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Sample records for butylenes

  1. 21 CFR 172.712 - 1,3-Butylene glycol.

    Science.gov (United States)

    2010-04-01

    ... Other Specific Usage Additives § 172.712 1,3-Butylene glycol. The food additive 1,3-butylene glycol (CAS... 20740, or may be examined at the Center for Food Safety and Applied Nutrition's Library, Food and...

  2. Structure-barrier property relationship of biodegradable poly(butylene succinate) and poly[(butylene succinate)-co-(butylene adipate)] nanocomposites: influence of the rigid amorphous fraction.

    Science.gov (United States)

    Charlon, S; Marais, S; Dargent, E; Soulestin, J; Sclavons, M; Follain, N

    2015-11-28

    Composites composed of polyesters, poly(butylene succinate) (PBS) or poly[(butylene succinate)-co-(butylene adipate)] (PBSA), and 5 wt% of montmorillonite (CNa) or organo-modified montmorillonite (C30B) were melt-processed and transformed into films by either compression-molding or extrusion-calendering. XRD, rheological measurements and TEM images clearly indicated that films containing CNa are microcomposites, while nanocomposites were observed for those containing C30B. Using Flash DSC, it was possible, for the first time, not only to measure the heat capacity step at the glass transition of these two materials in their amorphous state, but also to investigate whether the preparation technique influenced the Rigid Amorphous Fraction (RAF) in our PBS- and PBSA-based nanocomposites. In this work, we have successfully shown the correlation between the microstructure of the films and their barrier properties, and especially the role played by the RAF. Indeed, the lowest permeabilities to gases and to water were determined in the films containing the highest RAF in both PBS- and PBSA-based materials.

  3. Effect of organo-modified montmorillonite on poly(butylene succinate/poly(butylene adipate-co-terephthalate nanocomposites

    Directory of Open Access Journals (Sweden)

    2010-07-01

    Full Text Available The composite material based on poly(butylene succinate (PBS, poly(butylene adipate-co-terephthalate (PBAT and organo-modified montmorillonite (OMMT were prepared by melt blending technique and characterized. Sodium montmorillonite (Na-MMT was successfully modified by octadecylammonium (ODA and dimethyldioctadecylammonium (DDOA salts to become OMMT through cation exchange technique which is shown by the increase of basal spacing of clay by XRD. The addition of the OMMT to the PBS/PBAT blends produced nanocomposites which is proved by XRD and TEM. Tensile tests showed increase in tensile strength and modulus which is attributed to the existence of strong interactions between PBS/PBAT and clay, particularly with OMMT. Highest tensile strength of nanocomposite was observed at 1 wt% of OMMT incorporated. TGA study showed that the thermal stability of the blend increased after the addition of clays. SEM micrographs of the fracture surfaces show that the morphology of the blend becomes homogeneous and smoother with presence of OMMT.

  4. Thermo stabilisation of poly (butylene adipate-co-terephthalate

    Directory of Open Access Journals (Sweden)

    Rodrigo Paulino Chaves

    Full Text Available Abstract Poly (butylene adipate-co-terephthalate - PBAT is a synthetic biodegradable polymer commonly used for plastic film production from neat polymer or nanocomposites. The PBAT is submitted to high temperatures and shear rate during its processing. In the present study, the thermo stabilisation of PBAT by the addition of two types of stabilisers was studied using a torque rheometer at 60 rpm and two levels of temperature. The stabilisers were used as master batches with a percentage of 10% by weight of additive in the PBAT. Molecular weight, torque values after 10 minutes of mixing, and absorbance at 400 nm were used to evaluate the process of stabilisation. The primary and secondary antioxidant used here had a positive effect on both processing temperatures, 180 and 200 °C. The best results indicate that the primary antioxidant could be used alone to protect PBAT against thermodegradation reactions.

  5. COMPOSITIONAL HETEROGENEITY OF ETHYLENE OXIDE-BUTYLENE TEREPHTHALATE SEGMENTED COPOLYMER

    Institute of Scientific and Technical Information of China (English)

    De-zhu Ma; Dong-sheng Li; Ming-chuan Zhao; Mo-zhen Wang; Ran Ye; Xiao-lie Luo

    1999-01-01

    A series of ethylene oxide-butylene terephthalate (EOBT) segmented copolymers with different soft segment length and hard segment content were synthesized. The compositional heterogeneity was studied by solvent extraction. The results show that the compositional heterogeneity increases when soft segment length and hard segment content increase. The compositional heterogeneity is also reflected in the crystallization behavior and morphology of soft and hard segment in EOBT segmented copolymer. The more compositional heterogeneous the EOBT segmented copolymer is, the more different the morphology and the crystallization behavior between separated fractions. Compared with ethylene oxide-ethylene terephthalate (EOET) segmented copolymer, compositional heterogeneity in EOBT segmented copolymer is weaker. But the compositional heterogeneity in EOBT segmented copolymer with long soft segment and high hard segment content is still obvious.

  6. Poly(glycerol sebacate)/poly(butylene succinate-butylene dilinoleate) fibrous scaffolds for cardiac tissue engineering.

    Science.gov (United States)

    Tallawi, Marwa; Zebrowski, David C; Rai, Ranjana; Roether, Judith A; Schubert, Dirk W; El Fray, Miroslawa; Engel, Felix B; Aifantis, Katerina E; Boccaccini, Aldo R

    2015-06-01

    The present article investigates the use of a novel electrospun fibrous blend of poly(glycerol sebacate) (PGS) and poly(butylene succinate-butylene dilinoleate) (PBS-DLA) as a candidate for cardiac tissue engineering. Random electrospun fibers with various PGS/PBS-DLA compositions (70/30, 60/40, 50/50, and 0/100) were fabricated. To examine the suitability of these fiber blends for heart patches, their morphology, as well as their physical, chemical, and mechanical properties were measured before examining their biocompatibility through cell adhesion. The fabricated fibers were bead-free and exhibited a relatively narrow diameter distribution. The addition of PBS-DLA to PGS resulted in an increase of the average fiber diameter, whereas increasing the amount of PBS-DLA decreased the hydrophilicity and the water uptake of the nanofibrous scaffolds to values that approached those of neat PBS-DLA nanofibers. Moreover, the addition of PBS-DLA significantly increased the elastic modulus. Initial toxicity studies with C2C12 myoblast cells up to 72 h confirmed nontoxic behavior of the blends. Immunofluorescence analyses and scanning electron microscopy analyses confirmed that C2C12 cells showed better cell attachment and proliferation on electrospun mats with higher PBS-DLA content. However, immunofluorescence analyses of the 3-day-old rat cardiomyocytes cultured for 2 and 5 days demonstrated better attachment on the 70/30 fibers containing well-aligned sarcomeres and expressing high amounts of connexin 43 in cellular junctions indicating efficient cell-to-cell communication. It can be concluded, therefore, that fibrous PGS/PBS-DLA scaffolds exhibit promising characteristics as a biomaterial for cardiac patch applications.

  7. Radiation Yield and Radicals Produced in Irradiated Poly (Butylene Succinate

    Directory of Open Access Journals (Sweden)

    Meri Suhartini

    2004-01-01

    Full Text Available The main chemical effects of ionizing irradiation on polymers are crosslinking and chain scission. Both processes occur simultaneously and their yields determine the final results of processing. The radiation yield of crosslinking could be determined by several methods depending on the characteristics of the material and properties of the gel. Radiation parameters of gelation, such as gelation dose and ratio of scission yield to crosslinking yield, as well as their values were estimated. In this study, those parameters depend on the amount of Trimethallyl isocyanurate (TMAIC in Poly(butylene succinate (PBS, molecular weight of PBS, and irradiation condition. In the absence of TMAIC, higher molecular weight of PBS required less energy to start gelation process compare to lower molecular weight of PBS. While in the presence of TMAIC all of the PBS samples require similar energy to start gelation process. The existence of macroradicals were observed by Electron Spin Resonance measurements. The result showed that the spectra consisted of signals derived from radicals on carbon nearby carbonyl, and signals derived from radicals on carbon reside between two similar carbon on polymer, both of radicals lead to crosslinking.

  8. Organoclay nanocomposites of post-industrial waste poly(butylene terephthalate) from automotive parts.

    Science.gov (United States)

    Quispe, Noe B; Fernandes, Elizabeth G; Zanata, Fernanda; Bartoli, Julio R; Souza, Diego H S; Ito, Edson N

    2015-10-01

    Polymeric nanocomposites are novel materials of huge interest owing to their favourable cost/performance ratio with low amount of nanofillers, improved thermal resistance, flame retardancy and mechanical properties in relation to their matrices. In this work, composites based on post-industrial waste or primary recycled poly(butylene terephthalate) and 5 wt.% of organic modified montmorillonite clays were melt compounded using a twin-screw extruder. A 2(2) factorial experimental design was used to study the compounding and processing variables: Organic modified montmorillonite with one or two hydrogenated tallow (initial basal spacing) and screw speed of the extruder. X-ray diffraction and transmission electron microscopy suggest that a partial exfoliation of the organoclay in the recycled poly(butylene terephthalate) matrix was achieved for organic modified montmorillonite with lower initial basal spacing. On the other hand, formulations containing organic modified montmorillonite with higher initial basal spacing showed only intercalated structure. The recycled poly(butylene terephthalate)-organic modified montmorillonite nanocomposites did not drip flaming material during burning tests. Storage of dynamic-mechanical, tensile and flexural moduli of the recycled poly(butylene terephthalate)-organic modified montmorillonite were improved when compared with both virgin and recycled poly(butylene terephthalate)s, mainly for nanocomposites formulated at a lower initial basal spacing organoclay. This could be related to a better diffusion of polymer into organic modified montmorillonite layers compared with the higher initial basal spacing organoclay. The improvements on the physical properties of recycled poly(butylene terephthalate) showed the feasibility to add value to primary recycled engineering thermoplastics with a very small amount of organic modified montmorillonite.

  9. Preparation of biodegradable porous poly(butylene succinate microspheres

    Directory of Open Access Journals (Sweden)

    Pepić Dragana

    2008-01-01

    Full Text Available The aim of this study was to determine the optimal conditions for the fabrication of porous microspheres based on poly(butylene succinate, PBS. The biodegradable non-porous PBS microspheres were prepared by the oil-in-water (o/w emulsion solvent evaporation method using poly(vinyl alcohol, PVA, as the surfactant. Fabrication conditions, such as stirring rate, organic/aqueous ratio, PBS concentration and surfactant (PVA concentration, which have an important influence on both the particle size and the morphology of the microspheres, were varied. Scanning electron microscopy, SEM, observations confirmed the size, size distribution and surface morphology of the microspheres. The optimal conditions for the preparation of the non-porous microspheres were found to be: concentration the PBS solution, 10 mass%; PVA concentration, 1 mass%; the organic/ aqueous ratio CHCl3/H2O = 1/20 and stirring rate 800 rpm. Porous PBS microspheres were fabricated under the optimal conditions using various amounts of hexane and poly(ethylene oxide, PEO, as porogens. The influence of the amount of porogen on the pore size and the particle size was investigated using SEM and the apparent density. The microspheres exhibited various porosities and the pore sizes. The average particle size of the microspheres with PEO as the porogen was from 100 to 122μm and that of the microspheres with hexane as the porogen was from 87 to 97μm. The apparent density of the porous microspheres with PEO as the porogen, from 0.16 to 0.23 g/cm3, was much smaller than the non-porous microspheres, 0.40 g/cm3. In the in vitro degradation experiments, the porous microspheres were incubated in phosphate buffer solution (pH 7 at 37°C. After incubating for one month, the microspheres showed significant extent of the hydrolytic degradation of the porous PBS microspheres.

  10. Poly(ethylene-co-butylene) functionalized multi walled carbon nanotubes applied in polypropylene nanocomposites

    DEFF Research Database (Denmark)

    Daugaard, Anders Egede; Jankova Atanasova, Katja; Marín, Jose Manuel Roman;

    2012-01-01

    A novel functionalized multi walled carbon nanotube (MWCNT) was prepared through grafting with α-azido-poly(ethylene-co-butylene) (PEB-N3). The PEB-N3 was prepared through a two step procedure and grafted onto an industrial grade multi walled carbon nanotube (MWCNT) through a highly efficient nit...

  11. Synthesis and properties of poly(butylene terephthalate)-b-polyisobutylene segmented block copolymers

    NARCIS (Netherlands)

    Walch, E.; Gaymans, R.J.

    1994-01-01

    Segmented block copolymers of polyisobutylene (PIB) and poly(butylene terephthalate) (PBT) were made by condensation polymerization of α,θ-di-anhydride telechelic PIB, with 1,4-butanediol and dimethyl terephthalate. The inherent viscosity of the polymers was between 0.35 and 2.0 dl g−1. The extracta

  12. Gas-permeation properties of poly(ethylene oxide) poly(butylene terephthalate block copolymers

    NARCIS (Netherlands)

    Metz, S.J.; Mulder, M.H.V.; Wessling, M.

    2004-01-01

    This paper reports the gas-permeation properties of poly(ethylene oxide) (PEO) poly(butylene terephthalate) (PBT) segmented multiblock copolymers. These block copolymers allow a precise structural modification by the amount of PBT and the PEO segment length, enabling a systematic study of the relati

  13. Influence of Teflon substrate on crystallization and enzymatic degradation of polymorphic poly(butylene adipate)

    DEFF Research Database (Denmark)

    Ning, Zhenbo; Nielsen, Ronnie Bo Højstrup; Zhao, Lifen;

    2014-01-01

    Oriented and non-oriented Teflon films, which were found to have the same crystalline structure, but different surface morphologies, were used to sandwich poly(butylene adipate) (PBA) films during isothermal crystallization. It was found that both the Teflon surface structure and the PBA...

  14. Amorphous/crystal and polymer/filler interphases in biocomposites from poly(butylene succinate)

    Energy Technology Data Exchange (ETDEWEB)

    Signori, Francesca [Consiglio Nazionale delle Ricerche - Istituto per i Processi Chimico-Fisici (CNR-IPCF), Via G. Moruzzi 1, I-56124 Pisa (Italy); Pelagaggi, Martina [Universita di Pisa - Dipartimento di Chimica e Chimica Industriale, Via Risorgimento 35, I-56126 Pisa (Italy); Bronco, Simona [Consiglio Nazionale delle Ricerche - Istituto per i Processi Chimico-Fisici (CNR-IPCF), Via G. Moruzzi 1, I-56124 Pisa (Italy); Righetti, Maria Cristina, E-mail: righetti@ipcf.cnr.it [Consiglio Nazionale delle Ricerche - Istituto per i Processi Chimico-Fisici (CNR-IPCF), Via G. Moruzzi 1, I-56124 Pisa (Italy)

    2012-09-10

    Highlights: Black-Right-Pointing-Pointer The existence of intermolecular interactions between poly(butylene succinate) and hemp fibres was proved from specific heat capacities data. Black-Right-Pointing-Pointer Different degrees of mobility of the poly(butylene succinate) amorphous segments were evidenced at the amorphous/crystal interphase. Black-Right-Pointing-Pointer Devitrification of the rigid amorphous fraction in poly(butylene succinate) was found to occur before and simultaneously with the fusion. - Abstract: Poly(butylene succinate)-hemp composites (PBS-hemp), with hemp content in the range 0-40 wt.%, were prepared in the melt and characterized. This paper focuses on the detailed analysis of the thermal behaviour of the PBS-hemp composites, investigated by differential scanning calorimetry (DSC), to enlighten the polymer/fibre interphase features. The occurrence of specific intermolecular interactions between PBS and hemp was assessed from specific heat capacity data. Different degrees of mobility of the PBS amorphous segments were found at the amorphous/crystal interphases. A broadening of the bulk glass transition was observed, and attributed to the presence of polymer segments slightly constrained. Moreover, a rigid amorphous fraction that devitrifies at temperatures higher than the bulk glass transition, partly before the melting region and partly simultaneously with the fusion, was observed and quantified, and attributed to the presence of major constraints probably occurring in geometrically restricted areas.

  15. Electrospun Nanoporous Poly(butylenes succinate-co-bytylene terephthalate Nonwoven Mats

    Directory of Open Access Journals (Sweden)

    Liang Wang

    2011-01-01

    Full Text Available A traditional Chinese drug “Yunnan Baiyao” is used as an additive in poly(butylenes succinate-co-bytylene terephthalate (PBST solution, which is a kind of biodegradable aliphatic-aromatic copolyesters, to produce microspheres with nanoporosity by electrospinning; the tunable size of nanoporosity can be controlled by changing the voltage applied in the electrospinning process.

  16. Synthesis and properties of novel aliphatic polycarbonate from carbon dioxide with 1,2-butylene oxide and ε-caprolactone

    Institute of Scientific and Technical Information of China (English)

    Yan Fei Liu; Ke Long Huang; Dong Ming Peng; Su Qin Liu; Hong Wu

    2007-01-01

    A new degradable aliphatic poly(butylene-co-ε-caprolactone carbonate) (PBCL) was synthesized through the terpolymerization of carbon dioxide, 1,2-butylene oxide (BO) and ε-caprolactone (CL), a polymer supported bimetallic complex (PBM) was used as a catalyst. The terpolymers prepared were characterized by FT-IR, 1H NMR, 13C NMR, WXRD and DSC. The hydrolysis tests were carried out to appraise the degradability of the copolymers.

  17. Lenghty reverse poly(butylene oxide)-poly(ethylene oxide)-poly(butylene oxide) polymeric micelles and gels for sustained release of antifungal drugs.

    Science.gov (United States)

    Figueroa-Ochoa, Edgar B; Villar-Alvarez, Eva M; Cambón, Adriana; Mistry, Dharmista; Llovo, José; Attwood, David; Barbosa, Silvia; Soltero, J F Armando; Taboada, Pablo

    2016-08-20

    In this work, we present a detailed study of the potential application of polymeric micelles and gels of four different reverse triblock poly(butylene oxide)-poly(ethylene oxide)-poly(butylene oxide) copolymers (BOnEOmBOn, where n denotes the respective block lengths), specifically BO8EO90BO8, BO14EO378BO14, BO20EO411BO20 and BO21EO385BO21, as effective drug transport nanocarriers. In particular, we tested the use of this kind of polymeric nanostructures as reservoirs for the sustained delivery of the antifungals griseofulvin and fluconazole for oral and topical administration. Polymeric micelles and gels formed by these copolymers were shown to solubilize important amounts of these two drugs and to have a good stability in physiologically relevant conditions for oral or topical administration. These polymeric micellar nanocarriers were able to release drugs in a sustained manner, being the release rate slower as the copolymer chain hydrophobicity increased. Different sustained drug release profiles were observed depending on the medium conditions. Gel nanocarriers were shown to display longer sustained release rates than micellar formulations, with the existence of a pulsatile-like release mode under certain solution conditions as a result of their inner network structure. Certain bioadhesive properties were observed for the polymeric physical gels, being moderately tuned by the length and hydrophobicity of the polymeric chains. Furthermore, polymeric gels and micelles showed activity against the yeast Candida albicans and the mould demartophytes (Trichophyton rubrum and Microsporum canis) and, thus, may be useful for the treatment of different cutaneous fungal infections.

  18. Complex self-assembly of reverse poly(butylene oxide)-poly(ethylene oxide)-poly(butylene oxide) triblock copolymers with long hydrophobic and extremely lengthy hydrophilic blocks.

    Science.gov (United States)

    Cambón, Adriana; Figueroa-Ochoa, Edgar; Juárez, Josué; Villar-Álvarez, Eva; Pardo, Alberto; Barbosa, Silvia; Soltero, J F Armando; Taboada, Pablo; Mosquera, Víctor

    2014-05-15

    Amphiphilic block copolymers have emerged during last years as a fascinating substrate material to develop micellar nanocontainers able to solubilize, protect, transport, and release under external or internal stimuli different classes of cargos to diseased cells or tissues. However, this class of materials can also induce biologically relevant actions, which complement the therapeutic activity of their cargo molecules through their mutual interactions with biologically relevant entities (cellular membranes, proteins, organelles...); these interactions at the same time, are regulated by the nature, conformation, and state of the copolymeric chains. For these reasons, in this paper we investigated the self-assembly process and physico-chemcial properties of two reverse triblock poly(butylene oxide)-poly(ethylene oxide)-poly(butylene oxide) block copolymers, BO14EO378BO14 and BO21EO385BO21, which have been recently found to be very useful as drug delivery nanovehicles and biological response modifiers under certain conditions (A. Cambón et al. Int. J. Pharm. 2013, 445, 47-57) in order to obtain a clear picture of the solution behavior of this class or block copolymers and to understand their biological activity. These block copolymers are characterized by possessing long BO blocks and extremely lengthy central EO ones, which provide them with a rich rheological behavior characterized by the formation of flowerlike micelles with sizes ranging from 20 to 40 nm in aqueous solution and the presence of intermicellar bridging even at low copolymers concentrations as denoted by atomic force microscopy. Bridging is also clearly observed by analyzing the rheological response of these block copolymers both storage and loss moduli upon changes on time, temperature, and or concentration. Strikingly, the relatively wide Poisson distribution of the polymeric chains make the present copolymers behave rather distinctly to conventional associative thickeners. The observed rich

  19. THERMALLY STIMULATED SHAPE MEMORY BEHAVIOR OF (ETHYLENE OXIDE-BUTYLENE TEREPHTHALATE) SEGMENTED COPOLYMER

    Institute of Scientific and Technical Information of China (English)

    Xiao-lie Luo; Ming-chuan Zhao; Mo-zhen Wang; Lu-na Ding; De-zhu Ma

    2000-01-01

    The thermally stimulated shape memory behavior of ethylene oxide-butylene terephthalate (EOBT) segmented copolymers with different soft segment molecular weight and hard segment content was investigated. The deformation recovery ratio Rf of the EOBT samples increases with the soft segment molecular weight and the hard segment weight content, while the average overall deformation recovery speed Vr increases with the hard segment content. The temperature of maximum deformation recovery speed (TM) is determined by the melting temperature of the soft segment crystals and the stability of the crystallized hard segment domains.

  20. Poly(butylene succinate) and its copolymers: research, development and industrialization.

    Science.gov (United States)

    Xu, Jun; Guo, Bao-Hua

    2010-11-01

    Poly(butylene succinate) (PBS) and its copolymers are a family of biodegradable polymers with excellent biodegradability, thermoplastic processability and balanced mechanical properties. In this article, production of the monomers succinic acid and butanediol, synthesis, processing and properties of PBS and its copolymers are reviewed. The physical properties and biodegradation rate of PBS materials can be varied in a wide range through copolymerization with different types and various contents of monomers. PBS has a wide temperature window for thermoplastic processing, which makes the resin suitable for extrusion, injection molding, thermoforming and film blowing. Finally, we summarized industrialization and applications of PBS.

  1. Isothermal Crystallization Behavior of Biodegradable Poly (butylene succinate-co-terephthalate)(PBST) Copolyesters at High Undercoolings

    Institute of Scientific and Technical Information of China (English)

    XU Xin-jian; LI Fa-xue; LUO Sheng-li; YU Jian-yong

    2008-01-01

    Poly(butylene succinate-co-terephthalate)(PBST)copolyesters were prepared by polycondensation.The isothermal crystallization behavior of the as-prepared copolyesters was investigated by depolarized light intensity(DLI)at high undercoolings.According to Avrami equation,the exponent n,independent of the crystallization temperature,is at a range of 2.5 to 3.4,which probably corresponds to the heterogeneous nucleation and a 3-dimensional spherulitic growth.The maximum crystallization rate,very useful to polymer processing,was foundat about 90℃ based on the half-crystallization time t1/2 analysis.

  2. Alternating polyesteramides based on 1,4-butylene terephthalamide: 4. Alternating polyetheresteramides based on glycols (4NTglycol)

    NARCIS (Netherlands)

    Serrano, P.J.M.; Gaymans, R.J.

    1998-01-01

    Polyetheresteramides (PEEAs) have been synthesised in the melt from 1,4-butylene terephthalamide and ethylene or propylene glycols. The ethylene glycols were ethylenediol, diethylene glycol, triethylene glycol and tetraethylene glycol. The propylene glycols were 1,3-propanediol and the mixtures of 1

  3. Segmented block copolymers based on poly(butylene terephthalate) and telechelic polyesters and polyamides of dimerized fatty acids

    NARCIS (Netherlands)

    Manuel, H.J.; Gaymans, R.J.

    1993-01-01

    Segmented block copolymers (SBCs) based on poly(butylene terephthalate) (PBT) and telechelics based on dimerized fatty acids have been synthesized in the melt. The dimerized fatty acids were coupled with diols or diamines to synthesize polyesters and polyamides of low molar mass. With these telechel

  4. Poly(Butylene Terephthalate Based Composites Containing Alumina Whiskers: Influence of Filler Functionalization on Dielectric Properties

    Directory of Open Access Journals (Sweden)

    Pietro Russo

    2014-01-01

    Full Text Available Poly(butylene terephthalate (PBT is one of the most widely used semicrystalline thermoplastics polyester because of its superior thermal and mechanical properties, high dimensional stability and excellent processability. In this research PBT-based nanocomposites, including various amounts (up to 10 wt% of commercial alumina whiskers, have been prepared by using a Brabender internal chamber mixer and analysed in terms of morphological features and dielectric properties. Specific attention has been focused on the effect of the filler functionalization considering 3-glycidoxy propylmethoxysilane (GPS or 3-methacryloxypropyltrimethoxysilane (MPS as coupling agents. Tests, performed on compounds filled with neat and functionalized alumina whiskers, show a clear dependence of relative dielectric permittivity εr, invariance of dissipation factor (tgδ, and a sensible increase of volume electrical resistivity (ρv with the filler’s content and are encouraging for a future introduction of such composites in many electrical applications.

  5. Sulfonated Styrene-(ethylene-co-butylene-styrene/Montmorillonite Clay Nanocomposites: Synthesis, Morphology, and Properties

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    Ganguly Anirban

    2007-01-01

    Full Text Available AbstractSulfonated styrene-(ethylene-butylene-styrene triblock copolymer (SSEBS was synthesized by reaction of acetyl sulfate with SEBS. SSESB-clay nanocomposites were then prepared from hydrophilic Na-montmorillonite (MT and organically (quaternary amine modified hydrophobic nanoclay (OMT at very low loading. SEBS did not show improvement in properties with MT-based nanocomposites. On sulfonation (3 and 6 weight% of SEBS, hydrophilic MT clay-based nanocomposites exhibited better mechanical, dynamic mechanical, and thermal properties, and also controlled water–methanol mixture uptake and permeation and AC resistance. Microstructure determined by X-ray diffraction, atomic force microscopy, and transmission electron microscopy due to better dispersion of MT nanoclay particles and interaction of MT with SSEBS matrix was responsible for this effect. The resulting nanocomposites have potential as proton transfer membranes for Fuel Cell applications.

  6. Biodegradable Poly(butylene succinate Composites Reinforced by Cotton Fiber with Silane Coupling Agent

    Directory of Open Access Journals (Sweden)

    Masahiro Funabashi

    2013-01-01

    Full Text Available In this study, the use of cotton fiber (CF as a filler in poly(butylene succinate (PBS and the effect of silane treatment on the mechanical properties, thermal stability, and biodegradability of PBS/CF composites are investigated. The results showed that the tensile strength of PBS was improved (15%–78% with the incorporation of CF (10–40 wt% and was further increased (25%–118% when CF was treated with a silane coupling agent. Scanning electron microscopy (SEM observation of the fracture surfaces of PBS/CF composites showed that there was slight improvement in fiber-matrix compatibility. Thermogravimetric (TG analysis showed that the thermal stability of the composites was lower than that of neat PBS and decreased with increasing filler loading. The biobased carbon content of the composites increased with increasing CF content. The incorporation of CF (with and without silane treatment in PBS significantly increased the biodegradation rate of the composites.

