United States)

    Zhu, Shuzhe; Li, Zhan-Wei; Zhao, Hanying

    2015-04-14

    Patchy particles are a type of colloidal particles with one or more well-defined patches on the surfaces. The patchy particles with multiple compositions and functionalities have found wide applications from the fundamental studies to practical uses. In this research patchy micelles with thiol groups in the patches were prepared based on coassembly of free block copolymer chains and block copolymer brushes on silica particles. Thiol-terminated and cyanoisopropyl-capped polystyrene-block-poly(N-isopropylacrylamide) block copolymers (PS-b-PNIPAM-SH and PS-b-PNIPAM-CIP) were synthesized by reversible addition-fragmentation chain transfer polymerization and chemical modifications. Pyridyl disulfide-functionalized silica particles (SiO2-SS-Py) were prepared by four-step surface chemical reactions. PS-b-PNIPAM brushes on silica particles were prepared by thiol-disulfide exchange reaction between PS-b-PNIPAM-SH and SiO2-SS-Py. Surface micelles on silica particles were prepared by coassembly of PS-b-PNIPAM-CIP and block copolymer brushes. Upon cleavage of the surface micelles from silica particles, patchy micelles with thiol groups in the patches were obtained. Dynamic light scattering, transmission electron microscopy, and zeta-potential measurements demonstrate the preparation of patchy micelles. Gold nanoparticles can be anchored onto the patchy micelles through S-Au bonds, and asymmetric hybrid structures are formed. The thiol groups can be oxidized to disulfides, which results in directional assembly of the patchy micelles. The self-assembly behavior of the patchy micelles was studied experimentally and by computer simulation.

  15. Methacrylamide Copolymer Resists For Electron Beam Lithography

    Science.gov (United States)

    Namaste, Y. M. N.; Obendorf, S. K.; Rodriguez, F.

    1986-07-01

    Polymethacrylamide (PMAAm) and copolymers of MAAm with methyl methacrylate were synthesized and evaluated for their applicability to electron beam lithography. The sensitivity of PMAAm has previously been reported as less than 1 μC/cm2, with thermal stability at temperatures up to 330°C.' Despite these claims, further lithographic evaluation of this resist system is apparently absent from the literature. This research was conducted to further investigate the lithographic performance of these resists and to determine their sensitivity using current definitions. Using PMAAm homopolymer (Mw = 8.1 x 105), with a 15 minute prebake at 200°C, the lithographic results were much poorer than expected. Patterns exposed to doses of 10 μC/cm2 or lower could not be developed using water as the developing solvent. Forced developing with Na2SiO3 solution (pH=10) developed lower doses than water, but much greater thinning was observed. An unexposed thinning of 10% occurred when developing exposures of 15 μC/cm2 with water, and 40 μC/cm2 with Na2SiO3 solution (20 KV). Swelling of the unexposed polymer and some adhesion problems were observed. The high sensitivity previously reported for PMAAm' can not be attributed solely to chain scission efficiency (Gs), which has been reported to be only 1.5 times that of PMMA (Gs determined by Y-irradiation). An induction period in the dissolution of unexposed polymer has also been sugggested as contributing to the sensitivity of this resist. In the present work, dissolution induction periods were observed with laser interferometry for the unexposed films, but the magnitude of these induction periods could not account for a large enhancement of sensitivity. Imide crosslink formation may have been responsible for the previously reported sensitivity of PMAAm.' In the present work, imid formation was not observed, either after prebaking coated wafers at 180 to 240°C or heating of polymer solutions for 7 hours at 80°C. Apparently, the

  16. Light-Induced C-H Arylation of (Hetero)arenes by In Situ Generated Diazo Anhydrides.

    Science.gov (United States)

    Cantillo, David; Mateos, Carlos; Rincon, Juan A; de Frutos, Oscar; Kappe, C Oliver

    2015-09-07

    Diazo anhydrides (Ar-N=N-O-N=N-Ar) have been known since 1896 but have rarely been used in synthesis. This communication describes the development of a photochemical catalyst-free C-H arylation methodology for the preparation of bi(hetero)aryls by the one-pot reaction of anilines with tert-butyl nitrite and (hetero)arenes under neutral conditions. The key step in this procedure is the in situ formation and subsequent photochemical (>300 nm) homolytic cleavage of a transient diazo anhydride intermediate. The generated aryl radical then efficiently reacts with a (hetero)arene to form the desired bi(hetero)aryls producing only nitrogen, water, and tert-butanol as byproducts. The scope of the reaction for several substituted anilines and (hetero)arenes was investigated. A continuous-flow protocol increasing selectivity and safety has been developed enabling the experimentally straightforward preparation of a variety of substituted bi(hetero)aryls within 45 min of reaction time. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Cellulose-polyhydroxylated fatty acid ester-based bioplastics with tuning properties: Acylation via a mixed anhydride system.

    Science.gov (United States)

    Heredia-Guerrero, José A; Goldoni, Luca; Benítez, José J; Davis, Alexander; Ceseracciu, Luca; Cingolani, Roberto; Bayer, Ilker S; Heinze, Thomas; Koschella, Andreas; Heredia, Antonio; Athanassiou, Athanassia

    2017-10-01

    The synthesis of microcrystalline cellulose (MCC) and 9,10,16-hydroxyhexadecanoic (aleuritic) acid ester-based bioplastics was investigated through acylation in a mixed anhydride (trifluoroacetic acid (TFA)/trifluoroacetic acid anhydride (TFAA)), chloroform co-solvent system. The effects of chemical interactions and the molar ratio of aleuritic acid to the anhydroglucose unit (AGU) of cellulose were investigated. The degree of substitution (DS) of new polymers were characterized by two-dimensional solution-state NMR and ranged from 0.51 to 2.60. The chemical analysis by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) confirmed the presence of aleuritate groups in the structure induces the formation of new H-bond networks. The tensile analysis and the contact angle measurement confirmed the ductile behavior and the hydrophobicity of the prepared bioplastics. By increasing the aleuritate amounts, the glass transition temperature decreased and the solubility of bioplastic films in most common solvents was improved. Furthermore, this new polymer exhibits similar properties compared to commercial cellulose derivatives. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Simultaneous quantification of lyso-neutral glycosphingolipids and neutral glycosphingolipids by N-acetylation with [3H]acetic anhydride.

    Science.gov (United States)

    Bodennec, Jacques; Trajkovic-Bodennec, Selena; Futerman, Anthony H

    2003-07-01

    We describe a new method that permits quantification in the pmol to nmol range of three lyso-neutral glycosphingolipids (lyso-n-GSLs), glucosylsphingosine (GlcSph), galactosylsphingosine (GalSph), and lactosylsphingosine, in the same sample as neutral glycosphingolipids (n-GSLs). Lyso-n-GSLs and n-GSLs are initially obtained from a crude lipid extract using Sephadex G25 chromatography, followed by their isolation in one fraction, which is devoid of other contaminating lipids, by aminopropyl solid-phase chromatography. Lyso-n-GSLs and n-GSLs are subsequently separated from one another by weak cation exchange chromatography. N-GSLs are then deacylated by strong alkaline hydrolysis, and the N-deacylated-GSLs and lyso-n-GSLs are subsequently N-acetylated using [3H]acetic anhydride. An optimal concentration of 5 mM acetic anhydride was established, which gave >95% N-acetylation. We demonstrate the usefulness of this technique by showing an approximately 40-fold increase of both GlcSph and glucosylceramide in brain tissue from a glucocerebrosidase-deficient mouse, as well as significant lactosylceramide accumulation. The application and optimization of this technique for lyso-n-GSLs and lyso-GSLs will permit their quantification in small amounts of biological tissues, particularly in the GSL storage diseases, such as Gaucher and Krabbe's disease, in which GlcSph and GalSph, respectively, accumulate.

  19. Synthesis and interfacial behavior of polystyrene-polysaccharide diblock copolymers

    NARCIS (Netherlands)

    Bosker, W.T.E.; Ágoston, K.; Cohen Stuart, M.A.; Norde, W.; Timmermans, J.W.; Slaghek, T.M.

    2003-01-01

    Linear block copolymers of polystyrene and polysaccharide were synthesized using a block synthesis method with amino-terminated polystyrene and sodium cyanoborohydride as reducing agent. Different types of polysaccharides, dextrans, and maltodextrins with various molecular weights were used. IR

  20. Controlled Synthesis of Fluorinated Copolymers with Pendant Sulfonates

    DEFF Research Database (Denmark)

    Dimitrov, Ivaylo; Jankova Atanasova, Katja; Hvilsted, Søren

    2008-01-01

    Novel fluorinated copolymers of different architectures and bearing sulfopropyl groups were synthesized by atom transfer radical polymerization (ATRP) of aromatic fluorinated monomers and two modification reactions performed on the polymer chain - demethylation followed by sulfopropylation. As a ...

  1. Opto-electronic devices from block copolymers and their oligomers.

    NARCIS (Netherlands)

    Hadziioannou, G

    1997-01-01

    This paper presents research activities towards the development of polymer materials and devices for optoelectronics, An approach to controlling the conjugation length and transferring the luminescence properties of organic molecules to polymers through black copolymers containing well-defined

  2. Composition fluctuations in homopolymer blends and diblock copolymers

    DEFF Research Database (Denmark)

    Frielinghaus, H.; Mortensen, K.; Almdal, K.

    2000-01-01

    The thermal composition fluctuations of a deuterogenous polystyrene/polyethyleneoxide (dPS/PEO) homopolymer blend and corresponding diblock copolymer have been investigated by small angle neutron scattering (SANS). The measured susceptibilities could be described by theories, which take strong...

  3. HPMA and HEMA copolymer bead interactions with eukaryotic cells

    Directory of Open Access Journals (Sweden)

    Cristina D. Vianna-Soares

    2004-09-01

    Full Text Available Two different hydrophilic acrylate beads were prepared via aqueous suspension polymerization. Beads produced of a hydroxypropyl methacrylate (HPMA and ethyleneglycol methacrylate (EDMA copolymer were obtained using a polyvinyl alcohol suspending medium. Copolymers of 2hydroxyethyl methacrylate (HEMA, methyl methacrylate (MMA and ethyleneglycol methacrylate (EDMA beads were obtained using magnesium hydroxide as the suspending agent. Following characterization by scanning electron microscopy (SEM, nitrogen sorption analysis (NSA and mercury intrusion porosimetry (MIP, the beads were cultured with monkey fibroblasts (COS7 to evaluate their ability to support cell growth, attachment and adhesion. Cell growth behavior onto small HPMA/EDMA copolymer beads and large HEMA/MMA/EDMA copolymer beads is evaluated regarding their hidrophilicity/hidrophobicity and surface roughness.

  4. Surface morphology of PS-PDMS diblock copolymer films

    DEFF Research Database (Denmark)

    Andersen, T.H.; Tougaard, S.; Larsen, N.B.

    2001-01-01

    Spin coated thin films (∼400 Å) of poly(styrene)–poly(dimethylsiloxane) (PS–PDMS) diblock copolymers have been investigated using X-ray Photoelectron Spectroscopy and Atomic Force Microscopy. Surface segregation of the poly(dimethylsiloxane) blocks was studied for five diblock copolymers which...... by use of peak shape analysis of the X-ray Photoelectron Spectra via the Tougaard Method. The amount of dimethylsiloxane in the uppermost part of the films was quantified as a function of annealing time and temperature. For annealing above the PS glass transition temperature, surface segregation...... of the dimethylsiloxane chain-ends occurs for all the studied PS–PDMS diblock copolymers. At room temperature, surface segregation takes place only when the amount of dimethylsiloxane in the diblock copolymers is small....

  5. Blends of caprolactam/caprolactone copolymers and chlorinated polymers

    NARCIS (Netherlands)

    Alberda van Ekenstein, G.O.R.; Deuring, H.; ten Brinke, G.; Ellis, T.S.

    The phase behaviour of blends of chlorinated polyethylene, polyvinyl chloride (PVC) and chlorinated PVC with random copolymers of caprolactone and caprolactam has been investigated and the results correlated with a binary interaction model. The known miscibility of polycaprolactone in the

  6. Nanopatterned articles produced using reconstructed block copolymer films

    Science.gov (United States)

    Russell, Thomas P.; Park, Soojin; Wang; , Jia-Yu; Kim, Bokyung

    2017-05-02

    Nanopatterned surfaces are prepared by a method that includes forming a block copolymer film on a substrate, annealing and surface reconstructing the block copolymer film to create an array of cylindrical voids, depositing a metal on the surface-reconstructed block copolymer film, and heating the metal-coated block copolymer film to redistribute at least some of the metal into the cylindrical voids. When very thin metal layers and low heating temperatures are used, metal nanodots can be formed. When thicker metal layers and higher heating temperatures are used, the resulting metal structure includes nanoring-shaped voids. The nanopatterned surfaces can be transferred to the underlying substrates via etching, or used to prepare nanodot- or nanoring-decorated substrate surfaces.

  7. Stimuli-Responsive Peptide-based Triblock and Star Copolymers

    Science.gov (United States)

    Ray, Jacob; Naik, Sandeep; Johnson, Ashley; Ly, Jack; Savin, Daniel

    2011-03-01

    Stimuli-responsive copolymers demonstrate diverse aggregation behavior in aqueous solution. In general, the molecular architecture and the balance of hydrophilic and hydrophobic volumes influence morphology. This study involves polypeptide-based ABA linear triblock and AB2 star copolymer (which structurally resemble phospholipids) amphiphiles. Model systems for this study are poly(L-lysine)-b-poly(propylene oxide)-b-poly(L-lysine) (KPK) triblocks and poly(L-glutamate) (PE) based star copolymers. Extensive studies with KPK systems have resulted in morphological transitions by modifying pH, and we hypothesize that a change in individual chain conformation is the driving force for these transitions. Preliminary results for PE-based star copolymers with various hydrophobic moieties suggest polymersome (vesicle) formation. Light scattering (dynamic and static) and TEM were used to determine aggregate size and morphology as a function of pH; furthermore, circular dichroism (CD) spectroscopy was used to measure helix-to-coil transitions of the polypeptide blocks.

  8. Concentration Dependent Structure of Block Copolymer Solutions

    Science.gov (United States)

    Choi, Soohyung; Bates, Frank S.; Lodge, Timothy P.

    2015-03-01

    Addition of solvent molecules into block copolymer can induce additional interactions between the solvent and both blocks, and therefore expands the range of accessible self-assembled morphologies. In particular, the distribution of solvent molecules plays a key role in determining the microstructure and its characteristic domain spacing. In this study, concentration dependent structures formed by poly(styrene-b-ethylene-alt-propylene) (PS-PEP) solution in squalane are investigated using small-angle X-ray scattering. This reveals that squalane is essentially completely segregated into the PEP domains. In addition, the conformation of the PS block changes from stretched to nearly fully relaxed (i.e., Gaussian conformation) as amounts of squalane increases. NRF

  9. Interfacial properties of semifluorinated alkane diblock copolymers

    Science.gov (United States)

    Pierce, Flint; Tsige, Mesfin; Borodin, Oleg; Perahia, Dvora; Grest, Gary S.

    2008-06-01

    The liquid-vapor interfacial properties of semifluorinated linear alkane diblock copolymers of the form F3C(CF2)n-1(CH2)m-1CH3 are studied by fully atomistic molecular dynamics simulations. The chemical composition and the conformation of the molecules at the interface are identified and correlated with the interfacial energies. A modified form of the Optimized Parameter for Liquid Simulation All-Atom (OPLS-AA) force field of Jorgensen and co-workers [J. Am. Chem. Soc. 106, 6638 (1984); 118, 11225 (1996); J. Phys. Chem. A 105, 4118 (2001)], which includes specific dihedral terms for H-F blocks-and corrections to the H-F nonbonded interaction, is used together with a new version of the exp-6 force field developed in this work. Both force fields yield good agreement with the available experimental liquid density and surface tension data as well as each other over significant temperature ranges and for a variety of chain lengths and compositions. The interfacial regions of semifluorinated alkanes are found to be rich in fluorinated groups compared to hydrogenated groups, an effect that decreases with increasing temperature but is independent of the fractional length of the fluorinated segments. The proliferation of fluorine at the surface substantially lowers the surface tension of the diblock copolymers, yielding values near those of perfluorinated alkanes and distinct from those of protonated alkanes of the same chain length. With decreasing temperatures within the liquid state, chains are found to preferentially align perpendicular to the interface, as previously seen.

  10. Multicompartmental Microcapsules from Star Copolymer Micelles

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Ikjun; Malak, Sidney T.; Xu, Weinan; Heller, William T.; Tsitsilianis, Constantinos; Tsukruk, Vladimir V.

    2013-02-26

    We present the layer-by-layer (LbL) assembly of amphiphilic heteroarm pH-sensitive star-shaped polystyrene-poly(2-pyridine) (PSnP2VPn) block copolymers to fabricate porous and multicompartmental microcapsules. Pyridine-containing star molecules forming a hydrophobic core/hydrophilic corona unimolecular micelle in acidic solution (pH 3) were alternately deposited with oppositely charged linear sulfonated polystyrene (PSS), yielding microcapsules with LbL shells containing hydrophobic micelles. The surface morphology and internal nanopore structure of the hollow microcapsules were comparatively investigated for shells formed from star polymers with a different numbers of arms (9 versus 22) and varied shell thickness (5, 8, and 11 bilayers). The successful integration of star unimers into the LbL shells was demonstrated by probing their buildup, surface segregation behavior, and porosity. The larger arm star copolymer (22 arms) with stretched conformation showed a higher increment in shell thickness due to the effective ionic complexation whereas a compact, uniform grainy morphology was observed regardless of the number of deposition cycles and arm numbers. Small-angle neutron scattering (SANS) revealed that microcapsules with hydrophobic domains showed different fractal properties depending upon the number of bilayers with a surface fractal morphology observed for the thinnest shells and a mass fractal morphology for the completed shells formed with the larger number of bilayers. Moreover, SANS provides support for the presence of relatively large pores (about 25 nm across) for the thinnest shells as suggested from permeability experiments. The formation of robust microcapsules with nanoporous shells composed of a hydrophilic polyelectrolyte with a densely packed hydrophobic core based on star amphiphiles represents an intriguing and novel case of compartmentalized microcapsules with an ability to simultaneously store different hydrophilic, charged, and hydrophobic

  11. Supramolecular Multiblock Copolymers Featuring Complex Secondary Structures.

    Science.gov (United States)

    Elacqua, Elizabeth; Manning, Kylie B; Lye, Diane S; Pomarico, Scott K; Morgia, Federica; Weck, Marcus

    2017-09-06

    This contribution introduces main-chain supramolecular ABC and ABB'A block copolymers sustained by orthogonal metal coordination and hydrogen bonding between telechelic polymers that feature distinct secondary structure motifs. Controlled polymerization techniques in combination with supramolecular assembly are used to engineer heterotelechelic π-sheets that undergo high-fidelity association with both helical and coil-forming synthetic polymers. Our design features multiple advances to achieve our targeted structures, in particular, those emulating sheet-like structural aspects using poly(p-phenylenevinylene)s (PPVs). To engineer heterotelechelic PPVs in a sheet-like design, we engineer an iterative one-pot cross metathesis-ring-opening metathesis polymerization (CM-ROMP) strategy that affords functionalized Grubbs-II initiators that subsequently polymerize a paracyclophanediene. Supramolecular assembly of two heterotelechelic PPVs is used to realize a parallel π-sheet, wherein further orthogonal assembly with helical motifs is possible. We also construct an antiparallel π-sheet, wherein terminal PPV blocks are adjacent to a flexible coil-like poly(norbornene) (PNB). The PNB is designed, through supramolecular chain collapse, to expose benzene and perfluorobenzene motifs that promote a hairpin turn via charge-transfer-aided folding. We demonstrate that targeted helix-(π-sheet)-helix and helix-(π-sheet)-coil assemblies occur without compromising intrinsic helicity, while both parallel and antiparallel β-sheet-like structures are realized. Our main-chain orthogonal assembly approach allows the engineering of multiblock copolymer scaffolds featuring diverse secondary structures via the directional assembly of telechelic building blocks. The targeted assemblies, a mix of sequence-defined helix-sheet-coil and helix-sheet-helix architectures, are Nature-inspired synthetic mimics that expose α/β and α+β protein classes via de novo design and cooperative assembly

  12. Novel block, graft and random copolymers for biomedical applications

    DEFF Research Database (Denmark)

    Javakhishvili, Irakli; Jankova Atanasova, Katja; Tanaka, Masaru

    Despite the simple structure, poly(2-methoxyethyl acrylate) (PMEA) shows excellent blood compatibility [1]. Both the freezing-bound water (intermediate water: preventing the biocomponents from directly contacting the polymer surface) and non-freezing water on the polymer surface play important ro...... copolymers with MMA [4] utilizing ATRP. Here we present other block, graft and random copolymers of MEA intended for biomedical applications. These macromolecular architectures have been constructed by employing controlled radical polymerization methods such as RAFT and ATRP....

  13. Microbial production of polyhydroxyalkanoate block copolymer by recombinant Pseudomonas putida.

    Science.gov (United States)

    Li, Shi Yan; Dong, Cui Ling; Wang, Shen Yu; Ye, Hai Mu; Chen, Guo-Qiang

    2011-04-01

    Polyhydroxyalkanoate (PHA) synthesis genes phaPCJ(Ac) cloned from Aeromonas caviae were transformed into Pseudomonas putida KTOY06ΔC, a mutant of P. putida KT2442, resulting in the ability of the recombinant P. putida KTOY06ΔC (phaPCJ(A.c)) to produce a short-chain-length and medium-chain-length PHA block copolymer consisting of poly-3-hydroxybutyrate (PHB) as one block and random copolymer of 3-hydroxyvalerate (3HV) and 3-hydroxyheptanoate (3HHp) as another block. The novel block polymer was studied by differential scanning calorimetry (DSC), nuclear magnetic resonance, and rheology measurements. DSC studies showed the polymer to possess two glass transition temperatures (T(g)), one melting temperature (T(m)) and one cool crystallization temperature (T(c)). Rheology studies clearly indicated a polymer chain re-arrangement in the copolymer; these studies confirmed the polymer to be a block copolymer, with over 70 mol% homopolymer (PHB) of 3-hydroxybutyrate (3HB) as one block and around 30 mol% random copolymers of 3HV and 3HHp as the second block. The block copolymer was shown to have the highest tensile strength and Young's modulus compared with a random copolymer with similar ratio and a blend of homopolymers PHB and PHVHHp with similar ratio. Compared with other commercially available PHA including PHB, PHBV, PHBHHx, and P3HB4HB, the short-chain- and medium-chain-length block copolymer PHB-b-PHVHHp showed differences in terms of mechanical properties and should draw more attentions from the PHA research community. © Springer-Verlag 2010

  14. Fast & scalable pattern transfer via block copolymer nanolithography

    DEFF Research Database (Denmark)

    Li, Tao; Wang, Zhongli; Schulte, Lars

    2015-01-01

    A fully scalable and efficient pattern transfer process based on block copolymer (BCP) self-assembling directly on various substrates is demonstrated. PS-rich and PDMS-rich poly(styrene-b-dimethylsiloxane) (PS-b-PDMS) copolymers are used to give monolayer sphere morphology after spin-casting of s...... on long range lateral order, including fabrication of substrates for catalysis, solar cells, sensors, ultrafiltration membranes and templating of semiconductors or metals....

  15. Self-Assembled Antimicrobial and biocompatible copolymer films on Titanium

    OpenAIRE

    Pfaffenroth, Cornelia; Winkel, Andreas; Dempwolf, Wibke; Gamble, Lara J.; Castner, David G.; Stiesch, Meike; Menzel, Henning

    2011-01-01

    Biofilm formation on biomedical devices such as dental implants can result in serious infections and finally in device failure. Polymer coatings which provide antimicrobial action to surfaces without compromising the compatibility with human tissue are of great interest. Copolymers of 4-vinyl-N-hexylpyridinium bromide and dimethyl(2-methacryloyloxyethyl) phosphonate are interesting candidates in this respect. These copolymers form ultrathin polycationic layers on titanium surfaces. As the cop...

  16. Method of forming oriented block copolymer line patterns, block copolymer line patterns formed thereby, and their use to form patterned articles

    Energy Technology Data Exchange (ETDEWEB)

    Russell, Thomas P.; Hong, Sung Woo; Lee, Dong Hyun; Park, Soojin; Xu, Ting

    2017-08-01

    A block copolymer film having a line pattern with a high degree of long-range order is formed by a method that includes forming a block copolymer film on a substrate surface with parallel facets, and annealing the block copolymer film to form an annealed block copolymer film having linear microdomains parallel to the substrate surface and orthogonal to the parallel facets of the substrate. The line-patterned block copolymer films are useful for the fabrication of magnetic storage media, polarizing devices, and arrays of nanowires.

  17. Kinetics and mechanism of the cleavage of phthalic anhydride in glacial acetic acid solvent containing aniline.

    Science.gov (United States)

    Damit, Emmy Fadhiza; Ariffin, Azhar; Khan, M Niyaz

    2008-12-05

    Apparent second-order rate constants (k(n)(app)) for the nucleophilic reaction of aniline (Ani) with phthalic anhydride (PAn) vary from 6.30 to 7.56 M(-1) s(-1) with the increase of temperature from 30 to 50 degrees C in pure glacial acetic acid (AcOH). However, the values of pseudo-first-order rate constants (k(s)) for the acetolysis of PAn in pure AcOH increase from 16.5 x 10(-4) to 10.7 x 10(-3) s(-1) with the increase of temperature from 30 to 50 degrees C. The values of k(n)(app) and k(s) vary from 5.84 to 7.56 M(-1) s(-1) and from 35.1 x 10(-4) to 12.4 x 10(-4) s(-1), respectively, with the increase of CH(3)CN content from 1% to 80% v/v in mixed AcOH solvents at 35 degrees C. The plot of k(s) versus CH(3)CN content shows a minimum (with 10(4) k(s) = 4.40 s(-1)) at 50% v/v CH(3)CN. Similarly, the variations of k(n)(app) and k(s) with the increasing content of tetrahydrofuran (THF) in mixed AcOH solvent reveal respective a maximum (with k(n)(app) = 17.5-15.6 M(-1) s(-1)) at 40-60% v/v THF and a minimum (with k(s) = approximately 0-1.2 x 10(-4) s (-1)) at 60-70% v/v THF. The respective values of DeltaH* and DeltaS* are 15.3 +/- 1.2 kcal mol(-1) and -20.1 +/- 3.8 cal K(-1) mol(-1) for k(s) and 1.1 +/- 0.5 kcal mol(-1) and -51.2 +/- 1.7 cal K(-1) mol(-1) for k(n)(app), while the values of k(n) (= k(n)(app)/f(b) with f(b) representing the fraction of free aniline base) are almost independent of temperature within the range 30-50 degrees C. A spectrophotometric approach has been described to determine f(b) in AcOH as well as mixed AcOH-CH(3)CN and AcOH-THF solvents. Thus, the observed data, obtained under different reaction conditions, have been explained quantitatively. An optimum reaction condition, within the domain of present reaction conditions, has been suggested for the maximum yield of the desired product, N-phenylphthalamic acid.

  18. Real-time monitoring of the penetration of amphiphilic acrylate copolymer in leather using a fluorescent copolymer as tracer.