  7. Antimicrobial activity of electrospun poly(butylenes succinate) fiber mats containing PVP-capped silver nanoparticles.

    Science.gov (United States)

    Tian, Ligang; Wang, Pingli; Zhao, Zhiguo; Ji, Junhui

    2013-12-01

    In this study, biodegradable poly(butylenes succinate) (PBS) fiber mats containing silver nanoparticles (AgNPs) were prepared by the electrospinning process. Small AgNPs (fiber mats and the distribution of the AgNPs were well characterized by TEM and SEM. The release of Ag from the PBS fiber mats was quantitively determined by ICP. The PBS fiber mats with 0.29 % AgNPs content showed strong antimicrobial activity against both gram-positive Staphylococcus aureus and gram-negative Escherichia coli with the efficacy as high as 99 %. The effective bactericidal activity on E. coli was demonstrated for a short contacting time with the PBS-AgNPs fiber mats. In addition, the long-term release performance of Ag from the fiber mats can keep inhibiting the bacterial growth in the mats over a long period of time.

  8. Biocompatibility and characterization of polylactic acid/styrene-ethylene-butylene-styrene composites.

    Science.gov (United States)

    Tsou, Chi-Hui; Kao, Bo-Jyue; Yang, Ming-Chien; Suen, Maw-Cherng; Lee, Yi-Hsuan; Chen, Jui-Chin; Yao, Wei-Hua; Lin, Shang-Ming; Tsou, Chih-Yuan; Huang, Shu-Hsien; De Guzman, Manuel; Hung, Wei-Song

    2015-01-01

    Polylactic acid (PLA)/styrene-ethylene-butylene-styrene (SEBS) composites were prepared by melt blending. Differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WXRD) were used to characterize PLA and PLA/SEBS composites in terms of their melting behavior and crystallization. Curves from thermal gravimetric analysis (TGA) illustrated that thermostability increased with SEBS content. Further morphological analysis of PLA/SEBS composites revealed that SEBS molecules were not miscible with PLA molecules in PLA/SEBS composites. The tensile testing for PLA and PLA/SEBS composites showed that the elongation at the break was enhanced, but tensile strength decreased with increasing SEBS content. L929 fibroblast cells were chosen to assess the cytocompatibility; the cell growth of PLA was found to decrease with increasing SEBS content. This study proposes possible reasons for these properties of PLA/SEBS composites.

  9. STUDIES ON EPOXY RESINS MODIFIED WITH POLY (BUTYLENE TEREPHTHALATE)-b-POLY (TETRAMETHYLENE GLYCOL)

    Institute of Scientific and Technical Information of China (English)

    WANG Xia; ZHAO Binyi; LI Zhengyi; YU Yunzhao

    1997-01-01

    Poly(butylene terephthalate)-b-poly(tetramethylene glycol) (PBT-b-PTMG) was used as rheology modifier for the epoxy resin. The segmental copolymer formed spherulites in the epoxy medium. This copolymer was very effective in endowing yield stresses to the liquid resin. The PTMG segment brought in a lowering of the dissolution temperature of the spherulites in the epoxy gel. The cured resin with PBT-b-PTMG as modifier was twophase materials. The rheology modifier improved the mechanical properties of the cured resin as well. The flexible PTMG segments, however, were not in favour of the toughening effect of the modifier. This was attributed to the large domain size of the dispersed phase.

  10. Poly(lactide)-g-poly(butylene succinate-co-adipate) with High Crystallization Capacity and Migration Resistance

    OpenAIRE

    Xi Yang; Huan Xu; Karin Odelius; Minna Hakkarainen

    2016-01-01

    Plasticized polylactide (PLA) with increased crystallization ability and prolonged life-span in practical applications due to the minimal plasticizer migration was prepared. Branched plasticized PLA was successfully obtained by coupling poly(butylene succinate-co-adipate) (PBSA) to crotonic acid (CA) functionalized PLA. The plasticization behavior of PBSA coupled PLA (PLA-CA-PBSA) and its counterpart PBSA blended PLA (PLA/PBSA) were fully elucidated. For both PLA-CA-PBSA and PLA/PBSA, a decre...

  11. DIGITAL IMAGE ANALYSIS OF PHASE STRUCTURE IN THE BLEND OF POLY(BUTYLENE TEREPHTHALATE-COCAPROLACTONE) WITH POLYCARBONATE

    Institute of Scientific and Technical Information of China (English)

    MA Dezhu; HE Liling; ZOU Yingfang; LUO Xiaolie; Takafumi Hayashi; Toshio Nishi

    1992-01-01

    The digital image processing technique was used for the extraction of physical information from the temporal image of phase structure in the process of phase separation in the blend of poly (butylene terephthalate-co-caprolactone )with polycarbonate. The power spectrum images of the two-dimensional Fourier transformation (2DFT) of the temporal image of phase structure reflect the change of the phase size with time.

  12. New sulfonated polystyrene and styrene-ethylene/butylene-styrene block copolymers for applications in electrodialysis.

    Science.gov (United States)

    Müller, Franciélli; Ferreira, Carlos A; Franco, Lourdes; Puiggalí, Jordi; Alemán, Carlos; Armelin, Elaine

    2012-09-27

    In this study we prepared blends of polystyrene (PS) and high-impact polystyrene (HIPS) with poly(styrene-ethylene-butylene) (SEBS) triblock copolymer. After sulfonation, blends were used to fabricate ion-exchange membranes by solvent-casting and subsequent thermal treatment to obtain homogeneous packing densities. The morphology and structure of the blends were investigated by scanning electron microscopy, atomic force microscopy, and FTIR spectroscopy. Furthermore, the thermal transitions and stability of all the blends were characterized using calorimetric techniques and compared with those of the individual polymers. Analyses of the physical properties (i.e., ionic conductivity, ion-exchange capacity, water uptake, dimensional stability, mechanical properties, etc.) showed that the performance of the PS-containing membranes is, in general, higher than that of the HIPS containing one. Furthermore, the highest sulfonation degree was also found for the PS/SEBS membranes. The capabilities of the membranes were tested by investigating the extraction of Na(+) by electrodyalisis. Comparison of the percentage of extracted ions indicates that the incorporation of SEBS results in a significant improvement with respect to membranes made of individual polymers.

  13. Case of allergic contact dermatitis due to 1,3-butylene glycol.

    Science.gov (United States)

    Aizawa, Atsuko; Ito, Akiko; Masui, Yukiko; Ito, Masaaki

    2014-09-01

    1,3-Butylene glycol (1,3-BG) is widely used in cosmetics, including low-irritant skin care products and topical medicaments, as an excellent and low-irritation humectant. We report a case of allergic contact dermatitis caused by 1,3-BG. A 28-year-old woman suffered from an itchy erythematous eruption on her face. By 2 days of closed patch testing, her own cosmetics and many of the hypo-irritant skin care products showed positive results. A second patch testing showed positive reaction to 1,3-BG (1% and 5%). 1,3-BG was a common component in most of the products that had elicited a positive reaction in the first patch testing. Although allergic contact dermatitis due to 1,3-BG is not so common, we have to consider 1,3-BG as a possible contact allergen in the patients presenting with allergic contact dermatitis due to various cosmetics.

  14. Incorporation of isosorbide into poly(butylene terephthalate) via solid-state polymerization.

    Science.gov (United States)

    Sablong, Rafaël; Duchateau, Robbert; Koning, Cor E; de Wit, Gert; va Es, Daan; Koelewijn, Roelof; van Haveren, Jacco

    2008-11-01

    The biomass-based monomer isosorbide was incorporated into poly(butylene terephthalate) (PBT) by solid-state polymerization (SSP) using the macrodiol monomer BTITB-(OH) 2, which consists of isosorbide (I), terephthalic acid (T), and 1,4-butandiol (B) residues. This macromonomer can be synthesized by a simple one-pot, two-step reaction. Polymers with number-average molecular weights up to 100,000 g x mol (-1) were readily synthesized from various ratios of PBT/BTITB-(OH) 2. Their molecular weights, thermal properties, and colors were compared with corresponding copolyesters that were obtained by melt polycondensation. We found that T m, T c, and especially T g were superior for materials that were obtained by SSP. This is ascribed to differences in the microstructures of both types of copolyesters; the SSP products exhibit a more blocky structure than do the more random melt-polymerized counterparts. The SSP method resulted in much higher molecular weights and much less colored polymers, and it seems to be the preferred route for incorporating biobased monomers that exhibit limited thermal stability into engineering plastics.

  15. Poly(butylene cyclohexanedicarboxylate/diglycolate random copolymers reinforced with SWCNTs for multifunctional conductive biopolymer composites

    Directory of Open Access Journals (Sweden)

    E. Fortunati

    2016-02-01

    Full Text Available The objective of this work was to develop a versatile strategy for preparing multifunctional composite films with tunable properties. Novel conductive composites based on the combination of single walled carbon nanotubes (SWCNTs and biodegradable poly(butylene cyclohexanedicarboxylate/diglycolate random copolymers (P(BCEmBDGn are here presented. In particular, synthesized PBCE homopolymer and two copolymers containing different amounts of ether–oxygen containing co-units, P(BCE90BDG10 and P(BCE70BDG30, have been considered as matrices of SWCNTs based composites. The effect of incorporation of different amounts of SWCNTs (0.1–0.5–0.75–1 wt% on morphological, thermal, mechanical and electrical properties was deeply investigated. The morphology of the fracture surfaces is affected by the SWCNT presence, while the increase in the SWCNT content does not provide significant microstructure modifications. The thermal properties underlined that nanotubes can act as nucleating agents, favouring the polymer crystallization process. The mechanical behavior demonstrated that the introduction of carbon nanotubes both in the case of PBCE homopolymer and in random copolymers based formulations exerted a reinforcing effect. All composites exhibit high electrical conductivity in comparison to the neat polymers. This work demonstrates that this combinatorial approach can be used to develop materials with tunable and advanced functional properties.

  16. Effect of gamma irradiation on poly(butylene naphthalate) based polyesters

    Science.gov (United States)

    Malavasi, I.; Consolati, G.; Quasso, F.; Soccio, M.; Gigli, M.; Negrin, M.; Macerata, E.; Giacobbo, F.; Lotti, N.; Munari, A.; Mariani, M.

    2016-07-01

    The present work investigates the effect of gamma radiation on the properties of three naphthalate-based polyesters, i.e. poly(butylene naphthalate) (PBN), poly(diethylene naphthalate) (PDEN) and poly(thiodiethylene naphthalate) (PTDEN). In addition, the analogous terephthalate-based polymers of PDEN and PTDEN, i.e. poly(diethylene terephthalate) (PDET) and poly(thiodiethylene terephthalate) (PTDET), are also investigated, in order to check the effect of a lower number of aromatic rings. All the polymers, irradiated in air at different absorbed doses, were characterized by several techniques. The data obtained indicate that all the polymers, except PBN, show a decrease of molecular weight with the dose increase. The thermal behavior and the morphology confirm the previous results and show that the higher the crystallinity degree and number of aromatic rings, the higher the radiation resistance. The introduction of heteroatoms decreases the ability of a polymer to crystallize due to a reduction of polymer chain symmetry, thus worsening their radiation resistance.

  17. Thermal and Mechanical Properties of Poly(butylene succinate Films Reinforced with Silica

    Directory of Open Access Journals (Sweden)

    Sangviroon Nanthaporn

    2015-01-01

    Full Text Available In recent year, bioplastics have become more popular resulting from the growing concerns on environmental issues and the rising fossil fuel price. However, their applications were limited by its mechanical and thermal properties. The aim of this research is thus to improve mechanical and thermal properties of PBS bioplastic films by reinforcing with silica. Due to the poor interfacial interaction between the PBS matrix and silica, glycidyl methacrylate grafted poly(butylene succinate (PBS-g-GMA was used as a compatibilizer in order to improve the interaction between bioplastic films and filler. PBS-g-GMA was prepared in a twin-screw extruder and analyzed by the FTIR spectrometer. PBS and silica were then mixed in a twin-screw extruder and processed into films by a chill-roll cast extruder. The effects of silica loading on thermal and mechanical properties of the prepared bioplastic films were investigated. It was found that the mechanical properties of PBS/silica composite films were improved when 1%wt of silica was added. However, the mechanical properties decreased with increasing silica loading due to the agglomeration of silica particles. The results also show that the silica/PBS films with PBS-g-GMA possessed improved mechanical properties over the films without the compatibilizer.

  18. NONISOTHERMAL CRYSTALLIZATION AND MORPHOLOGY OF POLY(BUTYLENE SUCCINATE)/LAYERED DOUBLE HYDROXIDE NANOCOMPOSITES

    Institute of Scientific and Technical Information of China (English)

    Mei-qiu Zhan; Guang-yi Chen; Zhi-yong Wei; Yu-mei Shi; Wan-xi Zhang

    2013-01-01

    Biodegradable poly(butylene succinate) (PBS) and layered double hydroxide (LDH) nanocomposites were prepared via melt blending in a twin-screw extruder.The morphology and dispersion of LDH nanoparticles within PBS matrix were characterized by transmission electron microscopy (TEM),which showed that LDH nanoparticles were found to be well distributed at the nanometer level.The nonisothermal crystallization behavior of nanocomposites was extensively studied using differential scanning calorimetry (DSC) technique at various cooling rates.The crystallization rate of PBS was accelerated by the addition of LDH due to its heterogeneous nucleation effect; however,the crystallization mechanism and crystal structure of PBS remained almost unchanged.In kinetics analysis of nonisothermal crystallization,the Ozawa approach failed to describe the crystallization behavior of PBS/LDH nanocomposites,whereas both the modified Avrami model and the Mo method well represented the crystallization behavior of nanocomposites.The effective activation energy was estimated as a function of the relative degree of crystallinity using the isoconversional analysis.The subsequent melting behavior of PBS and PBS/LDH nanocomposites was observed to be dependent on the cooling rate.The POM showed that the small and less perfect crystals were formed in nanocomposites.

  19. Effect of Rubberwood Content on Biodegradability of Poly(butylene succinate Biocomposites

    Directory of Open Access Journals (Sweden)

    Hemhong Anankaphong

    2015-01-01

    Full Text Available Poly(butylene succinate (PBS biocomposites incorporated with rubberwood powder (RWP were fabricated with various RWP weight fractions (i.e., 0 to 40% wt by injection moulding process. The soil burial test was employed to examine the biodegradability of such biocomposites under outdoor environment for 60 days. The physical appearance, percentage weight loss, chemical structure, and mechanical properties before and after the soil burial test were determined. Apparent changes in physical appearance of the biocomposites from optical micrographs were detected in terms of surface morphology and colour. The percentage of crystallinity of PBS/RWP biocomposites was studied by the X-ray diffraction (XRD technique, and the XRD pattern revealed a decrease in percentage of crystallinity due to enhancing RWP weight fractions. This may be attributed to a presence of rubberwood powders providing more disordered molecular chain arrangement of PBS matrix and also an agglomeration of the rubberwood powder content at greater concentration as seen in SEM micrographs. With increasing RWP weight fractions and burial time, the results exhibited a considerable change in chemical structure (essentially ester linkage due to biodegradation mechanism of PBS, relatively greater percentage weight loss, and a substantial decrease in flexural properties. Consequently, the results indicate that incorporating RWP enhances biodegradability of PBS/RWP biocomposites; that is, the biodegradation rate of biocomposites increases with increasing RWP weight fractions and burial time.

  20. Analysis of Gas Permeability Characteristics of Poly(Lactic Acid/Poly(Butylene Succinate Nanocomposites

    Directory of Open Access Journals (Sweden)

    Amita Bhatia

    2012-01-01

    Full Text Available Gas permeability and morphological properties of nanocomposites prepared by the mixing of poly(lactic acid (PLA, poly(butylene succinate (PBS, and clay was investigated. While the composition of PLA and PBS polymers was fixed as 80% and 20% by weight, respectively, for all the nanocomposites, clay contents varied from 1 to 10 wt%. From the morphological studies using both wide angle X-ray diffraction and transmission electron microscopy, the nanocomposite having 1 wt% of clay was considered to have a mixed morphology of intercalated and delaminated structure, while some clusters or agglomerated particles were detected for nanocomposites having 3 and more than 3 wt% of clay content. However, the average particle size of the dispersed PBS phase was reduced significantly from 7 μm to 30–40 nm with the addition of clay in the blend. The oxygen barrier property was improved significantly as compared to the water vapor. A model based on gas barrier property was used for the validation of the oxygen relative permeabilities of PLA/PBS/clay nanocomposites. PLA/PBS/clay nanocomposites validated the Bharadwaj model up to 3 wt% of clay contents only, while for nanocomposites of higher clay contents the Bharadwaj model was invalid due to the clusters and agglomerates formed.

  1. Lewis acid/base character and crystallisation properties of poly(butylene terephthalate).

    Science.gov (United States)

    Santos, José M R C A; Guthrie, James T

    2015-01-30

    Two grades of poly(butylene terephthalate) were analysed by means of inverse gas chromatography (IGC) and the results correlated with the respective crystallisation properties. The following parameters were determined by IGC: the dispersive component of the surface tension, the enthalpy and the entropy of adsorption of selected polar and apolar probes, and the Lewis acidity and basicity constants, Ka and Kb respectively. The interpretation of the values determined for Ka and Kb is in agreement with the FTIR spectra relating to the carboxyl end-group and the hydroxyl end-group concentrations in these polymers. The differences in the molecular weight values and in the end-group type and concentration, between the two grades of PBT, do not cause differences in the crystallisation activation energy. This observation suggests that there is a leading contribution of the Lewis basic sites to the crystallisation activation energy of the grades of PBT that were analysed. However, the lower value of Ka and the greater molar mass of one of the PBT grades lead to a corresponding lower crystallisation degree.

  2. The Electroluminescence Characterization of Poly(p-phenyleneethynylene)——The π-conjugated Backbone Interrupted by a Butylene Unit

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    π-Conjugated poly(p-phenyleneethynylene) with the interruption of the conjugation by a butylene unit was synthesized. Its absorption, PL and EL spectra were investigated respectively. The spectral peaks shifted to the higher energy side with the interruption of the conjugation lengths. The model compound was synthesized, by which the results were proved. The thermal characteristics of the polymer was determined by DSC and TGA, indicating that the polymer has a good thermal stability. The electroluminescence(EL) in the green region of the spectrum with a maximum at 500 nm was observed from the polymer films sandwiched between indium-tin-oxide and an Al electrode.

  3. Radiation-Induced Crosslinking of Biodegradable Poly(Butylenes Adipate-Co-Terephthalate) Film With Various Crosslinking Agents

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Chanhee; Choi, Joonho; Kang, Dongwoo; Hwang, Intae; Choi, Jaehak; Nho, Youngchang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-03-15

    In this research, electron beam-induced crosslinking of poly(butylene adipate-co-terephthalate) (PBAT) in the presence of crosslinking agents was investigated. PBAT films containing different crosslinking agents were crosslinked by electron beam irradiation at various absorbed doses and the properties of the crosslinked PBAT films were characterized. The results of the crosslinking degree measurements revealed that 3 wt% triallyl isocyanurate was found to be optimal for the radiation crosslinking of PBAT. The thermal and mechanical properties of the crosslinked PBAT films were much improved whereas their biodegradability was reduced.

  4. Influences of hyperbranched poly(amide-ester) on the properties of poly(butylene succinate)

    Energy Technology Data Exchange (ETDEWEB)

    Run, Mingtao, E-mail: lhbx@hbu.cn [Key Laboratory of Chemical Biology of Hebei Province, College of Chemistry and Environmental Science, Hebei University, Baoding 071002 (China); Wang, Jian; Yao, Meng; Guo, Lijie; Wang, Hai-jun [Key Laboratory of Chemical Biology of Hebei Province, College of Chemistry and Environmental Science, Hebei University, Baoding 071002 (China); Ba, Xinwu, E-mail: baxw@hbu.cn [Key Laboratory of Chemical Biology of Hebei Province, College of Chemistry and Environmental Science, Hebei University, Baoding 071002 (China)

    2013-05-15

    The polymer blends of hyperbranched poly(amide-ester) and poly(butylene succinate) (HBP/PBS) were prepared by melt-blending method. The molecular interaction within the blends, phase morphology, crystal morphology, mechanical, rheological and dynamic mechanical properties were investigated by using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), tensile machine, polarized optical microscopy, rotational rheometer and dynamic mechanical analyzer (DMA), respectively. The results suggest that PBS and HBP have a certain compatibility at amorphous state. A certain number of H-bonding was detected between PBS and HBP phases and it influences the material properties. HBP not only serves partially as a nucleating agent for the crystallization of PBS but also plays a role of plasticizer for the rheology of PBS. The glass transition temperatures of the blends slightly decrease with increasing HBP content. The proper amount of HBP (4–6%) has a reinforcement effect on the PBS matrix at glassy state. However, the blend with 10%HBP content has an improved impact strength mainly due to the plasticization effect or H-bonding effect of HBP on PBS matrix. The storage modulus is increased with increasing HBP contents, and the loss modulus is much smaller than the storage modulus in each blend at glassy state. At rubbery state the storage modulus of different samples is independent of HBP content. The complex viscosity of the melt decreases with increasing HBP content; however, the blend with 10%HBP is a special sample because of its abnormal larger complex viscosity at low shear frequencies. In addition, the melt’s elasticity behavior increases slightly with increasing HBP content. - Highlights: ► H-bonding was detected between PBS and HBP phases by FTIR. ► HBP serves partly as a nucleating agent for the crystallization of PBS. ► HBP plays a role of plasticizer for PBS. ► The blend with 10%HBP has abnormal larger complex viscosity.

  5. Biodegradation of poly(lactic acid, poly(hydroxybutyrate-co-hydroxyvalerate, poly(butylene succinate and poly(butylene adipate-co-terephthalate under anaerobic and oxygen limited thermophilic conditions

    Directory of Open Access Journals (Sweden)

    Jutakan Boonmee

    2016-01-01

    Full Text Available In order to study the biodegradation behavior of biodegradable plastics in landfill conditions, four types of biodegradable plastics including poly(lactic acid (PLA, poly(hydroxybutyrate-co-hydroxyvalerate (PHBV, poly(butylene succinate (PBS, and poly(butylene adipate-co-terephthalate (PBAT were tested by burying in sludge mixed soil medium under anaerobic and oxygen limited conditions. The experiments were operated at 52 ± 2ºC in dark conditions according to ISO15985. The degree of biodegradation after 75 days was investigated by weight loss determination, visual examination, and surface appearance by scanning electronic microscopy (SEM. Under both anaerobic and oxygen limited conditions, the complete degradation (100% weight loss was found only in PHBV after 75 days. The plastic degradations were ranked in the order of PHBV> PLA> PBS> PBAT. The percentage of weight losses were significantly different at p ≤ 0.05. However, for all studied plastics, the degradation under anaerobic and oxygen limited conditions did not significantly different at 95% confidence.

  6. TRANSESTERIFICATION OF POLY(BISPHENOL A CARBONATE) WITH AROMATIC AND ALIPHATIC SEGMENTS IN BUTYLENE TEREPHTHALATE-CAPROLACTONE COPOLYESTER

    Institute of Scientific and Technical Information of China (English)

    Song Wang; Yi-ping Huang; Xiao-lie Luo; De-zhu Ma

    2004-01-01

    In this article, the transesterification ofpoly(bisphenol A carbonate) (PC) with butylene terephthalate-caprolactone copolyester at a weight ratio 50/50 (BCL(21)) was thoroughly investigated by proton nuclear magnetic resonance spectroscopy (1H-NMR), in conjunction with a model compound. The 1H-NMR results of the annealed blend PC/BCL(21)show that the formation of bisphenol A-terephthalate ester units is the same as in the annealed blend of PC with PBT, and the transesterification actually occurs between PC and butylene terephthalate (BT) segments in BCL(21). By comparison with the model compound bisphenol A dibutyrate, the new signal appearing at δ = 2.56 in the 1H-NMR spectrum confirms the existence of bisphenol A caprolactone ester units resulting from the exchange reaction of PC with caprolactone (CL)segments. 1H-NMR analysis of the transesterification rates reveals that the reaction of PC with aromatic and aliphatic segments in BCL(21) proceeds in a random manner. The miscibility of the blend PC/BCL(21) copolyester is favorable for the transesterification of PC with BT segments and CL segments.

  7. Effect of peroxide and chain extender on mechanical properties and morphology of poly (butylene succinate)/poly (lactic acid) blends

    Science.gov (United States)

    Cherykhunthod, W.; Seadan, M.; Suttiruengwong, S.

    2015-07-01

    Poly (butylene succinate) (PBS) and poly (lactic acid) (PLA) are biodegradable polymers with high potential to replace commodity fossil-based polymers in a wide range of applications. However, these two polymers are immiscible in most ratios, but partially miscible when one of the two is a major phase. In this study, a one-step process in a twin-screw extruder was used to prepare the blends between poly (butylene succinate) (PBS) as a matrix and poly (lactic acid) (PLA) as a dispersed phase. To improve mechanical properties and morphology of blends, two reactive agents, peroxide (Perkadox) and multifunctional epoxide chain extender (Joncryl) were selected and compared. All samples were characterized for melt flow index (MFI), morphology, tensile, and impact properties. The results showed that the mechanical properties and morphology of PBS/PLA blends were improved when using both reactive agents. It was demonstrated that the increased mechanical properties resulted from good interfacial adhesion between PBS and finely dispersed PLA particles. The addition of 0.075 phr Perkadox to PBS/PLA (75:25 and 80:20) blends increased elongation at break by 7.2% and 38.4%, respectively compared with the blends without reactive agents. The results from gel content also revealed the graft copolymer existed at the interface when reactive agents were added. In the case of using multifunctional epoxide chain extender, the impact strength of the blends increased.

  8. Controlled-release fertilizer prepared using a biodegradable aliphatic copolyester of poly(butylene succinate) and dimerized fatty acid.

    Science.gov (United States)

    Lubkowski, Krzysztof; Smorowska, Aleksandra; Grzmil, Barbara; Kozłowska, Agnieszka

    2015-03-18

    The preparation and characterization of a controlled-release multicomponent (NPK) fertilizer with the coating layer consisting of a biodegradable copolymer of poly(butylene succinate) and a butylene ester of dilinoleic acid (PBS/DLA) is reported. The morphology and structure of the resulting polymer-coated materials and the thickness of the covering layers were examined using X-ray diffraction and scanning electron microscopy coupled with energy dispersive X-ray analysis. The mechanical properties of these materials were determined with a strength-testing machine. Nutrient release was measured in water using spectrophotometry, potentiometry, and conductivity methods. The results of the nutrient release experiments from these polymer-coated materials were compared with the requirements for controlled-release fertilizers. A conceptual model is presented describing the mechanism of nutrient release from the materials prepared in this study. This model is based on the concentrations of mineral components inside the water-penetrated fertilizer granules, the diffusion properties of the nutrients in water, and a diffusion coefficient through the polymer layer. The experimental kinetic data on nutrient release were interpreted using the sigmoidal model equation developed in this study.

  9. Polystyrene/TiO2 composite electrospun fibers as fillers for poly(butylene succinate-co-adipate): Structure, morphology and properties

    NARCIS (Netherlands)

    Neppalli, Ramesh; Causin, Valerio; Benetti, Edmondo M.; Ray, Suprakas Sinha; Esposito, Antonella; Wanjale, Santosh; Birajdar, Mallinath; Saiter, Jean-Marc; Marigo, Antonio

    2014-01-01

    In this work, composite polystyrene/titanium dioxide (PS/TiO2) electrospun fibers were used as a reinforcement for a poly(butylene succinate-co-adipate) (PBSA) matrix. The structure, morphology, mechanical properties and degradation behavior of such materials were investigated, finding that, as a fu

  10. Stabilization of polypropylene, polypropylene blends with poly (styrene-b-(ethylene-co-butylene)-b-styrene) under irradiation: A comparative investigation

    Energy Technology Data Exchange (ETDEWEB)

    Luan Shifang; Yang Huawei; Shi Hengchong; Zhao Jie [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Wang Jianwei [Shandong Weigao Group Medical Polymer Company Limited, Weihai 264209 (China); Yin Jinghua, E-mail: yinjh@ciac.jl.c [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2011-01-15

    The aim of this paper is to investigate the stabilization of polypropylene in the poly (styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS)/polypropylene (PP) blends under irradiation with respect to PP. The PP films, SEBS/PP films were subjected to electron beam irradiation and characterized by wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), gel permeation chromatography (GPC), and dynamic mechanical thermal analysis (DMTA). It demonstrated that upon irradiation, the molecular weight of PP had a pronounced decrease due to the major chain scission, and the minor chain cross-linking or chain branching occurred at the higher irradiation dose. Stabilization of PP was improved in the presence of SEBS, exhibiting an enhanced irradiation resistance.

  11. Non-isothermal crystallization kinetics and characterization of biodegradable poly(butylene succinate-co-neopentyl glycol succinate) copolyesters.

    Science.gov (United States)

    Xie, Wen-Jie; Zhou, Xiao-Ming

    2015-01-01

    Both biodegradable aliphatic neat poly(butylene succinate) (PBS) and poly(butylene succinate-co-neopentyl glycol succinate) (P(BS-co-NPGS)) copolyesters with different 1,4-butanediol/neopentyl glycol ratios were synthesized through a two-step process of transesterification and polycondensation using stannous chloride and 4-Methylbenzenesulfonic acid as the co-catalysts. The structure, non-isothermal crystallization behavior, crystalline morphology and crystal structure of neat PBS and P(BS-co-NPGS) copolyesters were characterized by (1)H NMR, differential scanning calorimetry (DSC), polarized optical microscope (POM) and wide angle X-ray diffraction (WAXD), respectively. The Avrami equation modified by Jeziorny and Mo's method was employed to describe the non-isothermal crystallization kinetics of the neat PBS and its copolyesters. The modified Avrami equation could adequately describe the primary stage of non-isothermal crystallization kinetics of the neat PBS and its copolyesters. Mo's method provided a fairly satisfactory description of the non-isothermal crystallization of neat PBS and its copolyesters. Interestingly, the values of 1/t1/2, Zc and F(T) obtained by the modified Avrami equation and Mo's method analysis indicated that the crystallization rate increased first and then decreased with an increase of NPGS content compared that of neat PBS, whereas the crystallization mechanism almost kept unchanged. The results of tensile testing showed that the ductility of PBS was largely improved by incorporating NPGS units. The elongation at break increased remarkably with increasing NPGS content. In particular, the sample with 20% NPGS content showed around 548% elongation at break.

  12. 生物降解PBS聚醋的改性研究进展%Advances in Modification of Biodegradable Poly(Butylene Succinate)

    Institute of Scientific and Technical Information of China (English)

    孙桂香; 罗勇; 陆平晔

    2011-01-01

    聚丁二酸丁二醇酯(PBS)是一种具有良好生物降解性的聚酯,本文简述了PBS的基础物性和力学性能,综述了各种改善PBS生物降解性、生物相容性、热学和力学性能的方法,重点介绍了通过共聚、共混等方法对PBS进行改性的研究进展.%Poly(butylene succinate) (PBS) are polyesters with outstanding biodegradability. The basic physical and mechanical properties of PBS were introduced briefly in this article. Advances in modification research of biodegradation, biocompatibility, thermal and mechanical properties of poly (butylene succinate) were reviewed and the modification methods including copolymerization, blending,and so on, were presented emphatically.

  13. Degradation studies of 1, 6-diisocyanatohexane-extended poly (1, 4-butylene succinate) - bioactive glass scaffolds for bone tissue repair applications

    Science.gov (United States)

    Kaur, Kulwinder; Singh, K. J.; Anand, Vikas

    2016-05-01

    Bio composite scaffolds prepared from polymer and bio glass provide necessary sites for bone tissue regeneration. In the presented work, bioactive glass scaffolds have been prepared from 1, 6-diisocyanatohexane-extended poly (1, 4-butylene succinate) with different amount of bioactive glass powder by solvent casting method. Prepared scaffolds have been characterized by XRD, FTIR and FESEM techniques. Effect of content of bioactive glass on biodegradability has been investigated in detail.

  14. 聚(丁二酸丁二醇酯癸二酸丁二醇酯)的合成与表征%Synthesis and Characterization of Poly(Butylene Succinate-co-Butylene Sebacate)

    Institute of Scientific and Technical Information of China (English)

    郝瑞; 周艺峰; 聂王焰

    2012-01-01

    用熔融缩聚法合成了一系列聚(丁二酸丁二醇酯癸二酸丁二醇酯)的无规共聚物(PBSu-co-PBSe)。通过核磁共振(1H-NMR),差示扫描量热(DSC),热重分析(TGA),X射线衍射(XRD)和酶降解测试等方法表征了材料的结构与性能。XRD测试结果表明,共聚酯的晶体结构随着癸二酸含量的增加发生了改变,并产生了共结晶行为;DSC分析得出,随着PBSe组分在共聚酯中含量的增大,产物的熔点(Tm)由84.8℃降低至46.7℃,然后升高至55.9℃,玻璃化温度(Tg)单调降低至-58.7℃;TGA分析表明,癸二酸的引入提高了聚酯的热稳定性;酶降解测试得出产物具有良好的生物降解性,当PBSe占共聚酯含量的40%时,产物具有最快的降解速率。%A series of poly (butylene succinate-co-butylene sebacate)(PBSu-co-PBSe) random copolyesters were synthesized by polycondensation reaction. The structure and physical properties of the resulting aliphatic polyesters were characterized by hydrogen nuclear magnetic resonance spectrum (1H-NMR), X-ray diffraction (XRD), differential scanning calorimetry(DSC), thermogravimetry analysis(TGA) and lipase enzymatic degradation test. XRD patterns show that the crystal structure of copolyesters changes with the increasing of PBSe component and the cocrystallization behavior has appeared; DSC test shows that the melting point (Zm) of the product decreases from 84.8 ℃ to 46.7 ℃, and then increases to 55.9 ℃, the glass transition temperature(Tg) decreases monotonously to -58.7 ℃ ; TGA analysis indicates that copolymers have better thermal stability with the increasing content of sebaeic acid; The lipase enzymatic degradation test indicates that the copolyester has better degradability, when the content of PBSe reaches 40mol %, the copolyester has the fastest degradative rate

  15. Non-isothermal crystallization kinetics and characterization of biodegradable poly(butylene succinate-co-neopentyl glycol succinate) copolyesters

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Wen-Jie; Zhou, Xiao-Ming, E-mail: xiaomingzhou@tust.edu.cn

    2015-01-01

    Both biodegradable aliphatic neat poly(butylene succinate) (PBS) and poly(butylene succinate-co-neopentyl glycol succinate) (P(BS-co-NPGS)) copolyesters with different 1,4-butanediol/neopentyl glycol ratios were synthesized through a two-step process of transesterification and polycondensation using stannous chloride and 4-Methylbenzenesulfonic acid as the co-catalysts. The structure, non-isothermal crystallization behavior, crystalline morphology and crystal structure of neat PBS and P(BS-co-NPGS) copolyesters were characterized by {sup 1}H NMR, differential scanning calorimetry (DSC), polarized optical microscope (POM) and wide angle X-ray diffraction (WAXD), respectively. The Avrami equation modified by Jeziorny and Mo's method was employed to describe the non-isothermal crystallization kinetics of the neat PBS and its copolyesters. The modified Avrami equation could adequately describe the primary stage of non-isothermal crystallization kinetics of the neat PBS and its copolyesters. Mo's method provided a fairly satisfactory description of the non-isothermal crystallization of neat PBS and its copolyesters. Interestingly, the values of 1/t{sub 1/2}, Z{sub c} and F(T) obtained by the modified Avrami equation and Mo's method analysis indicated that the crystallization rate increased first and then decreased with an increase of NPGS content compared that of neat PBS, whereas the crystallization mechanism almost kept unchanged. The results of tensile testing showed that the ductility of PBS was largely improved by incorporating NPGS units. The elongation at break increased remarkably with increasing NPGS content. In particular, the sample with 20% NPGS content showed around 548% elongation at break. - Highlights: • The incorporation of NPGS units reduced the spherulite size of BS unit. • The existence of NPGS units did not change the crystal structure of BS unit. • The NPGS units incorporated in PBS could significantly improve the ductility of

  16. Preparation of surface-modified poly(butylene terephthalate) nonwovens and their application as leukocyte removal filters.

    Science.gov (United States)

    Kim, Eun Jin; Yeo, Gwu-Dong; Pai, Chaul-Min; Kang, Inn-Kyu

    2009-08-01

    Blood transfusion-related adverse reactions have been reported to be caused by leukocytes in blood products. It is now generally accepted that it would be highly desirable to reduce leukocytes level as low as possible. In this study, melt-blown poly(butylene terephthalate) nonwoven (PBT-NW) was treated with a hydroxyapatite (HA) surface-modification method for removal of leukocytes from blood components. Acrylic acid was graft-polymerized onto the surface of the PBT-NW after oxygen plasma glow discharge treatment. The PBT-NW surface was covered with a thin layer of HA produced by immersing the polymer surface in an aqueous solution containing high concentrations of PO(4) (3-) and Ca(2+) after graft-polymerization of acrylic acid, which provided the nucleus for HA crystallization. The surface was characterized using water contact angles, attenuated total reflection-Fourier transform infrared (ATR-FT-IR), and electron spectroscopy for chemical analysis. When filtration was performed with a unit of red blood cell concentrates, HA-deposited PBT-NW (PBT-HA) removed 98.5% of the leukocytes and recovered 99.5% of the erythrocytes, suggesting that HA-deposited PBT-NW is a very promising blood filter for selective removal of leukocytes.

  17. Hybrids of HNBR and in situ polymerizable cyclic butylene terephthalate (CBT oligomers: properties and dry sliding behavior

    Directory of Open Access Journals (Sweden)

    2008-07-01

    Full Text Available A peroxide curable hydrogenated nitrile rubber (HNBR was modified by cyclic butylene terephthalate oligomer (CBT, added in 100 parts per hundred rubber (phr. CBT polymerization was expected to occur simultaneously with that of the curing of the HNBR rubber (T = 190°C, t = 25 min. Differential scanning calorimetry (DSC indicated that only a minor part of CBT has been polymerized (pCBT in the hybrid. Dynamic mechanical thermal analysis (DMTA revealed that HNBR formed the continuous whereas (pCBT the dispersed phase. Mechanical properties (hardness, tensile modulus, ultimate tensile strength and strain, tear strength of the HNBR and HNBR/CBT were determined and collated. Tribological properties were investigated with pin(steel-onplate(rubber (POP, with roller(steel-on-plate (rubber (ROP, with oscillating steel cylinder on rubber plate (Fretting test configurations. Coefficient of friction (COF and specific wear rate of the HNBR-based systems were determined. It was found that the resistance to wear increases with CBT hybridization. On the other hand, COF did not change much with CBT content. The friction and wear characteristics strongly depended on the test configurations. The worn surface of the HNBR systems was inspected in scanning electron microscope (SEM to conclude the typical wear mechanisms. SEM investigation showed that the CBT was predominantly recrystallized from its molten state under the curing conditions set. The well developed prism- and platy-like, micron-scaled CBT crystals were made responsible for the reinforcing effect observed.

  18. Simultaneous ammonia and nitrate removal in an airlift reactor using poly(butylene succinate) as carbon source and biofilm carrier.

    Science.gov (United States)

    Ruan, Yun-Jie; Deng, Ya-Le; Guo, Xi-Shan; Timmons, Michael B; Lu, Hui-Feng; Han, Zhi-Ying; Ye, Zhang-Ying; Shi, Ming-Ming; Zhu, Song-Ming

    2016-09-01

    In this study, an airlift inner-loop sequencing batch reactor using poly(butylene succinate) as the biofilm carrier and carbon source was operated under an alternant aerobic/anoxic strategy for nitrogen removal in recirculating aquaculture system. The average TAN and nitrate removal rates of 47.35±15.62gNH4-Nm(-3)d(-1) and 0.64±0.14kgNO3-Nm(-3)d(-1) were achieved with no obvious nitrite accumulation (0.70±0.76mg/L) and the dissolved organic carbon in effluents was maintained at 148.38±39.06mg/L. Besides, the activities of dissimilatory nitrate reduction to ammonium and sulfate reduction activities were successfully inhibited. The proteome KEGG analysis illustrated that ammonia might be removed through heterotrophic nitrification, while the activities of nitrate and nitrite reductases were enhanced through aeration treatment. The microbial community analysis revealed that denitrifiers of Azoarcus and Simplicispira occupied the dominate abundance which accounted for the high nitrate removal performance. Overall, this study broadened our understanding of simultaneous nitrification and denitrification using biodegradable material as biofilm carrier.

  19. Solution viscosity – molar mass relationships for poly(butylene succinate and discussion on molar mass analysis

    Directory of Open Access Journals (Sweden)

    Q. Charlier

    2015-05-01

    Full Text Available Poly(butylene succinate (PBS is currently developing due to its biodegradability and the similarity of its mechanical properties to those of polyolefins. Relationships between the number average molar mass, Mn, and solution viscosity such as [η] and ηred were derived for this aliphatic polyester. Mn values were determined by end-group analysis and size exclusion chromatography (SEC. Mark-Houwink-Sakurada (MHS parameters were proposed in two solvents and for the different molar masses and viscosity measurement methods. As an example, the MHS equations were respectively, [η] =6.4•10–4•Mn0.67 in chloroform and [η] = 7.1•10–4•Mn0.69 in 50/50 wt% 1,2-dichlorobenzene/phenol at 25°C for molar masses measured by SEC in hexafluoro isopropanol (HFIP with poly(methyl methacrylate (PMMA standards. Empirical relationships were also suggested to derive Mn directly from reduced viscosity, ηred, which is much easier to determine than intrinsic viscosity. With these data, the number average molar mass of PBS can be conveniently estimated from a single viscosity measurement. In addition, it was shown that PBS contains 1–2 wt% of cyclic oligomers produced during esterification and that molar masses determined by taking this fraction into account or not were significantly different, especially for long chains.

  20. Characterization of partially sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene thin films for spectroelectrochemical sensing.

    Science.gov (United States)

    Pantelić, Nebojsa; Andria, Sara E; Heineman, William R; Seliskar, Carl J

    2009-08-15

    The spectroelectrochemical sensor uses thin, solid polyelectrolyte films as an essential element in its operation. In this work we explored the potential of partially sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SSEBS) thin polymer films for chemical sensing. Spectroscopic ellipsometry was used to measure optical and surface properties of the air-dried and hydrated material. SSEBS incorporates a relatively small amount of water (overall change of 25%) mainly determined by the complex dynamics of the film. The decrease in the refractive index after complete hydration of the film can be predicted based on the magnitude of swelling using effective medium approximation models. Adhesion of the material on various surfaces (glass, indium tin oxide, gold) was evaluated with the tape peel-off method. The ability of the SSEBS material to preconcentrate cations was evaluated by cyclic voltammetry, absorbance, and luminescence measurements using model analytes (Ru(bpy)(3)(2+), phenosafranine, and rhodamine 6G). The detection limits of the sensor for Ru(bpy)(3)(2+) under unoptimized conditions can be significantly improved if luminescence is used as the detection modality (DL = 5 x 10(-10) M) instead of absorbance (DL = 5 x 10(-7) M). Overall, the results demonstrate the effectiveness of the SSEBS material for spectroelectrochemical sensing.

  1. The influence of manganese-cobalt oxide/graphene on reducing fire hazards of poly(butylene terephthalate).

    Science.gov (United States)

    Wang, Dong; Zhang, Qiangjun; Zhou, Keqing; Yang, Wei; Hu, Yuan; Gong, Xinglong

    2014-08-15

    By means of direct nucleation and growth on the surface of graphene and element doping of cobalt oxide (Co3O4) nano-particles, manganese-cobalt oxide/graphene hybrids (MnCo2O4-GNS) were synthesized to reduce fire hazards of poly(butylene terephthalate) (PBT). The structure, elemental composition and morphology of the obtained hybrids were surveyed by X-ray diffraction, X-ray photoelectron spectrometer and transmission electron microscopy, respectively. Thermogravimetric analysis was applied to simulate and study the influence of MnCo2O4-GNS hybrids on thermal degradation of PBT during combustion. The fire hazards of PBT and its composites were assessed by the cone calorimeter. The cone test results had showed that peak HRR and SPR values of MnCo2O4-GNS/PBT composites were lower than that of pure PBT and Co3O4-GNS/PBT composites. Furthermore, the incorporation of MnCo2O4-GNS hybrids gave rise to apparent decrease of pyrolysis products containing aromatic compounds, carbonyl compounds, carbon monoxide and carbon dioxide, attributed to combined impact of physical barrier for graphene and cat O4 for organic volatiles and carbon monoxide.

  2. Crystallization behavior and thermal stability of poly(butylene succinate)/poly(propylene carbonate) blends prepared by novel vane extruder

    Science.gov (United States)

    Chen, Rongyuan; Zou, Wei; Zhang, Haichen; Zhang, Guizhen; Qu, Jinping

    2016-03-01

    This work focused on the study of crystallization behavior and thermal stability of degradable poly(butylene succinate) (PBS) and poly(propylene carbonate) (PPC) blends prepared by vane extruder based on elongation force field, which is novel equipment for polymer processing. Dicumyl peroxide (DCP) was applied in this work as compatibilizer for PBS/PPC blend. Crystallization behavior and melting behavior of the blends were investigated by differential scanning calorimetry (DSC) testing. Thermal stability of the blends was studied by thermogravimetric (TG) testing. Furthermore, the melt flow indices (MFI) of the blends were examined by a MFI instrument. The results showed that the crystallization temperature of PBS decreased with the addition of PPC and DCP. The glass transition temperature of PPC increased and the melting temperature of the blend increased with the addition of PPC and DCP, which indicated that the entanglement between the molecular chains of PBS and PPC was enhanced. Thermogravimetric analysis showed that a two-step decomposition process of the blend occurred due to the different thermal resistance of PBS and PPC, and the addition of PBS reduced the decomposition rate of PPC. Moreover, the addition of PBS improved the melt flow property of PPC.

  3. Phase Morphology and Mechanical Properties of Cyclic Butylene Terephthalate Oligomer-Containing Rubbers: Effect of Mixing Temperature

    Directory of Open Access Journals (Sweden)

    István Zoltán Halász

    2016-08-01

    Full Text Available In this work, the effect of mixing temperature (Tmix on the mechanical, rheological, and morphological properties of rubber/cyclic butylene terephthalate (CBT oligomer compounds was studied. Apolar (styrene butadiene rubber, SBR and polar (acrylonitrile butadiene rubber, NBR rubbers were modified by CBT (20 phr for reinforcement and viscosity reduction. The mechanical properties were determined in tensile, tear, and dynamical mechanical analysis (DMTA tests. The CBT-caused viscosity changes were assessed by parallel-plate rheometry. The morphology was studied by scanning electron microscopy (SEM. CBT became better dispersed in the rubber matrices with elevated mixing temperatures (at which CBT was in partially molten state, which resulted in improved tensile properties. With increasing mixing temperature the size of the CBT particles in the compounds decreased significantly, from few hundred microns to 5–10 microns. Compounding at temperatures above 120 °C and 140 °C for NBR and SBR, respectively, yielded reduced tensile mechanical properties most likely due to the degradation of the base rubber. The viscosity reduction by CBT was more pronounced in mixes with coarser CBT dispersions prepared at lower mixing temperatures.

  4. Toughening of biodegradable polylactide/poly(butylene succinate-co-adipate) blends via in situ reactive compatibilization.

    Science.gov (United States)

    Ojijo, Vincent; Ray, Suprakas Sinha; Sadiku, Rotimi

    2013-05-22

    Polylactide and poly(butylene succinate-co-adipate) (PLA/PBSA) were melt-blended in the presence of triphenyl phosphite (TPP). An increase in the torque during melt mixing was used to monitor the changes in viscosity as compatibilization of the blends occurred. Scanning electron micrographs showed not only a reduction in the dispersed-phase size with increased TPP content but also fibrillated links between the PLA and PBSA phases, signifying compatibilization. Moreover, optimization of parameters such as the mixing sequence and time, TPP content, and PBSA concentration revealed that blends containing 30 and 10 wt % PBSA and 2 wt % TPP, which were processed for 30 min, were optimal in terms of thermomechanical properties. The impact strength increased from 6 kJ/m(2) for PLA to 11 and 16 kJ/m(2) for blends containing 30 and 10 wt % PBSA, respectively, whereas the elongation-at-break increased from 6% for PLA to 20 and 37% for blends containing 30 and 10 wt % PBSA, respectively. Upon compatibilization, the failure mode shifted from the brittle fracture of PLA to ductile deformation, effected by the debonding between the two phases. With improved phase adhesion, compatibilized blends not only were toughened but also did not significantly lose tensile strength and thermal stability.

  5. Biodegradability and mechanical properties of poly(butylene succinate) composites with finely dispersed hydrophilic poly(acrylic acid)

    Science.gov (United States)

    Mizuno, Sawako; Hotta, Atsushi

    2014-03-01

    Biodegradability and mechanical properties of aliphatic poly(butylene succinate) (PBS) films with finely dispersed hydrophilic poly(acrylic acid) (PAA) were investigated. First, 3.5 wt% of PAA was chemically grafted onto the surface of the PBS films (surface-grafted PBS) by photo grafting polymerization, and then the grafted PAA was homogeneously and finely dispersed into PBS by dissolving the surface-grafted PBS into chloroform before mixing and drying to get solid PAA-dispersed PBS. Degradation of these modified PBS was investigated using gel permeation chromatography (GPC) and tensile testing. According to the GPC results, it was found that the PAA-dispersed PBS had intermediate biodegradability with the intermediate water intake, and the reaction constant of PAA-dispersed PBS was in between those of untreated PBS and surface-grafted PBS, in fact 25% higher and 17% lower, respectively. The experimental results presented that the biodegradability of PBS could be well controlled by the dispersion of PAA, possibly leading to the widespread use of PBS for biodegradable polymers.

  6. Morphology and mechanical properties of poly(butylene adipate-co-terephthalate)/potato starch blends in the presence of synthesized reactive compatibilizer or modified poly(butylene adipate-co-terephthalate).

    Science.gov (United States)

    Wei, Dafu; Wang, Hao; Xiao, Huining; Zheng, Anna; Yang, Yang

    2015-06-01

    The biodegradable poly(butylene adipate-co-terephthalate)(PBAT)/thermoplastic starch (TPS) composite has received considerable attention because of the environmental concerns raised by solid waste disposal. However, the application of PBAT/TPS blends was limited due to the poor mechanical properties originating from the incompatibility between PBAT and TPS. In this work, two approaches were developed to improve the mechanical properties of PBAT/TPS blends. One approach is to use compatibilizers, including the synthesized reactive compatibilizer - a styrene-maleic anhydride-glycidyl methacrylate (SMG) terpolymer, and the commercial compatibilizer (Joncryl-ADR-4368). The chemical structures of SMG were analyzed with (1)H NMR and FT-IR. The other approach is to use the modified PBAT (M-PBAT) to replace part of PBAT in the PBAT/TPS blends. M-PBATs with higher molecular weight were obtained via reactive extrusion of PBAT in the presence of a chain extender. The better dispersion of TPS in PBAT was observed in SEM images when using M-PBAT, leading to the higher tensile strength and elongation at break of PBAT/TPS blends. However, the elongation at break decreased in the presence of compatibilizer (SMG or 4368), though the tensile strength remained in a similar level or slightly higher. Overall, the tensile strength and the elongation at break of the resulting biodegradable PBAT/M-PBAT/TPS blends (TPS=40wt%) were above 27.0MPa and 500%, respectively, which is promising for various applications, including packaging and agricultural mulching films.

  7. Comparative Studies on the Mechanical Properties of Nonwoven- and Woven-Flax-Fiber-Reinforced Poly(Butylene Adipate-Co-Terephthalate)-Based Composite Laminates

    Science.gov (United States)

    Phongam, N.; Dangtungee, R.; Siengchin, S.

    2015-03-01

    Textile biocomposites made from woven- and nonwoven-flax-fiber-reinforced poly(butylene adipate-co-terephthalate) (PBAT) were prepared by compression molding using the film stacking method, and their tensile strength and stiffness, flexural strength and modulus, and impact strength were determined experimentally. The PBAT-based composites were subjected to water absorption tests. The mechanical properties of pure PBAT and the textile composites were compared, and the influence of flax weave styles on the properties were evaluated. The biocomposite reinforced with 4 × 4-plain weave fibers showed the highest strength and stiffness compared with those of the other textile biocomposites and pure PBAT.

  8. Novel biodegradable aliphatic poly(butylene succinate-co-cyclic carbonate)s bearing functionalizable carbonate building blocks: II. Enzymatic biodegradation and in vitro biocompatibility assay.

    Science.gov (United States)

    Yang, Jing; Tian, Weisheng; Li, Qiaobo; Li, Yang; Cao, Amin

    2004-01-01

    In a previous study, we have reported chemical synthesis of novel aliphatic poly(butylene succinate-co-cyclic carbonate) P(BS-co-CC)s bearing various functionalizable carbonate building blocks, and this work will continue to present our new studies on their enzymatic degradation and in vitro cell biocompatibility assay. First, enzymatic degradation of the novel P(BS-co-CC) film samples was investigated with two enzymes of lipase B Candida Antartic (Novozyme 435) and lipase Porcine Pancreas PPL, and it was revealed that copolymerizing linear poly(butylene succinate) PBS with a functionalizable carbonate building block could remarkably accelerate the enzymatic degradation of a synthesized product P(BS-co-CC), and its biodegradation behavior was found to strongly depend on the overall impacts of several important factors as the cyclic carbonate (CC) comonomer structure and molar content, molar mass, thermal characteristics, morphology, the enzyme-substrate specificity, and so forth. Further, the biodegraded residual film samples and water-soluble enzymatic degradation products were allowed to be analyzed by means of proton nuclear magnetic resonance (1H NMR), gel permeation chromatograph (GPC), differential scanning calorimeter (DSC), attenuated total reflection FTIR (ATR-FTIR), scanning electron microscope (SEM), and liquid chromatograph-mass spectrometry (LC-MS). On the experimental evidences, an exo-type mechanism of enzymatic chain hydrolysis preferentially occurring in the noncrystalline domains was suggested for the synthesized new P(BS-co-CC) film samples. With regard to their cell biocompatibilities, an assay with NIH 3T3 mouse fibroblast cell was conducted using the novel synthesized P(BS-co-CC) films as substrates with respect to the cell adhesion and proliferation, and these new biodegradable P(BS-co-CC) samples were found to exhibit as low cell toxicity as the PLLA control, particularly the two samples of poly(butylene succinate-co-18.7 mol % dimethyl

  9. The effect of epoxidized soybean oil on mechanical and rheological properties of poly(butylene succinate)/lignin via vane extruder

    Science.gov (United States)

    Liu, Huanyu; Huang, Zhaoxia; Qu, Jinping; Meng, Cong

    2016-03-01

    Epoxidized Soybean Oil (ESO) have been used as the compatilizer in the Poly (butylene succinate)/lignin (PBS/lignin) composites. Compatibilized composites were fabricated by a novel vane extruder (VE) which can generate global and dynamic elongational flow. The effects of ESO on the mechanical, rheological properties and morphology of PBS/lignin were studied. The results indicated that the use of ESO had plasticizing effect on the matrix PBS while the addition reduced tensile strength. From SEM micrographs it could be clearly observed that there was a better interfacial adhesion between lignin and matrix. Meanwhile, rheological tests showed the incorporation of ESO improved its Newtonian behavior and can enhance PBS's flexibility.