    Science.gov (United States)

    Du, Jin-Xia; Shi, Lu; Peng, Bi-Yu

    2015-12-01

    A fluorescent tracer, poly (acrylic-co-stearyl acrylate-co-3-acryloyl fluorescein) [poly (AA-co-SA-co-Ac-Flu)], used for real-time monitoring the penetration of amphiphilic acrylate copolymer, poly (acrylic-co-stearyl acrylate) [poly (AA-co-SA)], in leather was synthesized by radical polymerization of acrylic, stearyl acrylate and fluorescent monomer, 3-acryloyl fluorescein (Ac-Flu). The structure, molecular weight, introduced fluorescent group content and fluorescent characteristics of the fluorescent tracer and target copolymer, amphiphilic acrylate copolymer, were also characterized. The results show that the tracer presents the similar structural characteristics to the target and enough fluorescence intensity with 1.68 wt % of the fluorescent monomer introduced amount. The vertical section of the leather treated with the target copolymer mixing with 7% of the tracer exhibits evident fluorescence, and the change of fluorescence intensity along with the vertical section with treating time increasing can reflect the penetration depth of the target copolymer. The introduction of the fluorescent group in polymer structure through copolymerization with a limited amount of fluorescent monomer, Ac-Flu, is an effective way to make a tracer to monitor the penetration of the target in leather, which provides a new thought for the penetration research of syntans such as vinyl copolymer materials in leather manufacture. © 2015 Wiley Periodicals, Inc.

  19. Investigation of the ageing effects on phenol-urea-formaldehyde binder and alkanol amine-acid anhydride binder coated mineral fibres

    DEFF Research Database (Denmark)

    Zafar, Ashar; Schjødt-Thomsen, Jan; Sodhi, R.

    2013-01-01

    Phenol-Urea-Formaldehyde (PUF) binder coated mineral fibres' mechanical properties have been observed to degrade during ageing at elevated temperatures and humidity, while alkanol amine-acid anhydride binder based mineral fibres exhibited better ageing properties for same duration of ageing. X...

  20. An atom-economic approach to carboxylic acids via Pd-catalyzed direct addition of formic acid to olefins with acetic anhydride as a co-catalyst.

    Science.gov (United States)

    Wang, Yang; Ren, Wenlong; Shi, Yian

    2015-08-21

    An effective Pd-catalyzed hydrocarboxylation of olefins using formic acid with acetic anhydride as a co-catalyst is described. A variety of carboxylic acids are obtained in good yields with high regioselectivities under mild reaction conditions without the use of toxic CO gas.

  1. Greener Friedel-Crafts Acylation using Microwave-enhanced reactivity of Bismuth Triflate in the Friedel-Crafts Benzoylation of Aromatic Compounds with Benzoic Anhydride

    DEFF Research Database (Denmark)

    Tran, Phuong Hoang; Nguyen, Hai Truong; Hansen, Poul Erik

    2017-01-01

    An efficient and facile bismuth trifluoromethanesulfonate-catalyzed benzoylation of aromatic compounds using benzoic anhydride under solvent-free microwave irradiation has been developed. The microwave-assisted Friedel-Crafts benzoylation results in good yields within short reaction times. Bismuth...

  2. Reaction Behavior of Cellulose in the Homogeneous Esterification of Bagasse Modified with Phthalic Anhydride in Ionic Liquid 1-Allyl-3-methylimidazium Chloride

    National Research Council Canada - National Science Library

    Wang, Hui-Hui; Zhang, Xue-Qin; Long, Piao; Zhang, Ai-Ping; Liu, Chuan-Fu; Sun, Run-Cang

    2016-01-01

    ...) with phthalic anhydride (PA) at the dosage of 10-50 mmol/g. The phthalation degrees of bagasse and the isolated cellulose were in the range of 5.66% to 22.71% and 11.61% to 44.11%, respectively...

  3. Copper(II) sulfate pentahydrate (CuSO4.5H2O): a green catalyst for solventless acetylation of alcohols and phenols with acetic anhydride

    OpenAIRE

    Majid M. Heravi; Farahnaz K. Behbahani; Zadsirjan, Vahideh; Oskooie,Hossien A.

    2006-01-01

    Alcohols and phenols were efficiently acetylated with acetic anhydride in the presence of copper (II) sulfate at room temperature in high yields. Álcoois e fenóis foram acetilados eficientemente com anidrido acético na presença de sulfato de cobre (II) em temperatura ambiente, com altos rendimentos.

  4. Industrial production of difructose anhydride III (DFA III) from crude inulin extracted from chicory roots using Arthrobacter sp. H65-7 fructosyltransferase.

    Science.gov (United States)

    Kikuchi, Hiroto; Inoue, Masanao; Saito, Hidetoshi; Sakurai, Hiroaki; Aritsuka, Tsutomu; Tomita, Fusao; Yokota, Atsushi

    2009-03-01

    A practical, economical, and industrial process for the enzymatic production of difructose anhydride III (DFA III) was investigated for crude inulin prepared from chicory roots using Arthrobacter sp. H65-7 fructosyltransferase. A comparable level of DFA III production to that from commercial inulin was obtained using crude inulin, suggesting the feasibility of this production process.

  5. Redox Reaction in the Cyclization-aromatization of (R-(+-Citronellal with FeCl3/Acetic Anhydride

    Directory of Open Access Journals (Sweden)

    Edy Cahyono

    2012-02-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}  The effects of temperature, time of reaction, and the reactants mole ratio on the cyclization-acetylation of (R-(+-citronellal with FeCl3/acetic anhydride were studied.  Isopulegyl acetate (IPA and neoisopulegyl acetate (NIPA were obtained as the main products at room temperature (mole ratio of citronellal: acetic anhydride: FeCl3 = 6:12:1. Both products are relatively fixed after the 30th minute. The average concentration of IPA at 30-180 minutes was 44.71%, while the average concentration of NIPA was 28.47%. Increasing temperature (80 oC and the amount of acetic anhydride (mol ratio 2:6:1 gave p-cymene (17.53% and citronellyl acetate (11.31%. Autoredoks reaction on the transformation of citronellal into p-cymene and citronellyl acetate was studied with the carbon oxidation number concept. Key words: (R -(+- citronellal, cyclization-aromatization, FeCl3,  p-cymene, redox

  6. New adhesive systems based on functionalized block copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Kent, M.; Saunders, R.; Hurst, M.; Small, J.; Emerson, J.; Zamora, D.

    1997-05-01

    The goal of this work was to evaluate chemically-functionalized block copolymers as adhesion promoters for metal/thermoset resin interfaces. Novel block copolymers were synthesized which contain pendant functional groups reactive toward copper and epoxy resins. In particular, imidazole and triazole functionalities that chelate with copper were incorporated onto one block, while secondary amines were incorporated onto the second block. These copolymers were found to self-assemble from solution onto copper surfaces to form monolayers. The structure of the adsorbed monolayers were studied in detail by neutron reflection and time-of-flight secondary ion mass spectrometry. The monolayer structure was found to vary markedly with the solution conditions and adsorption protocol. Appropriate conditions were found for which the two blocks form separate layers on the surface with the amine functionalized block exposed at the air surface. Adhesion testing of block copolymer-coated copper with epoxy resins was performed in both lap shear and peel modes. Modest enhancements in bond strengths were observed with the block copolymer applied to the native oxide. However, it was discovered that the native oxide is the weak link, and that by simply removing the native oxide, and then applying an epoxy resin before the native oxide can reform, excellent bond strength in the as-prepared state as well as excellent retention of bond strength after exposure to solder in ambient conditions are obtained. It is recommended that long term aging studies be performed with and without the block copolymer. In addition, the functionalized block copolymer method should be evaluated for another system that has inherently poor bonding, such as the nickel/silicone interface, and for systems involving metals and alloys which form oxides very rapidly, such as aluminum and stainless steel, where bonding strategies involve stabilizing the native oxide.

  7. Disulfide-Functionalized Diblock Copolymer Worm Gels.

    Science.gov (United States)

    Warren, Nicholas J; Rosselgong, Julien; Madsen, Jeppe; Armes, Steven P

    2015-08-10

    Two strategies for introducing disulfide groups at the outer surface of RAFT-synthesized poly(glycerol monomethacrylate)-poly(2-hydroxypropyl methacrylate) (PGMA-PHPMA, or Gx-Hy for brevity) diblock copolymer worms are investigated. The first approach involved statistical copolymerization of GMA with a small amount of disulfide dimethacrylate (DSDMA, or D) comonomer to afford a G54-D0.50 macromolecular chain transfer agent (macro-CTA); this synthesis was conducted in relatively dilute solution in order to ensure mainly intramolecular cyclization and hence the formation of linear chains. Alternatively, a new disulfide-based bifunctional RAFT agent (DSDB) was used to prepare a G45-S-S-G45 (or (G45-S)2) macro-CTA. A binary mixture of a non-functionalized G55 macro-CTA was utilized with each of these two disulfide-based macro-CTAs in turn for the RAFT aqueous dispersion polymerization of 2-hydroxypropyl methacrylate (HPMA). By targeting a PHPMA DP of 130 and systematically varying the molar ratio of the two macro-CTAs, a series of disulfide-functionalized diblock copolymer worm gels were obtained. For both formulations, oscillatory rheology studies confirmed that higher disulfide contents led to stronger gels, presumably as a result of inter-worm covalent bond formation via disulfide/thiol exchange. Using the DSDB-based macro-CTA led to the strongest worm gels, and this formulation also proved to be more effective in suppressing the thermosensitive behavior that is observed for the nondisulfide-functionalized control worm gel. However, macroscopic precipitation occurred when the proportion of DSDB-based macro-CTA was increased to 50 mol %, whereas the DSDMA-based macro-CTA could be utilized at up to 80 mol %. Finally, the worm gel modulus could be reduced to that of a nondisulfide-containing worm gel by reductive cleavage of the inter-worm disulfide bonds using excess tris(2-carboxyethyl)phosphine (TCEP) to yield thiol groups. These new biomimetic worm gels are

  8. Acylation Modification of Antheraea pernyi Silk Fibroin Using Succinic Anhydride and Its Effects on Enzymatic Degradation Behavior

    Directory of Open Access Journals (Sweden)

    Xiufang Li

    2013-01-01

    Full Text Available The degradation rate of tissue engineering scaffolds should match the regeneration rate of new tissues. Controlling the degradation behavior of silk fibroin is an important subject for silk-based tissue engineering scaffolds. In this study, Antheraea pernyi silk fibroin was successfully modified with succinic anhydride and then characterized by zeta potential, ninhydrin method, and FTIR. In vitro, three-dimensional scaffolds prepared with modified silk fibroin were incubated in collagenase IA solution for 18 days to evaluate the impact of acylation on the degradation behavior. The results demonstrated that the degradation rate of modified silk fibroin scaffolds was more rapid than unmodified ones. The content of the β-sheet structure in silk fibroin obviously decreased after acylation, resulting in a high degradation rate. Above all, the degradation behavior of silk fibroin scaffolds could be regulated by acylation to match the requirements of various tissues regeneration.

  9. Preparation and Characterization of Extruded Composites Based on Polypropylene and Chitosan Compatibilized with Polypropylene-Graft-Maleic Anhydride

    Directory of Open Access Journals (Sweden)

    Fernando Javier Carrasco-Guigón

    2017-01-01

    Full Text Available The preparation of composites of synthetic and natural polymers represent an interesting option to combine properties; in this manner, polypropylene and chitosan extruded films using a different proportion of components and polypropylene-graft-maleic anhydride (PPgMA as compatibilizer were prepared. The effect of the content of the biopolymer in the polypropylene (PP matrix, the addition of compatibilizer, and the particle size on the properties of the composites was analyzed using characterization by fourier transform-infrared spectroscopy (FT-IR, scanning electron microscopy (SEM, differential scanning calorimetry (DSC, tensile strength, and contact angle, finding that in general, the addition of the compatibilizer and reducing the particle size of the chitosan, favored the physicochemical and morphological properties of the films.

  10. Chitosan: poly(N-vinylpyrrolidone-alt-itaconic anhydride) nanocapsules—a promising alternative for the lung cancer treatment

    Energy Technology Data Exchange (ETDEWEB)

    Raţă, Delia Mihaela, E-mail: iureadeliamihaela@yahoo.com [„Apollonia” University of Iasi, Faculty of Medical Dentistry, „Academician Ioan Haulică” Research Institute (Romania); Chailan, Jean-François, E-mail: chailan@univ-tln.fr [University of Sud Toulon-Var, « Matériaux-Polymères-Interfaces-Environnement Marin (MAPIEM) Laboratory (France); Peptu, Cătălina Anişoara, E-mail: catipeptu@yahoo.co.uk [“Gheorghe Asachi” Technical University of Iasi, Department of Natural and Synthetic Polymers, Faculty of Chemical Engineering and Environmental Protection (Romania); Costuleanu, Marcel, E-mail: mcostuleanu@yahoo.com [University of Medicine and Pharmacy “Grigore T. Popa”- Iaşi, Department of General Pathology, Faculty of Dental Medicine (Romania); Popa, Marcel, E-mail: marpopa2001@yahoo.fr [“Gheorghe Asachi” Technical University of Iasi, Department of Natural and Synthetic Polymers, Faculty of Chemical Engineering and Environmental Protection (Romania)

    2015-07-15

    This study reports the preparation of novel polymeric nanocapsules based on a natural polymer, chitosan and a synthetic one, poly(N-vinylpyrrolidone-alt-itaconic anhydride) [(poly(NVPAI)] using an interfacial condensation technique. The infrared spectroscopy studies confirmed the crosslinking through the presence of amide bonds, formed between the two polymers chains. The diameter of nanocapsules was found in the range of 126–214 nm and it was determined by dynamic light scattering method. Morphological characterization demonstrated their nano size, the spherical shape of the nanocapsules and the formation of hollow particles. The nanocapsules presented good swelling capacity in aqueous solutions. 5-Fluorouracil (5-FU) loading and release capacity was studied, the processes being controlled by the drug diffusion through the polymeric membrane. The obtained results were encouraging, showing that 5-FU-loaded nanocapsules had 70 % higher apoptotic effect on A549 tumour cells than the drug in free state or mixed with the nanocapsules.

  11. Deactivation properties of a high-productive vanadia-titania catalyst for oxidation of o-xylene to phthalic anhydride

    Directory of Open Access Journals (Sweden)

    A. T. Georgieva

    2008-06-01

    Full Text Available The behavior of a high-productive V2O5-TiO2 (anatase supported O 4-28 catalyst for oxidation of o-xylene to phthalic anhydride was investigated in the first three years of its exploitation in industry. By using a suitable mathematical model, an identification problem was solved and activation profiles of the catalyst along a fixed bed located in the tubes of an industrial reactor were determined. Experimental temperature regimes and yields of the main and side products for different periods of the catalyst life were used. The proper technological regimes providing for a maximum yield according to the requirements of the catalyst producer company were defined.

  12. Sulfonated Magnetic Nanocomposite Based on Reactive PGMA-MAn Copolymer@Fe3O4 Nanoparticles: Effective Removal of Cu(II Ions from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Reza Hasanzadeh

    2016-01-01

    Full Text Available Chelating magnetic nanocomposites have been considered as suitable materials for removal of heavy metal ions for water treatment. In this work poly(glycidyl methacrylate-maleic anhydride copolymer (PGMA-MAn is modified with 4-aminobenzenesulfonic acid (ABSAc and subsequently the product reacted with modified Fe3O4 nanoparticles and 1,2-ethanedithiol (EDT in the presence of ultrasonic irradiation for preparation of tridimensional chelating magnetic nanocomposite. Synthesized magnetic nanocomposite was characterized by Fourier transform infrared spectroscopy (FT-IR, scanning electron microscopy (SEM, X-ray diffraction analysis (XRD, vibrating sample magnetometer (VSM, energy dispersive X-ray analysis (EDX, elemental mapping analysis (EMA, Brunauer-Emmett-Teller (BET, and thermal gravimetric analysis (TGA. The adsorption behavior of Cu(II ions was investigated by synthesized nanocomposite in various parameters such as pH, contact time, metal ion concentration, and adsorbent dosage. The equilibrium distribution coefficient (kd was determined and the findings prove that the kd value is approximately high in the case of all selected metal ions. The synthesized nanocomposite exhibited good tendency for removing Cu(II ions from aqueous solutions even at an acidic pH.

  13. Monte Carlo simulations of the phase separation of a copolymer blend in a thin film

    KAUST Repository

    Wang, Zhexiao

    2014-12-11

    Monte Carlo simulations were carried out to study the phase separation of a copolymer blend comprising an alternating copolymer and/or block copolymer in a thin film, and a phase diagram was constructed with a series of composed recipes. The effects of composition and segregation strength on phase separation were discussed in detail. The chain conformation of the block copolymer and alternating copolymer were investigated with changes of the segregation strength. Our simulations revealed that the segment distribution along the copolymer chain and the segregation strength between coarse-grained beads are two important parameters controlling phase separation and chain conformation in thin films of a copolymer blend. A well-controlled phase separation in the copolymer blend can be used to fabricate novel nanostructures.

  14. Chromatographic examination of the chemical composition and sequence distribution of copolymers from ethyl and benzyl diazoacetate

    NARCIS (Netherlands)

    Reingruber, E.M.; Chojnacka, A.; Jellema, E.; de Bruin, B.; Buchberger, W.; Schoenmakers, P.J.

    2012-01-01

    Polymers, especially copolymers, are highly complex samples and, therefore, require various setups for their thorough characterization. In this work, one- and two-dimensional chromatographic approaches were applied to characterize two homopolymers and two dissimilar copolymers prepared by

  15. Modification of pineapple peel fibre with succinic anhydride for Cu2+, Cd2+ and Pb2+ removal from aqueous solutions.

    Science.gov (United States)

    Hu, Xiuyi; Zhao, Mouming; Song, Guosheng; Huang, Huihua

    2011-01-01

    Research on chemical modification of pineapple peel fibre with succinic anhydride was carried out to create a novel adsorbent for Cu2+, Cd2+ and Pb2+ removal from aqueous solution. After pretreatment with iso-propyl alcohol and NaOH, pineapple peel fibre was modified via reaction with succinic anhydride for introduction of carboxylic functional groups. The modified pineapple peel fibre was characterized with Fourier transform infrared (FTIR) spectroscopy and evaluated for its adsorptive ability for Cu2+, Cd2+ and Pb2+ from synthetic metal solutions. The FTIR analysis proved the introduction of carboxylic functional groups in the backbone of the modified pineapple peel fibre. The modified pineapple peel fibre showed higher adsorptive capacity for Cu2+, Cd2+ and Pb2+ compared with raw pineapple peel and pineapple peel fibre pretreated with iso-propyl alcohol. The adsorption of Cu2+, Cd2+ and Pb2+ on the modified pineapple peel fibre depended on solution pH value, adsorption time and initial metal concentration. The maximum adsorption capacities of the modified fibre were observed at pH 5.4 for Cu2+ (27.68 +/- 0.83 mg g(-1) or 0.44 mmol g(-1)), at pH 7.5 for Cd2+ (34.18 +/- 1.02 mg g(-1) or 0.30 mmol g(-1)) and at pH 5.6 for Pb2+ (70.29 +/- 2.11 mg g(-1) or 0.34 mmol g(-1)) respectively. The adsorption followed the pseudo-second-order kinetics model and the experimental data coincided well with the Langmuir model.

  16. Rapid microwaves synthesis of CoSi{sub x}/CNTs as novel catalytic materials for hydrogenation of phthalic anhydride

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Liangliang [School of Engineering and Technology, China University of Geosciences, Beijing 100083 (China); Chen, Xiao; Jin, Shaohua; Guan, Jingchao [Laboratory of Advanced Materials and Catalytic Engineering, Dalian University of Technology, Dalian 116024 (China); Williams, Christopher T. [Department of Chemical Engineering, University of South Carolina, Columbia, SC 29208 (United States); Peng, Zhijian, E-mail: pengzhijian@cugb.edu.cn [School of Engineering and Technology, China University of Geosciences, Beijing 100083 (China); Liang, Changhai, E-mail: changhai@dlut.edu.cn [Laboratory of Advanced Materials and Catalytic Engineering, Dalian University of Technology, Dalian 116024 (China)

    2014-09-15

    CoSi{sub x}/CNTs catalysts with different CoSi{sub x} phases (CoSi, CoSi{sub 2}) have been rapidly synthesized via a microwave-assisted route and applied for the liquid phase hydrogenation of phthalic anhydride. The synthesized catalysts were analyzed and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy-energy dispersive X-ray spectroscopy, thermogravimetric/derivative thermogravimetric analysis. The reaction progress of cobalt silicides and the ratio of Co:Si were monitored at different microwave irradiation times by XRD, giving insight into the formation mechanism. Compared to the Co/CNTs catalyst, all the prepared CoSi{sub x}/CNTs catalysts exhibited excellent activity and good selectivity to phthalide under mild reaction conditions (180–220 °C and 4.0 MPa H{sub 2}). This novel methodology can be applied to the synthesis of other transition metal silicides such as FeSi, Ni{sub 2}Si, and Cu{sub 4}Si. - Graphical abstract: CoSi{sub x}/CNTs catalysts with different CoSi{sub x} phases (CoSi{sub 2}, CoSi) have been rapidly synthesized via microwave-assisted route, which involves the vaporization of CoCl{sub 2} and subsequent reaction of CoCl{sub 2} with Si. - Highlights: • CoSi{sub x}/CNTs catalysts have been rapid synthesized via microwave-assisted route. • The phases of CoSi{sub x} were controlled by varying microwave time and Co:Si ratio. • FeSi, Ni{sub 2}Si and Cu{sub 4}Si were also synthesized via microwave-assisted route. • CoSi{sub x}/CNTs catalysts can be applied in hydrogenation of phthalic anhydride.

  17. Tough and Sustainable Graft Block Copolymer Thermoplastics

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jiuyang; Li, Tuoqi; Mannion, Alexander M.; Schneiderman, Deborah K.; Hillmyer, Marc A.; Bates, Frank S. (UMM)

    2016-03-15

    Fully sustainable poly[HPMC-g-(PMVL-b-PLLA)] graft block copolymer thermoplastics were prepared from hydroxypropyl methylcellulose (HPMC), β-methyl-δ-valerolactone (MVL), and l-lactide (LLA) using a facile two-step sequential addition approach. In these materials, rubbery PMVL functions as a bridge between the semirigid HPMC backbone and the hard PLLA end blocks. This specific arrangement facilitates PLLA crystallization, which induces microphase separation and physical cross-linking. By changing the backbone molar mass or side chain composition, these thermoplastic materials can be easily tailored to access either plastic or elastomeric behavior. Moreover, the graft block architecture can be utilized to overcome the processing limitations inherent to linear block polymers. Good control over molar mass and composition enables the deliberate design of HPMC-g-(PMVL-b-PLLA) samples that are incapable of microphase separation in the melt state. These materials are characterized by relatively low zero shear viscosities in the melt state, an indication of easy processability. The simple and scalable synthetic procedure, use of inexpensive and renewable precursors, and exceptional rheological and mechanical properties make HPMC-g-(PMVL-b-PLLA) polymers attractive for a broad range of applications.

  18. Molecular Exchange in Ordered Diblock Copolymer Micelles

    Science.gov (United States)

    Choi, Soo-Hyung; Lodge, Timothy; Bates, Frank

    2011-03-01

    Previously, molecular exchange between spherical micelles in dilute solution (1 vol% polymer) was investigated using time-resolved small-angle neutron scattering (TR-SANS). As the concentration of spherical micelles formed by the diblock copolymers increases, the micelles begin to overlap and eventually pack onto body-centered cubic (BCC) lattice. In this study, concentrated, ordered micelles (15 vol% polymers) prepared by dispersing isotopically labeled poly(styrene- b -ethylene-alt-propylene) in an isotopic squalane mixture was investigated to understand the micellar concentration dependence of the molecular exchange. Perfectly random mixing of isotopically labeled micelles on the BCC lattice was confirmed by SANS patterns where the interparticle contribution vanishes, resulting in an intensity that directly relates to the exchange kinetics. The measured molecular exchange process for the concentrated, ordered system is qualitatively consistent with the previous observations, but the rate is more than an order of magnitude slower than that for the dilute, disordered system. Infineum(IPrime), MRSEC(NSF), NIST.

  19. Molecular Exchange Dynamics in Block Copolymer Micelles

    Science.gov (United States)

    Bates, Frank; Lu, Jie; Choi, Soohyung; Lodge, Timothy

    2012-02-01

    Poly(styrene-b-ethylene propylene) (PS-PEP) diblock copolymers were mixed with squalane (C30H62) at 1% by weight resulting in the formation of spherical micelles. The structure and dynamics of molecular exchange were characterized by synchrotron small-angle x-ray scattering (SAXS) and time resolved small-angle neutron scattering (TR-SANS), respectively, between 100 C and 160 C. TR-SANS measurements were performed with solutions initially containing deuterium labeled micelle cores and normal cores dispersed in a contrast matched squalane. Monitoring the reduction in scattering intensity as a function of time at various temperatures revealed molecular exchange dynamics highly sensitive to the core molecular weight and molecular weight distribution. Time-temperature superposition of data acquired at different temperatures produced a single master curve for all the mixtures. Experiments conducted with isotopically labeled micelle cores, each formed from two different but relatively mondisperse PS blocks, confirmed a simple dynamical model based on first order kinetics and core Rouse single chain relaxation. These findings demonstrate a dramatic transition to nonergodicity with increasing micelle core molecular weight and confirm the origins of the logarithmic exchange kinetics in such systems.

  20. Heavy and toxic metal uptake by mesoporous hypercrosslinked SMA beads: Isotherms and kinetics

    Directory of Open Access Journals (Sweden)

    Renuka Gonte

    2016-09-01

    Full Text Available Hypercrosslinked styrene-maleic acid copolymer beads were used for the removal of metal ions from mimicked industrial effluents. The polymer was characterized by SEM which revealed the presence of a porous network. Carboxyl acid groups of the polymer were identified as active sites for metal uptake. Highly porous surface enhanced metal ion uptake was achieved through a physicochemical process. Equilibrium sorption of metal ions was best described by the Freundlich and Temkin model with R2 > 0.99. Adsorption followed pseudo first and pseudo second order reaction kinetics. Intraparticle diffusion model suggested a three step equilibrium. Desorption was a fast process with ∼90% in 60 min.

  1. Synthesis, characterization and antimicrobial activity of important heterocyclic acrylic copolymers

    Directory of Open Access Journals (Sweden)

    2008-10-01

    Full Text Available The acrylate monomer, 7-acryloyloxy-4-methyl coumarin (AMC has been synthesized by reacting 7-hydroxy-4-methyl coumarin, with acryloyl chloride in the presence of NaOH at 0–5°C. Copolymers of 7-acryloyloxy-4-methyl coumarin (AMC with vinyl acetate (VAc were synthesized in DMF (dimethyl formamide solution at 70±1°C using 2,2′-azobisisobutyronitrile (AIBN as an initiator with different monomer-to-monomer ratios in the feed. The copolymers were characterized by Fourier transform infra red (FTIR spectroscopy. The copolymer composition was evaluated by 1H-NMR (proton nuclear magnetic resonance and was further used to determine reactivity ratios. The monomer reactivity ratios for AMC (M1-VAc (M2 pair were determined by the application of conventional linearization methods such as Fineman-Ross (r1 = 0.6924; r2 = 0.6431, Kelen-Tüdõs (r1 = 0.6776; r2 = 0.6374 and extended Kelen-Tüdõs (r1 = 0.6657; r2 = 0.6256. Thermo gravimetric analysis showed that thermal decomposition of the copolymers occurred in single stage in the temperature range of 263–458°C. The molecular weights of the polymers were determined using gel permeation chromatography. The homo and copolymers were tested for their antimicrobial properties against selected microorganisms.