  10. THERMAL PROPERTY, MISCIBILITY AND CRYSTALLIZATION BEHAVIOR OF POLY(3-HYDROXYBUTYRATE-co 3-YDROXYHEXANOATE) AND POLY(BUTYLENE SUCCINATE-ADIPATE) (PHBHHX/PBSA) BLENDS

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Blends of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and poly(butylene succinate-adipate) (PBSA), both biodegradable semicrystalline polyesters, were prepared with the ratio of PHBHHx/PBSA ranging from 80/20 to 20/80 by melt mixing method. Differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), dynamic mechanical thermal analysis (DMA), polarizing optical microscopy (POM) and wide angle X-ray diffractometer (WAXD) were used to study the miscibility and crystallization behavior of PHBHHx/PBSA blends. Experimental results indicate that PHBHHx is immiscible with PBSA as shown by the almost unchanged glass transition temperature and the biphasic melt.

  11. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) elastomer via photo-initiated graft polymerization of poly(ethylene glycol)

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaomeng [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Luan Shifang, E-mail: sfluan@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yang Huawei; Shi Hengchong; Zhao Jie; Jin Jing [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yin Jinghua, E-mail: yinjh@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Stagnaro, Paola [Istituto per Io Studio delle Macromolecole, Consiglio Nazionale delle Ricerche, Via de Marini 6, 16149 Genova (Italy)

    2012-01-15

    Poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) copolymer biomedical elastomer was covalently grafted with poly(ethylene glycol) methyl ether methacrylate (PEGMA) via a photo-initiated graft polymerization technique. The surface graft polymerization of SEBS with PEGMA was verified by ATR-FTIR and XPS. Effect of graft polymerization parameters, i.e., monomer concentration, UV irradiation time and initiator concentration on the grafting density was investigated. Comparing with the virgin SEBS film, the PEGMA-modified SEBS film presented an enhanced wettability and a larger surface energy. Besides, the surface grafting of PEGMA imparted excellent anti-platelet adhesion and anti-protein adsorption to the SEBS surface.

  12. Biocompatibility and drug release behavior of scaffolds prepared by coaxial electrospinning of poly(butylene succinate) and polyethylene glycol

    Energy Technology Data Exchange (ETDEWEB)

    Llorens, E.; Ibañez, H. [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Valle, L.J. del, E-mail: luis.javier.del.valle@upc.edu [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Puiggalí, J. [Departament d' Enginyeria Química, Universitat Politècnica de Catalunya, Av. Diagonal 647, Barcelona E-08028 (Spain); Center for Research in Nano-Engineering (CrNE), Universitat Politècnica de Catalunya, Edifici C, C/Pasqual i Vila s/n, Barcelona E-08028 (Spain)

    2015-04-01

    Scaffolds constituted by electrospun microfibers of poly(ethylene glycol) (PEG) and poly(butylene succinate) (PBS) were studied. Specifically, coaxial microfibers having different core–shell distributions and compositions were considered as well as uniaxial micro/nanofibers prepared from mixtures of both polymers. Processing conditions were optimized for all geometries and compositions and resulting morphologies (i.e. diameter and surface texture) characterized by scanning electron microscopy. Chemical composition, molecular interactions and thermal properties were evaluated by FTIR, NMR, XPS and differential scanning calorimetry. The PEG component of electrospun fibers could be solubilized by immersion of scaffolds in aqueous medium, giving rise to high porosity and hydrophobic samples. Nevertheless, a small amount of PEG was retained in the PBS matrix, suggesting some degree of mixing. Solubilization was slightly dependent on fiber structure; specifically, the distribution of PEG in the core or shell of coaxial fibers led to higher or lower retention levels, respectively. Scaffolds could be effectively loaded with hydrophobic drugs having antibacterial and anticarcinogenic activities like triclosan and curcumin, respectively. Their release was highly dependent on their chemical structure and medium composition. Thus, low and high release rates were observed in phosphate buffer saline (SS) and SS/ethanol (30:70 v/v), respectively. Slight differences in the release of triclosan were found depending on fiber distribution and composition. Antibacterial activity and biocompatibility were evaluated for both loaded and unloaded scaffolds. - Highlights: • Coaxial microfibers with different hydrophobicities were studied. • The surface morphology of the coaxial fiber shows the distribution of polymers. • Coaxial fiber microstructure favors the polymer molecular orientation. • These hybrid materials have greater advantages for loading and drug release. • PEG

  13. Reinforcement effect of poly(butylene succinate) (PBS)-grafted cellulose nanocrystal on toughened PBS/polylactic acid blends.

    Science.gov (United States)

    Zhang, Xuzhen; Zhang, Yong

    2016-04-20

    Poly(butylene succinate) (PBS)/polylactic acid (PLA) blends modified with dicumyl peroxide (DCP) were reinforced by PBS-g-cellulose nanocrystal (CNC) through melt mixing. PBS-g-CNC was prepared through in situ polymerization and its structure was confirmed by FTIR, (13)C NMR, XPS and GPC analysis after saponification. The morphological analysis of PBS/PLA/PBS-g-CNC composites before and after etched by CH2Cl2 shows that the addition of DCP and PBS-g-CNC could decrease the size of PBS as a dispersed phase in PLA matrix and improve the dispersion of PBS-g-CNC in both PBS and PLA phases, which could affect the crystallization and mechanical properties of composites. The crystallinity of PLA α'-phase crystal in PBS/PLA/PBS-g-CNC composites is increased obviously by the addition of PBS-g-CNC, leading to an increase of the crystallinity of the composites. PBS/PLA blends modified by DCP have high Notched Izod impact strength and moduli, and the values are increased by the addition of PBS-g-CNC. Both storage modulus and glass translation temperature of PBS/PLA blend are increased by DCP and PBS-g-CNC, which is proved by DMA results, showing a weak molecular segment mobility of PBS/PLA matrix. The addition of DCP decreases the crystallization temperature and crystallinity of PBS/PLA composite, but increases the thermal stability of composites, mostly because of the crosslink effect of DCP on PBS/PLA matrix.

  14. The effect of electron-beam irradiation and halogen-free flame retardants on properties of poly butylene terephthalate

    Science.gov (United States)

    Hooshangi, Zhila; Feghhi, Seyed Amir Hossein; Sheikh, Nasrin

    2015-03-01

    Engineering plastics like Poly (butylene terephthalate) due to their desirable properties have various industrial applications. Neat PBT is highly combustible, so it is necessary to improve significantly its fire retardancy to meet the fire safety requirements. The combustion performance of PBT can be improved by addition of appropriate flame retardant additives. In this study we have investigated the effect of halogen free flame retardants, i.e. melamine and aluminum phosphate, and instantaneously electron beam radiation-induced crosslinking in the presence of Triallyl cyanurate on various properties of PBT. The results of gel content showed that a dose range of 200-400 kGy leads to high cross linked structure in this polymer. Also mechanical experiments showed that its structure became rigid and fragile due to irradiation. Radiation crosslinking of this polymer made its dielectric loss coefficient ten times lower than non-irradiated polymer, but had no effect on its dielectric constant. Moreover the addition of the fire retardant additives as impurity decreased the dielectric loss coefficient. TGA analysis in nitrogen exhibited that irradiation increases char formation and use of the fire retardant additives leads to reduction of onset temperature and formation of higher char quantity than pure PBT. According to the results of UL-94, irradiated samples burned with lower speed and less dripping in vertical and horizontal positions than pure polymer. Finally irradiation of the polymers containing fire retardant additives with a dose of 400 kGy led to self-extinguishing and non-dripping and reach to V-0 level in the UL-94 V.

  15. The influence of antioxidant and post-synthetic treatment on the properties of biodegradable poly(butylene succinates modified with poly(propylene oxide

    Directory of Open Access Journals (Sweden)

    DRAGANA PEPIC

    2007-12-01

    Full Text Available Novel poly(ester–ethers based on poly(butylene succinate (PBS as the hard segments and 30 mass % of poly(propylene oxide (PPO as the soft segments were synthesized with varying amount of the antioxidant (N,N'-diphenyl-p-phenylenediamine, DPPD. The influences of the addition of DPPD and the impact of post-synthetic treatment by precipitation on the molecular structure, thermal and physical properties, as well as on the storage stability of the biodegradable aliphatic copolyesters, were investigated. The structure and composition of the copolymers were determined by means of 1H-NMR spectroscopy. The molecular weight and polydispersity of the poly(ester–ethers were evaluated from solution viscosity and GPC measurements. The thermal properties and stability were evaluated, respecttively, by means of DSC and non-isothermal thermogravimetry in an inert nitrogen atmosphere. The biodegradability potential of the polymers was studied in hydrolytic and enzymatic degradation tests with Candida cylindracea lipase by monitoring the weight loss of polymer films after incubation. The weight losses of the samples increased with time and were in the range from 1 to 5 mass % after 4 weeks. GPC analysis confirmed that there were changes in the molecular weight of the copolyesters during both hydrolytic and enzymatic degradation tests, leading to the conclusion that the degradation mechanism of poly(butylenes succinate modified with PPO occurred through surface erosion and bulk degradation.

  16. Synthesis of poly ( butylene succinate)%聚丁二酸丁二醇酯的合成

    Institute of Scientific and Technical Information of China (English)

    郑文俊; 黄关葆

    2011-01-01

    A poly(butylene succinate) (PBS) with higher relative molecular weight was synthesized by direct esterification-polycondensation of succinic acid(SA) and 1,4-butanediol( BD), and it was the first time to investigate the side reaction of esterification in PBS by using refractometric analysis. The results showed that the esterification rate was significantly affected by SA/BD ratio, temperature and catalysts. The side reaction increased with the increase of the amount of BD and rising of the temperature. The viscosity- average molecular weight of the synthesized PBS was from 5. 7 x 104 g/mol to 8. 0 x 104 g/mol, and the highest molecular weight PBS was obtained when the esterification temperature was 150 ℃ , SA/ BD ratio was 1: 1. 2, the amount of titanium catalyst was 0. 1% of SA( mole ratio) , and the temperature of polycondensation was 220 ℃.%通过直接酯化-缩聚法,以丁二酸、丁二醇为原料,合成了相对分子质量较高的聚丁二酸丁二醇酯(PBS),并首次采用折光率法研究了PBS酯化反应中的副反应.结果表明:酯化反应中,酸醇比、反应温度及催化剂对酯化率的影响较大;随着丁二醇加入量的增加,酯化反应中的副反应增强,随着反应温度的升高也增强;缩聚反应所合成PBS的黏均摩尔质量在5.7 ×104~8.0×104 g/mol之间,且在酯化反应温度为150℃,酸醇比为1∶1.2,采用钛系催化剂,其用量为所加入丁二酸的0.1%(物质的量比),缩聚反应温度为220℃时,所得产物分子质量最高.

  17. The influence of manganese–cobalt oxide/graphene on reducing fire hazards of poly(butylene terephthalate)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dong; Zhang, Qiangjun; Zhou, Keqing; Yang, Wei [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Hu, Yuan, E-mail: yuanhu@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); USTC-CityU Joint Advanced Research Centre, Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute for Advanced Study, University of Science and Technology of China, 166 Ren’ai Road, Suzhou, Jiangsu 215123 (China); Gong, Xinglong, E-mail: gongxl@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); CAS Key Laboratory of Mechanical Behaviour and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2014-08-15

    Highlights: • MnCo{sub 2}O{sub 4}–GNS hybrids are synthesized by a two-stage liquid phase method. • MnCo{sub 2}O{sub 4}–GNS/PBT composites were prepared via a masterbatch-melt blending method. • Fire hazards are monitored and evaluated by cone calorimeter and TG-IR. • MnCo{sub 2}O{sub 4}–GNS hybrids decrease thermal hazards and smoke hazards of PBT composites. • MnCo{sub 2}O{sub 4}–GNS hybrids perform better catalytic oxidation of CO and organic volatile. - Abstract: By means of direct nucleation and growth on the surface of graphene and element doping of cobalt oxide (Co{sub 3}O{sub 4}) nano-particles, manganese–cobalt oxide/graphene hybrids (MnCo{sub 2}O{sub 4}–GNS) were synthesized to reduce fire hazards of poly(butylene terephthalate) (PBT). The structure, elemental composition and morphology of the obtained hybrids were surveyed by X-ray diffraction, X-ray photoelectron spectrometer and transmission electron microscopy, respectively. Thermogravimetric analysis was applied to simulate and study the influence of MnCo{sub 2}O{sub 4}–GNS hybrids on thermal degradation of PBT during combustion. The fire hazards of PBT and its composites were assessed by the cone calorimeter. The cone test results had showed that peak HRR and SPR values of MnCo{sub 2}O{sub 4}–GNS/PBT composites were lower than that of pure PBT and Co{sub 3}O{sub 4}–GNS/PBT composites. Furthermore, the incorporation of MnCo{sub 2}O{sub 4}–GNS hybrids gave rise to apparent decrease of pyrolysis products containing aromatic compounds, carbonyl compounds, carbon monoxide and carbon dioxide, attributed to combined impact of physical barrier for graphene and cat O{sub 4} for organic volatiles and carbon monoxide.

  18. Surface modification of poly(styrene-b-(ethylene-co-butylene)-b-styrene) elastomer via UV-induced graft polymerization of N-vinyl pyrrolidone.

    Science.gov (United States)

    Luan, Shifang; Zhao, Jie; Yang, Huawei; Shi, Hengchong; Jin, Jing; Li, Xiaomeng; Liu, Jingchuan; Wang, Jianwei; Yin, Jinghua; Stagnaro, Paola

    2012-05-01

    Poly(N-vinyl pyrrolidone) (PNVP) was covalently grafted onto the surface of biomedical poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) elastomer via a technique of UV-induced graft polymerization combined with plasma pre-treatment. The surface graft polymerization of N-vinyl pyrrolidone (NVP) was confirmed by ATR-FTIR and XPS. Effect of the parameters of graft polymerization, i.e., the initiator concentration, the UV irradiation time and the monomer concentration on the grafting density was investigated. The morphology and the wettability of the PNVP-modified surfaces were characterized by AFM and DSA, respectively. Protein adsorption and platelet adhesion were obviously suppressed after PNVP was grafted onto the SEBS substrates.

  19. Effects of thermal history in the ring opening polymerization of CBT and its mixtures with montmorillonite on the crystallization of the resulting poly(butylene terephthalate)

    Energy Technology Data Exchange (ETDEWEB)

    Lanciano, Giuseppina [Department of Innovation Engineering, University of Salento, Via per Arnesano, 73100 Lecce (Italy); Greco, Antonio, E-mail: antonio.greco@unile.it [Department of Innovation Engineering, University of Salento, Via per Arnesano, 73100 Lecce (Italy); Maffezzoli, Alfonso [Department of Innovation Engineering, University of Salento, Via per Arnesano, 73100 Lecce (Italy); Mascia, Leno [Department of Materials, Loughborough University, Loughborough, LE 11 3TU (United Kingdom)

    2009-09-10

    Differential scanning calorimetry was used to study the thermal characteristics and morphological structure of species produced during the ring opening polymerization of cyclic butylene terephthalate (CBT). Thermal programs consisting of a first ramp heating scan and an isothermal step, followed by cooling and a second ramp heating step, were used to study the effects of thermal history, catalyst (butyl chlorotin dihydroxide) at concentrations between 0.1 and 1.3% (w/w), and the presence of a layered silicate nanofiller (montmorillonite at 4.0%, w/w) on the structure of the resulting polymer (poly(butylene terephthalate), pCBT). Wide angle X-ray diffraction was used to monitor the degree of exfoliation of the nanocomposites. It was found that pCBT is formed in the amorphous state, and crystallizes during the heating step or during the isothermal step at temperatures lower than the equilibrium melting temperature of the polymer (T{sub m}{sup 0}). When premixed with the nanofiller, irrespective of whether this was previously intercalated with a tallow surfactant or used in its pristine form, polymerization took place at higher temperatures and most of the crystallization was found to occur during the cooling stage. In those cases where crystallization took place during either the first heating scan, or during a prolonged isothermal step below the T{sub m}{sup 0} of the polymer, the resulting crystals were found to have a higher lamellar thickness, as compared with the same polymer crystallized from the melt during the cooling step from temperatures above the polymer T{sub m}{sup 0}.

  20. Syntheses and physical characterization of new aliphatic triblock poly(L-lactide-b-butylene succinate-b-L-lactide)s bearing soft and hard biodegradable building blocks.

    Science.gov (United States)

    Ba, Chaoyi; Yang, Jing; Hao, Qinghui; Liu, Xiaoyun; Cao, Amin

    2003-01-01

    This study presents chemical syntheses and physical characterization of a new aliphatic poly(L-lactide-b-butylene succinate-b-L-lactide) triblock copolyester with soft and hard biodegradable building blocks. First, poly(butylene succinate) (PBS) prepolymers terminated with hydroxyl functional groups were synthesized through melt polycondensation from succinic acid and 1,4-butanediol. Further, a series of new PLLA-b-PBS-b-PLLA triblock copolyesters bearing various average PLLA block lengths were prepared via ring opening polymerization of L-lactide with the synthesized hydroxyl capped PBS prepolymer (Mn = 4.9 KDa) and stannous octanoate as the macroinitiator and catalyst, respectively. By means of GPC, NMR, FTIR, DSC, TGA, and wide-angle X-ray diffractometer (WAXD), the macromolecular structures and physical properties were intensively studied for these synthesized PBS prepolymer and PLLA-b-PBS-b-PLLA triblock copolyesters. 13C NMR and GPC experimental results confirmed the formation of sequential block structures without any detectable transesterification under the present experimental conditions, and the molecular weights of triblock copolyesters could be readily regulated by adjusting the feeding molar ratio of L-lactide monomer to the PBS macroinitiator. DSC measurements showed all single glass transitions, and their glass transition temperatures were found to be between those of PLLA and PBS, depending on the lengths of PLLA blocks. It was noteworthy that the segmental flexibilities of the hard PLLA blocks were found to be remarkably enhanced by the more flexible PBS block partner, and the PBS and PLLA building blocks were well mixed in the amorphous regions. Results of TGA analyses indicated that thermal degradation and stabilities of the PLLA blocks strongly depended on the average PLLA block lengths of triblock copolyesters. In addition, FTIR and WAXD results showed the coexistence of the assembled PLLA and PBS crystal structures when the average PLLA block

  1. Novel biodegradable aliphatic poly(butylene succinate-co-cyclic carbonate)s with functional carbonate building blocks. 1. Chemical synthesis and their structural and physical characterization.

    Science.gov (United States)

    Yang, Jing; Hao, Qinghui; Liu, Xiaoyun; Ba, Chaoyi; Cao, Amin

    2004-01-01

    This study presents chemical synthesis, structural, and physical characterization of novel biodegradable aliphatic poly(butylene succinate-co-cyclic carbonate)s P(BS-co-CC) bearing functional carbonate building blocks. First, five kinds of six-membered cyclic carbonate monomers, namely, trimethylene carbonate (TMC), 1-methyl-1,3-trimethylene carbonate (MTMC), 2,2-dimethyl-1,3-trimethylene carbonate (DMTMC), 5-benzyloxytrimethylene carbonate (BTMC), and 5-ethyl-5-benzyloxymethyl trimethylene carbonate (EBTMC), were well prepared from ethyl chloroformate and corresponding diols at 0 degrees C in THF solution with our modified synthetic strategies. Then, a series of new P(BS-co-CC)s were synthesized at 210 degrees C through a simple combination of poly-condensation and ring-opening-polymerization (ROP) of hydroxyl capped PBS macromers and the prepared carbonate monomers, and titanium tetra-isopropoxide Ti(i-OPr)4 was used as a more suitable catalyst of 5 candidate catalysts which could concurrently catalyze poly-condensation and ROP. By means of NMR, GPC, FTIR, and thermal analytical instruments, macromolecular structures and physical properties have been characterized for these aliphatic poly(ester carbonate)s. The experimental results indicated that novel biodegradable P(BS-co-CC)s were successfully synthesized with number average molecular weight Mn ranging from 24.3 to 99.6 KDa and various CC molar contents without any detectable decarboxylation and that the more bulky side group was attached to a cyclic carbonate monomer, the lower reactivity for its copolymerization would be observed. The occurrences of 13C NMR signal splitting of succinyl carbonyl attributed to the BS building blocks could be proposed due to the randomized sequences of BS and CC building blocks. FTIR characterization indicated two distinct absorption bands at 1716 and 1733 approximately 1735 cm(-1), respectively, stemming from carbonyl stretching modes for corresponding BS and CC units. With

  2. Biological and Tribological Assessment of Poly(Ethylene Oxide Terephthalate)/Poly(Butylene Terephthalate), Polycaprolactone, and Poly (L\\DL) Lactic Acid Plotted Scaffolds for Skeletal Tissue Regeneration.

    Science.gov (United States)

    Hendrikson, Wilhelmus J; Zeng, Xiangqiong; Rouwkema, Jeroen; van Blitterswijk, Clemens A; van der Heide, Emile; Moroni, Lorenzo

    2016-01-21

    Additive manufactured scaffolds are fabricated from three commonly used biomaterials, polycaprolactone (PCL), poly (L\\DL) lactic acid (P(L\\DL)LA), and poly(ethylene oxide terephthalate)/poly(butylene terephthalate) (PEOT/PBT). Scaffolds are compared biologically and tribologically. Cell-seeded PEOT/PBT scaffolds cultured in osteogenic and chondrogenic differentiation media show statistical significantly higher alkaline phosphatase (ALP) activity/DNA and glycosaminoglycans (GAG)/DNA ratios, followed by PCL and P(L\\DL)LA scaffolds, respectively. The tribological performance is assessed by determining the friction coefficients of the scaffolds at different loads and sliding velocities. With increasing load or decreasing sliding velocity, the friction coefficient value decreases. PEOT/PBT show to have the lowest friction coefficient value, followed by PCL and P(L\\DL)LA. The influence of the scaffold architecture is further determined with PEOT/PBT. Reducing of the fiber spacing results in a lower friction coefficient value. The best and the worst performing scaffold architecture are chosen to investigate the effect of cell culture on the friction coefficient. Matrix deposition is low in the cell-seeded scaffolds and the effect is, therefore, undetermined. Taken together, our studies show that PEOT/PBT scaffolds support better skeletal differentiation of seeded stromal cells and lower friction coefficient compared to PCL and P(L/DL)A scaffolds.

  3. Heat Treatment Effects on the Mechanical Properties and Morphologies of Poly (Lactic Acid/Poly (Butylene Adipate-co-terephthalate Blends

    Directory of Open Access Journals (Sweden)

    Hsien-Tang Chiu

    2013-01-01

    Full Text Available In this study the relationships between mechanicals properties and morphology of the poly (lactic acid (PLA/poly (butylene adipate-co-terephthalate (PBAT blends with or without heat treatment were investigated. The differential scanning calorimetry (DSC analysis showed that blends have a two-phase structure indicating that they are immiscible. On the other hand, the PLA/PBAT (30/70 blend achieved the best tensile and impact strength because of its sea-island morphology, except for high PBAT content. The PLA/PBAT (70/30 and PLA/PBAT (50/50 blends showed irregular and directive-layer morphologies, in scanning electron microscopy (SEM analysis, producing a break cross-section with various fiber shapes. Both blends showed lower tensile strength and impact strength than the PLA/PBAT (30/70. After heat treatment, the PLA/PBAT blends showed high modulus of tensile and HDT because of a high degree of crystallization. The high degree of crystallization in the blends, which originated in the heat treatment, reduced their impact strength and elongation. However, the effect of high degree of crystallization on the PLA/PBAT (30/70 blend was small because of its sea-island morphology.

  4. Poly(butylene terephthalate)/montmorillonite nanocomposites: Effect of montmorillonite on the morphology, crystalline structure, isothermal crystallization kinetics and mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Kalkar, Arun K., E-mail: drarunkalkar@gmail.com; Deshpande, Vineeta D.; Vatsaraj, Bhakti S.

    2013-09-20

    Graphical abstract: - Highlights: • Effect of amount of clay content, its dispersion on crystalline structure of PBT. • Regime break temperature shifts to lower temperature for PCN4 up to 197 °C. • Tensile modulus enhanced up to 95% for PCN3 compared to PBT. - Abstract: Nanocomposites (PCNs), based on poly(butylene terephthalte) (PBT) and organoclay (Cloisite-15A) MMT were prepared by melt intercalation compounding process. The nanoscale dispersion and the microcrystal structure studied qualitatively using; X-ray diffraction (XRD) and electron microscopy (SEM, TEM and AFM). The XRD results indicated that the crystal size is highly dependent on the crystallization temperature. The isothermal crystallization kinetics of PBT in PCNs analysis indicated that the overall crystallization of PBT involved heterogeneous nucleated three-dimensional spherical primary crystallization growth process. The crystallization rate, however, is dependent on the PCN-composition, crystallization temperature and the dispersion state of clay in PCNs. Further analysis, based on Hoffman-Lauritzen theory revealed that the neat PBT and PBT in PCNs crystallization follow regime-II kinetics for temperature 195 °C–205 °C and enters the regime-III kinetics in lower T{sub c} range, 185 °C–195 °C. The improvement in mechanical properties is highly dependent on the level of clay exfoliation in PBT matrix.

  5. Role of specific interfacial area in controlling properties of immiscible blends of biodegradable polylactide and poly[(butylene succinate)-co-adipate].

    Science.gov (United States)

    Ojijo, Vincent; Sinha Ray, Suprakas; Sadiku, Rotimi

    2012-12-01

    Binary blends of two biodegradable polymers: polylactide (PLA), which has high modulus and strength but is brittle, and poly[(butylene succinate)-co-adipate] (PBSA), which is flexible and tough, were prepared through batch melt mixing. The PLA/PBSA compositions were 100/0, 90/10, 70/30, 60/40, 50/50, 40/60, 30/70, 10/90, and 0/100. Fourier-transform infrared measurements revealed the absence of any chemical interaction between the two polymers, resulting in a phase-separated morphology as shown by scanning electron microscopy (SEM). SEM micrographs showed that PLA-rich blends had smaller droplet sizes when compared to the PBSA-rich blends, which got smaller with the reduction in PBSA content due to the differences in their melt viscosities. The interfacial area of PBSA droplets per unit volume of the blend reached a maximum in the 70PLA/30PBSA blend. Thermal stability and mechanical properties were not only affected by the composition of the blend, but also by the interfacial area between the two polymers. Through differential scanning calorimetry, it was shown that molten PBSA enhanced crystallization of PLA while the stiff PLA hindered cold crystallization of PBSA. Optimal synergies of properties between the two polymers were found in the 70PLA/30PBSA blend because of the maximum specific interfacial area of the PBSA droplets.