  2. Perfluorocyclobutyl Aryl Ether-Based ABC Amphiphilic Triblock Copolymer

    Science.gov (United States)

    Xu, Binbin; Yao, Wenqiang; Li, Yongjun; Zhang, Sen; Huang, Xiaoyu

    2016-12-01

    A series of fluorine-containing amphiphilic ABC triblock copolymers comprising hydrophilic poly(ethylene glycol) (PEG) and poly(methacrylic acid) (PMAA), and hydrophobic poly(p-(2-(4-biphenyl)perfluorocyclobutoxy)phenyl methacrylate) (PBPFCBPMA) segments were synthesized by successive atom transfer radical polymerization (ATRP). First, PEG-Br macroinitiators bearing one terminal ATRP initiating group were prepared by chain-end modification of monohydroxy-terminated PEG via esterification reaction. PEG-b-PBPFCBPMA-Br diblock copolymers were then synthesized via ATRP of BPFCBPMA monomer initiated by PEG-Br macroinitiator. ATRP polymerization of tert-butyl methacrylate (tBMA) was directly initiated by PEG-b-PBPFCBPMA-Br to provide PEG-b-PBPFCBPMA-b-PtBMA triblock copolymers with relatively narrow molecular weight distributions (Mw/Mn ≤ 1.43). The pendant tert-butyoxycarbonyls were hydrolyzed to carboxyls in acidic environment without affecting other functional groups for affording PEG-b-PBPFCBPMA-b-PMAA amphiphilic triblock copolymers. The critical micelle concentrations (cmc) were determined by fluorescence spectroscopy using N-phenyl-1-naphthylamine as probe and the self-assembly behavior in aqueous media were investigated by transmission electron microscopy. Large compound micelles and bowl-shaped micelles were formed in neutral aqueous solution. Interestingly, large compound micelles formed by triblock copolymers can separately or simultaneously encapsulate hydrophilic Rhodamine 6G and hydrophobic pyrene agents.

  3. Formation and structural properties of multi-block copolymer vesicles

    Science.gov (United States)

    Wang, Rong; Ma, Shiying

    2014-03-01

    Due to the unique structure, vesicles have attracted considerable attention for their potential applications, such as gene and drug delivery, microcapsules, nanoreactors, cell membrane mimetic, synthetic organelles, etc. By using dissipative particle dynamics, we studied the self-assembly of amphiphilic multi-block copolymer. The phase diagram was constructed by varying the interaction parameters and the composition of the block copolymers. The results show that the vesicles are stable in a large region which is different from the diblock copolymer or triblock copolymer. The structural properties of vesicles can be controlled by varying the interaction parameters and the length of the hydrophobic block. The relationship between the hydrophilic and hydrophobic block length vs the aqueous cavity size and vesicle size are revealed. The copolymers with shorter hydrophobic blocks length or the higher hydrophilicity are more likely to form vesicles with larger aqueous cavity size and vesicle size as well as thinner wall thickness. However, the increase in hydrophobic-block length results to form vesicles with smaller aqueous cavity size and larger vesicle size. Acknowledgments. This work has been supported by NNSFC (No. 21074053) and NBRPC (No. 2010CB923303).

  4. Controlling block copolymer phase behavior using ionic surfactant

    Energy Technology Data Exchange (ETDEWEB)

    Ray, D.; Aswal, V. K. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India E-mail: debes.phys@gmail.com (India)

    2016-05-23

    The phase behavior of poly(ethylene oxide)-poly(propylene oxide-poly(ethylene oxide) PEO-PPO-PEO triblock copolymer [P85 (EO{sub 26}PO{sub 39}EO{sub 26})] in presence of anionic surfactant sodium dodecyl sulfate (SDS) in aqueous solution as a function of temperature has been studied using dynamic light scattering (DLS) and small-angle neutron scattering (SANS). The measurements have been carried out for fixed concentrations (1 wt%) of block copolymer and surfactants. Each of the individual components (block copolymer and surfactant) and the nanoparticle–surfactant mixed system have been examined at varying temperature. The block copolymer P85 forms spherical micelles at room temperature whereas shows sphere-to-rod like micelle transition at higher temperatures. On the other hand, SDS surfactant forms ellipsoidal micelles over a wide temperature range. Interestingly, it is found that phase behavior of mixed micellar system (P85 + SDS) as a function of temperature is drastically different from that of P85, giving the control over the temperature-dependent phase behavior of block copolymers.

  5. Relaxation processes in a lower disorder order transition diblock copolymer

    Energy Technology Data Exchange (ETDEWEB)

    Sanz, Alejandro; Ezquerra, Tiberio A.; Nogales, Aurora, E-mail: aurora.nogales@csic.es [Instituto de Estructura de la Materia, IEM-CSIC. C/ Serrano 121, Madrid 28006 (Spain); Hernández, Rebeca [Instituto de Ciencia y Tecnología de Polímeros, ICTP-CSIC. C/ Juan de la Cierva 3, Madrid 28006 (Spain); Sprung, Michael [Petra III at DESY, Notkestr. 85, 22607 Hamburg (Germany)

    2015-02-14

    The dynamics of lower disorder-order temperature diblock copolymer leading to phase separation has been observed by X ray photon correlation spectroscopy. Two different modes have been characterized. A non-diffusive mode appears at temperatures below the disorder to order transition, which can be associated to compositional fluctuations, that becomes slower as the interaction parameter increases, in a similar way to the one observed for diblock copolymers exhibiting phase separation upon cooling. At temperatures above the disorder to order transition T{sub ODT}, the dynamics becomes diffusive, indicating that after phase separation in Lower Disorder-Order Transition (LDOT) diblock copolymers, the diffusion of chain segments across the interface is the governing dynamics. As the segregation is stronger, the diffusive process becomes slower. Both observed modes have been predicted by the theory describing upper order-disorder transition systems, assuming incompressibility. However, the present results indicate that the existence of these two modes is more universal as they are present also in compressible diblock copolymers exhibiting a lower disorder-order transition. No such a theory describing the dynamics in LDOT block copolymers is available, and these experimental results may offer some hints to understanding the dynamics in these systems. The dynamics has also been studied in the ordered state, and for the present system, the non-diffusive mode disappears and only a diffusive mode is observed. This mode is related to the transport of segment in the interphase, due to the weak segregation on this system.

  6. Design of block copolymer membranes using segregation strength trend lines

    KAUST Repository

    Sutisna, Burhannudin

    2016-05-18

    Block copolymer self-assembly and non-solvent induced phase separation are now being combined to fabricate membranes with narrow pore size distribution and high porosity. The method has the potential to be used with a broad range of tailor-made block copolymers to control functionality and selectivity for specific separations. However, the extension of this process to any new copolymer is challenging and time consuming, due to the complex interplay of influencing parameters, such as solvent composition, polymer molecular weights, casting solution concentration, and evaporation time. We propose here an effective method for designing new block copolymer membranes. The method consists of predetermining a trend line for the preparation of isoporous membranes, obtained by computing solvent properties, interactions and copolymer block sizes for a set of successful systems and using it as a guide to select the preparation conditions for new membranes. We applied the method to membranes based on poly(styrene-b-ethylene oxide) diblocks and extended it to newly synthesized poly(styrene-b-2-vinyl pyridine-b-ethylene oxide) (PS-b-P2VP-b-PEO) terpolymers. The trend line method can be generally applied to other new systems and is expected to dramatically shorten the path of isoporous membrane manufacture. The PS-b-P2VP-b-PEO membrane formation was investigated by in situ Grazing Incident Small Angle X-ray Scattering (GISAXS), which revealed a hexagonal micelle order with domain spacing clearly correlated to the membrane interpore distances.

  7. Perpendicularly Aligned, Anion Conducting Nanochannels in Block Copolymer Electrolyte Films

    Energy Technology Data Exchange (ETDEWEB)

    Arges, Christopher G.; Kambe, Yu; Suh, Hyo Seon; Ocola, Leonidas E.; Nealey, Paul F.

    2016-03-08

    Connecting structure and morphology to bulk transport properties, such as ionic conductivity, in nanostructured polymer electrolyte materials is a difficult proposition because of the challenge to precisely and accurately control order and the orientation of the ionic domains in such polymeric films. In this work, poly(styrene-block-2-vinylpyridine) (PSbP2VP) block copolymers were assembled perpendicularly to a substrate surface over large areas through chemical surface modification at the substrate and utilizing a versatile solvent vapor annealing (SVA) technique. After block copolymer assembly, a novel chemical vapor infiltration reaction (CVIR) technique selectively converted the 2-vinylpyridine block to 2-vinyl n-methylpyridinium (NMP+ X-) groups, which are anion charge carriers. The prepared block copolymer electrolytes maintained their orientation and ordered nanostructure upon the selective introduction of ion moieties into the P2VP block and post ion-exchange to other counterion forms (X- = chloride, hydroxide, etc.). The prepared block copolymer electrolyte films demonstrated high chloride ion conductivities, 45 mS cm(-1) at 20 degrees C in deionized water, the highest chloride ion conductivity for anion conducting polymer electrolyte films. Additionally, straight-line lamellae of block copolymer electrolytes were realized using chemoepitaxy and density multiplication. The devised scheme allowed for precise and accurate control of orientation of ionic domains in nanostructured polymer electrolyte films and enables a platform for future studies that examines the relationship between polymer electrolyte structure and ion transport.

  8. Highly conductive side chain block copolymer anion exchange membranes.

    Science.gov (United States)

    Wang, Lizhu; Hickner, Michael A

    2016-06-28

    Block copolymers based on poly(styrene) having pendent trimethyl styrenylbutyl ammonium (with four carbon ring-ionic group alkyl linkers) or benzyltrimethyl ammonium groups with a methylene bridge between the ring and ionic group were synthesized by reversible addition-fragmentation radical (RAFT) polymerization as anion exchange membranes (AEMs). The C4 side chain polymer showed a 17% increase in Cl(-) conductivity of 33.7 mS cm(-1) compared to the benzyltrimethyl ammonium sample (28.9 mS cm(-1)) under the same conditions (IEC = 3.20 meq. g(-1), hydration number, λ = ∼7.0, cast from DMF/1-propanol (v/v = 3 : 1), relative humidity = 95%). As confirmed by small angle X-ray scattering (SAXS), the side chain block copolymers with tethered ammonium cations showed well-defined lamellar morphologies and a significant reduction in interdomain spacing compared to benzyltrimethyl ammonium containing block copolymers. The chemical stabilities of the block copolymers were evaluated under severe, accelerated conditions, and degradation was observed by (1)H NMR. The block copolymer with C4 side chain trimethyl styrenylbutyl ammonium motifs displayed slightly improved stability compared to that of a benzyltrimethyl ammonium-based AEM at 80 °C in 1 M NaOD aqueous solution for 30 days.

  9. 78 FR 20032 - Styrene-Ethylene-Propylene Block Copolymer; Tolerance Exemption

    Science.gov (United States)

    2013-04-03

    ... AGENCY 40 CFR Part 180 Styrene-Ethylene-Propylene Block Copolymer; Tolerance Exemption AGENCY... from the requirement of a tolerance for residues of styrene-ethylene-propylene block copolymer (CAS Reg... permissible level for residues of styrene-ethylene-propylene block copolymer on food or feed commodities...

  10. 21 CFR 177.1480 - Nitrile rubber modified acrylonitrile-methyl acrylate copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Nitrile rubber modified acrylonitrile-methyl... Nitrile rubber modified acrylonitrile-methyl acrylate copolymers. Nitrile rubber modified acrylonitrile... rubber modified acrylonitrile-methyl acrylate copolymers consist of basic copolymers produced by the...

  11. 40 CFR 721.10101 - Copolymer of alkyl acrylate and ethyleneglycol dimethacrylate (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Copolymer of alkyl acrylate and... Significant New Uses for Specific Chemical Substances § 721.10101 Copolymer of alkyl acrylate and...) The chemical substance identified generically as copolymer of alkyl acrylate and ethyleneglycol...

  12. 21 CFR 177.1340 - Ethylene-methyl acrylate copolymer resins.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-methyl acrylate copolymer resins. 177.1340... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1340 Ethylene-methyl acrylate copolymer resins. Ethylene-methyl acrylate copolymer resins may be safely used as articles or components of...

  13. 21 CFR 177.1360 - Ethylene-vinyl acetate-vinyl alcohol copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ethylene-vinyl acetate-vinyl alcohol copolymers... for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1360 Ethylene-vinyl acetate-vinyl alcohol copolymers. Ethylene-vinyl acetate-vinyl alcohol copolymers (CAS Reg. No. 26221-27-2...

  14. 40 CFR 180.1162 - Acrylate polymers and copolymers; exemption from the requirement of a tolerance.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Acrylate polymers and copolymers... RESIDUES IN FOOD Exemptions From Tolerances § 180.1162 Acrylate polymers and copolymers; exemption from the requirement of a tolerance. (a) Acrylate polymers and copolymers are exempt from the requirement of a...

  15. Polystyrene-b-polyethylene oxide block copolymer membranes, methods of making, and methods of use

    KAUST Repository

    Peinemann, Klaus-Viktor

    2015-04-16

    Embodiments of the present disclosure provide for polystyrene-b-polyethylene oxide (PS-b-PEO) block copolymer nanoporous membranes, methods of making a PS-b-PEO block copolymer nanoporous membrane, methods of using PS-b-PEO block copolymer nanoporous membranes, and the like.

  16. 21 CFR 177.1040 - Acrylonitrile/styrene copoly-mer.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylonitrile/styrene copoly-mer. 177.1040 Section... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1040 Acrylonitrile/styrene copoly-mer. Acrylonitrile/styrene copolymers identified in this section may be safely used as a component...

  17. Responsive copolymers for enhanced petroleum recovery. Quarterly technical progress report, March 22, 1994--June 21, 1994

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, C.; Hester, R.

    1994-09-01

    In this report, the authors consider the synthesis of copolymers of interest in the enhanced recovery of petroleum. Acrylamide and N,N-dimethyl-N-dodecyl-N-(2-amidoethyl) ammonium bromide copolymers were synthesized and characterized by various instrumental methods. The rheological properties of this copolymer were investigated using a porous media elongation rheometer.

  18. 76 FR 42613 - National Emission Standards for Hazardous Air Pollutants for Polyvinyl Chloride and Copolymers...

    Science.gov (United States)

    2011-07-19

    ... Polyvinyl Chloride and Copolymers Production; Extension of Comment Period AGENCY: Environmental Protection... for Hazardous Air Pollutants for Polyvinyl Chloride and Copolymers Production is being extended for 14... extend the public comment period for the May 20, 2011, Proposed Polyvinyl Chloride and Copolymers...

  19. Solubility of dense CO2 in two biocompatible acrylate copolymers

    Directory of Open Access Journals (Sweden)

    A. R. C. Duarte

    2006-06-01

    Full Text Available Biocompatible polymers and copolymers are frequently being used as part of controlled delivery systems. These systems can be prepared using a "clean and environment friendly" technology like supercritical fluids. One great advantage of this process is that compressed carbon dioxide has excellent plasticizing properties and can swell most biocompatible polymeric matrixes, thus promoting drug impregnation processes. Mass sorption of two acrylate biocompatible copolymers contact with supercritical carbon dioxide is reported. Equilibrium solubility of dense carbon dioxide in poly(methylmethacrylate-co-ethylhexylacrylate and poly(methylmethacrylate-co-ethylhexylacrylate-co-ethyleneglycoldimethacrylate was studied by a static method at 10.0 MPa and 313 K. The reticulated copolymer had Fickean behavior and its diffusion coefficient was calculated, under operating conditions.

  20. Universality between Experiment and Simulation of a Diblock Copolymer Melt

    Science.gov (United States)

    Beardsley, T. M.; Matsen, M. W.

    The equivalent behavior among analogous block copolymer systems involving chemically distinct molecules or mathematically different models has long hinted at an underlying universality, but only recently has it been rigorously demonstrated by matching results from different simulations. The profound implication of universality is that simple coarse-grained models can be calibrated so as to provide quantitatively accurate predictions to experiment. Here, we provide the first compelling demonstration of this by simulating a polyisoprene-polylactide diblock copolymer melt using a previously calibrated lattice model. The simulation successfully predicts the peak in the disordered-state structure function, the position of the order-disorder transition and the latent heat of the transition in excellent quantitative agreement with experiment. This could mark a new era of precision in the field of block copolymer research. This work was funded by NSF under the Center for Sustainable Polymers (CHE-1413862), and computer resources were provided by SHARCNET of Compute Canada.

  1. Performance behavior of modified cellulosic fabrics using polyurethane acrylate copolymer.

    Science.gov (United States)

    Zuber, Mohammad; Shah, Sayyed Asim Ali; Jamil, Tahir; Asghar, Muhammad Irfan

    2014-06-01

    The surface of the cellulosic fabrics was modified using self-prepared emulsions of polyurethane acrylate copolymers (PUACs). PUACs were prepared by varying the molecular weight of polycaprolactone diol (PCL). The PCL was reacted with isophorone diisocyanate (IPDI) and chain was extended with 2-hydroxy ethyl acrylate (HEA) to form vinyl terminated polyurethane (VTPU) preploymer. The VTPU was further co-polymerized through free radical polymerization with butyl acrylate in different proportions. The FT-IR spectra of monomers, prepolymers and copolymers assured the formation of proposed PUACs structure. The various concentrations of prepared PUACs were applied onto the different fabric samples using dip-padding techniques. The results revealed that the application of polyurethane butyl acrylate copolymer showed a pronounced effect on the tear strength and pilling resistance of the treated fabrics. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Modification of ethylene-norbornene copolymer by Gamma irradiation

    Directory of Open Access Journals (Sweden)

    Kačarević-Popović Zorica M.

    2006-01-01

    Full Text Available The possibility of modifying polyethylene and many other polymers with high energy radiation has led to many useful applications. Due to their new combination of properties and the shortage of experimental data, the radiolysis of a new class of materials, cyclo-olefin copolymers (COC, polymerised from norbornene and ethylene using metallocene catalysts, is of great interest to the study of radiation chemistry and the physics of polymeric systems. Ethylenenorbornene copolymer, pristine and containing an antioxidant were subjected to gamma irradiation in the presence of air and in water. The irradiated copolymer was studied using IR and UV-vis spectrophotometric analysis. The radiation-induced changes in the molecular structure were correlated to changes in the glass transition temperature measured by the DSC method.

  3. Block copolymer/homopolymer dual-layer hollow fiber membranes

    KAUST Repository

    Hilke, Roland

    2014-12-01

    We manufactured the first time block copolymer dual-layer hollow fiber membranes and dual layer flat sheet membranes manufactured by double solution casting and phase inversion in water. The support porous layer was based on polystyrene and the selective layer with isopores was formed by micelle assembly of polystyrene-. b-poly-4-vinyl pyridine. The dual layers had an excellent interfacial adhesion and pore interconnectivity. The dual membranes showed pH response behavior like single layer block copolymer membranes with a low flux for pH values less than 3, a fast increase between pH4 and pH6 and a constant high flux level for pH values above 7. The dry/wet spinning process was optimized to produce dual layer hollow fiber membranes with polystyrene internal support layer and a shell block copolymer selective layer.

  4. Self-assembly of ABA triblock copolymers under soft confinement

    Science.gov (United States)

    Sheng, Yuping; An, Jian; Zhu, Yutian

    2015-05-01

    Using Monte Carlo method, the self-assembly of ABA triblock copolymers under soft confinement is investigated in this study. The soft confinement is achieved by a poor solvent environment for the polymer, which makes the polymer aggregate into a droplet. Various effects, including the block length ratio, the solvent quality for the blocks B, and the incompatibility between blocks A and B, on the micellar structures induced by soft confinement are examined. By increasing the solvent quality of B blocks, the micellar structure transforms from stacked lamella to bud-like structure, and then to onion-like structure for A5B8A5 triblock copolymers, while the inner micellar structure changes from spherical phase to various cylindrical phase, such as inner single helix, double helixes, stacked rings and cage-like structures, for A7B4A7 triblock copolymers. Moreover, the formation pathways of some typical aggregates are examined to illustrate their growth mechanisms.

  5. Poly(phenylene ether Based Amphiphilic Block Copolymers

    Directory of Open Access Journals (Sweden)

    Edward N. Peters

    2017-09-01

    Full Text Available Polyphenylene ether (PPE telechelic macromonomers are unique hydrophobic polyols which have been used to prepare amphiphilic block copolymers. Various polymer compositions have been synthesized with hydrophilic blocks. Their macromolecular nature affords a range of structures including random, alternating, and di- and triblock copolymers. New macromolecular architectures can offer tailored property profiles for optimum performance. Besides reducing moisture uptake and making the polymer surface more hydrophobic, the PPE hydrophobic segment has good compatibility with polystyrene (polystyrene-philic. In general, the PPE contributes to the toughness, strength, and thermal performance. Hydrophilic segments go beyond their affinity for water. Improvements in the interfacial adhesion between polymers and polar substrates via hydrogen bonding and good compatibility with polyesters (polyester-philic have been exhibited. The heterogeneity of domains in these PPE based block copolymer offers important contributions to diverse applications.

  6. Structure-Property Relationships in Polyolefin Block Copolymers

    Science.gov (United States)

    Mansour, Ameara Salah

    Poly(cyclohexylethylene) (PCHE for a homopolymer or C in a block copolymer) is created by hydrogenating polystyrene, and this polymer exhibits interesting properties, such as a high glass transition temperature (147 °C), high flexural modulus (2.8 GPa), low stress optical coefficient (-0.2 * 10-9 Pa-1), and low cost. However, the inherently brittle nature of PCHE prevents it from being used in applications that simultaneously require high modulus, ductility, thermal stability, and optical clarity. Previous research has shown that incorporating PCHE into a block copolymer with rubbery poly(ethylene-alt-propylene) (P) or poly(ethylethylene) (EE) or semicrystalline polyethylene (E) results in a tough material. In some cases, applications also require specific mechanical or optical properties. In order to tune these properties, this research examined tuning crystallinity using two methods: (1) by controlling the microstructure of the soft block by synthesizing a random copolymer of E and EE, and (2) by blending high C content pentablock copolymers with semicrystalline and rubbery minority components. In the first study, diblock copolymers of C(EcoEE) also were used to understand how the microstructure of the random copolymer affects the thermodynamics of the system. In the second study, CECEC and CPCPC, designed to form the same morphology (hexagonally packed cylinders with glassy C matrices), and have similar order-to-disorder transition temperatures and domain spacings, were blended together. Isothermal crystallization experiments were used to determine how the confining E and P in one domain affects the crystallization process. The effect of architecture, the state of the minority component, and the percent crystallinity on the mechanical properties of high glass content materials was also examined. These results were compared to the mechanical properties of homopolymer PCHE, polystyrene, and polycarbonate. The processing conditions needed to create smooth films of

  7. Functional Block Copolymers as Compatibilizers for Nanoclays in Polypropylene Nanocomposites

    DEFF Research Database (Denmark)

    Jankova Atanasova, Katja; Daugaard, Anders Egede; Stribeck, Norbert

    With the aim of creating tough nanocomposits (NC) [1] based on polypropylene (PP) and nanoclay (NCl) in the framework of the 7th EU program NANOTOUGH we have designed amphiphilic block copolymers utilizing Atom Transfer Radical Polymerization (ATRP) [2]. They consist of a hydrophobic block...... for the exchange of the Na+ ions of the used NCl (3.8 wt.-% aq. dispersion of montmorillonite, MMT from Laviosa Chimica Mineralia, Italy) by the synthesized charged block copolymer, which was performed in water. Modified nanoclays with 2.5 to 8.0 wt.-% of the quaternized PEB-b-PDMAEMA35 were prepared...

  8. Synthesis and Characterization of Organotin Containing Copolymers: Reactivity Ratio Studies

    Directory of Open Access Journals (Sweden)

    Mohamed H. El-Newehy

    2010-03-01

    Full Text Available Organotin monomers containing dibutyltin groups – dibutyltin citraconate (DBTC as a new monomer and dibutyltin maleate (DBTM – were synthesized. Free radical copolymerizations of the organotin monomers with styrene (ST and butyl acrylate (BA were performed. The overall conversion was kept low (≤15% wt/wt for all studied samples and the copolymers composition was determined from tin analysis using the Gillman and Rosenberg method. The reactivity ratios were calculated from the copolymer composition using the Fineman-Ross (FR method. The synthesized monomers were characterized by elemental analysis, 1H-, 13C-NMR and FTIR spectroscopy.

  9. Polymers and block copolymers of fluorostyrenes by ATRP

    DEFF Research Database (Denmark)

    Hvilsted, Søren; Borkar, Sachin; Abildgaard, Lillian

    2002-01-01

    Fully or partly fluorinated polymers have many desirable and intriguing properties. In the framework of a larger program on design and control of new functional block copolymers we recently employed the Atom Transfer Radical Polymerization (ATRP) protocol on 2,3,4,5,6-pentafluorostyrene (FS). We...... materials based on 2,3,5,6-tetrafiuoro-4-methoxy-styrene (TFMS). TFMS homopolymers as well as diblock copolymers with FS are produced by ATRP. Both types of novel polymers were subsequently demethylated and different side chains introduced on the resulting hydroxy sites....

  10. HPMA based amphiphilic copolymers mediate central nervous effects of domperidone.

    Science.gov (United States)

    Hemmelmann, Mirjam; Knoth, Christiane; Schmitt, Ulrich; Allmeroth, Mareli; Moderegger, Dorothea; Barz, Matthias; Koynov, Kaloian; Hiemke, Christoph; Rösch, Frank; Zentel, Rudolf

    2011-05-18

    In this study we give evidence that domperidone encapsulated into amphiphilic p(HPMA)-co-p(laurylmethacrylate) (LMA) copolymer aggregates is able to cross the blood-brain barrier, since it affected motor behaviour in animals, which is a sensitive measure for CNS actions. Carefully designed copolymers based on the clinically approved p(HPMA) were selected and synthesized by a combination of controlled radical polymerization and post-polymerization modification. The hydrodynamic radii (R(h) ) of amphiphilic p(HPMA)-co-p(LMA) alone and loaded with domperidone were determined by fluorescence correlation spectroscopy. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Pressure and temperature effects in homopolymer blends and diblock copolymers

    DEFF Research Database (Denmark)

    Frielinghaus, H.; Schwahn, D.; Mortensen, K.

    1997-01-01

    contribution of the Flory-Huggins parameter at larger pressure fields. This gives rise to a shift of the phase boundaries to higher temperatures and to a strong reduction of the Ginzburg parameter. Diblock copolymers show a different behavior. Neither the entropic term of the Flory-Huggins parameter nor......Thermal composition fluctuations in homopolymer mer blends and diblock copolymers were studied with SANS in varying pressure and temperature fields. For homopolymers we find a quite consistent behavior: The dominating effect of compressibility or packing leads to a reduction of the entropic...

  12. Chlorine resistant desalination membranes based on directly sulfonated poly(arylene ether sulfone) copolymers

    Science.gov (United States)

    McGrath, James E [Blacksburg, VA; Park, Ho Bum [Austin, TX; Freeman, Benny D [Austin, TX

    2011-10-04

    The present invention provides a membrane, kit, and method of making a hydrophilic-hydrophobic random copolymer membrane. The hydrophilic-hydrophobic random copolymer membrane includes a hydrophilic-hydrophobic random copolymer. The hydrophilic-hydrophobic random copolymer includes one or more hydrophilic monomers having a sulfonated polyarylsulfone monomer and a second monomer and one or more hydrophobic monomers having a non-sulfonated third monomer and a fourth monomer. The sulfonated polyarylsulfone monomer introduces a sulfonate into the hydrophilic-hydrophobic random copolymer prior to polymerization.

  13. 54 FR 38044: National Emission Standards for Hazardous Air Pollutants; Benzene Emissions From Maleic Anhydride Plants, Ethylbenzene/Styrene Plants, Benzene Storage Vessels, Benzene Equipment Leaks, and Coke By- Product Recovery Plants

    Science.gov (United States)

    Final Rule on National Emission Standards for Hazardous Air Pollutants; Benzene Emissions From Maleic Anhydride Plants, Ethylbenzene/Styrene Plants, Benzene Storage Vessels, Benzene Equipment Leaks, and Coke By-Product Recovery Plants.

  14. Micellization of St/MMA gradient copolymers: a general picture of structural transitions in gradient copolymer micelles.

    Science.gov (United States)

    Zheng, Chao; Huang, Haiying; He, Tianbai

    2013-10-01

    In this work, a gradient copolymer of styrene (St) and methyl methacrylate (MMA) is synthesized via reversible addition-fragmentation chain transfer living radical polymerization and its micellization behaviors in an acetone and water mixture are investigated by transmission electron microscopy, light scattering, and NMR spectroscopy. Three different kinds of transitions were found to coexist in a single system for the first time: a unimers to micelles transition, a star-like micelles to crew-cut micelles transition resulting from the shrinkage of micelles, and morphological transitions from spherical micelles to cylindrical micelles to vesicles. Our findings provide a general picture of structural transitions and relaxation processes in gradient copolymer micelles, which can lead to the development of novel materials and applications based on gradient copolymers. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Studies on Preparation of Poly(3,4-Dihydroxyphenylalanine-Polylactide Copolymers and the Effect of the Structure of the Copolymers on Their Properties

    Directory of Open Access Journals (Sweden)

    Dongjian Shi

    2016-03-01

    Full Text Available Properties of copolymers are generally influenced by the structure of the monomers and polymers. For the purpose of understanding the effect of polymer structure on the properties, two kinds of copolymers, poly(3,4-dihydroxyphenylalanine-g-polylactide and poly(3,4-dihydroxyphenylalanine-b-polylactide (PDOPA-g-PLA and PDOPA-b-PLA were designed and prepared by ring-opening polymerization of lactide with pre-prepared PDOPA as the initiator and the amidation of the functional PLA and PDOPA oligomer, respectively. The molecular weight and composition of the copolymers could be adjusted by changing the molar ratio of LA and DOPA and were confirmed by gel permeation chromatography (GPC and proton nuclear magnetic resonance (1H NMR spectra. The obtained copolymers with graft and block structures showed high solubility even in common organic solvents. The effects of the graft and block structures on the thermal and degradation properties were also detected. The PDOPA-g-PLA copolymers showed higher thermal stability than the PDOPA-b-PLA copolymers, due to the PDOPA-g-PLA copolymers with regular structure and strong π-π stacking interactions among the intermolecular and intramolecular chains. In addition, the degradation results showed that the PDOPA-g-PLA copolymers and the copolymers with higher DOPA composition had quicker degradation speeds. Interestingly, both two kinds of copolymers, after degradation, became undissolved in the organic solvents because of the oxidation and crosslinking formation of the catechol groups in the DOPA units during degradation in alkaline solution. Moreover, fluorescent microscopy results showed good biocompatibility of the PDOPA-g-PLA and PDOPA-b-PLA copolymers. The PDOPA and PLA copolymers have the potential applications to the biomedical and industrial fields.

  16. Morphology and electrical properties of electrochemically synthesized pyrrole–formyl pyrrole copolymer

    Energy Technology Data Exchange (ETDEWEB)

    Gholami, Mehrdad, E-mail: mehrdad897@um.edu.my [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia); Department of Chemistry, Marvdasht Branch, Islamic Azad University, P.O. Box 465, Marvdasht (Iran, Islamic Republic of); Nia, Pooria Moozarm, E-mail: pooriamn@yahoo.com [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia); Alias, Yatimah, E-mail: yatimah70@um.edu.my [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia)

    2015-12-01

    Graphical abstract: - Highlights: • The (Py–co-FPy) copolymer was synthesized electrochemically. • This copolymer has 1.6 times higher surface coverage compared to polypyrrole. • This copolymer showed 2.5 times lower resistance compared to polypyrrole. • The conjugated structure between Py and FPy causes enhancement of conductivity. • This conducting copolymer has a strong potential to be used in various applications. - Abstract: A direct electrochemical copolymerization of pyrrole–formyl pyrrole (Py–co-FPy) was carried out by oxidative copolymerization of formyl pyrrole and pyrrole in LiClO{sub 4} aqueous solution through galvanostatic method. The (Py–co-FPy) copolymer was characterized using Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (FESEM), energy-filtering transmission electron microscope (EFTEM), thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The FESEM images showed that the synthesized copolymer had a hollow whelk-like helixes structure, which justifies the enhancement of charge transportation through the copolymer film. Cyclic voltammetry studies revealed that the electrocatalytic activity of synthesized copolymer has improved and the surface coverage in copolymer enhanced 1.6 times compared to polypyrrole alone. Besides, (Py–co-FPy) copolymer showed 2.5 times lower electrochemical charge transfer resistance (R{sub ct}) value in impedance spectroscopy. Therefore, this copolymer has a strong potential to be used in several applications such as sensor applications.

  17. The critical role of phosphate in vanadium phosphate oxide for the catalytic activation and functionalization of n-butane to maleic anhydride.

    Science.gov (United States)

    Cheng, Mu-Jeng; Goddard, William A

    2013-03-27

    We used density functional theory to study the mechanism of n-butane oxidation to maleic anhydride on the vanadium phosphorus oxide (VPO) surface. We found that O(1)═P on the V(V)OPO4 surface is the active center for initiating the VPO chemistry through extraction of H from alkane C-H bonds. This contrasts sharply with previous suggestions that the active center is either the V-O bonds or else a chemisorbed O2 on the (V(IV)O)2P2O7 surface. The ability of O(1)═P to cleave alkane C-H bonds is due to its strong basicity coupled with large reduction potentials of nearby V(V) ions. We examined several pathways for the subsequent functionalization of n-butane to maleic anhydride and found that the overall barrier does not exceed 21.7 kcal/mol.

  18. Nano-Fe3O4/PEG/succinic anhydride: A novel and efficient catalyst for the synthesis of benzoxanthenes under ultrasonic irradiation.

    Science.gov (United States)

    Safaei-Ghomi, Javad; Eshteghal, Fahime

    2017-09-01

    In this paper, we reported the successful synthesis of Fe 3 O 4 /polyethyleneglycol (PEG)/succinic anhydride nanocatalyst. The catalyst was fully characterized by scanning electronic microscopy (SEM), vibrating sample magnetometer (VSM), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), dynamic laser scattering (DLS) and FT-IR spectroscopy. Fe 3 O 4 /PEG/succinic anhydride nanocatalyst as an efficient and green catalyst has been used for the synthesis of benzoxanthenes by the three-component condensation reaction of aldehydes, 2-hydroxynaphthalene-1,4-dione and 2-naphthol or dimedone under ultrasonic irradiation. This method offers several advantages such as easy work-up, excellent yields, short reaction times, using of ultrasonic as a green method, recoverability of the catalyst and little catalyst loading. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Synthesis and characterization of novel polymer-drug conjugates based on the poly(styrene-alt-maleic anhydride) as a potential method for drug release.

    Science.gov (United States)

    Khazaei, Ardeshir; Saednia, Shahnaz; Saien, Javad; Borazjani, Maryam Kiani; Rahmati, Sadegh; Hashempour-Zaviye, Ali; Abbasi, Fatemeh

    2013-01-01

    Six well known drugs, captopril, metformin-HCl, metroniazole, nortriptyline-HCl, fluoxetine-HCl and betahistin-HCl, were grafted to poly(styrene-alt-maleic anhydride) (PSMA). Grafting was attained by combining of anhydride groups in the PSMA with therapeutic agents containing NH, OH or SH groups. The covalently grafted drugs were identified by infrared, (1)H NMR and UV-Vis spectroscopy. The drug release data at different times fits well to the Korsmeyer-Peppas equation. The analysis of the exponent n of this model revealed a dominant Fickian diffusion mechanism under the in vitro conditions. Furthermore, mean dissolution time values (45.9 to 86.7 h) indicate a high resistance against drugs transport, the highest being obtained for betahistin-HCL.

  20. Epoxy/anhydride thermosets modified with end-capped star polymers with poly(ethyleneimine cores of different molecular weight and poly(ε–caprolactone arms

    Directory of Open Access Journals (Sweden)

    C. Acebo

    2015-09-01

    Full Text Available Multiarm star polymers, with a hyperbranched poly(ethyleneimine (PEI core and poly(ε-caprolactone (PCL arms end-capped with acetyl groups were synthesized by ring-opening polymerization of ε-caprolactone from PEI cores of different molecular weight. These star polymers were used as toughening agents for epoxy/anhydride thermosets. The curing process was studied by calorimetry, thermomechanical analysis and infrared spectroscopy. The final properties of the resulting materials were determined by thermal and mechanical tests. The addition of the star polymers led to an improvement up to 130% on impact strength and a reduction in the thermal stresses up to 55%. The structure and molecular weight of the modifier used affected the morphology of the resulting materials. Electron microscopy showed phase-separated morphologies with nano-sized fine particles well adhered to the epoxy/anhydride matrix when the higher molecular weight modifier was used.

  1. Efficient synthesis of zinc-containing mesoporous silicas by microwave irradiation method and their high activities in acetylation of 1,2-dimethoxybenzene with acetic anhydride

    Directory of Open Access Journals (Sweden)

    K. Bachari

    2016-09-01

    Full Text Available A series of acid zinc-containing mesoporous materials have been synthesized by microwave irradiation method with different Si/Zn ratios (Si/Zn = 100, 65, 15 and characterized by several spectroscopic techniques such as: N2 physical adsorption, ICP, XRD, TEM, FT-IR and a temperature-programmed-desorption (TPD of pyridine. The liquid phase of acetylation of 1,2-dimethoxybenzene with acetic anhydride has been investigated over this series of catalysts. In fact, the catalyst Zn-JLU-15 (15 showed bigger performance in the acid-catalyzed acetylation of 1,2-dimethoxybenzene employing acetic anhydride as an acylating agent. Furthermore, the kinetics of the acetylation of 1,2-dimethoxybenzene over these catalysts have also been investigated.

  2. Vapor-liquid equilibria and excess enthalpies for octane + N-methylacetamide, cyclooctane + N-methylacetamide, and octane + acetic acid anhydride at 125 C

    Energy Technology Data Exchange (ETDEWEB)

    Haan, A.B. de [DSM-Research, Geleen (Netherlands); Heine, A.; Fischer, K.; Gmehling, J. [Univ. Oldenburg (Germany)

    1995-11-01

    Isothermal P-x data and excess enthalpies have been measured at approximately 125 C for the binary mixtures of octane + N-methylacetamide, cyclooctane + N-methylacetamide, and octane + acetic anhydride. For each binary system linear temperature dependent interaction parameters were fitted to experimental data using the NRTL model. Activity coefficients at infinite dilution were derived from the P-x data at low concentrations using a flexible Legendre polynomial.

  3. Effect of hydrostatic pressure, temperature, and solvent on the rate of the Diels-Alder reaction between 9,10-anthracenedimethanol and maleic anhydride

    Science.gov (United States)

    Kiselev, V. D.; Kornilov, D. A.; Anikin, O. V.; Latypova, L. I.; Konovalov, A. I.

    2017-03-01

    The rate of the reaction between 9,10-anthracenedimethanol and maleic anhydride in 1,4-dioxane, acetonitrile, trichloromethane, and toluene is studied at 25, 35, 45°C in the pressure range of 1-1772 bar. The rate constants, enthalpies, entropies and activation volumes are determined. It is shown that the rate of reaction with 9,10-anthracenedimethanol is approximately one order of magnitude higher than with 9-anthracenemethanol.

  4. Inhibition of carbonic anhydrase isoforms I, II, IV, VII and XII with carboxylates and sulfonamides incorporating phthalimide/phthalic anhydride scaffolds.

    Science.gov (United States)

    El-Azab, Adel S; Abdel-Aziz, Alaa A-M; Ayyad, Rezk R; Ceruso, Mariangela; Supuran, Claudiu T

    2016-01-01

    We report a panel of carboxylates and sulfonamides incorporating phthalic anhydride and phthalimide moieties in their structure and their interaction with the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1). They were synthesized from substituted anthranilic acids and trimellitic anhydride chloride, followed by reaction with primary amines and were tested for the inhibition of five physiologically relevant CA isoforms, the human (h) hCA I, II, IV, VII and XII, some of which are involved in serious pathologies (CA II, IV and XII in glaucoma; CA VII in epilepsy; CA XII in some solid tumors). The carboxylic acids were generally poor inhibitors of isoforms hCA I, II and IV but were highly effective, low nanomolar inhibitors of hCA VII and XII. The sulfonamides inhibited all isoforms significantly, and some of them were sub-nanomolar hCA VII inhibitors, although their isoform selectivity was lower compared to the carboxylates. This study proves that carboxylic acids incorporating a phthalic anhydride/phthalimide based scaffold may lead to isoform-selective inhibitors by applying the tail approach, mostly used up until now for obtaining sulfonamide, sulfamide and sulfamate CA inhibitors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Biocompatibility of poly(DL-lactic acid/glycine) copolymers

    NARCIS (Netherlands)

    Schakenraad, J.M.; Dijkstra, Pieter J.

    1991-01-01

    In this review the authors discuss the polymer chemical, physical and cell biological aspects of poly (DL-lactic acid/glycine) copolymers, both in vitro and in vivo. The mechanism and rate of degradation and the degree of foreign body reaction were evaluated as a function of the molecular

  6. HIGH-STRENGTH POLY(METH)ACRYLAMIDE COPOLYMER HYDROGELS

    NARCIS (Netherlands)

    WIERSMA, JA; SOS, M; PENNINGS, AJ

    1994-01-01

    The hydrogels described here are copolymers of acrylamide and methacrylamide highly cross-linked with piperazine diacrylamide or 4,7,10-trioxa-1,13-tridecanediamine diacrylamide by radical polymerisation in highly concentrated aqueous and aqueous gelatin solutions. The hydrogels were characterised

  7. Unexpected phase behavior of an asymmetric diblock copolymer

    DEFF Research Database (Denmark)

    Papadakis, Christine Maria; Almdal, Kristoffer; Mortensen, Kell

    1999-01-01

    We report on measurements of the transmitted depolarized light intensity and on small-angle neutron scattering (SANS) measurements on a compositionally asymmetric poly(ethylene propylene)-poly(dimethylsiloxane) diblock copolymer studied in the bulk. SANS measurements were made both on isotropic a...

  8. Tough, semiconducting polyethylene-poly(3-hexylthiophene) diblock copolymers

    DEFF Research Database (Denmark)

    Müller, C.; Goffri, S.; Breiby, Dag Werner

    2007-01-01

    10(-2) cm(2)V(-1)s(-1) and ON-OFF ratios, I-on/I-off similar to 10(5) at contents of the insulating PE moiety as high as 90 wt %. In addition, the diblock copolymers display outstanding flexibility and toughness with elongations at break exceeding 600 % and true tensile strengths around 70 MPa...

  9. Fibronectin fixation on poly(ethyl acrylate)-based copolymers.

    Science.gov (United States)

    Briz, N; Antolinos-Turpin, C M; Alió, J; Garagorri, N; Ribelles, J L Gómez; Gómez-Tejedor, J A

    2013-08-01

    The aim of this paper is to quantify the adhered fibronectin (FN; by adsorption and/or grafting) and the exposure of its cell adhesive motifs (RGD and FNIII7-10) on poly(ethyl acrylate) (PEA) copolymers whose chemical composition has been designed to increase wettability and to introduce acid functional groups. FN was adsorbed to PEA, poly(ethyl acrylate-co-hydroxyethyl acrylate), poly(ethyl acrylate-co-acrylic acid), and poly(ethyl acrylate-co-methacrylic acid) copolymers, and covalently cross-linked to poly(ethyl acrylate-co-acrylic acid) and poly(ethyl acrylate-co-methacrylic acid) copolymers. Amount of adhered FN and exhibition of RGD and FNIII7- 10 fragments involved in cell adhesion were quantified with enzyme-linked immunosorbent assay tests. Even copolymers with a lower content of the hydrophilic component showed a decrease in water contact angle. In addition, FN was successfully fixed on all surfaces, especially on the hydrophobic surfaces. However, it was demonstrated that exposure of its cell adhesion sequences, which is the key factor in cell adhesion and proliferation, was higher for hydrophilic surfaces. Copyright © 2013 Wiley Periodicals, Inc.

  10. In vivo biocompatibility of radiation crosslinked acrylamide copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Saraydin, Dursun E-mail: saraydin@cumhuriyet.edu.tr; Uenver-Saraydin, Serpil; Karadag, Erdener; Koptagel, Emel; Gueven, Olgun

    2004-04-01

    In vitro swelling and in vivo biocompatibility of radiation crosslinked acrylamide copolymers such as acrylamide/crotonic acid (AAm/CA) and acrylamide/itaconic acid (AAm/IA) were studied. The swelling kinetics of acrylamide copolymers were performed in distilled water, human serum and some simulated physiological fluids such as phosphate buffer, pH 7.4, glycine-HCl buffer, pH 1.1, physiological saline solution, and some swelling and diffusion parameters have been calculated. AAm/CA and AAm/IA hydrogels were subcutaneously implanted in rats for up to 10 weeks and the immediate short- and long-term tissue response to these implants were investigated. Histological analysis indicated that tissue reaction at the implant site progressed from an initial acute inflammatory response. No necrosis, tumorigenesis or infection was observed at the implant site up to 10 weeks. The radiation crosslinked AAm/CA and AAm/IA copolymers were found well tolerated, non-toxic and highly biocompatible. However, AAm/IA copolymer was not found to be compatible biomaterials, because one of the AAm/IA samples was disintegrated into small pieces in the rat.

  11. Functional materials derived from block copolymer self-assembly

    DEFF Research Database (Denmark)

    Li, Tao

    The main objective of this project is to explore block copolymer self-assembly for generating functional materials with well-defined morphology on sub-20 nanometer length scale, which can be utilized in many important applications such as solar cells and nanolithography. One of the specific targe...

  12. Block copolymer-nanoparticle hybrid self-assembly

    KAUST Repository

    Hoheisel, Tobias N.

    2015-01-01

    © 2014 Published by Elsevier Ltd. Polymer-inorganic hybrid materials provide exciting opportunities as they may display favorable properties from both constituents that are desired in applications including catalysis and energy conversion and storage. For the preparation of hybrid materials with well-defined morphologies, block copolymer-directed nanoparticle hybrids present a particularly promising approach. As will be described in this review, once the fundamental characteristics for successful nanostructure formation at or close to the thermodynamic equilibrium of these nanocomposites are identified, the approach can be generalized to various materials classes. In addition to the discussion of recent materials developments based on the use of AB diblock copolymers as well as ABC triblock terpolymers, this review will therefore emphasize progress in the fundamental understanding of the underlying formation mechanisms of such hybrid materials. To this end, critical experiments for, as well as theoretical progress in the description of these nanostructured block copolymer-based hybrid materials will be discussed. Rather than providing a comprehensive overview, the review will emphasize work by the Wiesner group at Cornell University, US, on block copolymer-directed nanoparticle assemblies as well as their use in first potential application areas. The results provide powerful design criteria for wet-chemical synthesis methodologies for the generation of functional nanomaterials for applications ranging from microelectronics to catalysis to energy conversion and storage.

  13. Optical fibre Bragg grating recorded in TOPAS cyclic olefin copolymer

    DEFF Research Database (Denmark)

    Johnson, I.P.; Yuan, Scott Wu; Stefani, Alessio

    2011-01-01

    A report is presented on the inscription of a fibre Bragg grating into a microstructured polymer optical fibre fabricated from TOPAS cyclic olefin copolymer. This material offers two important advantages over poly (methyl methacrylate), which up to now has formed the basis for polymer fibre Bragg...

  14. Copolymer adsorption and the effect on colloidal stability

    NARCIS (Netherlands)

    Bijsterbosch, H.D.

    1998-01-01

    The main aim of the work described in this thesis is to study the effect of different types of copolymers on the stability of aqueous oxide dispersions. Such dispersions are a major component in water-borne paints. In order to obtain a better insight in steric stabilisation we first investigated the

  15. Characterization and micellization of a poloxamer block copolymer

    DEFF Research Database (Denmark)

    Hvidt, S.; Pedersen, Walther Batsberg

    2007-01-01

    Several poloxamers that are symmetrical EPE block copolymers (E and P are ethylene and propylene oxide, respectively) have been characterized by size exclusion chromatography on Superose columns in water. The poloxamers contain between 12 and 26 wt% of smaller-size UV-absorbing impurities...

  16. Heparin-containing block copolymers; Part I: Surface characterization

    NARCIS (Netherlands)

    Vulić, I.; Pijpers, A.P.; Okano, T.; Kim, S.W.; Feijen, Jan

    1993-01-01

    Newly synthesized heparin-containing block copolymers, consisting of a hydrophobic block of polystyrene (PS), a hydrophilic spacer-block of poly(ethylene oxide) (PEO) and covalently bound heparin (Hep) as bioactive block, were coated on aluminium, glass, polydimethylsiloxane (PDMS), PS or Biomer

  17. Blue superradiance from neat semiconducting alternating copolymer films

    NARCIS (Netherlands)

    Brouwer, H.J; Krasnikov, V.V.; Hilberer, A; Hadziioannou, G

    1996-01-01

    Blue superradiant emission in thin polymer films with a low energy threshold, as reported here, offers hope for the possible development of solid-state electrically pumped polymer lasers The absorbance, emission, and fluorescence spectra of the blue-light emitting copolymer

  18. Block-Copolymer Vesicles as Nanoreactors for Enzymatic Reactions

    NARCIS (Netherlands)

    Chen, Qi; Schönherr, Holger; Vancso, Gyula J.

    2009-01-01

    The impact of the spatial confinement of polystyrene-block-poly(acrylic acid) (PS-b-PAA) block copolymer (BCP) vesicles on the reactivity of encapsulated bovine pancreas trypsin is studied. Enzymes, as well as small molecules, are encapsulated with loading efficiencies up to 30% in BCP vesicles with

  19. Patterns of Surface Immobilized Block Copolymer Vesicle Nanoreactors

    NARCIS (Netherlands)

    Chen, Qi; de Groot, G.W.; Schönherr, Holger; Vancso, Gyula J.

    2011-01-01

    The immobilization and positioning of ultra small reaction vessels on solid supports open new pathways in applications such as lab-on-a-chip, sensors, microanalyses and microreactors. In our work block copolymer vesicles made from polystyrene-block-polyacrylic acid (PS-b-PAA) were immobilized from

  20. Synthesis and characterization of ferrocene containing block copolymers

    DEFF Research Database (Denmark)

    Chernyy, Sergey; Wang, Zhongli; Kirkensgaard, Jacob Judas Kain

    2017-01-01

    Narrowly dispersed diblock copolymers containing poly(methyl methacrylate) [PMMA] or poly(nonafluorohexyl methacrylate) [PF9MA] as the first block and poly(ferrocenylmethyl methacrylate) [PFMMA] as the second block, were prepared by anionic polymerization for the first time. Disordered bulk morph...

  1. Stability of ordered phases in block copolymer melts and solutions

    Indian Academy of Sciences (India)

    University of Copenhagen, Department of Natural Sciences, 1871 Frederiksberg, Denmark. E-mail: kell@life.ku.dk. Abstract. Block copolymer melts and solutions assemble into nanosized objects that or- der into a variety of phases, depending on molecular parameters and mutual interactions. Beyond the classical phases ...

  2. Segmented block copolymers with polyesteramide blocks of uniform length: synthesis

    NARCIS (Netherlands)

    Gaymans, R.J.; de Haan, J.L.

    1993-01-01

    Segmented copolymers were synthesized from poly(tetramethylene oxide) with hydroxy end-groups or aliphatic diols and a short-chain diester diamide with a uniform length. The diester diamide (N,N'-bis(p-carbomethoxybenzoyl)butanediamine) (Tm = 257°C) used is made from butanediamine and an excess of

  3. 21 CFR 175.210 - Acrylate ester copolymer coating.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Acrylate ester copolymer coating. 175.210 Section 175.210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: ADHESIVES AND COMPONENTS OF COATINGS Substances for Use as Components of Coatings...

  4. Asymmetric block copolymers confined in a thin film

    NARCIS (Netherlands)

    Huinink, HP; Brokken-Zijp, JCM; van Dijk, MA; Sevink, GJA

    2000-01-01

    We have used a dynamic density functional theory (DDFT) for polymeric systems, to simulate the formation of micro phases in a melt of an asymmetric block copolymer, A(n)B(m)(f(A) = 1/3), both in the bulk and in a thin film. In the DDFT model a polymer is represented as a chain of springs and beads.

  5. Controlled block copolymer micelle formation for encapsulation of hydrophobic ingredients

    NARCIS (Netherlands)

    Lebouille, G.J.L.; Vleugels, L.F.W.; Dias, A.A.; Leermakers, F.A.M.; Cohen Stuart, M.A.; Tuinier, R.

    2013-01-01

    We report on the formation of polymeric micelles in water using triblock copolymers with a polyethylene glycol middle block and various hydrophobic outer blocks prepared with the precipitation method. We form micelles in a reproducible manner with a narrow size distribution. This suggests that

  6. Physicochemical and functional characterization of the collagen-polyvinylpyrrolidone copolymer.

    Science.gov (United States)

    Leyva-Gómez, Gerardo; Lima, Enrique; Krötzsch, Guillermo; Pacheco-Marín, Rosario; Rodríguez-Fuentes, Nayeli; Quintanar-Guerrero, David; Krötzsch, Edgar

    2014-08-07

    Collagen-polyvinylpyrrolidone (C-PVP) is a copolymer that is generated from the γ irradiation of a mixture of type I collagen and low-molecular-weight PVP. It is characterized by immunomodulatory, fibrolytic, and antifibrotic properties. Here, we used various physicochemical and biological strategies to characterize the structure, biochemical susceptibility, as well as its effects on metabolic activity in fibroblasts. C-PVP contained 16 times more PVP than collagen, but only 55.8% of PVP was bonded. Nevertheless, the remaining PVP exerted strong structural activity due to the existence of weak bonds that provided shielding in the NMR spectra. On SEM and AFM, freeze-dried C-PVP appeared as a film that uniformly covered the collagen fibers. Size analysis revealed the presence of abundant PVP molecules in the solution of the copolymer with a unique dimension related to macromolecular combinations. Calorimetric analysis showed that the copolymer in solution exhibited structural changes at 110 °C, whereas the lyophilized form showed such changes at temperatures below 50 °C. The copolymer presented a rheopectic behavior, with a predominant effect of the collagen. C-PVP had biological effects on the expression of integrin α2 and prolyl-hydroxylase but did not interact with cells through the collagen receptors because it did not inhibit or slow contraction.

  7. Responsive copolymers for enhanced petroleum recovery. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, C.; Hester, R.

    1994-08-01

    A coordinated research program involving synthesis, characterization, and rheology has been undertaken to develop advanced polymer system which should be significantly more efficient than polymers presently used for mobility control and conformance. Unlike the relatively inefficient, traditional EOR polymers, these advanced polymer systems possess microstructural features responsive to temperature, electrolyte concentration, and shear conditions. Contents of this report include the following chapters. (1) First annual report responsive copolymers for enhanced oil recovery. (2) Copolymers of acrylamide and sodium 3-acrylamido-3-methylbutanoate. (3) Terpolymers of NaAMB, Am, and n-decylacrylamide. (4) Synthesis and characterization of electrolyte responsive terpolymers of acrylamide, N-(4-butyl)phenylacrylamide, and sodium acrylate, sodium-2-acrylamido-2-methylpropanesulphonate or sodium-3-acrylamido-3-methylbutanoate. (5) Synthesis and solution properties of associative acrylamido copolymers with pyrensulfonamide fluorescence labels. (6) Photophysical studies of the solution behavior of associative pyrenesulfonamide-labeled polyacrylamides. (7) Ampholytic copolymers of sodium 2-(acrylamido)-2-methylpropanesulfonate with [2-(acrylamido)-2-methypropyl]trimethylammonium chloride. (8) Ampholytic terpolymers of acrylamide with sodium 2-acrylamido-2-methylpropanesulphoante and 2-acrylamido-2-methylpropanetrimethyl-ammonium chloride and (9) Polymer solution extensional behavior in porous media.

  8. Epoxy-crosslinked sulfonated poly (phenylene) copolymer proton exchange membranes

    Science.gov (United States)

    Hibbs, Michael; Fujimoto, Cy H.; Norman, Kirsten; Hickner, Michael A.

    2010-10-19

    An epoxy-crosslinked sulfonated poly(phenylene) copolymer composition used as proton exchange membranes, methods of making the same, and their use as proton exchange membranes (PEM) in hydrogen fuel cells, direct methanol fuel cell, in electrode casting solutions and electrodes, and in sulfur dioxide electrolyzers. These improved membranes are tougher, have higher temperature capability, and lower SO.sub.2 crossover rates.