  6. Effect of nanoclay loading on the thermal and mechanical properties of biodegradable polylactide/poly[(butylene succinate)-co-adipate] blend composites.

    Science.gov (United States)

    Ojijo, Vincent; Sinha Ray, Suprakas; Sadiku, Rotimi

    2012-05-01

    Polylactide/poly[(butylene succinate)-co-adipate] (PLA/PBSA)-organoclay composites were prepared via melt compounding in a batch mixer. The weight ratio of PLA to PBSA was kept at 70:30, while the weight fraction of the organoclay was varied from 0 to 9%. Small angle X-ray scattering patterns showed slightly better dispersion in PBSA than PLA, and there was a tendency of the silicate layers to delaminate in PBSA at low clay content. Thermal analysis revealed that crystallinity was dependent on the clay content as well its localization within the composite. On the other hand, thermal stability marginally improved for composites with 2 wt %. Tensile properties showed dependence on clay content and localization. Composite with 2 wt % clay content showed slight improvement in elongation at break. Overall, the optimum property was found for a composite with 2 wt % of the organoclay. This paper therefore has demonstrated the significance of the clay content and localization on the properties of the PLA/PBSA blends.

  7. Investigation on Polylactide (PLA/Poly(butylene adipate-co-terephthalate (PBAT/Bark Flour of Plane Tree (PF Eco-Composites

    Directory of Open Access Journals (Sweden)

    Qiang Dou

    2016-05-01

    Full Text Available Polylactide (PLA/poly(butylene adipate-co-terephthalate (PBAT/bark flour of plane tree (PF eco-composites were prepared via melt blending. The morphologies, mechanical properties, crystal structures and melting and crystallization behaviors of the eco-composites were investigated by means of scanning electron microscopy (SEM, mechanical tests, polarized light microscopy (PLM, wide angle X-ray diffraction (WAXD and differential scanning calorimetry (DSC, respectively. It is shown that the interfacial adhesion between PLA matrix and PF is weak and the mechanical properties of PLA/PF eco-composites are poor. The titanate treatment improves the adhesion between the matrix and the filler and enhances the stiffness of the eco-composites. The toughness is improved by PBAT and ductile fractured surfaces can be found. The spherulitic size of PLA is decreased by the addition of PF. The α crystalline form of PLA remains in the composites. Compared with PF, T-PF (PF treated by a titanate coupling agent and PBAT have negative effects on the crystallization of PLA.

  8. Novel ether-linkages containing aliphatic copolyesters of poly(butylene 1,4-cyclohexanedicarboxylate) as promising candidates for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Gigli, Matteo [Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), University of Bologna, Via Terracini 28, 40131 Bologna (Italy); Lotti, Nadia, E-mail: nadia.lotti@unibo.it [Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), University of Bologna, Via Terracini 28, 40131 Bologna (Italy); Vercellino, Marco [Department of Molecular Medicine, UdR of INSTM, Viale Taramelli 3/B, University of Pavia, Pavia (Italy); Visai, Livia [Department of Molecular Medicine, UdR of INSTM, Viale Taramelli 3/B, University of Pavia, Pavia (Italy); Department of Occupational Medicine, Ergonomics and Disability, Salvatore Maugeri Foundation, IRCCS, Laboratory of Nanotechnology, Via S. Maugeri 8, 27100 Pavia (Italy); Munari, Andrea [Department of Civil, Chemical, Environmental and Materials Engineering (DICAM), University of Bologna, Via Terracini 28, 40131 Bologna (Italy)

    2014-01-01

    A new class of biodegradable and biocompatible poly(butylene 1,4-cyclohexanedicarboxylate) based random copolymers are proposed for biomedical applications. The introduction of ether–oxygen containing BDG sequences along the PBCE macromolecular chain is expected to remarkably improve chain flexibility and surface hydrophilicity due to the presence of highly electronegative oxygen atoms. P(BCExBDGy) copolymers were synthesized by polycondensation. The homopolymer PBCE and three copolymers, namely (P(BCE70BDG30), P(BCE55BDG45) and P(BCE40BDG60)) were characterized from the molecular, thermal, structural and mechanical point of view. Hydrolytic degradation studies in the presence and absence of hog-pancreas lipase were performed under physiological conditions. To evaluate the diffusion profile of small molecules through the polymer matrix, the release behaviour of fluorescein isothiocyanate (FITC) was investigated. For biocompatibility studies, cell adhesion and proliferation of murine fibroblast (L929) and endocrine pancreatic (INS-1) cells were performed on each polymeric film. Results showed that solid-state properties can be tailored by simply varying copolymers' composition. Crystallinity degree and hydrophobicity significantly decreased with the increase of BDG co-unit mol%. Moreover, mechanical properties and biodegradability of PBCE, both depending on crystallinity degree, were remarkably improved: P(BCE40BDG60) showed an elastomeric behaviour with ε{sub b} over 600% and, as regard to biodegradability, after 98 days it lost over 60% of its initial weight if incubated in the presence of the pancreatic lipase. Lastly, the newly developed biomaterials resulted not cytotoxic with both types of cells and could be properly tailored for biomedical applications varying the content of BDG co-unit mol%. - Highlights: • Ether–oxygen atoms along PBCE chain as winning strategy to improve its properties • Adjustable solid-state properties of copolymers simply

  9. Osteoconductive bio-based meshes based on Poly(hydroxybutyrate-co-hydroxyvalerate) and poly(butylene adipate-co-terephthalate) blends

    Energy Technology Data Exchange (ETDEWEB)

    Nar, Mangesh; Staufenberg, Gerrit; Yang, Bing [Department of Material Science and Engineering, University of North Texas, 1155 Union Circle #305310, Denton, TX 76203-5017 (United States); Robertson, Lesli [Department of Fibers, College of Visual Arts and Design, 1155 Union Circle #305100, Denton, TX 76203-5017 (United States); Patel, Rinkesh H. [Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A and M University Baylor College of Dentistry, Dallas, TX 75246 (United States); Varanasi, Venu G., E-mail: vvaranasi@bcd.tamhsc.edu [Department of Biomedical Sciences and Center for Craniofacial Research and Diagnosis, Texas A and M University Baylor College of Dentistry, Dallas, TX 75246 (United States); D' Souza, Nandika Anne, E-mail: nandika.dsouza@unt.edu [Department of Material Science and Engineering, University of North Texas, 1155 Union Circle #305310, Denton, TX 76203-5017 (United States); Department of Mechanical and Energy Engineering, University of North Texas, 1155 Union Circle # 311098, Denton, TX 76203-5017 (United States)

    2014-05-01

    Poly(butylene adipate-co-terephthalate) (PBAT) and Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) are biopolymers that have the potential to be used in applications of bone healing. In this study, it is hypothesized that the polymer blend has the combined strength and osteoconductivity to support osteoblast collagen formation. PBAT (PBAT 100), and a blend with 20% PHBV (PBAT 80) were extruded in the form of fibers and then knitted in the form of mesh. These were tested in the warp as well as weft direction for the tensile properties; these showed that the weft direction had higher performance than the warp. The individual fibers were kept in phosphate buffered saline (PBS) over the period of 8 weeks and were tested for the storage and loss modulus using a dynamic mechanical analyser (DMA). The results indicated that mechanical relaxation strength showed a decrease and then an increase. In vitro osteoconductivity studies were done by using differentiating osteoblasts (MC3T3-E1 subclone 4 cells). Environmental Scanning Electron Microscopy (ESEM) showed that pre-soaking the samples in α-MEM for two weeks resulted in cell attachment and growth. X-ray diffraction (XRD) was used to determine the change in structure of polymers due to in vitro degradation for two weeks. Raman spectroscopy showed that all scaffolds supported the formation of a collagenous network over the scaffold surfaces. For a combination of knittable manufacturing, mechanical performance and osteoconductivity, blends offer an effective route. - Highlights: • PBAT and PHBV blend can be knitted to form mesh with good mechanical properties. • PBAT and PHBV blend do not show significant weight loss over a period of 8 weeks in PBS. • Osteoblast cell culture was done on these samples. • They support extracellular matrix and growth and hence are osteoconductive.

  10. Novel electrospun nanofibrous matrices prepared from poly(lactic acid)/poly(butylene adipate) blends for controlled release formulations of an anti-rheumatoid agent.

    Science.gov (United States)

    Siafaka, Panoraia I; Barmbalexis, Panagiotis; Bikiaris, Dimitrios N

    2016-06-10

    In the present work, a series of novel formulations consisting of poly(lactic acid)/poly(butylene adipate) (PLA/PBAd) electrospun blends was examined as controlled release matrices for Leflunomide's active metabolite, Teriflunomide (TFL). The mixtures were prepared using different ratios of PLA and PBAd in order to produce nanofibrous matrices with different characteristics. Miscibility studies of the blended polymeric fibers were performed through differential scanning calorimetry (DSC) and X-ray diffractometry (XRD). Hydrolytic degradation in the prepared fibers was evaluated at 37°C using a phosphate buffered saline solution. Different concentrations of (TFL) (5, 10, 15wt.%) were incorporated into nanofibers for examining the drug release behavior in simulated body fluids (SBF), at 37°C. The drug-loaded nanofibrous formulations were further characterized by Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy, DSC and XRD. Gel permeation chromatography (GPC) analysis was used to evaluate the mechanism of TFL release. Artificial neural networks (ANN) and multi-linear-regression (MLR) models were used to evaluate the effect of % content of PBAd (X1) and TFL (X2) on an initial burst effect and a dissolution behavior. It was found that PLA/PBAd nanofibers have different diameters depending on the ratio of used polyesters and added drug. TFL was incorporated in an amorphous form inside the polymeric nanofibers. In vitro release studies reveal that a drug release behavior is correlated with the size of the nanofibers, drug loading and matrix degradation after a specific time. ANN dissolution modeling showed increased correlation efficacy compared to MLR.

  11. Preparation of High-viscous Poly ( butylene succinate )%高黏度聚丁二酸丁二醇酯复合材料的制备

    Institute of Scientific and Technical Information of China (English)

    罗宇; 戚嵘嵘; 胡新利; 陆佳琦; 金婕妤; 朱健

    2012-01-01

    High-viscous poly (butylene succinate ) (PBS )was prepared by means of blending and moulding, which was related to thermosetting reactive resin ( PME ) in situ.The results showed that the form of crosslinked network by PME could obviously improve the viscosity of PBS.Scanning electron microscope was employed to investigate the phase morphology and compatibility of the composites, the results revealed that they were immiscible but nevertheless showed some degree of adhesion between the two phases.Results of DSC showed that with the increase of PME, degree of crystallinity first rose then droped.As it clearly illustrated in stress strain curve, composites were deformed from brittleness to ductility by adding small amount of PME.%采用共混、模压的方法利用热固性反应树脂(PME)原位固化反应制备了高黏度的聚丁二酸丁二醇酯(PBS).结果表明,PME交联网络的形成可以使PBS的黏度得到明显提高.采用扫描电子显微镜研究了复合材料的相形态及相容性,表明复合材料存在相分离,是不相容的体系.差示扫描量热测试表明,随着PME含量的增加,复合材料的结晶度先上升后下降;从复合材料拉伸曲线可以明显地发现,加入少量PME可以使复合材料发生从脆性到韧性的转变.

  12. Effect of Fiber Esterification on Fundamental Properties of Oil Palm Empty Fruit Bunch Fiber/Poly(butylene adipate-co-terephthalate Biocomposites

    Directory of Open Access Journals (Sweden)

    Mohamad Zaki AB Rahman

    2012-01-01

    Full Text Available A new class of biocomposites based on oil palm empty fruit bunch fiber and poly(butylene adipate-co-terephthalate (PBAT, which is a biodegradable aliphatic aromatic co-polyester, were prepared using melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 wt% and characterized. Chemical treatment of oil palm empty fruit bunch (EFB fiber was successfully done by grafting succinic anhydride (SAH onto the EFB fiber surface, and the modified fibers were obtained in two levels of grafting (low and high weight percentage gain, WPG after 5 and 6 h of grafting. The FTIR characterization showed evidence of successful fiber esterification. The results showed that 40 wt% of fiber loading improved the tensile properties of the biocomposite. The effects of EFB fiber chemical treatments and various organic initiators content on mechanical and thermal properties and water absorption of PBAT/EFB 60/40 wt% biocomposites were also examined. The SAH-g-EFB fiber at low WPG in presence of 1 wt% of dicumyl peroxide (DCP initiator was found to significantly enhance the tensile and flexural properties as well as water resistance of biocomposite (up to 24% compared with those of untreated fiber reinforced composites. The thermal behavior of the composites was evaluated from thermogravimetric analysis (TGA/differential thermogravimetric (DTG thermograms. It was observed that, the chemical treatment has marginally improved the biocomposites’ thermal stability in presence of 1 wt% of dicumyl peroxide at the low WPG level of grafting. The improved fiber-matrix surface enhancement in the chemically treated biocomposite was confirmed by SEM analysis of the tensile fractured specimens.

  13. Effect of fiber esterification on fundamental properties of oil palm empty fruit bunch fiber/poly(butylene adipate-co-terephthalate) biocomposites.

    Science.gov (United States)

    Siyamak, Samira; Ibrahim, Nor Azowa; Abdolmohammadi, Sanaz; Yunus, Wan Md Zin Wan; Rahman, Mohamad Zaki Ab

    2012-01-01

    A new class of biocomposites based on oil palm empty fruit bunch fiber and poly(butylene adipate-co-terephthalate) (PBAT), which is a biodegradable aliphatic aromatic co-polyester, were prepared using melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 wt% and characterized. Chemical treatment of oil palm empty fruit bunch (EFB) fiber was successfully done by grafting succinic anhydride (SAH) onto the EFB fiber surface, and the modified fibers were obtained in two levels of grafting (low and high weight percentage gain, WPG) after 5 and 6 h of grafting. The FTIR characterization showed evidence of successful fiber esterification. The results showed that 40 wt% of fiber loading improved the tensile properties of the biocomposite. The effects of EFB fiber chemical treatments and various organic initiators content on mechanical and thermal properties and water absorption of PBAT/EFB 60/40 wt% biocomposites were also examined. The SAH-g-EFB fiber at low WPG in presence of 1 wt% of dicumyl peroxide (DCP) initiator was found to significantly enhance the tensile and flexural properties as well as water resistance of biocomposite (up to 24%) compared with those of untreated fiber reinforced composites. The thermal behavior of the composites was evaluated from thermogravimetric analysis (TGA)/differential thermogravimetric (DTG) thermograms. It was observed that, the chemical treatment has marginally improved the biocomposites' thermal stability in presence of 1 wt% of dicumyl peroxide at the low WPG level of grafting. The improved fiber-matrix surface enhancement in the chemically treated biocomposite was confirmed by SEM analysis of the tensile fractured specimens.

  14. Enhancement of Mechanical and Thermal Properties of Oil Palm Empty Fruit Bunch Fiber Poly(butylene adipate-co-terephtalate Biocomposites by Matrix Esterification Using Succinic Anhydride

    Directory of Open Access Journals (Sweden)

    Samira Siyamak

    2012-02-01

    Full Text Available In this work, the oil palm empty fruit bunch (EFB fiber was used as a source of lignocellulosic filler to fabricate a novel type of cost effective biodegradable composite, based on the aliphatic aromatic co-polyester poly(butylene adipate-co-terephtalate PBAT (EcoflexTM, as a fully biodegradable thermoplastic polymer matrix. The aim of this research was to improve the new biocomposites’ performance by chemical modification using succinic anhydride (SAH as a coupling agent in the presence and absence of dicumyl peroxide (DCP and benzoyl peroxide (BPO as initiators. For the composite preparation, several blends were prepared with varying ratios of filler and matrix using the melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 (wt % and characterized. The effects of fiber loading and coupling agent loading on the thermal properties of biodegradable polymer composites were evaluated using thermal gravimetric analysis (TGA. Scanning Electron Microscopy (SEM was used for morphological studies. The chemical structure of the new biocomposites was also analyzed using the Fourier Transform Infrared (FTIR spectroscopy technique. The PBAT biocomposite reinforced with 40 (wt % of EFB fiber showed the best mechanical properties compared to the other PBAT/EFB fiber biocomposites. Biocomposite treatment with 4 (wt % succinic anhydride (SAH and 1 (wt % dicumyl peroxide (DCP improved both tensile and flexural strength as well as tensile and flexural modulus. The FTIR analyses proved the mechanical test results by presenting the evidence of successful esterification using SAH/DCP in the biocomposites’ spectra. The SEM micrograph of the tensile fractured surfaces showed the improvement of fiber-matrix adhesion after using SAH. The TGA results showed that chemical modification using SAH/DCP improved the thermal stability of the PBAT/EFB biocomposite.

  15. Enhancement of mechanical and thermal properties of oil palm empty fruit bunch fiber poly(butylene adipate-co-terephtalate) biocomposites by matrix esterification using succinic anhydride.

    Science.gov (United States)

    Siyamak, Samira; Ibrahim, Nor Azowa; Abdolmohammadi, Sanaz; Yunus, Wan Md Zin Bin Wan; Rahman, Mohamad Zaki Ab

    2012-02-16

    In this work, the oil palm empty fruit bunch (EFB) fiber was used as a source of lignocellulosic filler to fabricate a novel type of cost effective biodegradable composite, based on the aliphatic aromatic co-polyester poly(butylene adipate-co-terephtalate) PBAT (Ecoflex™), as a fully biodegradable thermoplastic polymer matrix. The aim of this research was to improve the new biocomposites' performance by chemical modification using succinic anhydride (SAH) as a coupling agent in the presence and absence of dicumyl peroxide (DCP) and benzoyl peroxide (BPO) as initiators. For the composite preparation, several blends were prepared with varying ratios of filler and matrix using the melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 (wt %) and characterized. The effects of fiber loading and coupling agent loading on the thermal properties of biodegradable polymer composites were evaluated using thermal gravimetric analysis (TGA). Scanning Electron Microscopy (SEM) was used for morphological studies. The chemical structure of the new biocomposites was also analyzed using the Fourier Transform Infrared (FTIR) spectroscopy technique. The PBAT biocomposite reinforced with 40 (wt %) of EFB fiber showed the best mechanical properties compared to the other PBAT/EFB fiber biocomposites. Biocomposite treatment with 4 (wt %) succinic anhydride (SAH) and 1 (wt %) dicumyl peroxide (DCP) improved both tensile and flexural strength as well as tensile and flexural modulus. The FTIR analyses proved the mechanical test results by presenting the evidence of successful esterification using SAH/DCP in the biocomposites' spectra. The SEM micrograph of the tensile fractured surfaces showed the improvement of fiber-matrix adhesion after using SAH. The TGA results showed that chemical modification using SAH/DCP improved the thermal stability of the PBAT/EFB biocomposite.

  16. Modification of poly (butylene succinate-co-butylene adipate) (PBSA) by physical blending with poly (1,2-propylene succiate) (PPSu)%聚(丁二酸-1,2-丙二酯)(PPSu)对聚(丁二酸丁二酯-共聚-己二酸丁二酯)(PBSA)的物理改性的研究

    Institute of Scientific and Technical Information of China (English)

    王瑞冬; 徐军; 郭宝华

    2012-01-01

    聚(丁二酸丁二酯-共聚-己二酸丁二酯)(PBSA)是一种全生物降解材料,但由于其结晶度较高,无定形区比例较少,导致韧性不足.聚(丁二酸-1,2-丙二酯)(PPSu)是一种非结晶的生物可降解聚酯,在室温下处于无定型态.研究了PPSu对于PBSA的物理改性作用,通过DSC、DMA、POM、SEM测试对PBSA/PPSu的共混体系进行了表征,发现这2种脂肪族聚酯的共混物为部分相容体系,少量PPSu和PBSA相容.随PPSu质量分数的增加,共混体系玻璃化转变温度稍有升高,结晶速率下降.PPSu质量分数达10%时,断面刻蚀的SEM图片显示相分离结构.力学性能测试结果表明,在混入少量PPSu后,PBSA的抗冲击强度得到了较大提升.%Poly (butylene succinate-co-butylene adipate) (PBSA) is a kind of biodegradable material. However, due to its high degree of crystallinity and a low proportion of amorphou region,PBSA has low impact resistance. Poly( 1, 2-propylene succiate) (PPSu) is a kind of amorphous polymer,which can also be fully degraded in environment. In this study, PPSu is blended with PBSA. The miscibility, crystallization kinetics and the mechanical properties of the blends are investigated. Differential scanning caloreroetry, thermomechanical analysis, phase contrast optical microscopy and scanning electron microscopy have been adopted to study the miscibility of the two polymer components. The results show that PBSA and PPSu are miscible partially. When PPSu content is larger than 10 wt% , phase separation is observed in the blends. Increasing the amount of PPSu,the blends have higher glass transition temperature and slower crystallization rate. Compared with PBSA,the impact strength of the blends is greatly improved.

  17. Influence of low contents of superhydrophilic MWCNT on the properties and cell viability of electrospun poly (butylene adipate-co-terephthalate) fibers

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Bruno V.M.; Silva, Aline S. [Laboratory of Biomedical Nanotechnology, Institute of Research and Development - IP& D, University of Vale do Paraiba (UNIVAP), Av. Shishima Hifumi 2911, Sao Jose dos Campos, Sao Paulo (Brazil); Melo, Gabriela F.S.; Vasconscellos, Luana M.R. [Department of Bioscience and Oral Diagnosis, Institute of Science and Technology, Sao Paulo State University (UNESP), Av. Engenheiro Francisco Jose Longo 777, Sao Jose dos Campos, Sao Paulo (Brazil); Marciano, Fernanda R. [Laboratory of Biomedical Nanotechnology, Institute of Research and Development - IP& D, University of Vale do Paraiba (UNIVAP), Av. Shishima Hifumi 2911, Sao Jose dos Campos, Sao Paulo (Brazil); Lobo, Anderson O., E-mail: aolobo@pq.cnpq.br [Laboratory of Biomedical Nanotechnology, Institute of Research and Development - IP& D, University of Vale do Paraiba (UNIVAP), Av. Shishima Hifumi 2911, Sao Jose dos Campos, Sao Paulo (Brazil)

    2016-02-01

    The use of poly (butylene adipate-co-terephthalate) (PBAT) in tissue engineering, more specifically in bone regeneration, has been underexplored to date due to its poor mechanical resistance. In order to overcome this drawback, this investigation presents an approach into the preparation of electrospun nanocomposite fibers from PBAT and low contents of superhydrophilic multi-walled carbon nanotubes (sMWCNT) (0.1–0.5 wt.%) as reinforcing agent. We employed a wide range of characterization techniques to evaluate the properties of the resulting electrospun nanocomposites, including Field Emission Scanning Electronic Microscopy (FE-SEM), Transmission Electronic Microscopy (TEM), tensile tests, contact angle measurements (CA) and biological assays. FE-SEM micrographs showed that while the addition of sMWCNT increased the presence of beads on the electrospun fibers' surfaces, the increase of the neat charge density due to their presence reduced the fibers' average diameter. The tensile test results pointed that sMWCNT acted as reinforcement in the PBAT electrospun matrix, enhancing its tensile strength (from 1.3 to 3.6 MPa with addition of 0.5 wt.% of sMWCNT) and leading to stiffer materials (lower elongation at break). An evaluation using MG63 cells revealed cell attachment into the biomaterials and that all samples were viable for biomedical applications, once no cytotoxic effect was observed. MG-63 cells osteogenic differentiation, measured by ALP activity, showed that mineralized nodules formation was increased in PBAT/0.5%CNTs when compared to control group (cells). This investigation demonstrated a feasible novel approach for producing electrospun nanocomposites from PBAT and sMWCNT with enhanced mechanical properties and adequate cell viability levels, which allows for a wide range of biomedical applications for these materials. - Highlights: • Nanocomposites from PBAT and superhydrophilic MWCNT (sMWCNT) were successfully prepared by electrospinning

  18. EFFECT OF INTERMOLECULAR HYDROGEN-BONDING ON CRYSTALLIZATION, MELTING AND DYNAMIC MECHANICAL BEHAVIOR OF POLY(BUTYLENE SUCCINATE) IN POLY( BUTYLENE SUCCINATE)/BISPHENOL A BLENDS%分子间氢键的形成对聚丁二酸丁二酯结晶熔融及动态力学行为的影响

    Institute of Scientific and Technical Information of China (English)

    罗发亮; 张秀芹; 甘志华; 季君晖; 王笃金

    2011-01-01

    研究了含有酚羟基的小分子添加剂双酚A(BPA)对可生物降解高分子材料聚丁二酸丁二酯(PBS)的结晶、熔融及玻璃化转变的影响.研究表明在PBS中添加BPA,使PBS的结晶能力下降、熔点降低,这源于PBS与BPA通过氢键相互作用形成复合物,破坏了PBS的规整结晶结构.动态力学热分析表明,复合物的玻璃化转变温度随着BPA含量增加而升高,动态储能模量下降.%In order to investigate the effects of low molecular weight organic additives containing phenol hydroxyl group on the crystallization, melting and mechanical properties of biodegradable aliphatic polyester,poly(butylene succinate) (PBS) and bisphenol A(BAP) were selected to blend via solution mixing method.Then 13C-NMR spectroscopy was used to probe the interaction between PBS and BPA,and the effects of BPA on the crystallization, melting, glassy transition temperature (Tg) and dynamic mechanical properties were investigated using DSC (differential scanning calorimetry) and DMTA(dynamic mechanical thermal nalysis).The results indicate that hydrogen-bonding was formed between phenol hydroxyls in BPA and ester groups in PBS chain, leading to the decrease of crystallization ability and melting point for PBS, which is attributed to the formation of PBS-BPA complexes via intermolecular hydrogen-bonding that disrupts the regularity of the PBS chain structure. The storage modulus of PBS-BPA complexes decreases with the increase of BPA content above the glassy transition temperature due the decreasing of crystallization ability for PBS, while the maximun position of the loss factor shifts to high temperature.

  19. Preparation of nanocomposites based on poly(Butylene Succinate) and montmorillonite organoclay via in situ polymerization; Preparo de nanocompositos de poli(succinato de butileno) (PDS) e argila motmorilonita organofilica via polimerizaco in situ

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Leticia P.; Moreira, Andrei N.; Souza Junior, Fernando G. de, E-mail: fgsj@ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Inst. de Macromoleculas; Pinto, Jose Carlos Costa da Silva [Coordenacao dos Cursos de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Quimica

    2014-09-15

    Nanocomposites based on poly(butylene succinate) (PBS) and organophilic montmorillonite were synthesized via in situ polymerization using three different clay compositions (4, 6 and 8 wt%). The products were characterized by several different techniques. X-ray diffraction was useful to confirm the increase of the interlayer spacing of the clay due to the presence of the polymer chains among layers. Thermal analysis indicated that the polymerization method chosen led to materials with lower thermal stability compared to the pure PBS, due to the difficulty of chain growth in the presence of the clay. Low-field NMR technique was used to assess clay dispersion in the polymer, with exfoliated structures predominating in the nanocomposites. (author)

  20. 丙烯-1-丁烯共聚BOPP结构及其薄膜拉伸工艺%Propylene-1-butylene copolymer structure and BOPP film stretching process

    Institute of Scientific and Technical Information of China (English)

    高达利; 张师军; 郭梅芳; 施红伟; 宋文波; 张丽英; 邹浩; 邵静波

    2015-01-01

    选取一种丙烯-1-丁烯共聚双向拉伸聚丙烯(BOPP)原料进行了薄膜双向拉伸加工实验,在不同工艺条件下制得BOPP薄膜,并对所制薄膜试样的拉伸过程、力学性能、光学性能等进行研究,建立了丙烯-1-丁烯共聚BOPP原料的薄膜拉伸工艺与薄膜拉伸成型和薄膜性能间的对应关系.研究表明:所采用的丙烯-1-丁烯共聚BOPP原料的拉伸成膜性好,拉伸工艺可调节范围宽.拉伸温度较高时薄膜的雾度升高,力学性能降低;而拉伸温度较低时,薄膜易出现拉伸不均匀的情况.此外,BOPP中丙烯-1-丁烯共聚结构的存在降低了薄膜结晶度,使得薄膜的光学性能较好.%A kind of biaxial oriented polypropylene(BOPP)of propylene-1-butylene copolymer was used to prepare BOPP film in different processing conditions. The stretching process,mechanical properties, optical properties of the film were studied. The relationships of the raw material stretching technology,film stretch forming and film properties were established.The results indicate that the BOPP has wider processing temperatures. The haze of the film increases and mechanical property decreases at higher stretching temperature,while the film becomes uneven at lower temperature. In addition,the crystallization degree of the film is decreased and the optical property is improved because of the existence of propylene-1-butylene copolymer.