  9. Dispersion characteristics of nanocomposites based on functionalized block copolymers

    Science.gov (United States)

    Ke, Linping

    The dispersion characteristics of organoclay nanocomposites based on functionalized block copolymers have been investigated. For the investigation, polystyrene-block-polybutadiene (SB diblock) copolymers synthesized via anionic polymerization were first hydroxylated via hydroboration/oxidation to obtain polystyrene-block-hydroxylated polybutadiene (SBOH diblock) copolymers. Then, the SBOH diblock copolymer was attached with pyridine, pyrimidine, terpyridine, or terpyridine-Ruthenium (Ru) complex functional groups to obtain SB-pyridine, SB-pyrimidine, SB-terpyridine (SB-Terpy), and SB-Terpy-Ru complex diblock copolymers. Subsequently, each of these functionalized block copolymers was used to prepare, via solution blending, organoclay nanocomposites, for which natural clay (montmorillonite, MMT) and two commercial organoclays (Cloisite 30B and Cloisite 15A) were employed. The dispersion characteristics of the organoclay nanocomposites were investigated using X-ray diffraction (XRD), transmission electron microscopy (TEM), and oscillatory rheometry (OR). We have made the following observations. The SBOH/Cloisite 30B nanocomposite had a very high degree of dispersion of Cloisite 30B aggregates, whereas the SBOH/Cloisite 15A and SBOH/MMT nanocomposites had a very low degree of dispersion of the aggregates of Cloisite 15A or MMT. In situ Fourier transform infrared (FTIR) spectroscopy has revealed that hydrogen bonds were formed between the hydroxyl groups in the SBOH diblock copolymer and the surfactant residing at the surface of Cloisite 30B in the former nanocomposite, yielding a very high degree of dispersion of Cloisite 30B aggregates, while no hydrogen bonds were formed in the latter two nanocomposites. The (SB-pyridine)/Cloisite 30B nanocomposite had intercalation of aggregates of Cloisite 30B, while the (SB-pyridine)/Cloisite 15A and (SB-pyridine)/MMT nanocomposites had a very low degree of dispersion of the aggregates of Cloisite 15A or MMT in the SB

  10. Incorporating different vegetable oils into an aqueous dispersion of hybrid organic nanoparticles

    Science.gov (United States)

    Samyn, Pieter; Schoukens, Gustaaf; Stanssens, Dirk; Vonck, Leo; Van den Abbeele, Henk

    2012-08-01

    Different vegetable oils including soy oil, high-oleic sunflower oil, corn oil, castor oil (CO), rapeseed oil, and hydrogenated CO were added to the imidization reaction of poly(styrene-maleic anhydride) or SMA, with ammonium hydroxide in aqueous medium. The oils favorably reduce viscosity during ammonolysis of the anhydride moieties and increase the maximum solid content of the dispersed imidized SMA to at least 50 wt%, compared to a maximum of 35 wt% for pure imidized SMA. The viscosity of imidized SMA with polyunsaturated oils was generally larger than for monosaturated oils, but it was highest for COs due to high contents of hydroxyl groups. Depending on the oil reactivity, homogeneous or core-shell nanoparticles with 20-60 nm diameters formed. The interactions of oil and organic phase were studied by Fourier-transform infrared spectroscopy, indicating qualitative variances between different oils, the fraction imidized SMA and remaining fraction of ammonolyzed SMA without leakage of oil upon diluting the dispersion and precipitation at low pH. A quantitative analysis with calculation of imide contents, amounts of reacted oil and chemical interactions was made by Fourier-transform-Raman spectroscopy suggesting that most interactions take place around the unsaturated oil moieties and ammonolyzed anhydride.

  11. Incorporating different vegetable oils into an aqueous dispersion of hybrid organic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Samyn, Pieter, E-mail: Pieter.Samyn@fobawi.uni-freiburg.de [Albert-Luedwigs-University Freiburg, Institute for Forest Utilization (Germany); Schoukens, Gustaaf [Ghent University, Department of Textiles (Belgium); Stanssens, Dirk; Vonck, Leo; Van den Abbeele, Henk [Topchim N.V. (Belgium)

    2012-08-15

    Different vegetable oils including soy oil, high-oleic sunflower oil, corn oil, castor oil (CO), rapeseed oil, and hydrogenated CO were added to the imidization reaction of poly(styrene-maleic anhydride) or SMA, with ammonium hydroxide in aqueous medium. The oils favorably reduce viscosity during ammonolysis of the anhydride moieties and increase the maximum solid content of the dispersed imidized SMA to at least 50 wt%, compared to a maximum of 35 wt% for pure imidized SMA. The viscosity of imidized SMA with polyunsaturated oils was generally larger than for monosaturated oils, but it was highest for COs due to high contents of hydroxyl groups. Depending on the oil reactivity, homogeneous or core-shell nanoparticles with 20-60 nm diameters formed. The interactions of oil and organic phase were studied by Fourier-transform infrared spectroscopy, indicating qualitative variances between different oils, the fraction imidized SMA and remaining fraction of ammonolyzed SMA without leakage of oil upon diluting the dispersion and precipitation at low pH. A quantitative analysis with calculation of imide contents, amounts of reacted oil and chemical interactions was made by Fourier-transform-Raman spectroscopy suggesting that most interactions take place around the unsaturated oil moieties and ammonolyzed anhydride.

  12. Modification of pineapple peel fiber as metal ion adsorbent through reaction with succinic anhydride in pyridine and dimethyl sulfoxide solvents.

    Science.gov (United States)

    Hu, Xiuyi; Zhao, Mouming; Huang, Huihua

    2010-08-01

    Reactions between saponified pineapple peel fiber (SPPF) and succinic anhydride were performed in refluxed pyridine and dimethyl sulfoxide to obtain modified pineapple peel fiber in pyridine (MPPF-PY) and modified pineapple peel fiber in dimethyl sulfoxide at room temperature (MPPF-DMRT) and at 70 degrees C (MPPF-DM70) as novel metal ionic adsorbents. The modified pineapple peel fibers were characterized by Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The MPPF-PY, MPPF-DMRT, and MPPF-DM70 showed higher Cu2+, Cd2+, and Pb2+ adsorption capacity than raw pineapple peel fiber (RPPF) and SPPF. Dimethyl sulfoxide favored introduction of a carboxylic function group into pineapple peel fiber compared with pyridine. The elevated reaction temperature of dimethyl sulfoxide could increase the adsorption capacity of the modified pineapple fiber. Optimum pH values for Cu2+, Cd2+, and Pb2+ removal by MPPF-DM70 were pH 5.5, 7.5, and 5.5, respectively. The Cu2+, Cd2+, and Pb2+ adsorptions by MPPF-DM70 followed the pseudo second-order kinetics model and Langmuir model.

  13. Development of a guided bone regeneration device using salicylic acid-poly(anhydride-ester) polymers and osteoconductive scaffolds.

    Science.gov (United States)

    Mitchell, Ashley; Kim, Brian; Cottrell, Jessica; Snyder, Sabrina; Witek, Lukasz; Ricci, John; Uhrich, Kathryn E; O'Connor, J Patrick

    2014-03-01

    Successful repair of craniofacial and periodontal tissue defects ideally involves a combined therapy that includes inflammation modulation, control of soft tissue infiltration, and bone regeneration. In this study, an anti-inflammatory polymer, salicylic acid-based poly(anhydride-ester) (SAPAE) and a three-dimensional osteoconductive ceramic scaffold were evaluated as a combined guided bone regeneration (GBR) system for concurrent control of inflammation, soft tissue ingrowth, and bone repair in a rabbit cranial defect model. At time periods of 1, 3, and 8 weeks, five groups were compared: (1) scaffolds with a solid ceramic cap (as a GBR structure); (2) scaffolds with no cap; (3) scaffolds with a poly(lactide-glycolide) cap; (4) scaffolds with a slow release SAPAE polymer cap; and (5) scaffolds with a fast release SAPAE polymer cap. Cellular infiltration and bone formation in these scaffolds were evaluated to assess inflammation and bone repair capacity of the test groups. The SAPAE polymers suppressed inflammation and displayed no deleterious effect on bone formation. Additional work is warranted to optimize the anti-inflammatory action of the SAPAE, GBR suppression of soft tissue infiltration, and stimulation of bone formation in the scaffolds and create a composite device for successful repair of craniofacial and periodontal tissue defects. Copyright © 2013 Wiley Periodicals, Inc.

  14. Preparation of High Density Polyethylene/Waste Polyurethane Blends Compatibilized with Polyethylene-Graft-Maleic Anhydride by Radiation

    Directory of Open Access Journals (Sweden)

    Jong-Seok Park

    2015-04-01

    Full Text Available Polyurethane (PU is a very popular polymer that is used in a variety of applications due to its good mechanical, thermal, and chemical properties. However, PU recycling has received significant attention due to environmental issues. In this study, we developed a recycling method for waste PU that utilizes the radiation grafting technique. Grafting of waste PU was carried out using a radiation technique with polyethylene-graft-maleic anhydride (PE-g-MA. The PE-g-MA-grafted PU/high density polyethylene (HDPE composite was prepared by melt-blending at various concentrations (0–10 phr of PE-g-MA-grafted PU. The composites were characterized using fourier transform infrared spectroscopy (FT-IR, and their surface morphology and thermal/mechanical properties are reported. For 1 phr PU, the PU could be easily introduced to the HDPE during the melt processing in the blender after the radiation-induced grafting of PU with PE-g-MA. PE-g-MA was easily reacted with PU according to the increasing radiation dose and was located at the interface between the PU and the HDPE during the melt processing in the blender, which improved the interfacial interactions and the mechanical properties of the resultant composites. However, the elongation at break for a PU content >2 phr was drastically decreased.

  15. Slow digestion property of octenyl succinic anhydride modified waxy maize starch in the presence of tea polyphenols.

    Science.gov (United States)

    Peng, Shanli; Xue, Lei; Leng, Xue; Yang, Ruobing; Zhang, Genyi; Hamaker, Bruce R

    2015-03-18

    The in vivo slow digestion property of octenyl succinic anhydride modified waxy corn starch (OSA-starch) in the presence of tea polyphenols (TPLs) was studied. Using a mouse model, the experimental results showed an extended and moderate postprandial glycemic response with a delayed and significantly decreased blood glucose peak of OSA-starch after cocooking with TPLs (5% starch weight base). Further studies revealed an increased hydrodynamic radius of OSA-starch molecules indicating an interaction between OSA-starch and TPLs. Additionally, decreased gelatinization temperature and enthalpy and reduced viscosity and emulsifiability of OSA-starch support their possible complexation to form a spherical OSA-starch-TPLs (OSAT) complex. The moderate and extended postprandial glycemic response is likely caused by decreased activity of mucosal α-glucosidase, which is noncompetitively inhibited by tea catechins released from the complex during digestion. Meanwhile, a significant decrease of malondialdehyde (MDA) and increased DPPH free radical scavenging activity in small intestine tissue demonstrated the antioxidative functional property of the OSAT complex. Thus, the complex of OSAT, acting as a functional carbohydrate material, not only leads to a flattened and prolonged glycemic response but also reduces the oxidative stress, which might be beneficial to health.

  16. A 3-week dietary safety study of octenyl succinic anhydride (OSA)-modified starch in neonatal farm piglets.

    Science.gov (United States)

    Mahadevan, Brinda; Thorsrud, Bjorn A; Brorby, Gregory P; Ferguson, Heather E

    2014-10-01

    Octenyl succinic anhydride (OSA)-modified starch functions as both an emulsifier and emulsion stabilizer in foods, and is intended for use in infant formula, follow-on formula, and formulae for special medical purposes. These formulae predominantly include extensively hydrolyzed protein or free amino acids, rather than intact protein, which otherwise would provide emulsifying functionality. The study objectives were to evaluate (1) the safety of OSA-modified starch after three weeks of administration to neonatal farm piglets, beginning 2 days after birth and (2) the impact of OSA-modified starch on piglet growth. OSA-modified starch was added to formula at concentrations of 2, 4, and 20 g/L. The vehicle control, low-dose, and mid-dose diets were supplemented with Amioca™ Powder to balance the nutritional profiles of all formulations. There were no test article-related effects of any diet containing OSA-modified starch on piglet growth and development (clinical observations, body weight, feed consumption), or clinical pathology parameters (hematology, clinical chemistry, coagulation, urinalysis). In addition, there were no adverse effects at terminal necropsy (macro- and microscopic pathology evaluations). Therefore, dietary exposure to OSA-modified starch at concentrations up to 20 g/L was well tolerated by neonatal farm piglets and did not result in adverse health effects or impact piglet growth. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Intranasal Administration of Maleic Anhydride-Modified Human Serum Albumin for Pre-Exposure Prophylaxis of Respiratory Syncytial Virus Infection

    Directory of Open Access Journals (Sweden)

    Zhiwu Sun

    2015-02-01

    Full Text Available Respiratory syncytial virus (RSV is the leading cause of pediatric viral respiratory tract infections. Neither vaccine nor effective antiviral therapy is available to prevent and treat RSV infection. Palivizumab, a humanized monoclonal antibody, is the only product approved to prevent serious RSV infection, but its high cost is prohibitive in low-income countries. Here, we aimed to identify an effective, safe, and affordable antiviral agent for pre-exposure prophylaxis (PrEP of RSV infection in children at high risk. We found that maleic anhydride (ML-modified human serum albumin (HSA, designated ML-HSA, exhibited potent antiviral activity against RSV and that the percentages of the modified lysines and arginies in ML- are correlated with such anti-RSV activity. ML-HSA inhibited RSV entry and replication by interacting with viral G protein and blocking RSV attachment to the target cells, while ML-HAS neither bound to F protein, nor inhibited F protein-mediated membrane fusion. Intranasal administration of ML-HSA before RSV infection resulted in significant decrease of the viral titers in the lungs of mice. ML-HSA shows promise for further development into an effective, safe, affordable, and easy-to-use intranasal regimen for pre-exposure prophylaxis of RSV infection in children at high risk in both low- and high-income countries.

  18. Separator Membrane from Crosslinked Poly(Vinyl Alcohol and Poly(Methyl Vinyl Ether-alt-Maleic Anhydride

    Directory of Open Access Journals (Sweden)

    Charu Vashisth Rohatgi

    2015-03-01

    Full Text Available In this work, we report separator membranes from crosslinking of two polymers, such as poly vinyl alcohol (PVA with an ionic polymer poly(methyl vinyl ether-alt-maleic anhydride (PMVE-MA. Such interpolymer-networked systems were extensively used for biomedical and desalination applications but they were not examined for their potential use as membranes or separators for batteries. Therefore, the chemical interactions between these two polymers and the influence of such crosslinking on physicochemical properties of the membrane are systematically investigated through rheology and by critical gel point study. The hydrogen bonding and the chemical interaction between PMVE-MA and PVA resulted in highly cross-linked membranes. Effect of the molecular weight of PVA on the membrane properties was also examined. The developed membranes were extensively characterized by studying their physicochemical properties (water uptake, swelling ratio, and conductivity, thermal and electrochemical properties using differential scanning calorimetry (DSC, dynamic mechanical analysis (DMA, thermo-gravimetric analysis (TGA and electrochemical impedance spectroscopy (EIS. The DSC study shows the presence of a single Tg in the membranes indicating compatibility of the two polymers in flexible and transparent films. The membranes show good stability and ion conductivity suitable for separator applications.

  19. Micelles Formed by Polypeptide Containing Polymers Synthesized Via N-Carboxy Anhydrides and Their Application for Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Dimitrios Skoulas

    2017-06-01

    Full Text Available The development of multifunctional polymeric materials for biological applications is mainly guided by the goal of achieving the encapsulation of pharmaceutical compounds through a self-assembly process to form nanoconstructs that control the biodistribution of the active compounds, and therefore minimize systemic side effects. Micelles are formed from amphiphilic polymers in a selective solvent. In biological applications, micelles are formed in water, and their cores are loaded with hydrophobic pharmaceutics, where they are solubilized and are usually delivered through the blood compartment. Even though a large number of polymeric materials that form nanocarrier delivery systems has been investigated, a surprisingly small subset of these technologies has demonstrated potentially curative preclinical results, and fewer have progressed towards commercialization. One of the most promising classes of polymeric materials for drug delivery applications is polypeptides, which combine the properties of the conventional polymers with the 3D structure of natural proteins, i.e., α-helices and β-sheets. In this article, the synthetic pathways followed to develop well-defined polymeric micelles based on polypeptides prepared through ring-opening polymerization (ROP of N-carboxy anhydrides are reviewed. Among these works, we focus on studies performed on micellar delivery systems to treat cancer. The review is limited to systems presented from 2000–2017.

  20. Anhydride-functional silane immobilized onto titanium surfaces induces osteoblast cell differentiation and reduces bacterial adhesion and biofilm formation.

    Science.gov (United States)

    Godoy-Gallardo, Maria; Guillem-Marti, Jordi; Sevilla, Pablo; Manero, José M; Gil, Francisco J; Rodriguez, Daniel

    2016-02-01

    Bacterial infection in dental implants along with osseointegration failure usually leads to loss of the device. Bioactive molecules with antibacterial properties can be attached to titanium surfaces with anchoring molecules such as silanes, preventing biofilm formation and improving osseointegration. Properties of silanes as molecular binders have been thoroughly studied, but research on the biological effects of these coatings is scarce. The aim of the present study was to determine the in vitro cell response and antibacterial effects of triethoxysilypropyl succinic anhydride (TESPSA) silane anchored on titanium surfaces. X-ray photoelectron spectroscopy confirmed a successful silanization. The silanized surfaces showed no cytotoxic effects. Gene expression analyses of Sarcoma Osteogenic (SaOS-2) osteoblast-like cells cultured on TESPSA silanized surfaces reported a remarkable increase of biochemical markers related to induction of osteoblastic cell differentiation. A manifest decrease of bacterial adhesion and biofilm formation at early stages was observed on treated substrates, while favoring cell adhesion and spreading in bacteria-cell co-cultures. Surfaces treated with TESPSA could enhance a biological sealing on implant surfaces against bacteria colonization of underlying tissues. Furthermore, it can be an effective anchoring platform of biomolecules on titanium surfaces with improved osteoblastic differentiation and antibacterial properties. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Insight into the informational-structure behavior of the Diels-Alder reaction of cyclopentadiene and maleic anhydride.

    Science.gov (United States)

    Molina-Espíritu, Moyocoyani; Esquivel, Rodolfo O; Kohout, Miroslav; Angulo, Juan Carlos; Dobado, José A; Dehesa, Jesús S; LópezRosa, Sheila; Soriano-Correa, Catalina

    2014-08-01

    The course of the Diels-Alder reactions of cyclopentadiene and maleic anhydride were studied. Two reaction paths were modelled: endo- and exo-selective paths. All structures within the transient region were characterized and analyzed by means of geometrical descriptors, physicochemical parameters and information-theoretical measures in order to observe the linkage between chemical behavior and the carriage of information. We have shown that the information-theoretical characterization of the chemical course of the reaction is in complete agreement with its phenomenological behavior in passing from reactants to products. In addition, we were able to detect the main differences between the two reaction mechanisms. This type of informational analysis serves to provide tools to help understand the chemical reactivity of the two simplest Diels-Alder reactions, which permits the establishment of a connection between the quantum changes that molecular systems exert along reaction coordinates and standard physicochemical phenomenology. In the present study, we have shown that every reaction stage has a family of subsequent structures that are characterized not solely by their phenomenological behavior but also by informational properties of their electronic density distribution (localizability, order, uniformity). Moreover, we were able to describe the main differences between endo-adduct and exo-adduct pathways. With the advent of new experimental techniques, it is in principle possible to observe the structural changes in the transient regions of chemical reactions. Indeed, through this work we have provided the theoretical concepts needed to unveil the concurrent processes associated with chemical reactions.

  2. Preparation of a Sepia Melanin and Poly(ethylene-alt-maleic Anhydride Hybrid Material as an Adsorbent for Water Purification

    Directory of Open Access Journals (Sweden)

    Guido Panzarasa

    2018-01-01

    Full Text Available Meeting the increasing demand of clean water requires the development of novel efficient adsorbent materials for the removal of organic pollutants. In this context the use of natural, renewable sources is of special relevance and sepia melanin, thanks to its ability to bind a variety of organic and inorganic species, has already attracted interest for water purification. Here we describe the synthesis of a material obtained by the combination of sepia melanin and poly(ethylene-alt-maleic anhydride (P(E-alt-MA. Compared to sepia melanin, the resulting hybrid displays a high and fast adsorption efficiency towards methylene blue (a common industrial dye for a wide pH range (from pH 2 to 12 and under high ionic strength conditions. It is easily recovered after use and can be reused up to three times. Given the wide availability of sepia melanin and P(E-alt-MA, the synthesis of our hybrid is simple and affordable, making it suitable for industrial water purification purposes.

  3. Preparation of a Sepia Melanin and Poly(ethylene-alt-maleic Anhydride) Hybrid Material as an Adsorbent for Water Purification.

    Science.gov (United States)

    Panzarasa, Guido; Osypova, Alina; Consolati, Giovanni; Quasso, Fiorenza; Soliveri, Guido; Ribera, Javier; Schwarze, Francis W M R

    2018-01-23

    Meeting the increasing demand of clean water requires the development of novel efficient adsorbent materials for the removal of organic pollutants. In this context the use of natural, renewable sources is of special relevance and sepia melanin, thanks to its ability to bind a variety of organic and inorganic species, has already attracted interest for water purification. Here we describe the synthesis of a material obtained by the combination of sepia melanin and poly(ethylene- alt -maleic anhydride) (P(E- alt -MA)). Compared to sepia melanin, the resulting hybrid displays a high and fast adsorption efficiency towards methylene blue (a common industrial dye) for a wide pH range (from pH 2 to 12) and under high ionic strength conditions. It is easily recovered after use and can be reused up to three times. Given the wide availability of sepia melanin and P(E- alt -MA), the synthesis of our hybrid is simple and affordable, making it suitable for industrial water purification purposes.

  4. Molecular Orientation and Structural Transformations in Phthalic Anhydride Thin Films on MgO(100)/Ag(100).

    Science.gov (United States)

    Mohr, Susanne; Xu, Tao; Döpper, Tibor; Laurin, Mathias; Görling, Andreas; Libuda, Jörg

    2015-07-21

    Structural control of organic thin films on dielectric substrates is the key to tailoring the physical properties of hybrid materials, for example, for application in solar energy conversion, molecular electronics, or catalysis. In this work, we investigate the molecular orientation of phthalic anhydride (PAA) films on atomically well-defined MgO(100) on Ag(100) using temperature-programmed infrared reflection absorption spectroscopy (TP-IRAS) in combination with density-functional theory (DFT). A robust procedure is presented to determine the orientation of the PAA molecules, which relies on the intensity ratios of vibrational bands only. We show that even at deposition temperatures of 110 K, the PAA multilayer grows with a specific molecular orientation; that is, the PAA molecular plane is preferentially aligned parallel with the MgO surface. No change of molecular orientation occurs up to a temperature of 145 K. Between 145 and 160 K, the film restructures adopting a nearly flat-lying molecular orientation. Between 170 and 205 K, the film undergoes a second structural transition to a crystalline phase. This transition is associated with a pronounced molecular reorientation. The molecules adopt a tilted orientation and, simultaneously, rotate around their C2 axes. The reorientation behavior suggests that the molecular orientation in the crystalline phase is controlled by the interaction with the MgO(100) substrate. At higher temperature, no further restructuring is observed until the PAA multilayer desorbs at temperatures above 230 K.

  5. Diosgenin effectively suppresses skin inflammation induced by phthalic anhydride in IL-4/Luc/CNS-1 transgenic mice.

    Science.gov (United States)

    Kim, Ji Eun; Go, Jun; Koh, Eun Kyoung; Song, Sung Hwa; Sung, Ji Eun; Lee, Hyun Ah; Kim, Dong Seob; Son, Hong Joo; Lee, Hee Seob; Lee, Chung Yeoul; Hong, Jin Tae; Hwang, Dae Youn

    2016-05-01

    To quantitatively evaluate the therapeutic effects of diosgenin (DG) and investigate the role of IL-4 on skin inflammation, alterations in luciferase-derived signal and general phenotype biomarkers were measured in IL-4/Luc/CNS-1 transgenic mice with phthalic anhydride (PA)-induced skin inflammation after treatment with DG for 4 weeks. High levels of luciferase-derived signal detected in the abdominal region and submandibular lymph node (SL) of the PA treated group was significantly decreased by 67-88% in the PA + DG cotreated group. Furthermore, the weight of the lymph node and spleen, IgE concentration, epidermis thickness, and number of infiltrated mast cells were lower in the PA + DG treated group than the PA + Vehicle treated group. Moreover, expression of IL-6 and vascular endothelial growth factor (VEGF) also decreased in the PA + DG cotreated group. These results suggest that PA-induced skin inflammation could be successfully suppressed by DG treatment in IL-4/Luc/CNS-1 Tg mice through attenuation of IL-4 and IL-6 expression, as well as decreased IgE concentration and mast cells infiltration.

  6. Rapid microwaves synthesis of CoSix/CNTs as novel catalytic materials for hydrogenation of phthalic anhydride

    Science.gov (United States)

    Zhang, Liangliang; Chen, Xiao; Jin, Shaohua; Guan, Jingchao; Williams, Christopher T.; Peng, Zhijian; Liang, Changhai

    2014-09-01

    CoSix/CNTs catalysts with different CoSix phases (CoSi, CoSi2) have been rapidly synthesized via a microwave-assisted route and applied for the liquid phase hydrogenation of phthalic anhydride. The synthesized catalysts were analyzed and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy-energy dispersive X-ray spectroscopy, thermogravimetric/derivative thermogravimetric analysis. The reaction progress of cobalt silicides and the ratio of Co:Si were monitored at different microwave irradiation times by XRD, giving insight into the formation mechanism. Compared to the Co/CNTs catalyst, all the prepared CoSix/CNTs catalysts exhibited excellent activity and good selectivity to phthalide under mild reaction conditions (180-220 °C and 4.0 MPa H2). This novel methodology can be applied to the synthesis of other transition metal silicides such as FeSi, Ni2Si, and Cu4Si.

  7. Using monosaccharide anhydrides to estimate the impact of wood combustion on fine particles in the Helsinki Metropolitan Area

    Energy Technology Data Exchange (ETDEWEB)

    Saarnio, K.; Saarikoski, S. [Finnish Meteorological Institute, Helsinki (Finland); Niemi, J.V. [HSY Helsinki Region Environmental Services Authority, Helsinki (Finland)

    2012-11-01

    The spatiotemporal variation of ambient particles under the influence of biomass burning emissions was studied in the Helsinki Metropolitan Area (HMA) in selected periods during 2005-2009. Monosaccharide anhydrides (MAs; levoglucosan, mannosan and galactosan), commonly known biomass burning tracers, were used to estimate the wood combustion contribution to local particulate matter (PM) concentration levels at three urban background sites close to the city centre, and at three suburban sites influenced by local small-scale wood combustion. In the cold season (October-March), the mean MAs concentrations were 115-225 ng m{sup -3} and 83-98 ng m{sup -} {sup 3}at the suburban and urban sites, respectively. In the warm season, the mean MAs concentrations were low (19-78 ng m{sup -3}), excluding open land fire smoke episodes (222-378 ng m{sup -}3{sup )}. Regionally distributed wood combustion particles raised the levels over the whole HMA while particles from local wood combustion sources raised the level at suburban sites only. The estimated average contribution of wood combustion to fine particles (PM{sub 2.5}) ranged from 18% to 29% at the urban sites and from 31% to 66% at the suburban sites in the cold season. The PM measurements from ambient air and combustion experiments showed that the proportions of the three MAs can be utilised to separate the wildfire particles from residential wood combustion particles. (orig.)

  8. Anhydride-functional silane immobilized onto titanium surfaces induces osteoblast cell differentiation and reduces bacterial adhesion and biofilm formation

    Energy Technology Data Exchange (ETDEWEB)

    Godoy-Gallardo, Maria, E-mail: maria.godoy.gallardo@upc.edu [Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgy, Technical University of Catalonia (UPC), ETSEIB, Av. Diagonal 647, 08028 Barcelona (Spain); Centre for Research in NanoEngineering (CRNE) — UPC, C/ Pascual i Vila 15, 08028 Barcelona (Spain); Guillem-Marti, Jordi, E-mail: jordi.guillem.marti@upc.edu [Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgy, Technical University of Catalonia (UPC), ETSEIB, Av. Diagonal 647, 08028 Barcelona (Spain); Centre for Research in NanoEngineering (CRNE) — UPC, C/ Pascual i Vila 15, 08028 Barcelona (Spain); Sevilla, Pablo, E-mail: psevilla@euss.es [Department of Mechanics, Escola Universitària Salesiana de Sarrià (EUSS), C/ Passeig de Sant Bosco, 42, 08017 Barcelona (Spain); Manero, José M., E-mail: jose.maria.manero@upc.edu [Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgy, Technical University of Catalonia (UPC), ETSEIB, Av. Diagonal 647, 08028 Barcelona (Spain); Centre for Research in NanoEngineering (CRNE) — UPC, C/ Pascual i Vila 15, 08028 Barcelona (Spain); Gil, Francisco J., E-mail: francesc.xavier.gil@upc.edu [Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Metallurgy, Technical University of Catalonia (UPC), ETSEIB, Av. Diagonal 647, 08028 Barcelona (Spain); Centre for Research in NanoEngineering (CRNE) — UPC, C/ Pascual i Vila 15, 08028 Barcelona (Spain); and others

    2016-02-01

    Bacterial infection in dental implants along with osseointegration failure usually leads to loss of the device. Bioactive molecules with antibacterial properties can be attached to titanium surfaces with anchoring molecules such as silanes, preventing biofilm formation and improving osseointegration. Properties of silanes as molecular binders have been thoroughly studied, but research on the biological effects of these coatings is scarce. The aim of the present study was to determine the in vitro cell response and antibacterial effects of triethoxysilypropyl succinic anhydride (TESPSA) silane anchored on titanium surfaces. X-ray photoelectron spectroscopy confirmed a successful silanization. The silanized surfaces showed no cytotoxic effects. Gene expression analyses of Sarcoma Osteogenic (SaOS-2) osteoblast-like cells cultured on TESPSA silanized surfaces reported a remarkable increase of biochemical markers related to induction of osteoblastic cell differentiation. A manifest decrease of bacterial adhesion and biofilm formation at early stages was observed on treated substrates, while favoring cell adhesion and spreading in bacteria–cell co-cultures. Surfaces treated with TESPSA could enhance a biological sealing on implant surfaces against bacteria colonization of underlying tissues. Furthermore, it can be an effective anchoring platform of biomolecules on titanium surfaces with improved osteoblastic differentiation and antibacterial properties. - Highlights: • TESPSA silane induces osteoblast differentiation. • TESPSA reduces bacterial adhesion and biofilm formation. • TESPSA is a promising anchoring platform of biomolecules onto titanium.

  9. Microencapsulation of white champaca (Michelia alba D.C.) extract using octenyl succinic anhydride (OSA) starch for controlled release aroma.

    Science.gov (United States)

    Samakradhamrongthai, Rajnibhas; Thakeow, Prodpran; Kopermsub, Phikunthong; Utama-Ang, Niramon

    2016-12-01

    The objective of the study was to optimise the encapsulation of Michelia alba D.C. (MAD) extract using octenyl succinic anhydride (OSA) starch. The MAD extract (5-10 g/100 g of dry starch) and the OSA starch (25-100 g/100 ml of water) was used in microcapsule preparation and analysed for the physicochemical and encapsulation properties. The optimised formula using the MAD extract and the OSA starch were 15.00 g/100 g of dry starch and 96.32 g/100 g water, which provided the highest in yield recovery (40.65% ± 0.99) and encapsulation efficiency (68.91% ± 1.50), with the lowest moisture content (3.19% ± 0.06) and water activity (0.236 ± 0.004). The aroma release from the optimum encapsulated powder in simulated artificial saliva fluid (SSF) suggested that linalool retention in microcapsules was higher than verbenone and 2-methyl butanoic acid. This study shows that the optimised formulation of MAD encapsulated flavour powder was found to be effective for controlling the aroma release.

  10. Dynamic photoinduced realignment processes in photoresponsive block copolymer films: effects of the chain length and block copolymer architecture.

    Science.gov (United States)

    Sano, Masami; Shan, Feng; Hara, Mitsuo; Nagano, Shusaku; Shinohara, Yuya; Amemiya, Yoshiyuki; Seki, Takahiro

    2015-08-07

    A series of block copolymers composed of an amorphous poly(butyl methacrylate) (PBMA) block connected with an azobenzene (Az)-containing liquid crystalline (PAz) block were synthesized by changing the chain length and polymer architecture. With these block copolymer films, the dynamic realignment process of microphase separated (MPS) cylinder arrays of PBMA in the PAz matrix induced by irradiation with linearly polarized light was studied by UV-visible absorption spectroscopy, and time-resolved grazing incidence small angle X-ray scattering (GI-SAXS) measurements using a synchrotron beam. Unexpectedly, the change in the chain length hardly affected the realignment rate. In contrast, the architecture of the AB-type diblock or the ABA-type triblock essentially altered the realignment feature. The strongly cooperative motion with an induction period before realignment was characteristic only for the diblock copolymer series, and the LPL-induced alignment change immediately started for triblock copolymers and the PAz homopolymer. Additionally, a marked acceleration in the photoinduced dynamic motions was unveiled in comparison with a thermal randomization process.

  11. Temperature-dependent optical properties of gold nanoparticles coated with a charged diblock copolymer and an uncharged triblock copolymer.

    Science.gov (United States)

    Volden, Sondre; Kjøniksen, Anna-Lena; Zhu, Kaizheng; Genzer, Jan; Nyström, Bo; Glomm, Wilhelm R

    2010-02-23

    We demonstrate that the optical properties of gold nanoparticles can be used to detect and follow stimuli-induced changes in adsorbed macromolecules. Specifically, we investigate thermal response of anionic diblock and uncharged triblock copolymers based on poly(N-isopropylacrylamide) (PNIPAAM) blocks adsorbed onto gold nanoparticles and planar gold surfaces in a temperature range between 25 and 60 degrees C. By employing a palette of analytical probes, including UV-visible spectroscopy, dynamic light scattering, fluorescence, and quartz crystal microbalance with dissipation monitoring, we establish that while the anionic copolymer forms monolayers at both low and high temperature, the neutral copolymer adsorbs as a monolayer at low temperatures and forms multilayers above the cloud point (T(C)). Raising the temperature above T(C) severely affects the optical properties of the gold particle/polymer composites, expelling associated water and altering the immediate surroundings of the gold nanoparticles. This effect, stronger for the uncharged polymer, is related to the amount of polymer adsorbed on the surface, where a denser shell influences the surface plasmon band to a greater degree. This is corroborated with light scattering experiments, which reveal that flocculation of the neutral polymer-coated particles occurs at high temperatures. The flocculation behavior of the neutral copolymer on planar gold surfaces results in multilayer formation. The observed effects are discussed within the framework of the Mie-Drude theory.

  12. Electrochemical behavior and conductivity measurements of electropolymerized selenophene-based copolymers

    Directory of Open Access Journals (Sweden)

    Alakhras Fadi

    2015-03-01

    Full Text Available Electrochemical copolymerization of selenophene and thiophene was performed at a constant electrode potential. The obtained homopolymer films and copolymers were studied and characterized with cyclic voltammetry and conductivity measurements, from which conductivity values around 13.35 S · cm-1 were determined. The influence of the applied electropolymerization potential and the monomer feed ratio of selenophene and thiophene on the copolymers properties was investigated. The obtained copolymers showed good stability of the redox activity in an acetonitrile-based electrolyte solution. At higher polymerization potentials and at higher concentrations of thiophene in the feed, more thiophene units were incorporated into the copolymer chain. The conductivities of the copolymers were between those of homopolymers, implying that oxidation of both monomers was possible and the copolymer chains might accordingly be composed of both selenophene and thiophene units.

  13. Effect of ionic surfactant on the self-assembly of triblock copolymer

    Science.gov (United States)

    Ray, D.; Kohlbrecher, J.; Aswal, V. K.

    2017-05-01

    The effect of anionic surfactant sodium dodecyl sulfate (SDS) on the self-assembly of PEO-PPO-PEO triblock copolymer in aqueous solution has been studied using small-angle neutron scattering (SANS). The measurements have been carried out for fixed concentrations (1 wt%) of block copolymer and surfactant, and at varying temperatures between 20 to 80°C. Micelles of pure ionic surfactants show little change in their sizes with increasing temperature, whereas structures of the non-ionic micelles increase significantly (sphere-to-rod transition for some block copolymers). Contrast variation SANS measurement suggests addition of SDS to aqueous copolymer solutions leads to the formation of mixed micelles. Interestingly, the self-assembly of block copolymer is found to get completely arrested by the ionic surfactant in the mixed micelles which gives a control over the block copolymer phase behavior.

  14. Recent Advances in Dual Temperature Responsive Block Copolymers and Their Potential as Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Yohei Kotsuchibashi

    2016-10-01

    Full Text Available The development of stimuli responsive polymers has progressed significantly with novel preparation techniques, which has allowed access to new materials with unique properties. Dual thermoresponsive (double temperature responsive block copolymers are particularly of interest as their properties can change depending on the lower critical solution temperature (LCST or upper critical solution temperature (UCST of each segment. For instance, these block copolymers can change from being hydrophilic, to amphiphilic or to hydrophobic simply by changing the solution temperature without any additional chemicals and the block copolymers can change from being fully solubilized to self-assembled structures to macroscopic aggregation/precipitation. Based on the unique solution properties, these dual thermo-responsive block copolymers are expected to be suitable for biomedical applications. This review is divided into three parts; LCST-LCST types of block copolymers, UCST-LCST types of block copolymers, and their potential as biomedical applications.

  15. Novel fluorescent amphiphilic block copolymers: photophysics behavior and interactions with DNA

    Directory of Open Access Journals (Sweden)

    2007-06-01

    Full Text Available In this study, novel amphiphilic fluorescent copolymers poly(N-vinylpyrrolidone-b-poly(N-methacryloyl-N'-(α-naphthylthiourea (PVP-b-PNT were synthesized via ATRP with poly(N-vinylpyrrolidone-Cl as macroinitiator and N-methacryloyl-N'-α-naphthylthiourea (NT as hydrophobic segment. PVP-b-PNT copolymers were characterized by 1H NMR, GPC-MALLS and fluorescence measurements. The aggregation behavior of PVP-b-PNT in water was investigated by transmission electron microscope (TEM and dynamic light scattering (DLS measurement. The photophysics behavior of PVP-b-PNT showed that block copolymer formed strong excimer. The interaction of DNA with the block copolymer made the excimer of block copolymer quench. The cytotoxicity result of PVP-b-PNT in cell culture in vitro indicated that this copolymer PVP-b-PNT had good biocompatibility.

  16. Experimental investigation of the behaviour and fate of block copolymers in fouling-release coatings

    DEFF Research Database (Denmark)

    Noguer, Albert Camós

    Fouling-release coatings (FRC) were developed as an environmentally friendly alternative after the ban of highly toxic antifouling coatings based on tributyltin. Poly(dimethylsiloxane) (PDMS) has been the most widely used polymer for FRC, and its fouling-inhibition properties have been enhanced...... the distribution and behaviour of PEG-b-PDMS-b-PEG copolymers in PDMS coatings by fluorescence means. Chapter 5 investigates the degradation of PDMS-PEG-based copolymers in FRC immersed in seawater. Chapter 6 consists of a long-term field study regarding the release/loss of these block copolymers from fouling...... and stability of the copolymer on the surface of the coating are proven to be a central aspect of the performance of these FRC. A novel fluorescent-labelled triblock PEG-b-PDMS-b-PEG copolymer was synthesized in this project to visualize the distribution and behaviour of PDMS-PEG-based copolymers in PDMS...

  17. Improving dielectric permittivity by incorporating PDMS-PEG block copolymer into PDMS network

    DEFF Research Database (Denmark)

    A Razak, Aliff Hisyam; Szabo, Peter; Skov, Anne Ladegaard

    .Combination of both polymers as a block copolymer depicts a possibility for substantial improvement of properties such as high permittivity and non-conductivity – if carefully designed 2. The objective of my research is to synthesize PDMS-PEG block copolymer assembling into different morphologies such as lamellae...... introduces different properties in terms of contact angles, dielectric permittivity and rheological behaviour. All morphologies of PDMS-PEG block copolymer in this study exhibit high storage permittivity; at the same time the loss permittivity is even higher which implies that the synthesized PDMS-PEG block...... copolymers are conductive. By incorporating conductive PDMS-PEG block copolymer into commercial PDMS elastomer from Wacker Chemie,the storage permittivity is significantly enhanced by 38% with 20% of PDMS-PEG block copolymer incorporated in pure PDMS network as depicted in Fig. 2....

  18. Interaction between PEO-PPO-PEO copolymers and a hexapeptide in aqueous solutions.

    Science.gov (United States)

    Jia, Lianwei; Guo, Chen; Xiang, Junfeng; Wang, Ning; Yang, Liangrong; Tang, Yalin; Liu, Huizhou

    2012-01-24

    Interaction between PEO-PPO-PEO copolymers and a hexapeptide, growth hormone releasing peptide-6 (GHRP-6), was investigated by NMR to study the potential use of the copolymers in peptide drug delivery. (1)H NMR and nuclear Overhauser effect spectroscopy (NOESY) measurements determined that PO methyl protons interacted with methyl protons of the Ala moiety, aromatic protons of the Trp moiety, and some of the Phe aromatic protons. The Lys moiety and part of the Phe moiety entered the hydrophilic EO environment via hydrogen bonding. PEO-PPO-PEO copolymers and the peptide formed a complex in 1:1 stoichiometry. Binding constants between copolymers and GHRP-6 were determined, and it was indicated that the copolymers containing more EO and PO units will lead to greater affinity with the peptide. Isothermal titration calorimetry (ITC) measurements confirmed the results of NMR experiments. This study indicates that PEO-PPO-PEO copolymers have great potential in delivering peptide drugs.

  19. Synthesis, Characterization and Photoinduction of Optical Anisotropy in Liquid Crystalline Diblock Azo-Copolymers

    DEFF Research Database (Denmark)

    Forcén, P; Oriol, L; Sánchez, C

    2007-01-01

    behavior similar to that of the azo homopolymers. Thin films of these copolymers were characterized by transmission elevtron microscopy (TEM). A lamellar nanostructure was observed for azo content down to 20 wt %, while no structure is observed for the copolymer with a 7% azo content. The optical......Diblock copolymers with polymethyl methacrylate and side chain liquid crystalline WC) azopolymethacrylate blocks were synthesized by atom transfer radical polymerization (ATRP). The azobeazene content in these copolymers ranges from 52 to 7 wt %. For an azo conteat dowri to 20% they exhibit a LC...... the homopolymer to the copolymers. Photoinduced azo orientation perpendicular to the 488 nm light polarization was found in aH the polymers. The orientational order parameter is very similar in the homopolymer and in the block copolymers with an azo content down to 20 wt %, while it is much lower in the random...

  20. Topology and Shape Control for Assemblies of Block Copolymer Blends in Solution

    KAUST Repository

    Moreno Chaparro, Nicolas

    2015-10-27

    We study binary blends of asymmetric diblock copolymers (AB/AC) in selective solvents with a mesoscale model. We investigate the morphological transitions induced by the concentration of the AC block copolymer and the difference in molecular weight between the AB and AC copolymers, when segments B and C exhibit hydrogen-bonding interactions. To the best of our knowledge, this is the first work modeling mixtures of block copolymers with large differences in molecular weight. The coassembly mechanism localizes the AC molecules at the interface of A and B domains and induces the swelling of the B-rich domains. The coil size of the large molecular weight block copolymer depends only on the concentration of the short block copolymer (AC or AB), regardless of the B–C interactions. However, the B–C interactions control the morphological transitions that occur in these blends.

  1. Self-organization of amphiphilic block copolymers in the presence of water: A mesoscale simulation

    Science.gov (United States)

    Komarov, Pavel V.; Veselov, Igor N.; Khalatur, Pavel G.

    2014-06-01

    Using dissipative particle dynamics, we analyze the suitability of amphiphilic diblock copolymers as a material for high-performance proton conducting membranes of fuel cells. It is shown that the topology of water channel network within hydrated block copolymer-based membranes can be controlled by varying the copolymer blocks length. In particular, our simulations predict the formation of bicontinuous cubic phases for hydrophilic, hydrophobic blocks, and water. The interfaces between microphase-separated subphases form triply periodic minimal surfaces.

  2. Evaluation of methods for measuring relative permeability of anhydride from the Salado Formation: Sensitivity analysis and data reduction

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, R.L.; Kalbus, J.S. [Colorado School of Mines, Golden, CO (United States). Petroleum Engineering Dept.; Howarth, S.M. [Sandia National Labs., Albuquerque, NM (United States)

    1997-05-01

    This report documents, demonstrates, evaluates, and provides theoretical justification for methods used to convert experimental data into relative permeability relationships. The report facilities accurate determination of relative permeabilities of anhydride rock samples from the Salado Formation at the Waste Isolation Pilot Plant (WIPP). Relative permeability characteristic curves are necessary for WIPP Performance Assessment (PA) predictions of the potential for flow of waste-generated gas from the repository and brine flow into repository. This report follows Christiansen and Howarth (1995), a comprehensive literature review of methods for measuring relative permeability. It focuses on unsteady-state experiments and describes five methods for obtaining relative permeability relationships from unsteady-state experiments. Unsteady-state experimental methods were recommended for relative permeability measurements of low-permeability anhydrite rock samples form the Salado Formation because these tests produce accurate relative permeability information and take significantly less time to complete than steady-state tests. Five methods for obtaining relative permeability relationships from unsteady-state experiments are described: the Welge method, the Johnson-Bossler-Naumann method, the Jones-Roszelle method, the Ramakrishnan-Cappiello method, and the Hagoort method. A summary, an example of the calculations, and a theoretical justification are provided for each of the five methods. Displacements in porous media are numerically simulated for the calculation examples. The simulated product data were processed using the methods, and the relative permeabilities obtained were compared with those input to the numerical model. A variety of operating conditions were simulated to show sensitivity of production behavior to rock-fluid properties.

  3. Evaporative derivatization of phenols with 2-sulfobenzoic anhydride for detection by matrix-assisted laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Yao, Yuanyuan; Wang, Poguang; Giese, Roger

    2014-03-30

    Phenols are an important class of analytes, for example as bioactive environmental contaminants. Towards a goal of improving their detection by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) or MALDI-tandem time-of-flight (TOF/TOF)-MS, we studied their derivatization with 2-sulfobenzoic anhydride (SBA). We chose SBA for this purpose since it is commercially available, inexpensive, and forms an anionic derivative. Under the selected conditions developed here for phenols, a reaction mixture of one or more of such compounds in acetonitrile containing SBA and 4-dimethylaminopyridine (DMAP) is evaporated to a solid, heated at 60 °C for 1 h, redissolved in 50% acetonitrile containing matrix, spotted onto a MALDI target, and subjected to negative ion MALDI-TOF/TOF-MS. While conventional (solution-phase) reaction of 4-phenylphenol (model analyte) with SBA and DMAP only gave a 47% yield of SBA-tagged 4-phenylphenol, evaporative derivatization as above gave a 96% yield, and 25 pmol (4.3 ng) of 4-phenylphenol could be detected in this way by MALDI-TOF/TOF-MS at signal-to-noise ratio (S/N) = 260, whereas even 1 nmol of the nonderivatized phenol was not detected in the absence of derivatization. A wide range of responses was observed when a mixture of 15 phenols was derivatized, with the higher responses coming from phenols with a pKa value above 9. Without derivatization, phenols with pKa values below 5 were the most readily detected. Evaporative derivatization with SBA (a convenient reagent) can improve the detection of phenols with relatively high pKa values (above 9) by negative ion MALDI-TOF-MS, and accomplish this in the absence of post-derivatization reaction cleanup. Copyright © 2014 John Wiley & Sons, Ltd.

  4. Preparation and characterization of new succinic anhydride grafted Posidonia for the removal of organic and inorganic pollutants.

    Science.gov (United States)

    Chadlia, Aguir; Mohamed, Khalfaoui; Najah, Laribi; Farouk, M'henni Mohamed

    2009-12-30

    The present work describes the preparation of new chelating materials derived from Posidonia for adsorption of heavy metal ions and dye in aqueous solution. The first part of this report deals with the chemical modification of Posidonia with succinic anhydride. Thus, we have obtained materials with various succinyl groups contents (from 29.8 to 39.2%). The obtained materials were characterized by infrared and CP/MAS (13)C-RMN spectroscopy. The rate of succinyl content of the modified Posidonia was determined by saponification. The second part is devoted to the evaluation of the adsorption capacity of metal ions such as Pb(2+) and dye such as direct red 75 (DR75) for raw and modified Posidonia materials. Two possible ways for the adsorption of these pollutants are studied: adsorption of each pollutant alone onto these supports, and cumulative adsorption of both metal ions and dye on the same supports. In the last case, the pollutant is adsorbed successively from two different solutions. The effects of pollutants concentration, support dose, pH, contact time and temperature on adsorption of each pollutant were evaluated. The results showed that the raw and modified Posidonia show a high capacity for Pb(2+) adsorption. The capacity of modified Posidonia saturated with Pb(2+) to adsorb DR75 was found 147.12 mg g(-1). While the adsorption capacity of the nonsaturated modified Posidonia was equal to 81.63 mg g(-1). The pseudo-second-order model was the best to represent adsorption kinetics of DR75. The pseudo-first-order model would be better for fitting the adsorption kinetic process of Pb(2+) onto raw and modified Posidonia. The adsorption isotherms of Pb(2+) could be described by the Jossens equation model. Any of the tested models can describe the adsorption of DR75 onto the studied materials. These results confirm that the adsorption of DR75 from aqueous solution was multilayer.

  5. Anti-Inflammatory Effect of Titrated Extract of Centella asiatica in Phthalic Anhydride-Induced Allergic Dermatitis Animal Model.

    Science.gov (United States)

    Park, Ju Ho; Choi, Ji Yeon; Son, Dong Ju; Park, Eun Kyung; Song, Min Jong; Hellström, Mats; Hong, Jin Tae

    2017-03-30

    Centella asiatica has potent antioxidant and anti-inflammatory properties. However, its anti-dermatitic effect has not yet been reported. In this study, we investigated the anti-dermatitic effects of titrated extract of Centella asiatica (TECA) in a phthalic anhydride (PA)-induced atopic dermatitis (AD) animal model as well as in vitro model. An AD-like lesion was induced by the topical application of five percent PA to the dorsal skin or ear of Hos:HR-1 mouse. After AD induction, 100 μL of 0.2% and 0.4% of TECA (40 μg or 80 μg/cm²) was spread on the dorsum of the ear or back skin three times a week for four weeks. We evaluated dermatitis severity, histopathological changes and changes in protein expression by Western blotting for inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and NF-κB activity, which were determined by electromobility shift assay (EMSA). We also measured TNF-α, IL-1β, IL-6, and IgE concentration in the blood of AD mice by enzyme-linked immunosorbent assay (ELISA). TECA treatment attenuated the development of PA-induced atopic dermatitis. Histological analysis showed that TECA inhibited hyperkeratosis, mast cells and infiltration of inflammatory cells. TECA treatment inhibited expression of iNOS and COX-2, and NF-κB activity as well as the release of TNF-α, IL-1β, IL-6, and IgE. In addition, TECA (1, 2, 5 μg/mL) potently inhibited Lipopolysaccharide (LPS) (1 μg/mL)-induced NO production, expression of iNOS and COX-2, and NF-κB DNA binding activities in RAW264.7 macrophage cells. Our data demonstrated that TECA could be a promising agent for AD by inhibition of NF-κB signaling.

  6. Chemical modification with phthalic anhydride and chitosan: Viable options for the stabilization of raw starch digesting amylase from Aspergillus carbonarius.

    Science.gov (United States)

    Nwagu, Tochukwu Nwamaka; Okolo, Bartholomew; Aoyagi, Hideki; Yoshida, Shigeki

    2017-06-01

    The raw starch digesting type of amylase (RSDA) presents greater opportunities for process efficiency at cheaper cost and shorter time compared to regular amylases. Chemical modification is a simple and rapid method toward their stabilization for a wider application. RSDA from Aspergillus carbonarius was modified with either phthalic anhydride (PA) or chitosan. Activity retention was 87.3% for PA-modified and 80.9% for chitosan-modified RSDA. Optimum pH shifted from 5 to 7 after PA-modification. Optimum temperature changed from 30°C (native) to 30-40°C and 60°C for PA-modified and chitosan-modified, respectively. Activation energy (kJmol-1) for hydrolysis was 13.5, 12.7, and 10.2 while the activation energy for thermal denaturation was 32.8, 80.3, 81.9 for free, PA-modified and chitosan-modified, respectively. The specificity constants (Vmax/Km) were 73.2 for PA-modified, 63.1 for chitosan-modified and 77.1 for native RSDA. The half-life (h) of the RSDA at 80°C was increased from 6.1 to 25.7 for the PA-modified and 138.6 for the chitosan derivative. Modification also led to increase in D value, activation enthalpy and Gibbs free energy of enzyme deactivation. Fluorescence spectra showed that center of spectral mass decreased for the PA-modified RSDA but increased for chitosan modified RSDA. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Photophysical properties of 1,8-naphthalic anhydride in aprotic solvents: An electron acceptor in excited state

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Sujay; Biswas, Subhanip; Mondal, Mousumi; Basu, Samita, E-mail: samita.basu@saha.ac.in

    2014-01-15

    1,8-Naphthalic anhydride (NAN) has long been known as an intermediate for the synthesis of 1,8-naphthalimide derivatives with diverse applications. Uses of NAN for other purposes are restricted because it hydrolyzes in water and other protic solvents. In the current work we have investigated the absorption, steady-state and time-resolved fluorescence spectroscopy of NAN in eight different aprotic solvents of varying polarity. The compound is found to have different quantum yields in all the solvents. Astoundingly, NAN shows minimal fluorescence yield in dimethyl sulphoxide and N,N-dimethylformamide which is found to originate from pure collisional quenching owing to proton affinity of the solvent. In aprotic solvents acetonitrile and ethyl acetate, fluorescence emission and lifetime of NAN are quenched on addition of aliphatic amines namely triethylamine (TEA), tri-N-butylamine (TBA) and diisopropylethylamine (DIEA). Laser flash photolysis experiments in acetonitrile solvent have been used to find out the transient intermediates, which depict the involvement of photo-induced electron transfer from the amines to NAN. Hence, NAN has the potential to act as an efficient photo-induced electron acceptor in aprotic medium. -- Highlights: • In aprotic solvents NAN absorbs with maximum around 330–340 nm. • NAN fluoresce in aprotic solvents with maximum around 345–395 nm. • NAN has negligibly poor fluorescence in DMSO and DMF. • Fluorescence of NAN in aprotic solvents is quenched by TEA, TBA and DIEA. • Photo-induced electron transfer from the amines to NAN is the reason for such interaction.

  8. Determination of fatty alcohol ethoxylates by derivatization with phthalic anhydride followed by liquid chromatography with UV-vis detection.