  1. Biodegradation of poly(butylene succinate) powder in a controlled compost at 58°C evaluated by naturally-occurring carbon 14 amounts in evolved CO(2) based on the ISO 14855-2 method.

    Science.gov (United States)

    Kunioka, Masao; Ninomiya, Fumi; Funabashi, Masahiro

    2009-11-20

    The biodegradabilities of poly(butylene succinate) (PBS) powders in a controlled compost at 58 degrees C have been studied using a Microbial Oxidative Degradation Analyzer (MODA) based on the ISO 14855-2 method, entitled "Determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions-Method by analysis of evolved carbon dioxide-Part 2: Gravimetric measurement of carbon dioxide evolved in a laboratory-scale test". The evolved CO(2) was trapped by an additional aqueous Ba(OH)(2) solution. The trapped BaCO(3) was transformed into graphite via a serial vaporization and reduction reaction using a gas-tight tube and vacuum manifold system. This graphite was analyzed by accelerated mass spectrometry (AMS) to determine the percent modern carbon [pMC (sample)] based on the (14)C radiocarbon concentration. By using the theory that pMC (sample) was the sum of the pMC (compost) (109.87%) and pMC (PBS) (0%) as the respective ratio in the determined period, the CO(2) (respiration) was calculated from only one reaction vessel. It was found that the biodegradabilities determined by the CO(2) amount from PBS in the sample vessel were about 30% lower than those based on the ISO method. These differences between the ISO and AMS methods are caused by the fact that part of the carbons from PBS are changed into metabolites by the microorganisms in the compost, and not changed into CO(2).

  2. 聚丁二酸丁二醇酯环状二聚物的纯化、表征及其开环聚合%Purification, Characterization and Ring-opening Polymerization of Cyclic Dimer of Poly (butylenes succinate)

    Institute of Scientific and Technical Information of China (English)

    杨群; 崔进; 陆大年

    2013-01-01

    从聚丁二酸丁二醇酯(PBS)的环状低聚物中分离提纯出了PBS的环状二聚物[cyclic dimer of poly(butylene succinate),CDBS],采用核磁、质谱对该环状二聚物进行了表征,研究表明,通过分离纯化得到了纯度高的PBS的环状二聚物.以纯化的CDBS为原料、十二醇为初始剂、辛酸锡作催化剂,采用开环聚合的方法合成了PBS,采用核磁、红外光谱对合成的PBS的结构进行了表征,并研究了开环聚合温度、聚合时间以及催化剂用量对PBS的分子量、单体转化率的影响,结果表明,开环反应温度220℃左右,反应3h,PBS的相对分子质量(简称分子量,下同)可达到63 300,与直接酯化-缩聚法相比,采用开环聚合法能提高PBS的制备效率.

  3. 高韧性PET/PBT合金的制备及性能%Preparation and Properties of Poly(Ethylene Terephthalate) / Poly(Butylene Terephthalate) Alloys with High Toughness

    Institute of Scientific and Technical Information of China (English)

    曹宇飞; 孙树林; 沙莎; 郭菲; 郝润佳; 张会轩

    2009-01-01

    甲基丙烯酸环氧丙酯接枝乙烯-辛烯共聚物(POE-g-GMA)用于聚时苯二甲酸乙二醇酯(PET)/聚对苯二甲酸丁二醇酯(PBT)共混物的增韧改性,同时考察了PET、PBT组成变化对共混体系性能的影响.结果表明,加入15%~20%(质量分数,下同)的POE-g-GMA共混体系发生脆韧转变,冲击强度最高可达890 J/m,实现超韧;基体的剪切屈服和橡胶粒子的空洞化是增韧PET/PBT共混物主要形变机理.%Glycidyl methacrylate grafted poly(ethylene octane) copolymer (POE-g-GMA) was used as modifiers to improve the toughness of poly(ethylene terephthalate) (PET)/Poly (butylene terephthalate) (PBT) blends. The influence of PET and PBT ratio change on the properties of the blends was investigated. The results show that brittle-ductile transition takes place with 15%~20% POE-g-GMA addition. Impact strength value of 890 J/m is achieved which displays the super-toughness. Shear yielding of matrix and cavitation of rubber particles are the major toughening mechanisms of the rubber toughened PET/PBT blends.

  4. Processing and rheological characterization of poly(butylene adipate co-terephalate)/montmorillonite nanocomposites;Processamento e caracterizacao reologica de nanocompositos de poli(butileno adipato co-tereftalato)/montmorilonita

    Energy Technology Data Exchange (ETDEWEB)

    Beatrice, Cesar A.G.; Marini, Juliano; Bretas, Rosario E.S., E-mail: bretas@power.ufscar.b [Universidade Federal de Sao Carlos (PPGUFSCar), SP (Brazil). Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais; Branciforti, Marcia C.; Favaro, Marcia M. [Universidade Federal de Sao Carlos (DEMa/UFSCar), SP (Brazil). Dept. de Engenharia de Materiais

    2009-07-01

    The rheological steady state and the linear viscoelastic properties of poly(butylene adipate co-terephthalate) (PBAT) / nanoclay nanocomposites were investigated. For this study, nanocomposites of PBAT and a chemically modified montmorillonite (MMT) were prepared by melt blending in a Haake Rheomix 600p rheometer at 140 and 160 deg C. The concentration of nanoclay was 5wt%. The samples obtained were characterized by x-ray diffraction (WAXS) and rheological measurements in an ARES (Rheometric Scientific) and AR-G2 (TA) rheometers, both with parallel plates geometry. It was confirmed by WAXS that the platelets of the nanoclay were intercalated in all samples, as the discernible sharp reflection of the (001) clay's diffraction was found in the x-ray diffractions patterns. The storage moduli (G') and the loss moduli (G) of the nanocomposites increased with nanoclay content, at low frequencies. The presence of nanoclay caused these nanocomposites melts to have solid-like behaviors, which can be explained in terms of the development of a percolated network structure. (author)

  5. Review of the blend of natural polymers/poly(butylene succinate)%天然高分子/聚丁二酸丁二醇酯共混物研究进展

    Institute of Scientific and Technical Information of China (English)

    解肖鹏; 汪鹏; 黄嘉荣; 张水洞

    2015-01-01

    Due to its biodegradable,mechanical properties,poly( butylene succinate) ( PBS) will be widely applied in the fields such as plastic,biomedical carrier or devices and so on. However,the defects in mechanical and biodegradable properties of PBS,and its high price limits the application. To increase the properties and applied fields of PBS,method such as modified PBS by physical blend was adopted. The paper reviewed the new development of the natural polymers/PBS blend, and some suggestions were de-scribed to prepare natural polymers/PBS blend with higher mechanical and thermal properties.%聚丁二酸丁二醇酯( PBS)是一种热塑性脂肪族聚酯,因力学和生物降解性等性能良好而具有广泛应用前景,但仍存在拉伸强度和生物降解速率低,成本高等缺陷,限制了其应用。通过物理改性是提高其性能和应用领域的重要研究方向之一。本文综述了近年天然高分子/PBS共混物制备和性能研究,并对天然高分子/PBS共混物的发展作了总结和展望。

  6. Biodegradation of Poly(butylene succinate Powder in a Controlled Compost at 58 °C Evaluated by Naturally-Occurring Carbon 14 Amounts in Evolved CO2 Based on the ISO 14855-2 Method

    Directory of Open Access Journals (Sweden)

    Masahiro Funabashi

    2009-09-01

    Full Text Available The biodegradabilities of poly(butylene succinate (PBS powders in a controlled compost at 58 °C have been studied using a Microbial Oxidative Degradation Analyzer (MODA based on the ISO 14855-2 method, entitled “Determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions—Method by analysis of evolved carbon dioxide—Part 2: Gravimetric measurement of carbon dioxide evolved in a laboratory-scale test”. The evolved CO2 was trapped by an additional aqueous Ba(OH2 solution. The trapped BaCO3 was transformed into graphite via a serial vaporization and reduction reaction using a gas-tight tube and vacuum manifold system. This graphite was analyzed by accelerated mass spectrometry (AMS to determine the percent modern carbon [pMC (sample] based on the 14C radiocarbon concentration. By using the theory that pMC (sample was the sum of the pMC (compost (109.87% and pMC (PBS (0% as the respective ratio in the determined period, the CO2 (respiration was calculated from only one reaction vessel. It was found that the biodegradabilities determined by the CO2 amount from PBS in the sample vessel were about 30% lower than those based on the ISO method. These differences between the ISO and AMS methods are caused by the fact that part of the carbons from PBS are changed into metabolites by the microorganisms in the compost, and not changed into CO2.

  7. Research on Epoxybutane from 1-Butylene by Ti-MSU Molecular Sieve Catalytic Oxidation%Ti-MSU分子筛催化1-丁烯氧化制环氧丁烷的研究

    Institute of Scientific and Technical Information of China (English)

    吴美玲; 周灵杰; 陈玮娜

    2014-01-01

    5.5%Ti-MSU molecular sieve catalyst was prepared by liquid phase impregnation method. The sam-ple was characterized by X-ray diffraction and N2 adsorption-desorption. With cumene hydroperoxide ( CHP) ,1-bu-tene as raw material,the influence of the process conditions of 5.5%Ti-MSU catalyst on epoxybutane had been in-vestigated. The conversion of CHP was 81.2%,1,2-epoxybutane ( BO) selectivity was 60.2%, benzyl alcohol ( DMBA) selectivity was 87.2%, when the optimum reaction conditions was 100℃ catalyst bed,3.0 MPa reactivity pressure,10∶1 1-butylene/CHP molar ratio and 2h-1 space velocity of CHP.%通过液相浸渍法制备Ti 质量分数为5�5%的Ti-MSU分子筛催化剂,并采用X射线衍射、N2吸附-脱附对催化剂样品进行表征。考察了Ti-MSU催化剂对以过氧化氢异丙苯( CHP)、1-丁烯为原料制备环氧丁烷的反应工艺条件的影响。结果表明,当催化剂床层温度为100℃、反应压力为3�0 MPa、1-丁烯/CHP摩尔比为10∶1、CHP空速为2 h-1时,CHP的转化率达到81�2%,1,2-环氧丁烷( BO)选择性为60�2%,苄醇( DMBA)选择性为87�2%。

  8. Spectroelectrochemical sensing based on multimode selectivity simultaneously achievable in a single device. 21. Selective chemical sensing using sulfonated polystyrene-block-poly(ethylene-ran-butylene)block-polystyrene thin films.

    Science.gov (United States)

    Andria, Sara E; Seliskar, Carl J; Heineman, William R

    2009-12-01

    Spectroelectrochemical sensors combine three modes of selectivity in a single device (electrochemistry, spectroscopy, and selective partitioning). A thin polymer film is coated onto the sensing platform in order to facilitate chemically selective transport to the electrode. The film is an essential part of the sensor because it provides an increase in selectivity and sensitivity by selectively preconcentrating the analyte. Here, we report the next step in the characterization of partially sulfonated polystyrene-block-poly(ethylene-ran-butylene)block-polystyrene (SSEBS) films for the purpose of chemical sensing by examining the selectivity of the sensor fabricated with this novel thin film material. Binary mixtures using model analytes were used to demonstrate the sensor's ability to detect an analyte in the presence of a direct interference. The binary mixtures consisted of Ru(bpy)(3)(2+)/Fe(CN)(6)(3-), Ru(bpy)(3)(2+)/Fe(bpy)(3)(2+), and Ru(bpy)(3)(2+)/Cu(bpy)(2)(2+). Demonstration of the selective partitioning mode using the Ru(bpy)(3)(2+)/Fe(CN)(6)(3-) mixture and absorption detection showed the SSEBS film's preference for Ru(bpy)(3)(2+) over Fe(CN)(6)(3-), and therefore, Fe(CN)(6)(3-) did not interfere with the sensor's response to Ru(bpy)(3)(2+). Furthermore, the importance of the use of three modes together was demonstrated by analysis of the Ru(bpy)(3)(2+)/Fe(bpy)(3)(2+) and the Ru(bpy)(3)(2+)/Cu(bpy)(2)(2+) test mixtures, where both selection of a specific wavelength for absorption and selection of a specific potential window were required to reduce or eliminate the signal from the interference. Finally, analysis of the Ru(bpy)(3)(2+)/Fe(bpy)(3)(2+) test mixture was also demonstrated using fluorescence detection.

  9. 热处理对聚己二酸丁二醋多晶结构和降解行为的影响%Polymorphic Crystals from Different Thermal Treatments and Its Effect on Biodegradation Behavior of Poly( butylene adipate)

    Institute of Scientific and Technical Information of China (English)

    赵丽芬; 蒋妮; 甘志华

    2011-01-01

    On the basis of characteristic polymorphic crystals of poly ( butylene adipate) ( PBA), the PBA films with α crystal structure were prepared by melt crystallization and annealing treatment. The polymorphic crystal structure, crystal size and crystalline morphology of PBA α crystals with different thermal history were studied by wide angle X-ray diffraction ( WAXD), atomic force microscope ( AFM ) and differential scanning calorimeter(DSC). The biodegradation behavior of PBA α crystals from different thermal treatments was investigated by following the mass loss with time. The results indicate that the difference of PBA α crystals in spatial orientation of polymer chains in the same crystal lattice due to the different thermal history is the essential reason which results in the different biodegradation rates.%通过熔融结晶并结合退火处理方法得到多晶结构的聚己二酸丁二酯(PBA)及具有不同热历史的热力学稳定的a晶型,采用广角X射线衍射仪(WAXD)、原子力显微镜(AFM)和差示扫描量热仪(DSC)研究了PBA的多晶结构、晶体尺寸和结晶形貌,跟踪了退火处理PBA的生物降解行为.结果表明,分子链在相同晶格排列中围绕c轴空间取向的不同是决定多晶PBA降解速率差别的根本因素.

  10. 超支化聚氨酯共混改性聚丁二酸丁二醇酯的性能%Properties of Poly(Butylene Succinate) Blending Modified with Hyperbranched Polyurethane

    Institute of Scientific and Technical Information of China (English)

    夏青; 张敏; 赵莹; 李莉

    2013-01-01

    Hyperbaranched polyurethane (HBPU) / poly(butylene succinate) (PBS) composite films were obtained through melt blending and mixing rolling.The thermal property,crystallization behavior and mechanical performance of composites were investigated by TG,DSC,XRD and universal testing machine.Also the degradation property was studied using the soil burial method in Shaanxi garden soil.The results show that the crystallinity of composite films declines with increase of HBPU content.The crystallinity of PBS reaches the minimum value of 25.7 % when HBPU content is 6 %.DSC curves reveal that the crystallization temperature of PBS is improved with the addition of HBPU.However,the thermal stability of composite films decreases.Tensile testing results show that with HBPU content increasing,the elongation at break of composites is significantly improved.The elongation at break reaches the maximum value of 75 % when HBPU content of is 6 %.There are significant cracks on the surfaces of composite films.The crystallinity of PBS reduces after HBPU was added into PBS,but the toughness of composites improves.%采用熔融共混与开炼压延制备聚丁二酸丁二醇酯(PBS)和羟基封端超支化聚氨酯(HBPU)的复合膜.使用X射线衍射(XRD)、差示扫描量热(DSC)、热重分析(TG)和万能试验机对其结晶性、热性能和力学性能进行了研究;采用土埋法在陕西花园土中对复合膜进行降解.结果表明,随着HBPU的增加,复合膜结晶度均有所降低,当HBPU的质量分数为6%时达到25.7%;DSC结果表明,HBPU提高了PBS的结晶温度;随着HBPU的增加,复合材料的热稳定性有所下降;在拉力测试中,复合材料的断裂伸长率得到了显著提高,6%时复合材料的断裂伸长率达到75%;复合膜降解后表面出现明显裂纹.HBPU对PBS改性,降低了PBS的结晶度,提高了复合材料的韧性.

  11. 热塑性淀粉/PBS共混物的微生物降解性研究%Biodegradation of starch/poly(butylene succinate) blends by the selected cultured fungi

    Institute of Scientific and Technical Information of China (English)

    李陶; 李辉章; 曾建兵; 王玉忠

    2009-01-01

    In recent years,much progress has been achieved in the development of biodegradable products using agricultural materials as basis,for the environmental threats restrict the use of non-degradable polymers.In order to obtain a cost-effective biodegradable plastic,a novel environmental-friendly starch/poly(butylene succinate) (PBS) blends with improved compatibility were successfully prepared using glycerol as plasticizer.In this work,the biodegradation behavior of starch/PBS blends was studied by the selected cultured fungi according to the ISO846-1997.The ultimate biodegradation percentage revealed that the blends showed good biodegradability.Rates of weight loss increased with the decrease of PBS contents or the increase of the molecular weight of PBS,which is ascribed to the fact that the dispersed PBS blocked the fungi to attack starch matrix.Moreover,the presence of plasticizer such as glycerol can further influence the biodegradation percentage.For all samples,the weight loss was accompanied by a rapid deterioration in tensile strength and elongation at break.In addition,biodegradation resulted in an increase of crystallinity and melting point in starch/PBS blends.%以甘油作为增塑剂,采用玉米淀粉与改性后的聚丁二酸丁二醇酯(PBS)熔融共混制备出淀粉/PBS共混材料.对这种改善了两相相容性的共混材料在特定微生物条件下的降解行为进行了研究.结果显示,共混物降解28天后,含有30%PBS的共混物质量损失达到35%左右,其力学性能只有降解前的20%,甘油含量减小和PBS含量增加均能减缓材料的降解.且随着降解时间的延长,PBS的结晶度和熔点有所提高.

  12. 热塑性淀粉/聚丁二酸丁二醇酯合金的制备和结构性能表征%Preparation and Characterization of Thermoplastic Starch /Poly(butylene-succinate) Blends

    Institute of Scientific and Technical Information of China (English)

    王伟; 傅晓伟; 肖鹏程; 周玉丽; 郭卫红

    2012-01-01

    Thermoplastic starch plasticised by glycerol(GTPS) /poly(butylene-succinate)(PBS) blends were prepared using glycerol as the plasticizer.Besides,structure and performance of the blends were also characterized.Results showed that during processing the torque of GTPS/PBS blends and mechanical properties increased with the rising of PBS mass fraction and the decreasing of glycerol mass fraction.Scanning electron microscope(SEM) showed that more glycerol would improve the compatibility of the blends.Dynamic mechanical analysis(DMA) results suggested that storage modulus of blends in glassy state was higher than PBS,but conversely in rubbery state.Furthermore,the blends with higher PBS and glycerol mass fraction exhibited better thermal stability.Absorption rate decreased from more than 100% to less than 10% by adding PBS.Both starch and glycerol could improve the biodegradation rate of PBS.%制备了高填充的甘油塑化淀粉(GTPS)/聚丁二酸丁二醇酯(PBS)合金,并对其结构性能进行了表征。结果表明:GTPS/PBS在合金加工过程中其扭矩以及力学性能随PBS质量分数的增加及甘油质量分数的减小而增大;扫描电镜(SEM)显示甘油可提高合金的相容性;动态力学分析(DMA)表明合金在玻璃态时的储存模量高于纯PBS,黏流态时则相反;合金的热稳定性随PBS和甘油质量分数的增加而有所提高;PBS的加入将合金的吸水率由100%以上降低到10%以下;淀粉和甘油的存在则均可提高PBS的降解率。

  13. Denitrification of saline water with poly butylene succinate as carbon source and biofilm carriers%以聚丁酸丁二醇酯为碳源去除含盐水体硝酸盐的研究

    Institute of Scientific and Technical Information of China (English)

    罗国芝; 董明来; 刘倩; 邓棚文; 谭洪新

    2013-01-01

    以可生物降解聚合物为碳源和生物膜载体可以解决异养反硝化有机碳源的添加不足或过量的问题.在序批式反应条件下,以聚丁酸丁二醇酯(PBS)为碳源和生物膜载体,对含盐水体异养反硝化过程中的细菌群落特征进行了研究.结果表明,试验条件下硝酸盐可以得到很好的去除,虽然有亚硝酸盐的明显积累,但最终被降低.硝酸盐的存在会降低含PBS水体中溶解性有机物的含量.应用变性梯度凝胶电泳和16S rDNA的方法鉴别到的细菌包括:Pseudomonas stutzeri,Pseudomonas sp.,Alteromonas sp.,Marinobacter salsuginis,Thalassospira xianheensis,Itellibacter vladivostokensis,Euplotopsis encysticus,Alcanivorax venustensis,Halomonas sp.,Agrobacterium tume aciens,Pannonibacter phragmitetus,Vitellibacter vladivostokensis.试验结果表明,反硝化条件下PBS具有较好的可生物降解性和明显的NO3--N去除能力,是比较理想的低C/N含盐水体异养反硝化碳源.%The problem of improper addition of organic carbon source in heterotrophic denitrification process could be well solved by using biodegradable polymer as both solid carbon source and biofilm carriers. Batch experiments were carried out to use poly butylene succinate (PBS) as solid carbon source and biofilm carriers to remove nitrate-nitrogen from saline wastewater. The bacterial community was identified using denaturing gradient gel electro-phoresis (DGGE) and 16S rDNA sequencing. The results showed that large amount of nitrate was removed under the experiment condition, although the obvious nitrite accumulation was found during denitrification process, but they eventually be removed. The existence of nitrate could reduce the content of dissolving organic matter in PBS containing wastewater. The bacteria found in bioreactor were assigned to Pseudomonas stutzri, Pseudomonas sp. , Alteromonas sp. ,Marinobacter salsuginis , Thalassospira xianheensis , Itellibacter vladivostokensis

  14. 聚丁二酸丁二醇酯/聚碳酸亚丙酯生物膜的制备及相关性能评价%Poly(butylene succinate)/polypropylenecarbonate biofilms: preparation and performance

    Institute of Scientific and Technical Information of China (English)

    马遥; 储顺礼; 孙悦; 马珊珊; 李雪; 张天首; 周延民

    2015-01-01

    BACKGROUND:Poly(butylene succinate) (PBS) and polypropylenecarbonate (PPC) are new medical materials developed in recent years, characterized as good biocompatibility, biodegradability and the low price. OBJECTIVE:To prepare the PBS/PPC biofilm by electrostatic spinning method and evaluate its physical and chemical properties, degradation performance and effect on cel proliferationin vitro. METHODS:The PBS/PPC biofilm was prepared using electrostatic spinning method: 0.9 g PBS and 0.9 g PPC were dissolved in 10 mL of trichloromethane at room temperature and stirred magneticaly until they were fulydissolved. Then, the spinning solution was added into a spinning tube with a distance of about 15 cm and at a voltage of 18 kV. The surface morphology was observed by scanning electron microscopy. The intensity, contact angle and water absorption, pH value and weight loss in the process ofin vitro degradation were measured. MG63 cels were co-cultured with the biofilm for 7 days and cel proliferation was detected by cel counting kit-8. RESULTS AND CONCLUSION: The PBS/PPC biofilm showed a porous structure with interconnected pores. The fiber diameter was about 0.88 μm, the average aperture was about 5.68 μm, the porosity was 78.3%, the fracture intensity was 2.31 MPa, the elongation rate at break was 23.48%, the average value of contact angle was 87°, and the water absorption rate was 68.54%. During the biofilm degradation, the pH value decreased gradualy andreduced to 6.76 at 12 weeks; meanwhile, the biofilm degraded equaly and gradualy, and the weight loss rate was 6.04% at the end of the 12th week. The results of cel counting kit-8 showed that the PBS/PPC biofilm could promote cel proliferation. Overal, the PBS/PPC biofilm has good physical and chemical properties, good space-making feature, wettability and degradability, which can provide sufficient time for bone tissue regeneration.%背景:聚丁二酸丁二醇酯、聚碳酸亚丙酯是近年来发展的新型医

  15. 一种新型聚对苯二甲酸丁二醇酯-层状硅酸盐纳米复合材料的制备与性能%Preparation and Properties of a New Type of Poly (butylene-terephthalate) with Layered Silicate Nanocomposites

    Institute of Scientific and Technical Information of China (English)

    柯扬船

    2003-01-01

    In this paper, poly(butylene-terephthalate)-layered silicate of clay nanocomposites (NPBT) are reported. Their thermal properties, heat distortion temperature (HDT) and crystallization nucleation are investigated. NPBT samples have apparent viscosity over 0.85, HDT of 30℃ to 50℃ higher than that of poly (butyleneterephthalate) (PBT) for clay load from 1.0% to 10.0% (by mass), and higher capability to accommodate clay than other polymers. The nonisothermal crystallization experiments indicate that the better thermal degradation behavior and crystallization rate of NPBT are 50% higher than PBT, and its injection mould processing temperature is lowered from 110℃ to 55℃. NPBT samples are characterized by several techniques. X-ray shows an original clay interlayer distance enlarged from 1.0 nm to 2.5 nm, while both TEM and AFM indicate an average size from 30nm to 100nm of exfoliated clay layers, and 3%(by mass) of particle agglomeration being phase separated from PBT matrix, which are factors on some mechanical properties decrease of NPBT. The disappearance of spherulitic morphology in NPBT resulted from layers nucleation is detected. Improving NPBT properties by treating clay with long chain organic reagent and controlling the way to load it is suggested.

  16. Development in Synthesis and Modification of Biodegradable Poly(butylene succinate) and its Copolymers%可生物降解聚丁二酸丁二醇酯及其共聚物的合成及改性研究进展

    Institute of Scientific and Technical Information of China (English)

    王国利; 徐军; 郭宝华

    2011-01-01

    Poly(butylene succinate) (PBS) as one of most important biodegradable polymers are paid lot of concerns in its synthesis and modification. The use of biodegradable polymers can decrease “White Pollution" caused by using of common polymers, such as PP, PE and etc. In this paper the polycondensation methods and process of PBS are reviewed. In order to enhance their properties and extend their application fields, the physical and chemical modifications of PBS are also given an introduction.%聚丁二酸丁二醇酯(PBS)是一种重要的可生物降解聚合物材料,在一定程度上可以缓解由于使用传统聚合物材料造成的"白色污染"问题.其合成和改性研究受到广泛的关注.本论文对PBS的聚合工艺及方法等方面进行了综述,并对PBS材料物理或化学改性进行了阐述.