    Science.gov (United States)

    Micó-Tormos, A; Simó-Alfonso, E F; Ramis-Ramos, G

    2008-08-29

    The esterification of fatty alcohol ethoxylates (FAEs) with phthalic anhydride in 1,4-dioxane was studied. At 110 degrees C and in the presence of urea, which increased the reaction rate, esterification was completed in 60 min. The reaction yield did not decrease when the sample contained up to 50% water. For the non-ethoxylated alcohols, the UV-vis response factors of the derivatives were not significantly different from each other (f=1 for C12E0 as reference). The response factors decreased when the number of ethylene oxide units, m, increased, reaching constant values of ca. 0.40 and 0.65 for the n=8 and 18 series, respectively, when m>or=3. Using a C8 column and gradient elution with acetonitrile/water plus 0.1% acetic acid, FAEs in industrial mixtures and cleaning products were characterized. At column temperatures of 25 and 35 degrees C, homologous series with even values of n from 8 up to 20, were resolved up to m=14 and 18, respectively, and at 25 degrees C, series with consecutive even and odd values of n were resolved up to m=7. Within the series, superior resolution of the ethoxymers with large values of m was achieved; however, the elution order was reversed for the m=1 and 0 ethoxymers, which produced overlapping of a few peaks within the series. A simple procedure for the accurate prediction of the concentrations of all the ethoxymers in industrial samples was described. After preconcentration with C18 solid-phase extraction cartridges, FAEs were also characterized and quantified in environmental samples (river and sea water). The LODs were ca. 2 microM (S/N=3) in the injected solutions.

  9. Biological materials: Part A. tuning LCST of raft copolymers and gold/copolymer hybrid nanoparticles and Part B. Biobased nanomaterials

    Science.gov (United States)

    Chen, Ning

    The research described in this dissertation is comprised of two major parts. The first part studied the effects of asymmetric amphiphilic end groups on the thermo-response of diblock copolymers of (oligo/di(ethylene glycol) methyl ether (meth)acrylates, OEGA/DEGMA) and the hybrid nanoparticles of these copolymers with a gold nanoparticle core. Placing the more hydrophilic end group on the more hydrophilic block significantly increased the cloud point compared to a similar copolymer composition with the end group placement reversed. For a given composition, the cloud point was shifted by as much as 28 °C depending on the placement of end groups. This is a much stronger effect than either changing the hydrophilic/hydrophobic block ratio or replacing the hydrophilic acrylate monomer with the equivalent methacrylate monomer. The temperature range of the coil-globule transition was also altered. Binding these diblock copolymers to a gold core decreased the cloud point by 5-15 °C and narrowed the temperature range of the coil-globule transition. The effects were more pronounced when the gold core was bound to the less hydrophilic block. Given the limited numbers of monomers that are approved safe for in vivo use, employing amphiphilic end group placement is a useful tool to tune a thermo-response without otherwise changing the copolymer composition. The second part of the dissertation investigated the production of value-added nanomaterials from two biorefinery "wastes": lignin and peptidoglycan. Different solvents and spinning methods (melt-, wet-, and electro-spinning) were tested to make lignin/cellulose blended and carbonized fibers. Only electro-spinning yielded fibers having a small enough diameter for efficient carbonization (≤ 5-10 μm), but it was concluded that cellulose was not a suitable binder. Cellulose lignin fibers before carbonization showed up to 90% decrease in moisture uptake compared to pure cellulose. Peptidoglycan (a bacterial cell wall

  10. Development of mass production technology for block copolymer lithographic materials

    Science.gov (United States)

    Himi, Toshiyuki; Matsuki, Ryota; Kosaka, Terumasa; Ogaki, Ryosuke; Kawaguchi, Yukio; Shimizu, Tetsuo

    2017-03-01

    We have successfully synthesized various and over wide range molecular weight block copolymers (BCPs): these are polystyrene(PS)-polymethylmethacrylate(PMMA) as general components and poly(4-trimethylsilylstyrene)(PTMSS)- poly(4-hydroxystyrene)(PHS) system as very strong segregated components (high chi) and multiblock type of those copolymers which form the microphase-separated structure pattern using living anionic polymerizing method by which the size of polymer can be precisely controlled. In addition, we were able to observe alternating lamellar and cylinder structures which were formed by our various BCPs using small angle X-ray scattering (SAXS). Moreover, we have successfully developed new apparatus for high volume manufacturing including our original technologies such as purification of monomer, improvement of wetted surface, and mechanical technology for high vacuum. And we have successfully synthesized all the BCPs with narrow molecular weight distribution (PDI <1.1) with large-scale apparatus.

  11. Supramolecular association of a triblock copolymer in water.

    Science.gov (United States)

    Gente, Giacomo; Iovino, Alessandro; La Mesa, Camillo

    2004-06-15

    Solutions of a poly(oxyethylene)-poly(oxypropylene)-poly(oxyethylene) triblock copolymer, Pluronic F(68), were investigated in isothermal and isopleth mode. Surface tension, sigma, dynamic shear viscosity, n(omega), QELS experiments, and volumetric, colligative, and refractive index measurements characterize the system behavior in a wide range of compositions and temperatures. The thermodynamic properties associated with micelle formation, above the critical micellar temperature, were determined by different experimental methods. The large entropic contributions to the system stability are ascribed to significant dehydration of the oxypropylene portion in the copolymer, consequent to micelle formation. Temperature has a pronounced effect on the association features of F(68). It gives rise to abrupt changes in QELS and rheological properties when the critical micellar temperature is approached. Such effects are explained in terms of thermally driven micellization processes and interconnection between micelles.

  12. Barite formation in the presence of a commercial copolymer

    Science.gov (United States)

    Ruiz-Agudo, Cristina; Putnis, Christine; Ruiz-Agudo, Encarnacion; Putnis, Andrew

    2015-04-01

    Fluid composition can significantly modify the mechanisms of mineral formation. Particularly, the presence of organic additives in the aqueous media has been shown to alter the precipitation of minerals substantially (e.g. calcium carbonate, barium carbonate and barium sulfate). Despite the numerous studies dealing with barite precipitation and the influence of organic additives (e.g. Benton et al. 1993, Qi et al., 2000, Wang and Cölfen, 2006, Mavredaki et al., 2011), the details of the mechanism of barite formation in the presence of organic additives, particularly at the early stages of this process, are yet to be fully resolved. Here, we present observations on the initial stages of barite formation from aqueous solutions, as well as the alterations induced by a commercial copolymer (maleic acid/allyl sulfonic acid copolymer with phosphonate groups), commonly used as a scale inhibitor in oil recovery. Most synthetic commercial additives contain the same functional groups (e.g. carboxylate, phosphonate and/or sulfonate groups). Thus our work may help to understand the mechanism by which copolymers modify crystallization processes and aid in the selection of the most appropriate inhibitors for hindering or controlling barite scale formation. Barite scaling is one of the main problems in many industrial processes (such as, paper-making, chemical manufacturing, cement operations, off-shore oil extraction, geothermal energy production). Using Atomic Force Microscopy (AFM), we show that barite growth is significantly influenced by the presence of the copolymer. In its absence, barium sulfate growth occurs by 2D island nucleation and spreading. The addition of small amounts (0.1 ppm and 0.5 ppm) of the copolymer enhances 2D nucleation but blocks growth. Just 1 ppm of inhibitor is enough to block barite nucleation and growth by adsorption of a copolymer layer onto the barite surface. Transmission electron microscopy (TEM) was also used to gain better insights into the

  13. Magnetic Alignment of Block Copolymer Microdomains by Intrinsic Chain Anisotropy

    Science.gov (United States)

    Rokhlenko, Yekaterina; Gopinadhan, Manesh; Osuji, Chinedum O.; Zhang, Kai; O'Hern, Corey S.; Larson, Steven R.; Gopalan, Padma; Majewski, Paweł W.; Yager, Kevin G.

    2015-12-01

    We examine the role of intrinsic chain susceptibility anisotropy in magnetic field directed self-assembly of a block copolymer using in situ x-ray scattering. Alignment of a lamellar mesophase is observed on cooling across the disorder-order transition with the resulting orientational order inversely proportional to the cooling rate. We discuss the origin of the susceptibility anisotropy, Δ χ , that drives alignment and calculate its magnitude using coarse-grained molecular dynamics to sample conformations of surface-tethered chains, finding Δ χ ≈2 ×1 0-8. From field-dependent scattering data, we estimate that grains of ≈1.2 μ m are present during alignment. These results demonstrate that intrinsic anisotropy is sufficient to support strong field-induced mesophase alignment and suggest a versatile strategy for field control of orientational order in block copolymers.

  14. Copolymers Formation by Photopolymerization of (Methacrylates Containing Dissolved Polyheteroarylenes

    Directory of Open Access Journals (Sweden)

    Dmitriy A. Sapozhnikov

    2009-01-01

    Full Text Available Radical photopolymerization of (methacrylates in the presence of dissolved polyheteroarylenes has been investigated. The kinetics of radical polymerization of unsaturated monomers in the presence of polyheteroarylenes and model compounds has been studied by Differential Scanning Photocalorimetry and Infrared Spectroscopy. From the results of investigations into the kinetics and the polymer structures (Fourier Transform Infrared Spectroscopy, Nuclear Magnetic Resonance, Size-exclusion Chromatography, Thermogravimetric analysis, it has been established that radical photopolymerization of vinyl monomers in the presence of polyheteroarylenes leads to the formation of copolymers owing to chain transfer reactions and/or chain termination by the relevant condensation polymer. Using Electron Spin Resonance Spectroscopy the novel radicals upon the addition of model compounds for the polyheteroarylenes have been detected, and a mechanism of copolymer formation has been proposed.

  15. Numerical investigation of local defectiveness control of diblock copolymer patterns

    Directory of Open Access Journals (Sweden)

    D. Jeong

    2016-09-01

    Full Text Available We numerically investigate local defectiveness control of self-assembled diblock copolymer patterns through appropriate substrate design. We use a nonlocal Cahn-Hilliard (CH equation for the phase separation dynamics of diblock copolymers. We discretize the nonlocal CH equation by an unconditionally stable finite difference scheme on a tapered trench design and, in particular, we use Dirichlet, Neumann, and periodic boundary conditions. The value at the Dirichlet boundary comes from an energy-minimizing equilibrium lamellar profile. We solve the resulting discrete equations using a Gauss-Seidel iterative method. We perform various numerical experiments such as effects of channel width, channel length, and angle on the phase separation dynamics. The simulation results are consistent with the previous experimental observations.

  16. Substrate-Induced Ordering of Diblock Copolymer Micelles

    Science.gov (United States)

    Fasolka, Michael; Mayes, A. M.; Mochrie, S. G. J.

    1997-03-01

    In the bulk, blends of AB diblock copolymers with A homopolymers will microphase separate to form randomly distributed micelles of the B component in an A matrix. Recently, we have deposited thin films of such blends onto silicon substrates which have been processed such that they are covered with fine sawtooth-type ridges. The substrate ridges have a regular and tunable peak-to-peak spacing on the order of 100nm(S. Song, S.G.J Mochrie and G.B. Stephenson, Phys. Rev. Lett., 62 (1989) 1852.). Upon annealing, the copolymer micelles are found to order themselves with respect to the substrate topography, i.e., they align into the ridge troughs. In order to understand this newly discovered phenomenon, we have conducted a series of experiments which probe the ordering process as a function of blend composition and substrate ridge spacing.

  17. Pressure and temperature effects in homopolymer blends and diblock copolymers

    DEFF Research Database (Denmark)

    Frielinghaus, H.; Schwahn, D.; Mortensen, K.

    1997-01-01

    fluctuations. Phase boundaries, the Flory-Huggins interaction parameter and the Ginzburg number were obtained. The packing of the molecules changes with pressure. Therefore, the degree of thermal fluctuation as a function of packing and temperature was studied. While in polymer blends packing leads, in some......Thermal composition fluctuations in a homogeneous binary polymer blend and in a diblock copolymer were measured by small-angle neutron scattering as a function of temperature and pressure. The experimental data were analyzed with theoretical expressions, including the important effect of thermal...... of the 'mean-field' approximation and the three-dimensional Ising model. The phase boundaries in blends increase with pressure, while the phase boundary of the studied block copolymer shows an unusual shape: with increasing pressure it first decreases and then increases. Its origin is an increase...

  18. Formulation and Characterization of Epoxy Resin Copolymer for Graphite Composites

    Science.gov (United States)

    Keck, F. L.

    1983-01-01

    Maximum char yield was obtained with a copolymer containing 25% mol fraction DGEBE and 75% mol fraction DGEBA (Epon 828). To achieve the high values (above 40%), a large quantity of catalyst (trimethoxyboroxine) was necessary. Although a graphite laminate 1/8" thick was successfully fabricated, the limited life of the catalyzed epoxy copolymer system precludes commercial application. Char yields of 45% can be achieved with phenolic cured epoxy systems as indicated by data generated under NAS2-10207 contract. A graphite laminate using this type of resin system was fabricated for comparison purposes. The resultant laminate was easier to process and because the graphite prepreg is more stable, the fabrication process could readily be adapted to commercial applications.

  19. Low molecular weight block copolymers as plasticizers for polystyrene

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Karsten; Nielsen, Charlotte Juel; Hvilsted, Søren

    2005-01-01

    Polystyrene-b-alkyl, polystyrene-b-polybutadiene-b-polystyrene, and polystyrene-b-poly(propylene glycol)monotridecyl ether were synthesized using macro initiators and atom transfer radical polymerization or by esterifications of homopolymers. The aim was a maximum molecular weight of 4 kg....../mol and minimum polystyrene content of 50 w/w%, which by us is predicted as the limits for solubility of polystyrene-b-alkyl in polystyrene. DSC showed polystyrene was plasticized, as seen by a reduction in glass transition temperature, by block copolymers consisting of a polystyrene block with molecular weight...... of approximately 1 kg/mol and an alkyl block with a molecular weight of approximately of 0.3 kg/mol. The efficiency of the block copolymers as plasticizers increases with decreasing molecular weight and polystyrene content. In addition, polystyrene-b-alkyl is found to be an efficient plasticizer also...

  20. Magnetic Alignment of Block Copolymer Microdomains by Intrinsic Chain Anisotropy.

    Science.gov (United States)

    Rokhlenko, Yekaterina; Gopinadhan, Manesh; Osuji, Chinedum O; Zhang, Kai; O'Hern, Corey S; Larson, Steven R; Gopalan, Padma; Majewski, Paweł W; Yager, Kevin G

    2015-12-18

    We examine the role of intrinsic chain susceptibility anisotropy in magnetic field directed self-assembly of a block copolymer using in situ x-ray scattering. Alignment of a lamellar mesophase is observed on cooling across the disorder-order transition with the resulting orientational order inversely proportional to the cooling rate. We discuss the origin of the susceptibility anisotropy, Δχ, that drives alignment and calculate its magnitude using coarse-grained molecular dynamics to sample conformations of surface-tethered chains, finding Δχ≈2×10^{-8}. From field-dependent scattering data, we estimate that grains of ≈1.2  μm are present during alignment. These results demonstrate that intrinsic anisotropy is sufficient to support strong field-induced mesophase alignment and suggest a versatile strategy for field control of orientational order in block copolymers.

  1. Transient instability upon temperature quench in weakly ordered block copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Shuyan [Department of Chemical Engineering, University of California, Berkeley, California 94610 (United States); Wang, Zhen-Gang [Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125 (United States)

    1999-12-15

    We report a novel transient instability upon temperature quench in weakly ordered block copolymer microphases possessing a soft direction or directions, such as the lamellar and hexagonal cylinder (HEX) phases. We show that reequilibration of the order parameter is accompanied by transient long wavelength undulation of the layers or cylinders--with an initial wavelength that depends on the depth of the temperature quench--that eventually disappears as the structure reaches its equilibrium at the new temperature. Such undulation leads to a transient transverse broadening of the scattering peaks near the Bragg positions. We argue that this instability might be responsible for the experimentally observed unusual ordering dynamics of the HEX phase of a diblock copolymer after quenching from the disordered state. (c) 1999 American Institute of Physics.

  2. Room-Temperature-Cured Copolymers for Lithium Battery Gel Electrolytes

    Science.gov (United States)

    Meador, Mary Ann B.; Tigelaar, Dean M.

    2009-01-01

    Polyimide-PEO copolymers (PEO signifies polyethylene oxide) that have branched rod-coil molecular structures and that can be cured into film form at room temperature have been invented for use as gel electrolytes for lithium-ion electric-power cells. These copolymers offer an alternative to previously patented branched rod-coil polyimides that have been considered for use as polymer electrolytes and that must be cured at a temperature of 200 C. In order to obtain sufficient conductivity for lithium ions in practical applications at and below room temperature, it is necessary to imbibe such a polymer with a suitable carbonate solvent or ionic liquid, but the high-temperature cure makes it impossible to incorporate and retain such a liquid within the polymer molecular framework. By eliminating the high-temperature cure, the present invention makes it possible to incorporate the required liquid.

  3. Controlling effective interactions and spatial dispersion of nanoparticles in multiblock copolymer melts

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Debapriya [Univ. of Illinois, Urbana, IL (United States). Dept. of Materials Science and Frederick Seitz Materials Research Lab.; Schweizer, Kenneth S. [Univ. of Illinois, Urbana, IL (United States). Dept. of Materials Science and Frederick Seitz Materials Research Lab.

    2015-06-04

    The microscopic Polymer Reference Interaction Site Model theory is employed to study, for the first time, the effective interactions, spatial organization, and miscibility of dilute spherical nanoparticles in non-microphase separating, chemically heterogeneous, compositionally symmetric AB multiblock copolymer melts of varying monomer sequence or architecture. The dependence of nanoparticle wettability on copolymer sequence and chemistry results in interparticle potentials-of-mean force that are qualitatively different from homopolymers. An important prediction is the ability to improve nanoparticle dispersion via judicious choice of block length and monomer adsorption-strengths which control both local surface segregation and chain connectivity induced packing constraints and frustration. The degree of dispersion also depends strongly on nanoparticle diameter relative to the block contour length. Small particles in copolymers with longer block lengths experience a more homopolymer-like environment which renders them relatively insensitive to copolymer chemical heterogeneity and hinders dispersion. Larger particles (sufficiently larger than the monomer diameter) in copolymers of relatively short block lengths provide better dispersion than either a homopolymer or random copolymer. The theory also predicts a novel widening of the miscibility window for large particles upon increasing the overall molecular weight of copolymers composed of relatively long blocks. The influence of a positive chi-parameter in the pure copolymer melt is briefly studied. Quantitative application to fullerenes in specific copolymers of experimental interest is performed, and miscibility predictions are made.

  4. Directed assembly of non-equilibrium ABA triblock copolymer morphologies on nanopatterned substrates.

    Science.gov (United States)

    Ji, Shengxiang; Nagpal, Umang; Liu, Guoliang; Delcambre, Sean P; Müller, Marcus; de Pablo, Juan J; Nealey, Paul F

    2012-06-26

    The majority of past work on directed assembly of block copolymers on chemically nanopatterned surfaces (or chemical patterns) has focused on AB diblock copolymers, and the resulting morphologies have generally corresponded to equilibrium states. Here we report a study on directed assembly of ABA triblock copolymers. Directed assembly of thin films of symmetric poly(methyl methacrylate-b-styrene-b-methyl methacrylate) (PMMA-b-PS-b-PMMA) triblock copolymers is shown to be capable of achieving a high degree of perfection, registration, and accuracy on striped patterns having periods, L(s), commensurate with the bulk period of the copolymer, L(o). When L(s) is incommensurate with L(o), the triblock copolymer domains can reach dimensions up to 55% larger or 13% smaller than L(o). The range over which triblock copolymers tolerate departures from a commensurate L(s) is significantly larger than that accessible with the corresponding diblock copolymer material on analogous directed assembly systems. The assembly kinetics of the triblock copolymer is approximately 3 orders of magnitude slower than observed in the diblock system. Theoretically informed simulations are used to interpret our experimental observations; a thermodynamic analysis reveals that triblocks can form highly ordered, non-equilibrium metastable structures that do not arise in the diblock.

  5. Investigation of some copolymers based on acrylic salts as circulation loss control agents

    Directory of Open Access Journals (Sweden)

    Ahmed Mohamed Alsabagh

    2013-12-01

    The prepared copolymers were investigated as loss circulation control materials by measuring different filtration parameters such as; spurt loss, fluid loss and permeability plugging tester value according to the American Petroleum Institute (API standard. From the obtained data, it was found that the 0.6% from the poly[PA-co-AM](0.4:0.6 exhibited the best results of the filtration parameters among the other copolymers. At the same time all the studied copolymers enhanced the rheological properties of the drilling mud. These results were discussed on the light of the swelling capacity of the copolymers.

  6. Microtome Sliced Block Copolymers and Nanoporous Polymers as Masks for Nanolithography

    DEFF Research Database (Denmark)

    Shvets, Violetta; Schulte, Lars; Ndoni, Sokol

    2014-01-01

    Introduction. Block copolymers self-assembling properties are commonly used for creation of very fine nanostructures [1]. Goal of our project is to test new methods of the block-copolymer lithography mask preparation: macroscopic pieces of block-copolymers or nanoporous polymers with cross......-b-PDMS) of different morphologies with period of structure ~24nm [2]. It was shown that mechanical shear-alignment of cylindrical block copolymer with PDMS cylinders in PB matrix orients cylinders in the direction of shearing. Subsequently PB is cross-linked by dicumyl peroxide to fix cylinder orientation. Afterwards...

  7. Thermodynamics of Surfactants, Block Copolymers and Their Mixtures in Water: The Role of the Isothermal Calorimetry

    Science.gov (United States)

    De Lisi, Rosario; Milioto, Stefania; Muratore, Nicola

    2009-01-01

    The thermodynamics of conventional surfactants, block copolymers and their mixtures in water was described to the light of the enthalpy function. The two methodologies, i.e. the van’t Hoff approach and the isothermal calorimetry, used to determine the enthalpy of micellization of pure surfactants and block copolymers were described. The van’t Hoff method was critically discussed. The aqueous copolymer+surfactant mixtures were analyzed by means of the isothermal titration calorimetry and the enthalpy of transfer of the copolymer from the water to the aqueous surfactant solutions. Thermodynamic models were presented to show the procedure to extract straightforward molecular insights from the bulk properties. PMID:19742173

  8. HPMA copolymers: Origins, early developments, present, and future☆

    OpenAIRE

    Kopeček, Jindřich; Kopečková, Pavla

    2009-01-01

    The overview covers the discovery of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers, initial studies on their synthesis, evaluation of biological properties, and explorations of their potential as carriers of biologically active compounds in general and anticancer drugs in particular. The focus is on the research in the authors’ laboratory – the development of macromolecular therapeutics for the treatment of cancer and musculoskeletal diseases. In addition, the evaluation of HPMA (co)pol...

  9. Flocculation and Rheological Characteristics of Graft Copolymers of ...

    African Journals Online (AJOL)

    Des mensurations de la viscosité dans un milieu aqueux (eau bi-distillée) de la cellulose carboxyméthylique et son copolymère greffé, et en présence des cations mono -, di et trivalents ont été effectuées. Les résultats ont montré que le greffage du polyacrylamide sur la cellulose carboxyméthylique augmente dans plus de ...

  10. A novel notch filter based on block copolymer photonic crystal

    Science.gov (United States)

    Hara, Shigeo; Yamanaka, Takahiko; Hirohata, Toru; Niigaki, Minoru

    2011-11-01

    We demonstrate filtering characteristics of a polymer notch filter (PNF) with highly-ordered microphase-separated structure of block copolymers (BCPs). This PNF is characterized by an Optical Density > 5 blocking at the center wavelength and narrow blocking full bandwidth of 8 nm. Moreover, the wavelength is easily tuned by blending two BCPs with different molecular-weight. A low frequency Raman shift of 200 cm-1 are, in fact, detected with a sufficient resolution by using this filter in Raman spectroscopy.

  11. Acrylic Triblock Copolymers Incorporating Isosorbide for Pressure Sensitive Adhesives

    Energy Technology Data Exchange (ETDEWEB)

    Gallagher, James J.; Hillmyer, Marc A.; Reineke, Theresa M. (UMM)

    2016-05-10

    A new monomer acetylated acrylic isosorbide (AAI) was prepared in two steps using common reagents without the need for column chromatography. Free radical polymerization of AAI afforded poly(acetylated acrylic isosorbide) (PAAI), which exhibited a glass transition temperature (Tg) = 95 °C and good thermal stability (Td, 5% weight loss; N2 = 331 °C, air = 291 °C). A series of ABA triblock copolymers with either poly(n-butyl acrylate) (PnBA) or poly(2-ethylhexyl acrylate) (PEHA) as the low Tg midblocks and PAAI as the high Tg end blocks were prepared using Reversible Addition–Fragmentation chain Transfer (RAFT) polymerization. The triblock copolymers ranging from 8–24 wt % PAAI were evaluated as pressure sensitive adhesives by 180° peel, loop tack, and static shear testing. While the PAAI-PEHA-PAAI series exhibited poor adhesive qualities, the PAAI-PnBA-PAAI series of triblock copolymers demonstrated peel forces up to 2.9 N cm–1, tack forces up to 3.2 N cm–1, and no shear failure up to 10000 min. Dynamic mechanical analysis indicated that PAAI-PEHA-PAAI lacked the dissipative qualities needed to form an adhesive bond with the substrate, while the PAAI-PnBA-PAAI series exhibited a dynamic mechanical response consistent with related high performing PSAs.

  12. Simple, generalizable route to highly aligned block copolymer thin films

    Science.gov (United States)

    Qiang, Zhe; Cavicchi, Kevin; Vogt, Bryan; University of Akron Team

    Macroscopic alignment of block copolymer domains in thin films is desired for many applications, such as cell responsive surfaces or optical polarizers. Alignment generally requires specialized tools that apply external fields, shear force gradient, or produce topological patterned substrates. This requirement limits the broad academic application of aligned BCPs. Here, we describe a simple modification of commonly utilized solvent vapor annealing (SVA) process for macroscopic alignment of BCPs. Adhering a flat, crosslinked elastomer pad to the BCP film leads to differential swelling between the elastomer pad and BCP to produce a shear force that aligns the ordered BCP domains. The role of elastomer properties, solvent quality, drying rate and degree of segregation of the block copolymer will be discussed to provide generalized rules for alignment with this technique. Cylindrical nanostructures formed in polystyrene-block-polydimethylsiloxane can be transformed into arrays of silica lines and increasing the thickness from a monolayer to bilayer can effectively halve the spacing of the lines. These results illustrate a generalized method for BCP alignment and a potential route for the generation of complex hierarchical assembled structures. A generalized method for block copolymer thin film alignment: solvent vapor annealing with shear.

  13. Donor-Acceptor Block Copolymers: Synthesis and Solar Cell Applications

    Directory of Open Access Journals (Sweden)

    Kazuhiro Nakabayashi

    2014-04-01

    Full Text Available Fullerene derivatives have been widely used for conventional acceptor materials in organic photovoltaics (OPVs because of their high electron mobility. However, there are also considerable drawbacks for use in OPVs, such as negligible light absorption in the visible-near-IR regions, less compatibility with donor polymeric materials and high cost for synthesis and purification. Therefore, the investigation of non-fullerene acceptor materials that can potentially replace fullerene derivatives in OPVs is increasingly necessary, which gives rise to the possibility of fabricating all-polymer (polymer/polymer solar cells that can deliver higher performance and that are potentially cheaper than fullerene-based OPVs. Recently, considerable attention has been paid to donor-acceptor (D-A block copolymers, because of their promising applications as fullerene alternative materials in all-polymer solar cells. However, the synthesis of D-A block copolymers is still a challenge, and therefore, the establishment of an efficient synthetic method is now essential. This review highlights the recent advances in D-A block copolymers synthesis and their applications in all-polymer solar cells.

  14. Stereocomplex Formation in Incompatible Racemic Chiral Polylactide Block Copolymers

    Science.gov (United States)

    Sun, Lu; Zhu, Lei

    2006-03-01

    Stereocomplexes in incompatible racemic chiral polylactide (PLA) block copolymers have not been widely studied. In this work, we synthesized PLLA and PDLA containing block copolymers by ring opening polymerization of L- and D-lactides from hydroxyl-terminated hydrophilic [poly(ethylene oxide) (PEO)] and hydrophobic [poly(ethylene-co-1,2-butylene) (PEB)] oligomers, respectively. Two samples PEO-b-PLLA (2,000-5,400) and PEB-b-PDLA (4,200-5,400) were chosen. The stereocomplexes were cast from equal molar blends of above two block copolymers in chloroform solution, followed by two different thermal treatments before stereocomplex formation; The blend was either heated to 250 C and quickly quench to 160 C or heated to 250 C for 15 min and quench to 160 C for stereocomplex crystal growth. Before the formation of stereocomplexes, lamellar and cylindrical morphologies were observed in blends for the first and second thermal treatments, respectively, as evidenced by small-angle X-ray scattering (SAXS). After complete crystal growth, the 100% stereocomplexes was confirmed by differential scanning calorimetry and wide-angle X-ray diffraction (WAXD). The morphologies of stereocomplexes grown from these two pre-existing microphases (lamellar vs. cylindrical) were studied by time-resolved SAXS and transmission electron microscopy (TEM).

  15. Stereocomplex Formation in Racemic Chiral Polylactide Block Copolymers

    Science.gov (United States)

    Sun, Lu

    2005-03-01

    Stereocomplexes can be formed for chiral polymers, e.g., isotactic and syndiotactic poly(methyl methacrylate) (PMMA) and poly(L- lactide) (PLLA)/poly(D-lactide) (PDLA). Stereocomplexes in racemic chiral polylactide (PLA) block copolymers have not been widely studied. In this work, we successfully synthesized PLLA and PDLA containing block copolymers using stannous octoate as catalyst for ring opening polymerization from hydroxyl-terminated oligomers. After fractionation by preparative size-exclusion chromatograph, narrow polydispersity samples (Mw/Mn = 1.1˜1.2) were obtained. Stereocomplex of PLA block copolymer blends was prepared by growing stereocomplex crystals either in solution or from the melt. The formation of stereocomplexes was confirmed by differential scanning calorimetry and wide-angle X-ray diffraction (WAXD). The evolution kinetics of stereocomplexes in the bulk was investigated by time-resolved synchrotron small-angle X-ray scattering (SAXS) and WAXD. The morphology of these stereocomplex crystals was studied by transmission electron microscopy.

  16. Pigment encapsulation by emulsion polymerization using macro-RAFT copolymers.

    Science.gov (United States)

    Nguyen, Duc; Zondanos, Hollie S; Farrugia, Jason M; Serelis, Algirdas K; Such, Chris H; Hawkett, Brian S

    2008-03-04

    A new method is described, based on living amphipathic random macro-RAFT copolymers, which enables the efficient polymeric encapsulation of both inorganic and organic particulate materials via free-radical polymerization. The mechanism for this new approach is examined in the context of the polymer coating of zirconia- and alumina-coated titanium dioxide particles and its breadth of application demonstrated by the coating of organic phthalocyanine blue pigment particles. The particulate materials were first dispersed in water using a macro-RAFT copolymer as a stabilizer. Monomer and water-soluble initiator were then added to the system, and the monomer polymerized to form the coating. If nucleation of new polymer particles in the aqueous phase was to be avoided, it was found necessary to use a macro-RAFT copolymer that did not form micelles; within this constraint, a broad range of RAFT agents could be used. The macro-RAFT agents used in this work were found not to transfer competitively in the aqueous phase and therefore did not support growth of aqueous-phase polymer. Successful encapsulation of particles was demonstrated by TEM. The process described enables 100% of the particles to be encapsulated with greater than 95% of the polymer finishing up in the polymeric shells around the particles. Moreover, the coating reaction can be carried out at greater than 50% solids in many cases and avoids the agglomeration of particles during the coating step.

  17. Synthesis and thermal behavior of polyacrylonitrile/vinylidene chloride copolymer

    Directory of Open Access Journals (Sweden)

    Robson Fleming

    2014-06-01

    Full Text Available Polyacrylonitrile fiber encompasses a broad range of products based on acrylonitrile (AN which is readily copolymerized with a wide range of ethylenic unsaturated monomers giving rise to polymers with different characteristics and applications. Such products can be designed for cost-effective, flame and heat resistant solutions for the textile industry, aircraft and automotive markets. In the present work acrylonitrile was copolymerized with vinylidene chloride (VDC by conventional suspension polymerization process via redox system, with an initial content of 10%/mass of the VDC monomer. The copolymer average molecular weight was obtained by Gel Permeation Chromatography (GPC and by intrinsic viscosity analysis. To control the polymerization process continuously, qualitative and quantitative analysis of the chloride content in the PAN AN/VDC copolymer structure was accomplished by using X-ray fluorescence and potentiometric titration techniques. A good correlation was found between these two techniques, leading to a straightforward verification of VDC in the polymer structure. The thermal behavior of PAN AN/VDC copolymer was performed by Differential Scanning Calorimetry (DSC and Thermogravimetric Analysis (TGA. The results showed that VDC monomers exhibited a nearly stoichiometric reaction with acrylonitrile, copolymerizing about 90% of its initial mass. VDC changed significantly the polyacrylonitrile thermal behavior, decreasing the polymer degradation temperature by about 40-50°C.

  18. Theoretical study of polymeric mixtures with different sequence statistics. II. Brazovskii class: Linear random copolymers with diblock copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Shuyan [Department of Chemical Engineering, Department of Chemistry, and Materials Science Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States); Chakraborty, Arup K. [Department of Chemical Engineering, Department of Chemistry, and Materials Science Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States)

    2000-01-15

    We use a Landau theory to study the instability of the homogeneous state of a mixture of linear random copolymers and diblock copolymers. Interesting features of the calculated structure factors for different components of the mixture are found, which can be directly compared with scattering experiments with selectively deuterated samples. We also investigate the least stable concentration fluctuations and find four different types of segregation modes at the spinodal depending upon the characteristics of the mixture (e.g., average compositions, statistical correlation lengths and volume fractions). The different segregation modes are also indicative of the kinetic pathways leading to the formation of ordered microstructures. Experiments probing these pathways are suggested. (c) 2000 American Institute of Physics.

  19. Selective CO2 Sequestration with Monolithic Bimodal Micro/Macroporous Carbon Aerogels Derived from Stepwise Pyrolytic Decomposition of Polyamide-Polyimide-Polyurea Random Copolymers.

    Science.gov (United States)

    Saeed, Adnan M; Rewatkar, Parwani M; Majedi Far, Hojat; Taghvaee, Tahereh; Donthula, Suraj; Mandal, Chandana; Sotiriou-Leventis, Chariklia; Leventis, Nicholas

    2017-04-19

    Polymeric aerogels (PA-xx) were synthesized via room-temperature reaction of an aromatic triisocyanate (tris(4-isocyanatophenyl) methane) with pyromellitic acid. Using solid-state CPMAS (13)C and (15)N NMR, it was found that the skeletal framework of PA-xx was a statistical copolymer of polyamide, polyurea, polyimide, and of the primary condensation product of the two reactants, a carbamic-anhydride adduct. Stepwise pyrolytic decomposition of those components yielded carbon aerogels with both open and closed microporosity. The open micropore surface area increased from CO2 opened access to the closed pores and the micropore area increased by almost 4× to 1150 m(2) g(-1) (out of 1750 m(2) g(-1) of a total BET surface area). At 0 °C, etched carbon aerogels demonstrated a good balance of adsorption capacity for CO2 (up to 4.9 mmol g(-1)), and selectivity toward other gases (via Henry's law). The selectivity for CO2 versus H2 (up to 928:1) is suitable for precombustion fuel purification. Relevant to postcombustion CO2 capture and sequestration (CCS), the selectivity for CO2 versus N2 was in the 17:1 to 31:1 range. In addition to typical factors involved in gas sorption (kinetic diameters, quadrupole moments and polarizabilities of the adsorbates), it is also suggested that CO2 is preferentially engaged by surface pyridinic and pyridonic N on carbon (identified with XPS) in an energy-neutral surface reaction. Relatively high uptake of CH4 (2.16 mmol g(-1) at 0 °C/1 bar) was attributed to its low polarizability, and that finding paves the way for further studies on adsorption of higher (i.e., more polarizable) hydrocarbons. Overall, high CO2 selectivities, in combination with attractive CO2 adsorption capacities, low monomer cost, and the innate physicochemical stability of carbon render the materials of this study reasonable candidates for further practical consideration.

  20. Isobaric (vapor + liquid) equilibria of the binary system maleic anhydride and diethyl phthalate at p = (2.67, 5.33, and 8.00) kPa

    Energy Technology Data Exchange (ETDEWEB)

    Xu Wei [Department of Chemistry, Institute of Science, Tianjin University, Tianjin 300072 (China); Liu Zhihua [Department of Chemistry, Institute of Science, Tianjin University, Tianjin 300072 (China); Tian Yiling [Department of Chemistry, Institute of Science, Tianjin University, Tianjin 300072 (China)]. E-mail: sdwfliu@yahoo.com.cn; Zhu Rongjiao [Department of Chemistry, Institute of Science, Tianjin University, Tianjin 300072 (China)

    2006-11-15

    Saturated vapor pressures of pure diethyl phthalate were measured with the ebulliometer. And isobaric (vapor + liquid) equilibrium data for the binary system (maleic anhydride + diethyl phthalate) at p = (2.67, 5.33, and 8.00) kPa were determined using the ebulliometric method. The parameters of the NRTL model for the binary system were obtained by calculating equilibrium compositions of the liquid and vapor phase with the experimental equilibrium temperatures, pressures and feed compositions. Moreover (vapor + liquid) equilibrium data for the binary system were predicted by use of the UNIFAC model. Predicted results were compared with those from the ebulliometric method, and showed good agreement.

  1. A computational study of the Diels-Alder reactions between 2,3-dibromo-1,3-butadiene and maleic anhydride

    Science.gov (United States)

    Rivero, Uxía; Meuwly, Markus; Willitsch, Stefan

    2017-09-01

    The neutral and cationic Diels-Alder-type reactions between 2,3-dibromo-1,3-butadiene and maleic anhydride have been computationally explored as the first step of a combined experimental and theoretical study. Density functional theory calculations show that the neutral reaction is concerted while the cationic reaction can be either concerted or stepwise. Further isomerizations of the Diels-Alder products have been studied in order to predict possible fragmentation pathways in gas-phase experiments. Rice-Ramsperger-Kassel-Marcus (RRKM) calculations suggest that under single-collision experimental conditions the neutral product may reform the reactants and the cationic product will most likely eliminate CO2.

  2. Synthesis of Medium-Chain-Length Polyhydroxyalkanoate Homopolymers, Random Copolymers, and Block Copolymers by an Engineered Strain of Pseudomonas entomophila.

    Science.gov (United States)

    Wang, Ying; Chung, Ahleum; Chen, Guo-Qiang

    2017-04-01

    Medium-chain-length polyhydroxyalkanoates (mcl-PHAs), widely used in medical area, are commonly synthesized by Pseudomonas spp. This study tries to use β-oxidation pathways engineered P. entomophila to achieve single source of a series of mcl-monomers for microbial production of PHA homopolymers. The effort is proven successful for the first time to obtain a wide range of mcl-PHA homopolymers from engineered P. entomophila LAC23 grown on various fatty acids, respectively, ranging from poly(3-hydroxyheptanoate) to poly(3-hydroxytetradecanoate). Effects of a PHA monomer chain length on thermal and crystallization properties including the changes of Tm , Tg , and Td5% are investigated. Additionally, strain LAC23 is used to synthesize random copolymers of 3-hydroxyoctanoate (3HO) and 3-hydroxydodecanoate (3HDD) or 3-hydroxytetradecanoates, their compositions could be controlled by adjusting the ratios of two related fatty acids. Meanwhile, block copolymer P(3HO)-b-P(3HDD) is synthesized by the same strain. It is found for the first time that even- and odd number mcl-PHA homopolymers have different physical properties. When the gene of the PHA synthase in the engineered P. entomophila is replaced by phaC from Aeromonas hydrophila 4AK4, poly(3-hydroxybutyrate-co-30 mol%-3-hydroxyhexanoate) is synthesized. Therefore, P. entomophila can be used to synthesize the whole range of PHA (C7-C14) homopolymers, random- and block copolymers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. How does dense phase CO2 influence the phase behaviour of block copolymers synthesised by dispersion polymerisation?

    NARCIS (Netherlands)

    Jennings, J.; Bassett, S. P.; Hermida-Merino, D.; Portale, G.; Bras, W.; Knight, L.; Titman, J. J.; Higuchi, T.; Jinnai, H.; Howdle, S. M.

    2016-01-01

    Block copolymers synthesised in supercritical CO2 dispersion undergo in situ self-assembly which can result in a range of nanostructured microparticles. However, our previous study revealed that copolymers with different block combinations possessed different microphase separated morphologies at

  4. Self-Assembled Structures of PMAA-PMMA Block Copolymers : Synthesis, Characterization, and Self-Consistent Field Computations

    NARCIS (Netherlands)

    Li, Feng; Schellekens, Mike; de Bont, Jens; Peters, Ron; Overbeek, Ad; Leermakers, Frans A. M.; Tuinier, Remco

    2015-01-01

    Block copolymers composed of methacrylic acid (MAA) and methyl methacrylate (MMA) blocks are interesting candidates for replacing surfactants in emulsion polymerization methods. Here the synthesis and experimental characterization of well-defined PMAA-PMMA block copolymers made via RAFT

  5. Self-assembled structures of PMAA-PMMA block copolymers: Synthesis, characterization, and self-consistent field computations

    NARCIS (Netherlands)

    Li, F.; Schellekens, J.; Bont, de J.A.M.; Peters, R.; Overbeek, A.; Leermakers, F.A.M.; Tuinier, R.

    2015-01-01

    Block copolymers composed of methacrylic acid (MAA) and methyl methacrylate (MMA) blocks are interesting candidates for replacing surfactants in emulsion polymerization methods. Here the synthesis and experimental characterization of well-defined PMAA–PMMA block copolymers made via RAFT

  6. Microspheres for protein delivery prepared from amphiphilic multiblock copolymers. 1. influence of preparation techniques on particle characteristics and protein delivery

    NARCIS (Netherlands)

    Bezemer, J.M.; Radersma, R.; Grijpma, Dirk W.; Dijkstra, Pieter J.; van Blitterswijk, Clemens; Feijen, Jan

    2000-01-01

    The entrapment of lysozyme in amphiphilic multiblock copolymer microspheres by emulsification and subsequent solvent removal processes was studied. The copolymers are composed of hydrophilic poly(ethylene glycol) (PEG) blocks and hydrophobic poly(butylene terephthalate) (PBT) blocks. Direct solvent

  7. Evaluation of bactericidal action of 2-vinylpiridine copolymers containing quaternary ammonium groups and their charge transfer complexes

    Directory of Open Access Journals (Sweden)

    Aline S. S. Valle

    2013-01-01

    Full Text Available We report the development of copolymers based on 2-vinylpyridine with different porosity degrees. The copolymers were quaternized with methyl iodide and acrylonitrile to introduce quaternary ammonium groups on pyridine units. To prepare charge transfer complexes, the unmodified copolymers and their derivatives quaternized were impregnated with iodine. The antibacterial properties of all the polymers were evaluated ranging from of the Escherichia coli strain. The unmodified copolymers did not have antibacterial activity against E.Coli suspensions. The quaternization with methyl iodine and acrylonitrile increased the biocidal performance of these copolymers, but only the copolymer with the lowest porosity modified with methyl iodine showed significant bactericidal action for all E. Coli concentrations. The 2-vinylpiridine copolymers quaternized and impregnated with iodine had higher antibacterial activity than the impregnated ones. The charge transfer complexes derived from the copolymer with the lowest porosity and highest swelling capacity in water had the best bactericidal performance.

  8. Synthesis and Characterization of Stimuli Responsive Block Copolymers, Self-Assembly Behavior and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Determan, Michael Duane [Iowa State Univ., Ames, IA (United States)

    2005-12-17

    The central theme of this thesis work is to develop new block copolymer materials for biomedical applications. While there are many reports of stimuli-responsive amphiphilic [19-21] and crosslinked hydrogel materials [22], the development of an in situ gel forming, pH responsive pentablock copolymer is a novel contribution to the field, Figure 1.1 is a sketch of an ABCBA pentablock copolymer. The A blocks are cationic tertiary amine methacrylates blocked to a central Pluronic F127 triblock copolymer. In addition to the prerequisite synthetic and macromolecular characterization of these new materials, the self-assembled supramolecular structures formed by the pentablock were experimentally evaluated. This synthesis and characterization process serves to elucidate the important structure property relationships of these novel materials, The pH and temperature responsive behavior of the pentablock copolymer were explored especially with consideration towards injectable drug delivery applications. Future synthesis work will focus on enhancing and tuning the cell specific targeting of DNA/pentablock copolymer polyplexes. The specific goals of this research are: (1) Develop a synthetic route for gel forming pentablock block copolymers with pH and temperature sensitive properties. Synthesis of these novel copolymers is accomplished with ATRP, yielding low polydispersity and control of the block copolymer architecture. Well defined macromolecular characteristics are required to tailor the phase behavior of these materials. (2) Characterize relationship between the size and shape of pentablock copolymer micelles and gel structure and the pH and temperature of the copolymer solutions with SAXS, SANS and CryoTEM. (3) Evaluate the temperature and pH induced phase separation and macroscopic self-assembly phenomenon of the pentablock copolymer. (4) Utilize the knowledge gained from first three goals to design and formulate drug delivery formulations based on the multi

  9. Comparative Study Of The Preparation Of Maleic Anhydride-g-Polypropylene By Two Grafting Processes Using Peroxide; Estudo comparativo de dois processos de graftizacao de polipropileno com anidrido maleico utilizando peroxidos

    Energy Technology Data Exchange (ETDEWEB)

    Sakahara, R.M.; Wang, S.H., E-mail: sakahara@usp.b, E-mail: wangshui@usp.b [Universidade de Sao Paulo (EPUSP), SP (Brazil). Escola Politecnica. Dept. de Engenharia Metalurgica e de Materiais

    2010-07-01

    The Polypropylene grafting with Maleic anhydride is a thoroughly known technique. Its wide application is due, mainly,to the controlled changing in the polarity of this polymer, which increases the interfacial adhesion in blends and compounds. In this study, two grafting processes were compared. In the first, the maleic anhydride was grafted on polypropylene in a solution batch process, carried out in a round-bottom vessel. The second approach was carried out by reactive extrusion of polypropylene in the presence of peroxide and maleic anhydride. The samples thus prepared were characterized by DSC, TGA, FTIR, WAXS, EDS e SEM. It was possible to conclude that the solution technique was more efficient than the reactive extrusion; however the later was easier to accomplish due to the high viscosity of PP. (author)

  10. Preparation and characterization of new succinic anhydride grafted Posidonia for the removal of organic and inorganic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Chadlia, Aguir, E-mail: aguirc@yahoo.ca [Unite de Recherche de Chimie Appliquee et Environnement, Faculte des Sciences de Monastir, 5000 (Tunisia); Mohamed, Khalfaoui [Unite de Recherche de Physique Quantique, Faculte des Sciences de Monastir, 5000 (Tunisia); Najah, Laribi; Farouk, M' henni Mohamed [Unite de Recherche de Chimie Appliquee et Environnement, Faculte des Sciences de Monastir, 5000 (Tunisia)

    2009-12-30

    The present work describes the preparation of new chelating materials derived from Posidonia for adsorption of heavy metal ions and dye in aqueous solution. The first part of this report deals with the chemical modification of Posidonia with succinic anhydride. Thus, we have obtained materials with various succinyl groups contents (from 29.8 to 39.2%). The obtained materials were characterized by infrared and CP/MAS {sup 13}C-RMN spectroscopy. The rate of succinyl content of the modified Posidonia was determined by saponification. The second part is devoted to the evaluation of the adsorption capacity of metal ions such as Pb{sup 2+} and dye such as direct red 75 (DR75) for raw and modified Posidonia materials. Two possible ways for the adsorption of these pollutants are studied: adsorption of each pollutant alone onto these supports, and cumulative adsorption of both metal ions and dye on the same supports. In the last case, the pollutant is adsorbed successively from two different solutions. The effects of pollutants concentration, support dose, pH, contact time and temperature on adsorption of each pollutant were evaluated. The results showed that the raw and modified Posidonia show a high capacity for Pb{sup 2+} adsorption. The capacity of modified Posidonia saturated with Pb{sup 2+} to adsorb DR75 was found 147.12 mg g{sup -1}. While the adsorption capacity of the nonsaturated modified Posidonia was equal to 81.63 mg g{sup -1}. The pseudo-second-order model was the best to represent adsorption kinetics of DR75. The pseudo-first-order model would be better for fitting the adsorption kinetic process of Pb{sup 2+} onto raw and modified Posidonia. The adsorption isotherms of Pb{sup 2+} could be described by the Jossens equation model. Any of the tested models can describe the adsorption of DR75 onto the studied materials. These results confirm that the adsorption of DR75 from aqueous solution was multilayer.

  11. Adsorption kinetics of diblock copolymers from a micellar solution on silica and titania.

    NARCIS (Netherlands)

    Bijsterbosch, H.D.; Cohen Stuart, M.A.; Fleer, G.J.

    1998-01-01

    The solution and adsorption behavior of a series of diblock copolymers of hydrophobic poly(dimethyl siloxane) and hydrophilic poly(2-ethyl-2-oxazoline) was studied. These block copolymers formed large polydisperse micelles in an aqueous solution. The critical micelle concentration was lower than 2

  12. The optimization of polymalic acid peptide copolymers for endosomolytic drug delivery.

    Science.gov (United States)

    Ding, Hui; Portilla-Arias, Jose; Patil, Rameshwar; Black, Keith L; Ljubimova, Julia Y; Holler, Eggehard

    2011-08-01

    Membranolytic macromolecules are promising vehicles for cytoplasmic drug delivery, but their efficiency and safety remains primary concerns. To address those concerns, membranolytic properties of various poly(β-L-malic acid) (PMLA) copolymers were extensively investigated as a function of concentration and pH. PMLA, a naturally occurring biodegradable polymer, acquires membranolytic activities after substitution of pendent carboxylates with hydrophobic amino acid derivatives. Ruled by hydrophobization and charge neutralization, membranolysis of PMLA copolymers increased as a function of polymer molecular weight and demonstrated a maximum with 50% substitution of carboxylates. Charge neutralization was achieved either conditionally by pH-dependent protonation or permanently by masking carboxylates. Membranolysis of PMLA copolymers containing tripeptides of leucine, tryptophan and phenylalanine were pH-dependent in contrast to pH-independent copolymers of Leucine ethyl ester and Leu-Leu-Leu-NH(2) with permanent charge neutralization. PMLA and tripeptides seemed a unique combination for pH-dependent membranolysis. In contrast to nontoxic pH-dependent PMLA copolymers, pH-independent copolymers were found toxic at high concentration, which is ascribed to their nonspecific disruption of plasma membrane at physiological pH. pH-Dependent copolymers were membranolytically active only at acidic pH typical of maturating endosomes, and are thus devoid of cytotoxicity. The PMLA tripeptide copolymers are useful for safe and efficient cytoplasmic delivery routed through endosome. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. 21 CFR 172.808 - Copolymer condensates of ethylene oxide and propylene oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Copolymer condensates of ethylene oxide and propylene oxide. 172.808 Section 172.808 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... ethylene oxide and propylene oxide. Copolymer condensates of ethylene oxide and propylene oxide may be...

  14. 21 CFR 175.365 - Vinylidene chloride copolymer coatings for polycarbonate film.

    Science.gov (United States)

    2010-04-01

    ... polycarbonate film. 175.365 Section 175.365 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... chloride copolymer coatings for polycarbonate film. Vinylidene chloride copolymer coatings identified in this section and applied on polycarbonate film may be safely used as food-contact surfaces, in...

  15. The effect of heat treatment on the internal structure of nanostructured block copolymer films

    DEFF Research Database (Denmark)

    Sepe, Alessandro; Hoppe, E T; Jaksch, S

    2011-01-01

    We report on the temperature dependence of the nanostructure of thin block copolymer films, as studied using in situ grazing-incidence small-angle x-ray scattering (GISAXS). We focus on spin-coated poly(styrene-b-butadiene) diblock copolymer thin films featuring lamellae perpendicular to the subs...

  16. Transparent Heat-Resistant PMMA Copolymers for Packing Light-Emitting Diode Materials

    OpenAIRE

    Shu-Ling Yeh; Chao-Yuan Zhu; Shiao-Wei Kuo

    2015-01-01

    Transparent and heat-resistant poly(methyl methacrylate) copolymers were synthesized by bulk polymerizing methyl methacrylate (MMA), isobornyl methacrylate (IBMA), and methacrylamide (MAA) monomers. Copolymerization was performed using a chain transfer agent to investigate the molecular weight changes of these copolymers, which exhibited advantages including a low molecular weight distribution, excellent optical properties, high transparency, high glass transition temperature, low moisture a...

  17. Hierarchical assembly of nanostructured organosilicate networks via stereocomplexation of block copolymers.

    Science.gov (United States)

    Kim, Sung Ho; Nederberg, Fredrik; Zhang, Lei; Wade, Charles G; Waymouth, Robert M; Hedrick, James L

    2008-01-01

    The effect of the stereochemistry of polylactide (PLA)-based block copolymers on templated inorganic nanostructures has been investigated from the self-assembly of a stereoisomer pair/organosilicate mixture followed by organosilicate vitrification and copolymer thermolysis. Isomeric PLA homopolymers, block copolymers, and a stereoblock copolymer were prepared by ring-opening polymerization of D-, L-, or rac-lactide using an organocatalytic catalyst. Both differential scanning calorimetry and atomic force microscopy showed the formation of a stereocomplex between enantiomeric stereoisomers, that is, block copolymer/block copolymer and block copolymer/homopolymer mixtures as well as a stereoblock copolymer. The unique noncovalent interactions driven by stereocomplexation of D- and L-lactide provided supramolecular structures with a hierarchical order as characterized by distinctive vertical and horizontal growth of toroidal nanostructured inorganic features. This study demonstrates the potential of hierarchically assembling suprastructures that bridge the nano- to mesoscale feature sizes in the design of tunable functional nanomaterials suitable for future applications of microelectronics, material science, and bioengineering.

  18. Stereocomplex mediated gelation of PEG-(PLA)2 and PEG(PLA)8 block copolymers

    NARCIS (Netherlands)

    Hiemstra, C.; Zhong, Zhiyuan; Dijkstra, Pieter J.; Feijen, Jan

    2005-01-01

    Stereocomplex mediated hydrogels have been prepared by mixing solutions of polymers of opposite chirality of either PEG-(PLA)2 triblock copolymers or PEG-(PLA)8 star block copolymers. The critical gel concentrations of the mixed enantiomer solutions were considerably lower compared to polymer

  19. Organometallic Block Copolymers As Catalyst Precursors For Templated Carbon Nanotube Growth

    NARCIS (Netherlands)

    Hinderling, Christian; Keles, Yanki; Stöckli, Thomas; Knapp, Helmut F.; De los Arcos, Teresa; Oelhafen, Peter; Korczagin, I.; Hempenius, Mark A.; Vancso, Gyula J.; Pugin, Raphaël; Heinzelmann, Harry

    2004-01-01

    The use of organic-organometallic block copolymers as catalyst precursors for templated carbon nanotube (CNT) growth (see Figure) is demonstrated for the first time. A thin film of block copolymer was treated with O2 plasma to produce ordered iron-containing catalyst nanoparticle arrays, which are

  20. Controlled Functionalization of Olefin/styrene Copolymers through Free Radical Processes

    NARCIS (Netherlands)

    Passaglia, Elisa; Aglietto, Mauro; Ciardelli, Francesco; Picchioni, Francesco

    2000-01-01

    The functionalization of styrene-b-(ethylene-co-1-butene)-b-styrene triblock copolymer (SEBS) and styrene-co-butadiene (SBR) random copolymer by free radical processes is presented. SEBS was functionalized in the melt with diethyl maleate (DEM) and dicumyl peroxide (DCP) as initiator. The