  17. 聚丁二酸丁二醇酯/天然石榴皮黄色素复合材料的抗菌性能%The Antibacterial Properties of Poly (butylene succinate)/Natural Punica Granatum L.Pigments Composite

    Institute of Scientific and Technical Information of China (English)

    张敏; 安莎莎; 宋洁; 袁慧; 宋吉青

    2012-01-01

    采用天然植物源石榴皮色素添加在可生物降解聚丁二酸丁二醇酯(PBS)中,以取代对环境有害的化学色素,制备了PBS/石榴皮色素复合材料,研究了复合材料的热稳定性、抗菌性、亲水性和生物降解性能.研究结果表明:复合材料的综合性能较纯PBS有很大的提高.当复合材料中色素质量分数为9%时,复合材料表现出明显的抗菌性,其对金黄色葡萄球菌和大肠杆菌的抗菌率分别达到99.18%和99.62%,亲水性提高了16.36%,生物降解性能提高了166.28%,复合材料的热稳定性能也有很天提高.%Adding rialural punica granatum L. pigments into biodegradable poly (butylene succinate) ( PBS) to replace the environmentally harmful chemical substances,the PBS/natural punica granatum L. pigments composites were prepared. The thermal stability,antibacterial ability and hydrophilicity of the composite were tested. The results showed that the properties of the compoaites were greatly improved. When the content of pigments was 9 % ,the composite had obvious antibacterial ability, and its antimicrobial ratio to staphylococcus cereus and escherichia coli was respectively 99. 18 % and 99. 62 % , and the hydrophilicity and degradation of ihe composites were increased by 16. 36 % and 166. 28 % respectively. The thermal stability of the composite was obviously improved.

  18. 1,4-环己烷二甲醇改性生物可降解聚酯PBS的合成与性能表征%Synthesis and Characterization of Biodegradable Poly butylenes succinate Modified by 1,4-Cyclohexane Dimethanol

    Institute of Scientific and Technical Information of China (English)

    李修莲; 周艺峰; 聂王焰; 宋林勇

    2012-01-01

    A series of poly(butylene succinate-co-1,4-cyclohexane dimethanol succinate) random copolyes- ters were synthesized by melt polycodensation. The structure and physical properties of the aliphatic poly- esters were characterized by hydrogen nuclear magnetic resonance spectrum (1 H-NMR), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), X-ray diffraction (XRD) and lipase enzymatic degradation test. Results show that the synthetic copolyesters are the expected products, the crystal structure of copolyesters has been changed and the cocrystallization behavior has appeared. The melting point of the product decreases from 113.7 ℃ to 64.6℃, and then increases to 114.2 ℃. Moreover, the glass transition temperature increases monotonously from -33.8 ℃ to 5.4 ℃ along with the increasing of 1,4-cyclohexane dimethanol succinate (CHDM) component. With the increasing of 1,4-cyclohexane dimethanol component, the eopolyesters have better thermal stability. The lipase enzymatic degradation tests indicate that the copolyesters PS1 and P31 have better degradability, and P51 has the fastest degradation.%用熔融缩聚法合成了一系列聚(丁二酸丁二醇酯丁二酸-1,4-环己烷二甲醇酯)无规共聚物。通过。H—NMR、FT—IR、DSC、TGA、XRD、酶降解测试等方法表征了材料的结构与性能。结果表明:合成得到的共聚酯为预期产物;共聚酯的晶体结构发生了改变,并产生了共晶行为;随着1,4-环己烷二甲醇(CHDM)含量的增加,产物的熔点由113.7℃降至64.6℃,然后升至114.2℃,玻璃化转变温度由-33.8℃单调升高至5.4℃;CHDM的引入增强了共聚酯的热稳定性;酶降解测试得出产物P51、P31具有良好的生物降解性,且P51降解最快。

  19. 高剪切应力对苯乙烯-乙烯/丁烯-苯乙烯三嵌段聚合物马来酸酐化反应的影响%Influence of high shear stress on functionalization of maleic anhydride with styrene-ethylene/butylene-styrene terblock polymer

    Institute of Scientific and Technical Information of China (English)

    杜丽; 张玲; 张云灿

    2013-01-01

    The functionalization reaction of styrene-ethylene/butylene-styrene terblock polymer (SEBS) with maleic anhydride (MAH) was investigated through the high shear stress-induced initiation by increasing the screw rotation speed of twin-screw extruder.The results showed that the percent of grafting and the melt flow rate of functionalized products (SEBS-g-MAH) increased obviously with the increase of screw rotation speed,indicating that the high shear stress produced by increasing screw rotation speed led to the chain scission and the macro-radical,thus initiating the grafting reaction between SEBS and MAH.The crosslinking reaction could be effectively suppressed through increasing screw rotation speed to prepare the functionalized product SEBS-g-MAH with higher percent of grafting (mass fraction 0.79%-0.89%) and appropriate melt flow rate (1.859-4.398 g/min) and lower gel content (no more than mass fraction 0.32%).Meanwhile,the toughening effect of SEBS-g-MAH on nylon (PA 66) was much better.The Izod notched impact strength of the blend reached up to 94 kJ/m2,which was 30 times more than that of pure PA 66 without significant decrease of tensile and flexural strengthes.%通过提高双螺杆挤出机螺杆转速的应力引发方法,研究了高剪切应力下马来酸酐(MAH)与苯乙烯-乙烯/丁烯-苯乙烯三嵌段聚合物(SEBS)的官能化反应.结果表明,随着双螺杆挤出机螺杆转速的提高,官能化产物的接枝率和熔体流动速率明显增大.高剪切应力的作用引起大分子链断链,形成大分子自由基,从而引发SEBS的接枝反应.通过提高螺杆转速可有效地抑制交联副反应,制得接枝率较高(质量分数0.79%~0.89%)、熔体流动速率适宜(1.859 ~4.398 g/min)和凝胶含量较低(质量分数不大于0.32%)的官能化产物.同时,由应力诱导引发所得官能化产物SEBS-g-MAH对尼龙(PA 66)的增韧效果较好,其共混物的悬臂梁缺口冲击强度能达到约94 kJ/m2,

  20. Structure and Properties of Starch/Poly(butylene succinate) Blends Plasticized by [ BMIM] Cl%离子液体增塑改性玉米淀粉/聚丁二酸丁二醇酯共混材料的结构与性能

    Institute of Scientific and Technical Information of China (English)

    雷蓓; 罗辉; 石孟可; 张熙

    2016-01-01

    为考察离子液体对淀粉/聚丁二酸丁二醇酯( PBS)的作用效果,降低淀粉/PBS的脆性,以离子液体(1-丁基-3-甲基咪唑氯盐[ BMIM] Cl)作为增塑改性剂通过熔融共混法制备了玉米淀粉/聚丁二酸丁二醇酯( PBS)共混材料,采用红外光谱( FTIR)、扫描电镜( SEM)、热重分析( TGA)、 X射线衍射分析( XRD)及力学性能测试方法研究了[ BMIM] Cl对淀粉/PBS共混材料结构和性能的影响。结果表明,[ BMIM] Cl能与淀粉/PBS分子发生强相互作用,破坏淀粉/PBS共混物中原有的氢键与结晶结构,增强界面相互作用,改善相容性,进而改变淀粉/PBS共混材料的结构与性能;[ BMIM] Cl的加入不影响淀粉/PBS的热稳定性,可使材料玻璃化转变温度( Tg )、结晶温度( Tc )、冷结晶温度( Tcc )及结晶度( Xc )降低。[ BMIM] Cl具有显著降低淀粉/PBS脆性的作用,使其断裂伸长率大幅度增加,拉伸强度和弹性模量降低。%In order to study the effect of the ionic liquid on starch/poly ( butylene succinate ) ( PBS ) blends and reduce the brittleness of the blends, starch/PBS blends plasticized with ionic liquid([BMIM]Cl) were prepared by melt blending. Infrared absorption spectroscopy ( IR ) , scanning electron microscopy ( SEM ) , thermal gravimetric analysis(TGA), X-ray diffraction(XRD) and mechanical test were adopted to study the effects of [ BMIM ] Cl on the structure and performance of starch/PBS blends. The results showed that [ BMIM] Cl can form strong interactions between starch and PBS molecules, thus disrupting the inter and intra hydrogen bonding of starch and PBS chains and also destroying the crystal structure, which improved the interfacial bonding strength and compatibility between starch and PBS. The glass transition temperature( Tg ) , crystallization point(Tc), cold crystallization temperatures(Tcc) and crystallinity(Xc) of starch/PBS blends declined with addition of [ BMIM] Cl, that

  1. Hidrofilicidade de filmes de amido/poli(butileno adipato co-tereftalato (Pbat adicionados de tween 80 e óleo de soja Hydrophilicity of starch and poly(butylene adipate-co-terephthalate (Pbat films containing tween 80 and soybean oil

    Directory of Open Access Journals (Sweden)

    Renata P. Herrera Brandelero

    2013-01-01

    Full Text Available A incorporação de amido ao polímero poli (butilenoadipatoco-tereftalato (PBAT através de blendas com alto teor de amido pode ser uma alternativa para obter embalagens biodegradáveis, minimizar custos e o uso de recursos não renováveis. No entanto, a adição de amido aumenta a permeabilidade ao vapor de água (PVA. A incorporação em filmes com amido de substâncias como óleos vegetais e surfactantes pode diminuir a hidrofilicidade, favorecendo as aplicações destes como embalagens. A hidrofilicidade dos filmes elaborados por blendas de amido/PBAT adicionados de óleo de soja (OS e tween 80 (TW foi avaliada considerando o efeito do OS e TW nas isotermas de sorção dos filmes, na PVA e nos coeficientes de difusão (Dw e solubilidade (β do vapor de água. Filmes com OS com ou sem TW apresentaram menor quantidade de água de sorção, sendo os filmes com menores quantidades de OS e sem TW menos hidrofílicos e menos permeáveis aos vapores de água. A adição de OS reduziu os valores de β e Dw dos filmes de amido/PBAT. O efeito foi relacionado com o aumento das porções hidrofóbicas e da compatibilidade entre o amido e PBAT na presença de OS.Incorporating starch into the poly(butylene adipate-co-terephthalate (PBAT polymer by means of blends with high starch contents is a possible option for producing biodegradable packaging using renewable resources and reducing costs. However, the addition of starch increases the water vapour permeability (WVP. The incorporation of substances as lipids and surfactants can reduce the hydrophilicity of films containing starch, favouring their use as packaging. The hydrophilicity of films produced from blends of starch/PBAT with added soybean oil (SO and tween 80 (TW was studied. The effects of these substances on the sorption isotherm, on the WVP and on the water vapour diffusion (Dw and solubility (β coefficients of the films were evaluated. The water sorption in films with SO, with or without TW

  2. INVESTIGATION ON THE GELATION BEHAVIOR OF BIODEGRADABLE POLY(BUTYLENE SUCCINATE) DURING ISOTHERMAL CRYSTALLIZATION PROCESS

    Institute of Scientific and Technical Information of China (English)

    Fa-liang Luo; Xiu-qin Zhang; Wei Ning; Du-jin Wang

    2011-01-01

    The early stage of polymer crystallization may be viewed as physical gelation process, ie., the phase transition of polymer from liquid to solid. Determination of the gel point is of significance in polymer processing. In this work, the gelation behavior ofpoly(bntylene succinate) (PBS) at different temperatures has been investigated by theological method. It was found that during the isothermal crystallization process of PBS, both the storage modulus (G′) and the loss modulus (G")increase with time, and the theological response of the system varies from viscous-dominated (G′ < G") to elastic-dominated (G′ > G"), meaning the phase transition from liquid to solid. The physical gel point was determined by the intersection point of loss tangent curves measured under different frequencies. The gel time (tc) for PBS was found to increase with increasing crystallization temperature. The relative crystallinity of PBS at the gel point is very low (2.5%-8.5%) and increases with increasing the crystallization temperature. The low crystallinity of PBS at the gel point suggests that only a few junctions are necessary to form a spanning network, indicating that the network is “loosely” connected, in another word, the critical gel is soft. Due to the elevated crystallinity at gel point under higher crystallization temperature, the gel strength Sg increases,while the relaxation exponent n decreases with increasing the crystallization temperature. These experimental results suggest that rheological method is an effective tool for verifying the gel point of biodegradable semi-crystalline polymers.

  3. Aerogel Poly(butylene succinate) Biomaterial Substrate for RF and Microwave Applications

    Science.gov (United States)

    Habib Ullah, M.; Mahadi, W. N. L.; Latef, T. A.

    2015-08-01

    Polybutylene succinate (PBS) has become a potential candidate, similar to polypropylene (PP) and acrylonitrile butadiene styrene (ABS), for use as an organic plastic material due to its outstanding mechanical properties as well as high thermal deformation characteristics. A new composition of silica aerogel nanoparticles extracted from rice waste with PBS is proposed for use as a dielectric (ɛr = 4.5) substrate for microwave applications. A microstrip patch antenna was fabricated on the proposed dielectric substrate for multi-resonant ultra-wideband (UWB) applications. The performance characteristics of the proposed biomaterial-based antenna were investigated in a far-field measurement environment. The results indicate that the proposed biocompatible material-based antenna covered a bandwidth of 9.4 (2.3-11.7) GHz with stop bands from 5.5 GHz to 5.8 GHz and 7.0 GHz to 8.3 GHz. Peak gains of 9.82 dBi, 7.59 dBi, 8.0 dBi and 7.68 dBi were measured at resonant frequencies of 2.7 GHz, 4.6 GHz, 6.3 GHz and 9.5 GHz, respectively.

  4. Multi walled carbon nanotube nanocomposites with biodegradable poly(butylene succinate) and their physical characteristics.

    Science.gov (United States)

    Hong, M K; Ko, S W; Park, J H; Choi, H J; Kim, J H

    2011-06-01

    In order to examine the influence of multi walled carbon nanotube (MWNT) on physical properties of its biodegradable polymer nanocomposite, biodegradable poly(buthylene succinate) (PBS), which was synthesized from diols and dicarboxylic acids, and MWNT nanocomposites were prepared via a melt-mixing method using a co-rotating intermeshing twin screw extruder. Microstructure of the PBS/MWNT nanocomposites and MWNT were investigated via both scanning electron microscopy and transmission electron microscopy. Their rheological properties were also characterized via rotation and oscillation tests using a rotational rheometer with parallel-plate geometry. It was found that shear viscosity, storage modulus and loss modulus of the nanocomposites examined by a rotational rheometer increased with the MWNT content. Especially their sharp increase for MWNT content of ca. 2.0 wt% was observed, indicating its percolation threshold from the rheological viewpoint which was higher than its electrical percolation threshold (1.0 wt%).

  5. 聚丁二酸丁二醇-共-对苯二甲酸丁二酯等温结晶性能%Isothermal Crystallization Kinetics of Biodegradable Poly(butylene succinate-co-butylene terephthalate)

    Institute of Scientific and Technical Information of China (English)

    许新建; 李发学; 余燕平; 俞建勇

    2007-01-01

    利用差示扫描量热仪(DSC)对制备的生物降解性聚丁二酸丁二醇-共-对苯二甲酸丁二醇酯(PBST)的等温结晶性能进行了研究.根据Avrami方程计算发现:PBST共聚酯的Avrami指数n基本上均大于3,表明结晶时聚合物趋向于以球晶形式三维生长.偏光显微镜(POM)直观地证明了这一结果.

  6. Biodegradation of poly(lactic acid) and poly(butylene succinate-co-adipate) by Paenibacillus amylolyticus strain TB-13

    OpenAIRE

    2003-01-01

    Polymer materials developed during the last 80 years are generally resistant to microbial attack, a property that is now currently regarded as a shortcoming concerning solid waste management. As a source of alternative environmental friendly materials, the synthesis of degradable polymers is becoming of considerable interest.Recently, increasing iterest has been devoted to understanding the degradation mechanisms of polymers in the environment. A number of synthetic polymers have been referre...

  7. Synthesis and characterization of polyester copolymers based on poly(butylene succinate) and poly(ethylene glycol)

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xiao-Ming, E-mail: xiaomingzhou@tust.edu.cn

    2012-12-01

    A series of polyester copolymers was synthesized from 1,4-succinic acid with 1,4-butanediol and poly(ethylene glycol) through a two-step process of esterification and polycondensation in this article. The composition and physical properties of copolyesters were investigated via GPC, {sup 1}HNMR, DSC and PLM. The copolymer composition was in good agreement with that expected from the feed composition of the reactants. The melting temperature (T{sub m}), crystallization temperature (T{sub c}), and crystallinity (X{sub c}) of these copolyesters decreased gradually as the content of PEG unit increased. Otherwise, experimental results also showed that the contents of PEG in copolymers had an effect on the molecular weight, distribution, thermal properties, hydrolysis degradation properties, and crystalline morphology of polyester copolymers. - Graphical abstract: The composition of polyester copolymer was determined from the {sup 1}H NMR spectra using the relative intensities of the proton peaks. As a sample, the {sup 1}H NMR spectrum of polyester copolymer with 10 mol% of PEG is shown in Fig. 2: CO-(CH{sub 2}){sub 2}-CO; O-CH{sub 2}- and C-(CH{sub 2}){sub 2}-C from the SA and BD unit at {delta}2.59; {delta} 4.08 and {delta}1.67; O-(CH{sub 2}CH{sub 2}){sub n}-O from the PEG unit at {delta} 3.61. The molar composition of polyester copolymer was measured as the area ratio of {delta}3.61/({delta}4.08 + {delta}1.67) peak. The PEG unit is incorporated into the copolymers in an amount of about 9.12mol% less than that of the feed proportion. These results showed that the composition of the copolymers is in good agreement with that expected from the feed proportion. Highlights: Black-Right-Pointing-Pointer The introduction of PEG unit changed the flexibility of PBS main chain. Black-Right-Pointing-Pointer PEG unit did not alter the crystal form of PBS in copolymers. Black-Right-Pointing-Pointer PEG unit hindered the formation of ring-banded spherulite morphology in copolymers. Black-Right-Pointing-Pointer The copolyesters had good in vitro degradation performance. Black-Right-Pointing-Pointer The composition ratio of PEG unit can adjust the in vitro degradation performance.

  8. Biodegradability of Poly (Butylene Succinate)%聚丁二酸丁二醇酯生物降解性能研究

    Institute of Scientific and Technical Information of China (English)

    孙炳新; 揣成智; 韩春阳; 罗思; 郭迎

    2014-01-01

    目的 研究酶解与水解对聚丁二酸丁二醇酯(PBS)生物降解性能的影响.方法 将PBS薄膜分别置于酶液与磷酸缓冲液中进行酶解与水解试验,利用热失重分析(TG)、X射线衍射(X-RD)、扫描电镜(SEM)以及失重率等测试手段或指标,对材料的生物降解性能进行表征.结果 TG与X-RD的测试结果表明,酶解后材料的热稳定性下降,热分解温度由308.83℃降低到282.85℃,同时材料的结晶度呈现一定程度的下降.水解后材料的热稳定性呈现出先降低再升高的趋势,而结晶度则基本维持不变.SEM与失重率结果证实,PBS的酶解主要通过表面侵蚀的方式进行,材料的失重率呈线性增长的趋势,降解10周后失重率约为33.2%;而水解则主要以整体侵蚀的方式进行,材料的失重率变化并不明显,降解20周后失重率仅为4.7%.结论 PBS的酶解与水解是2个截然不同的过程,酶解是表面侵蚀,而水解则是整体侵蚀.

  9. Effect of planar extension on the structure and mechanical properties of polystyrene-poly(ethylene-¤co¤-butylene)-polystyrene triblock copolymers

    DEFF Research Database (Denmark)

    Daniel, C.; Hamley, I.W.; Mortensen, K.

    2000-01-01

    with a spherical microstructure adopts a body-centred cubic (bcc) structure with a [111] orientation along the Row direction. For the pre-oriented triblock with a cylindrical microstructure, the cylinder axis is aligned along the extensional Row direction. Investigation of the mechanical properties showed...... that Young's moduli of the pre-oriented copolymers are highly anisotropic. Specimens were then subject to uniaxial deformation along the extensional Row direction and at the same time microstructural changes induced by the deformation were investigated by SANS. It was found that the deformation of the bcc...

  10. Surface functionalization of a poly(butylene terephthalate) (PBT) melt-blown filtration membrane by wet chemistry and photo-grafting.

    Science.gov (United States)

    Salvagnini, Claudio; Roback, Alexandre; Momtaz, Maryam; Pourcelle, Vincent; Marchand-Brynaert, Jacqueline

    2007-01-01

    The surface functionalization of PBT melt-blown membrane, making up a whole filter of blood components, was achieved via two methods. Hydroxyl chain-end activation by tosylation (method A), followed by coupling of F- and (3)H-tagged molecules (probes), led to 1% of surface derivatization (XPS) and 290 pmol/cm(2) of lysine fixation (LSC). Deposition of O-succinimidyl 4-(p-azido-phenyl)butanoate ("molecular clip") and 2 h irradiation at 254 nm led to the implanting of activated ester functions, randomly on the polymer surface (method B). Further coupling of F- and (3)H-probes by wet chemistry gave highly functionalized surface (4% by XPS and 1000 pmol/cm(2) by LSC). However, control experiments showed that about 80% of the surface derivatization resulted from the UV treatment alone. Thus, the effect of UV irradiation on PBT membrane was systematically studied and analyzed by XPS, contact angle measurements, GPC and surface reactivity assays. The optimized conditions of "molecular clip" photo-grafting (negligible polymer photo-oxidation/photo-degradation) led to the covalent fixation of 45 pmol/cm(2) of (3)H-probe. Throughout our study, the behaviour of PBT melt-blown membrane was compared to PBT film and PET track-etched membrane similarly treated. Lastly, the method B was applied to couple GRGDS peptide on the PBT membrane; this material showed improved properties of leukocyte depletion in buffy coat filtration experiments.

  11. Effect of uncoated calcium carbonate and stearic acid coated calcium carbonate on mechanical, thermal and structural properties of poly(butylene terephthalate) (PBT)/calcium carbonate composites

    Indian Academy of Sciences (India)

    G S Deshmukh; S U Pathak; D R Peshwe; J D Ekhe

    2010-06-01

    PBT/CaCO3 composites were prepared in a single screw extruder with particle content varying from 0–30% by weight. The influence of surface treatment of the particles, with and without stearic acid (SA), on the mechanical, thermal and structural properties was studied. The experiments included tensile tests, impact tests, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy. The composite systems containing SA coated CaCO3 were found to exhibit better mechanical properties as compared to composite systems containing uncoated CaCO3, with the S3 system (20% of SA coated CaCO3) exhibiting best combination of mechanical properties. Thermal study revealed that particle type and content had no influence on the melting temperature but the crystallization temperature, % crystallinity and thermal stability increased on increasing the CaCO3 content in PBT matrix. Morphological observation indicated that in PBT composites containing SA coated CaCO3, the coupling agent favours a better polymer filler interaction rendering inorganic polymer interface compatible, which is also evident from better mechanical and thermal properties.

  12. Surface modification of poly (styrene-b-(ethylene-co-butylene)-b-styrene) elastomer and its plasma protein adsorption by QCM-D

    Energy Technology Data Exchange (ETDEWEB)

    Li, Rui [Northeast Normal University, School of Physics, Changchun 130022 (China); Jin, Jing, E-mail: jjin@ciac.ac.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Sun, Yingchun, E-mail: sunyc149@nenu.edu.cn [Northeast Normal University, School of Physics, Changchun 130022 (China)

    2014-05-01

    Graphical abstract: - Highlights: • Grafting concentration of PEG was defined by the peak-area ratio of [C–O]/[C]. • Quantitatively investigated the adsorption processes of BSA and fibrinogen using QCM-D. • The inactivated BSA on SEBS surface could induce the subsequent fibrinogen adsorption. • SEBS-g-PEG with graft concentration of 0.207 has excellent protein resistance. - Abstract: Protein adsorption is a dynamic process and plays a major role in determining the hemocompatibility of biomaterials. We have obtained different poly (ethylene glycol) (PEG) graft concentrations of SEBS-g-PEG and the surface chemical compositions are confirmed by X-ray photoelectron spectroscopy (XPS). Graft concentration is defined by peak-area ratio of [C-O]/[C] on modified SEBS surface. With increasing graft concentration, water contact angles of the modified SEBS have significantly decreased. The platelet adhesion and static protein adsorption demonstrate that the hemocompatibility of copolymers films are improved effectively and SEBS-g-PEG-2 with larger graft concentration has more superior anticoagulation than that of SEBS-g-PEG-1. Moreover, we have quantitatively investigated the adsorption process of bovine serum albumin (BSA) and fibrinogen (Fib) on the surfaces of pristine SEBS and modified SEBS using quartz crystal microbalance with dissipation (QCM-D) in real time. The results indicate that the inactivated BSA on the pristine SEBS can continuously induce the subsequent Fib adsorption. The hemocompatibility of SEBS-g-PEG-2 with the graft concentration of 0.207 has excellent anti-protein property and the bio-inert BSA layer on the film can resist the subsequent Fib adsorption.

  13. Cell-seeded scaffolds based on poly(ethylene oxide) and poly(butylene terephthalate) block copolymers for bone tissue engineering

    OpenAIRE

    Claase, Menno Bernard

    2004-01-01

    This thesis describes the development of polymeric scaffolds containing bone marrow stromal cells (BMSCs) that are cultured in an osteogenic medium and can be used for the formation of functional bone tissue upon implantation

  14. Surface modification of poly (styrene-b-(ethylene-co-butylene)-b-styrene) elastomer and its plasma protein adsorption by QCM-D

    Science.gov (United States)

    Li, Rui; Jin, Jing; Sun, Yingchun

    2014-05-01

    Protein adsorption is a dynamic process and plays a major role in determining the hemocompatibility of biomaterials. We have obtained different poly (ethylene glycol) (PEG) graft concentrations of SEBS-g-PEG and the surface chemical compositions are confirmed by X-ray photoelectron spectroscopy (XPS). Graft concentration is defined by peak-area ratio of [C--O]/[C] on modified SEBS surface. With increasing graft concentration, water contact angles of the modified SEBS have significantly decreased. The platelet adhesion and static protein adsorption demonstrate that the hemocompatibility of copolymers films are improved effectively and SEBS-g-PEG-2 with larger graft concentration has more superior anticoagulation than that of SEBS-g-PEG-1. Moreover, we have quantitatively investigated the adsorption process of bovine serum albumin (BSA) and fibrinogen (Fib) on the surfaces of pristine SEBS and modified SEBS using quartz crystal microbalance with dissipation (QCM-D) in real time. The results indicate that the inactivated BSA on the pristine SEBS can continuously induce the subsequent Fib adsorption. The hemocompatibility of SEBS-g-PEG-2 with the graft concentration of 0.207 has excellent anti-protein property and the bio-inert BSA layer on the film can resist the subsequent Fib adsorption.

  15. Study on biodegradation of poly (butylene succinate) and environmental impact evaluation%PBS降解性能与环境影响评价的研究

    Institute of Scientific and Technical Information of China (English)

    刘俊玲; 侯小刚; 秦俊岭; 张敏

    2009-01-01

    The biodegradation process of PBS from synthetic raw materials,oligomer and degradation products was studied, the effect on the seed germination, plant growth and physical and chemical properties of the environment was investigated, and the impact on the environment of PBS was evaluated emphatically during the biodegradation process. The results showed that when the concentration of butanedioic acid was higher than 500 mg/L, the seeds growth was restrained; the seedlings was restrained by the oligomer of PBS at the initial degradation. During the degradation process in 40 d, it showed the degradability in some degree. The experiment provides that Shaanxi local soil can be screened and planted microorganism for degrading PBS.%从聚丁二酸丁二醇酯(PBS)的合成原料、低聚物及降解产物等方面探讨了PBS在生物降解过程中对种子发芽、植物的生长和环境理化性状的影响,旨在评价PBS在生物降解过程中对环境的影响.结果表明,当丁二酸浓度高于500 mg/L时,抑制种子的生长;PBS低聚物降解初期的产物,抑制植物幼苗的生长;在40 d的降解过程中,PBS显示了一定的降解性,并为能在陕西当地土壤中筛选、培养出降解PBS的微生物提供了依据.

  16. Effect of Hydroxyapatite Nanoparticles on the Degradability of Random Poly(butylene terephthalate-co-aliphatic dicarboxylates Having a High Content of Terephthalic Units

    Directory of Open Access Journals (Sweden)

    Nina Heidarzadeh

    2016-07-01

    Full Text Available Copolyesters derived from 1,4-butanediol and constituted also of aliphatic and aromatic dicarboxylate units in a molar ratio of 3:7 were synthesized by a two-step polycondensation procedure. Succinic, adipic, and sebacic acids were specifically selected as the aliphatic component whereas terephthalic acid was chosen as the aromatic moiety. The second synthesis step was a thermal transesterification between the corresponding homopolymers, always attaining a random distribution as verified by NMR spectroscopy. Hybrid polymer composites containing 2.5 wt % of hydroxyapatite (HAp were also prepared by in situ polymerization. Hydroxyl groups on the nanoparticle surface allowed the grafting of polymer chains in such a way that composites were mostly insoluble in the typical solvents of the parent copolyesters. HAp had some influence on crystallization from the melt, thermal stability, and mechanical properties. HAp also improved the biocompatibility of samples due to the presence of Ca2+ cations and the damping effect of phosphate groups. Interestingly, HAp resulted in a significant increase in the hydrophilicity of samples, which considerably affected both enzymatic and hydrolytic degradability. Slight differences were also found in the function of the dicarboxylic component, as the lowest degradation rates was found for the sample constituted of the most hydrophobic sebacic acid units.

  17. Synthesis and Characterization of Biodegradable Poly(butylene succinate-co-diethylene succinate)%生物降解聚丁二酸丁二醇/二甘醇酯的合成与性能研究

    Institute of Scientific and Technical Information of China (English)

    肖峰; 王庭慰; 丁培; 包艳华; 王景春

    2011-01-01

    以丁二酸(SA)、1,4-丁二醇(BD)和二甘醇(DEG)为原料,通过直接聚合法合成了可生物降解的聚丁二酸丁二醇/二甘醇酯(PBDGS).采用 1H-NMR,GPC,DSC等对产物进行了表征,研究了物料配比对共聚酯热性能、力学性能、降解性能和亲水性的影响.结果表明,DEG的引入能够有效抑制聚酯链段的结晶能力,同时改善材料的亲水性,使其降解性能较纯PBS有显著提高.

  18. Synergistic effect of selectively distributed AlN/MWCNT hybrid fillers on the morphological, mechanical and thermal properties of polycarbonate/maleated poly[styrene-b-(ethylene-co-butylene)- b-styrene] triblock copolymer (SEBS-g-MA) composites

    Science.gov (United States)

    Xiao, Chao; Leng, Xinyu; Wang, Hui; Su, Zheng; Zhang, Xian; Chen, Lin; Zheng, Kang; Tian, Xingyou

    2017-02-01

    A quaternary nanocomposite polycarbonate (PC)- multi-walled carbon nanotubes (MWCNT)/SEBS-g-MA (SM)-AlN is prepared by controlling the selective distribution of nano-fillers via melt-blending. Through a two-step mixing method, surface modified AlN is selectively dispersed in the island-like SM phase; meanwhile, MWCNT acting as bridges are mainly located in the continuous phase of PC. This ‘island-bridge’ morphology is confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The selective localization results agree well with the theoretical predictions. Dynamic mechanical analysis (DMA) indicates that the addition of hybrid fillers improved the storage modulus selectively. Thermogravimetric analysis (TGA) shows that the thermal stability of the PC/SM blends increased significantly; the degradation kinetic has also been changed due to the synergistic effects of the fillers. This novel ‘island-bridge’ network contributes a higher thermal conductivity at low filler content as the effective thermal conductivity reached 0.72 W m‑1 K‑1, which is three times higher than that of 70PC/30SM. The experimental observations coincide well with the optimizing model results.

  19. Radiation Crosslinking of Biodegradable Poly(butylene succinat e) and Its Biodegradability%聚琥珀酸丁二酯的辐射交联及其生物降解性

    Institute of Scientific and Technical Information of China (English)

    宋春雷; 王宇明; 张文德; 罗云霞

    2002-01-01

    对聚琥珀酸丁二酯(PBS1)采用两步法辐照,比其它辐照法得到的凝胶含量高,这是由于在室温下预先辐射所形成的交联网络结构减少了聚 合物的降解.交联后的PBS1有较高的耐热变形性.通过酶降解试验和土埋法降解实验,P BS1 有很高的生物降解性,即使它产生了很高的交联结构.在65℃时,酶的降解率最高. 由于 交联样品所含有的交联网络结构阻碍它的降解,交联PBS1的生物降解失重低于未交联样品.

  20. RADIATION CROSSLINKING OF BIODEGRADABLE POLY(BUTYLENE SUCCINAT E AND ITS HEAT DISTORTION BEHAVIOR%聚琥珀酸丁二酯的辐射交联和它的热变形行为

    Institute of Scientific and Technical Information of China (English)

    宋春雷; 姜炳政; 吉井文男

    2001-01-01

    @@ 近年来,塑料废弃物污染环境的问题日趋严重.对于环境的关心,已经使越来越多的科研人员对于研究环境友好化合物的发展产生了极大的兴趣.发达国家先后制订了限制或禁止某些场合使用非降解性塑料,因此,多种可生物降解性塑料已经发展起来.目前已经商业化的可生物降解性聚合物主要有脂肪族聚酯、聚醚、聚乙烯醇和聚多糖.其中,利用化学合成法开发的可生物降解性聚合物是非常重要的.脂肪族聚酯,例如聚乳酸(PLA).聚乙二酸(PGA) 等被广泛地用于药物的载体[1],聚(ε-己内酯)(PCL)也已经被用作生产生物降解性薄膜.脂肪族聚酯是今后最有前途的可用于生产可生物降解的纤维和薄膜材料之一.

  1. 单宁与聚磷酸铵复配体系对聚丁二酸丁二酯的催化成炭作用%Catalytic Charring Effect of Tannin and Ammonium Polyphosphate on Poly(Butylene Succinate)

    Institute of Scientific and Technical Information of China (English)

    冉诗雅; 陈超; 徐灵钢; 郭正虹

    2014-01-01

    采用热失重分析仪、微型量热仪及扫描电镜研究了单宁(Tannin)与聚磷酸铵(APP)复配体系对聚丁二酸丁二酯(PBS)的催化成炭作用以及炭层对其燃烧行为的影响.热失重分析表明,无论在空气还是氮气下,APP与Tannin复配使用都可以催化PBS体系成炭.当APP与Tannin的质量比为3∶1时,在空气中PBS体系700℃时残炭的实验值为9.3%,在氮气中残炭的实验值为11.3%,都远远高于理论计算值.微型量热仪分析显示,炭层可以作为基体与火焰之间的屏障,尤其当APP与Tannin的比例为5∶1时,PHRR降低了33%.此外,残炭形貌分析表明,APP和Tannin复配使用后,材料表面形成较为均匀、致密的炭层结构.

  2. Feasibility study of naphthalene removal: Naphthalene solubilization in aqueous solutions of a triblock copolymer of ethylene oxide and 1,2-butylene oxide, E64B20E64

    Directory of Open Access Journals (Sweden)

    Colin Booth

    2003-11-01

    Full Text Available Block copolymer E64B20E64, where E denotes oxyethylene, OCH2CH2, B denotes oxybutylene, OCH2CH (C2H5, and the subscripts denote number-average block lengths in repeat units, was synthesized by sequential anionic polymerization. Characterization was by gel permeation chromatography (for molar mass distribution and 13C-NMR spectroscopy (for absolute molar mass and conformation of block architecture. Dynamic and static light scattering were used to study micellization and micelle properties of this copolymer in dilute aqueous solution and in the presence of naphthalene. Dynamic light scattering was used to analyze hydrodynamic radius, rh and hydrodynamic expansion factor, δh. Static light scattering was used to study micelle association number, Nw, thermodynamic expansion factor, δt, and thermodynamic radius, rt. The presence of naphthalene in micellar core increased Nw by 50% and increased micellar size.

  3. 含稀土元素LDHs对PBS膨胀阻燃体系的协效作用%Synergistic Effect of Layered Double Hydroxides Containing Rare Earth Element on the Intumescent Flame Retardant Poly (butylene succinate) Composites

    Institute of Scientific and Technical Information of China (English)

    刘跃军; 毛龙

    2013-01-01

    将稀土元素La引入碳酸根型镁铝锌层状双羟基金属氧化物(LDHs)层板中,合成了晶态结构规整的含稀土元素LDHs(MgAlZnLa-CO3LDHs),将含稀土元素LDHs、膨胀阻燃剂(IFR)和聚丁二酸丁二醇酯(PBS)熔融共混制备出新型PBS膨胀阻燃体系,研究了PBS膨胀阻燃体系的阻燃性能和热性能.结果表明:含稀土元素LDHs的添加量为1%(阻燃剂的总添加量为20%)时PBS阻燃阻燃体系的极限氧指数(LOI)达到33%,垂直燃烧测试达到UL 94 V-0级别;LOI不仅取决于残炭量,还与燃烧炭层的结构有关;含稀土元素LDHs的加入能提高膨胀碳层的致密度和强度,燃烧形成致密度高的碳层能明显降低热释放速率和烟生成速率,有效地降低可燃小分子和烟尘的释放,使膨胀阻燃效率提高.

  4. Reduction of protein adsorption to a solid surface by a coating composed of polymeric micelles with a glass-like core

    NARCIS (Netherlands)

    Hofs, B.; Brzozowska, A.; de Keizer, A.; Norde, W.; Stuart, Martien A. Cohen

    2008-01-01

    Adsorption studies by optical reflectometry show that complex coacervate core micelles (C3Ms) composed of poly([4-(2-amino-ethylthio)-butylene]hydrochloride)(49)-block-poly(ethylene oxide)(212) and poly([4-(2carboxy-ethylthio)-butylene] sodium salt)(47)-block-poly(ethylene oxide)(212) adsorb in equa

  5. Microstructural Investigation of Deformation and Failure Mechanisms in Polypropylene

    Science.gov (United States)

    2011-02-08

    propylene random copolymer (EPR), maleated ethylene-propylene-diene monomer ( EPDM ), and maleated styrene-ethylene-butylene- styrene block copolymers... stability . Consequently, the arrangement of these crystalline phases (parallel or perpendicular to the applied stress) completely controls the fracture

  6. Preparation, Mechanical, and Thermal Properties of Biodegradable Polyesters/Poly(Lactic Acid Blends

    Directory of Open Access Journals (Sweden)

    Peng Zhao

    2010-01-01

    Full Text Available Series of biodegradable polyesters poly(butylene adipate (PBA, poly(butylene succinate (PBS, and poly(butylene adipate-co-butylene terephthalate (PBAT were synthesized successfully by melt polycondensation. The polyesters were characterized by Fourier transform infrared spectroscopy (FTIR, 1H-NMR, differential scanning calorimetry (DSC, and gel permeation chromatography (GPC, respectively. The blends of poly(lactic acid (PLA and biodegradable polyester were prepared using a twin screw extruder. PBAT, PBS, or PBA can be homogenously dispersed in PLA matrix at a low content (5–20 wt%, yielding the blends with much higher elongation at break than homo-PLA. DSC analysis shows that the isothermal and nonisothermal crystallizabilities of PLA component are promoted in the presence of a small amount of PBAT.

  7. Analise térmica e microscópica de laminados biodegradáveis obtidos a partir de farinha de mandioca, sorbitol e poli (butileno adipato co-tereftalato PBAT. Thermal and microscopic analysis of biodegradable laminates made from cassava flour, sorbitol and poly (butylene adipate-co-terephthalate PBAT - doi: 10.4025/actascitechnol.v35i4.13183

    Directory of Open Access Journals (Sweden)

    Henrique Tirolli Rett

    2013-10-01

    Full Text Available O objetivo deste trabalho foi desenvolver blendas de materiais laminados biodegradáveis, utilizando farinha de mandioca como fonte de amido, fibras naturais, sorbitol como plastificante e PBAT. Primeiro obteve-se peletes de três formulações diferentes e a partir destes, utilizou-se a termoprensagem a alta temperatura como alternativa na formação dos laminados. A caracterização foi feita através de microscopia eletrônica de varredura (MEV e calorimetria diferencia de varredura (CDV. A quantidade se sorbitol que melhor se ajustou à extrusão foi a de 15% (peso/peso; a formulação do laminado mais homogêneo, observada pela microscopia, foi de 55:40:15 (farinha/sorbitol/PBAT. As fibras ficaram dispersas por toda a superfície nos três tratamentos estudados, porém, por dentre eles, observaram-se zonas dispersas das fibras. Conforme se aumentou o teor de farinha, houve aumento no ponto de fusão dos laminados em comparação ao PBAT puro.Blends of biodegradable laminated materials were developed using cassava flour as starch and natural fibers source, sorbitol as a plasticizer and PBAT as a biodegradable polyester. After obtaining pellets from three different formulations, high temperature thermopressure was used to form laminates. The characterization was performed by scanning electron microscopy (SEM and by differential scanning calorimetry (DSC. The amount of sorbitol for the best extrusion process was 15% (weight/weight and the formulation of the best homogeneity observed by microscopy was 55:40:15 (flour/sorbitol/PBAT. Although fibers were dispersed throughout the surface in the three treatments, scattered areas of fibers could be found among them. As rates of flour increased, an increase in the melting point of the laminates occurred when compared to pure PBAT.  

  8. 聚对苯二甲酸丁二醇酯/多壁碳纳米管复合材料的流变及结晶行为%Reology and Crystallization Behavior of Poly(Butylene Terephthalate) /Multi-Walled Carbon Nanotubes Composites

    Institute of Scientific and Technical Information of China (English)

    吴亮; 吴德峰; 张明

    2007-01-01

    采用熔融共混的方法制备了对聚对苯二甲酸丁二醇酯(PBT)/多壁碳纳米管(MWNT)复合材料,研究了复合体系的流变及结晶行为.结果表明:MWNT具有显著的增强作用,使得复合体系低频区的模量出现类固态黏弹响应,这源于MWNT逾渗网络结构的形成.MWNT的加入并未改变PBT的α晶型结构,但其异相成核作用却能有效地促进复合体系PBT基体的结晶.

  9. Biomineralization of Engineered Spider Silk Protein-Based Composite Materials for Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    John G. Hardy

    2016-07-01

    Full Text Available Materials based on biodegradable polyesters, such as poly(butylene terephthalate (PBT or poly(butylene terephthalate-co-poly(alkylene glycol terephthalate (PBTAT, have potential application as pro-regenerative scaffolds for bone tissue engineering. Herein, the preparation of films composed of PBT or PBTAT and an engineered spider silk protein, (eADF4(C16, that displays multiple carboxylic acid moieties capable of binding calcium ions and facilitating their biomineralization with calcium carbonate or calcium phosphate is reported. Human mesenchymal stem cells cultured on films mineralized with calcium phosphate show enhanced levels of alkaline phosphatase activity suggesting that such composites have potential use for bone tissue engineering.

  10. Radiation crosslinking of Bionolle and its biodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Suhartini, Meri; Mitomo, H. [Gunma Univ., Faculty of Engineering, Dept. of Biological and Chemical Engineering, Kiryu, Gunma (Japan); Nagasawa, Naotsugu; Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2002-03-01

    Biodegradable aliphatic polymer such as poly(butylene succinate) (Bionolle no.1001), poly(butylene succinate adipate copolymer) (Bionolle no.3001 and no.3020) were irradiated to give crosslinking structure in the presence of inorganic materials. Pure Bionolle no.1001, Bionolle no.3001 and no. 3020 have low gel fraction in radiation. These samples have high gel fraction by irradiation in the presence of silicon dioxide and carbon black, especially for Bionolle no.3001. Biodegradability of crosslinked Bionolle no.3001 evaluated by enzymatic and soil burial tests were accelerated by addition of inorganic materials. (author)

  11. Polypropylene/organoclay/SEBS nanocomposites with toughness-stiffness properties

    DEFF Research Database (Denmark)

    Sanporean (nee Potarniche), Catalina-Gabriela; Vuluga, Zina; Radovici, Constantin;

    2014-01-01

    Polypropylene nanocomposites with a different amount of styrene-ethylene-butylene-styrene block copolymer (SEBS)/clay were prepared via a melt mixing technique. To improve the dispersion of commercial organoclay (denoted as OMMT), various amounts of SEBS were incorporated. At a fixed content of O...

  12. Stability aspects of salmon calcitonin entrapped in poly(ether-ester) sustained release systems

    NARCIS (Netherlands)

    Dijkhuizen-Radersma, van R.; Nicolas, H.M.; Weert, van de M.; Blom, M.; Groot, de K.; Bezemer, J.M.

    2002-01-01

    Poly(ether-ester)s composed of hydrophilic poly(ethylene glycol)-terephthalate (PEGT) blocks and hydrophobic poly(butylene terephthalate) (PBT) blocks were studied as matrix for the controlled release of calcitonin. Salmon calcitonin loaded PEGT/PBT films were prepared from water-in-oil emulsions. T

  13. Catalyst Design and Development for the Direct Production of Lower Olefins from Synthesis Gas

    NARCIS (Netherlands)

    Xie, Jingxiu

    2017-01-01

    The increase in global demand for lower olefins (ethylene, propylene, and butylenes) coupled with the regional diversification of carbon raw materials bring about opportunities and challenges for emerging technologies. Crude oil has been the primary carbon feedstock for the past 50 years, but altern

  14. CO2-selective PEO–PBT (PolyActive™)/graphene oxide composite membranes

    KAUST Repository

    Karunakaran, M.

    2015-07-31

    CO2-selective graphene oxide (GO) nano-composite membranes were prepared for the first time by embedding GO into a commercially available poly(ethylene oxide)–poly(butylene terephthalate) (PEO–PBT) copolymer (PolyActive™). The as-prepared GO membrane shows high CO2 permeability (143 Barrer) and CO2/N2 selectivity (α = 73).

  15. Materials Research Society Symposium on the Electrical, Optical and Magnetic Properties of Organic Solid State Materials Held in Boston Massachusetts on 27 November-2 December 1989

    Science.gov (United States)

    1989-12-01

    VINYL ALCOHOL) (PVA)/ MELAMINE FORMALDEHYDE (MF) MOLECULAR COMPOSITES, Kecheng Gono and Xinghua Zhang, South China University of Technology, Polymer...varied. In properties, such as adhesion or load transfer efficiency, are addtion, a titanate/polyether sulfone coupling agent was synthesized in-situ...BLOCK COPOLYMER IONOMERS: SULFONATED POLYSTYRENE, Robert M. Briber, National STYRENE-(ETHYLENE-CO-BUTYLENE)-STYRENE Institute of Standards and

  16. Advances in Application of New Catalytic Materials in Petroleum Refining and Petrochemicals Production

    Institute of Scientific and Technical Information of China (English)

    He Yigong; Lin Min; Mu Xuhong; Shu Xingtian

    2006-01-01

    This article introduces the solid acid catalyst for isobutene/butylenes alkylation, the HTS Ti/Si zeolite for ammonoxidation of cyclohexanone and the noncrystalline alloy catalyst and magnetically stabilized bed for hydrofining of caprolactam that were developed recently by SINOPEC Research Institute of Petroleum Processing (RIPP).

  17. DEVELOPMENT OF A PHYSIOLOGICALLY-BASED PHARMACOKINETIC (PBPK) MODEL FOR THE INHALATION OF 2,2,4-TRIMETHYLPENTANE (TMP) IN LONG EVANS RATS.

    Science.gov (United States)

    TMP (2,2,4-trimethylpentane,“isooctane”) is a colorless liquid used primarily in the alkylation of isobutene and butylene reactions to derive high-octane fuels. TMP is released in the environment through the manufacture, use, and disposal of products associated with the gasoline ...

  18. Are reactive thermoplastic polymers suitable for future wind turbine composite materials blades?

    DEFF Research Database (Denmark)

    Raghavalu Thirumalai, Durai Prabhakaran

    2014-01-01

    , it was found that only two potential reactive thermoplastic resin systems qualify for different processing requirements for blade manufacturing. Hence, the article focuses on the issues with the use of reactive polymers like APA-6 (Caprolactam) and CBT (Cyclic Butylene Terephtalate) resin systems for composite...

  19. Direct production of lower olefins from synthesis gas using supported iron catalysts

    NARCIS (Netherlands)

    Torres Galvis, H.M.

    2013-01-01

    Lower olefins (ethylene, propylene and butylenes) are important commodity chemicals used for the manufacture of, amongst others, plastics, solvents and lubricants to cosmetics and drugs. C2 to C4 olefins are conventionally produced by steam cracking of naphtha. In view of economic, strategic, and en

  20. A calibration test for latent fingerprint development on thermal paper.

    Science.gov (United States)

    Spencer, Caroline A; Bond, John W

    2014-11-01

    A calibration test is described for monitoring the operation of equipment used to develop latent fingerprints on thermal paper by the application of either controlled or uncontrolled heat. A working solution of a water/glycerol emulsion and butylene glycol is applied to thermal paper by means of either a vinyl stamp and pad, or a marker pen. Varying the amount of butylene glycol enables the thermal paper to change color at different temperatures between approximately 40 and 60°C, which is below the normal color change temperature of the paper. The described test may be used to verify the correct operation, at different temperatures, of a controlled heat source during and after fingerprint development (such as the Hot Print System) or to monitor the paper temperature with an uncontrolled heat source (such as a warm air blower), thereby avoiding unintentional coloring of the entire paper surface.

  1. Isolation and characterization of a bacterium that degrades various polyester-based biodegradable plastics.

    Science.gov (United States)

    Teeraphatpornchai, T; Nakajima-Kambe, T; Shigeno-Akutsu, Y; Nakayama, M; Nomura, N; Nakahara, T; Uchiyama, H

    2003-01-01

    Microorganisms isolated from soil samples were screened for their ability to degrade various biodegradable polyester-based plastics. The most active strain, designated as strain TB-13, was selected as the best strain for degrading these plastics. From its phenotypic and genetic characteristics, strain TB-13 was closely related to Paenibacillus amyloyticus. It could degrade poly(lactic acid), poly(butylene succinate), poly(butylene succinate-co-adipate), poly(caprolactone) and poly(ethylene succinate) but not poly(hydroxybutylate-co-valerate). However, it could not utilize these plastics as sole carbon sources. Both protease and esterase activities, which may be involved in the degradation of plastic, were constitutively detected in the culture broth.

  2. Phyllosphere yeasts rapidly break down biodegradable plastics.

    Science.gov (United States)

    Kitamoto, Hiroko K; Shinozaki, Yukiko; Cao, Xiao-Hong; Morita, Tomotake; Konishi, Masaaki; Tago, Kanako; Kajiwara, Hideyuki; Koitabashi, Motoo; Yoshida, Shigenobu; Watanabe, Takashi; Sameshima-Yamashita, Yuka; Nakajima-Kambe, Toshiaki; Tsushima, Seiya

    2011-11-29

    The use of biodegradable plastics can reduce the accumulation of environmentally persistent plastic wastes. The rate of degradation of biodegradable plastics depends on environmental conditions and is highly variable. Techniques for achieving more consistent degradation are needed. However, only a few microorganisms involved in the degradation process have been isolated so far from the environment. Here, we show that Pseudozyma spp. yeasts, which are common in the phyllosphere and are easily isolated from plant surfaces, displayed strong degradation activity on films made from poly-butylene succinate or poly-butylene succinate-co-adipate. Strains of P. antarctica isolated from leaves and husks of paddy rice displayed strong degradation activity on these films at 30°C. The type strain, P. antarctica JCM 10317, and Pseudozyma spp. strains from phyllosphere secreted a biodegradable plastic-degrading enzyme with a molecular mass of about 22 kDa. Reliable source of biodegradable plastic-degrading microorganisms are now in our hands.

  3. Biodegradable Plastic-degrading Activity of Various Species of Paraphoma.

    Science.gov (United States)

    Koitabashi, Motoo; Sameshima-Yamashita, Yuka; Koike, Hideaki; Sato, Toyozo; Moriwaki, Jouji; Morita, Tomotake; Watanabe, Takashi; Yoshida, Shigenobu; Kitamoto, Hiroko

    2016-07-01

    The fungal strain B47-9, isolated from barley, was previously selected as an effective degrader of various biodegradable plastic (BP) films such as poly(butylene succinate-co-adipate) (PBSA) and poly(butylene succinate) (PBS). The strain has not been identified based on mycological methods because it does not form fruiting bodies, which are the key to morphological identification. Here, we performed molecular phylogenetic analyses of the nuclear ribosomal RNA gene regions and their internal transcribed spacer region of B47-9 and related fungi. The results suggest that B47-9 is closely related to the genus Paraphoma. Investigation of the abilities of six strains belonging to the genus Paraphoma to degrade BPs indicated that all strains could degrade PBSA and PBS films to varying degrees. Based on our approach, we conclude that strain B47-9 is a species belonging to the genus Paraphoma.

  4. Biodegradable plastic-degrading enzyme from Pseudozyma antarctica: cloning, sequencing, and characterization.

    Science.gov (United States)

    Shinozaki, Yukiko; Morita, Tomotake; Cao, Xiao-hong; Yoshida, Shigenobu; Koitabashi, Motoo; Watanabe, Takashi; Suzuki, Ken; Sameshima-Yamashita, Yuka; Nakajima-Kambe, Toshiaki; Fujii, Takeshi; Kitamoto, Hiroko K

    2013-04-01

    Pseudozyma antarctica JCM 10317 exhibits a strong degradation activity for biodegradable plastics (BPs) such as agricultural mulch films composed of poly(butylene succinate) (PBS) and poly(butylene succinate-co-adipate) (PBSA). An enzyme named PaE was isolated and the gene encoding PaE was cloned from the strain by functional complementation in Saccharomyces cerevisiae. The deduced amino acid sequence of PaE contains 198 amino acids with a predicted molecular weight of 20,362.41. High identity was observed between this sequence and that of cutinase-like enzymes (CLEs) (61-68%); therefore, the gene encoding PaE was named PaCLE1. The specific activity of PaE against emulsified PBSA was 54.8±6.3 U/mg. In addition to emulsified BPs, PaE degraded solid films of PBS, PBSA, poly(ε-caprolactone), and poly(lactic acid).

  5. Enzymatic degradation of polyester films by a cutinase-like enzyme from Pseudozyma antarctica: surface plasmon resonance and atomic force microscopy study.

    Science.gov (United States)

    Shinozaki, Yukiko; Kikkawa, Yoshihiro; Sato, Shun; Fukuoka, Tokuma; Watanabe, Takashi; Yoshida, Shigenobu; Nakajima-Kambe, Toshiaki; Kitamoto, Hiroko K

    2013-10-01

    Enzymatic degradation of polyester films by a cutinase-like enzyme from Pseudozyma antarctica JCM10317 (PaE) was analyzed by surface plasmon resonance (SPR). The adsorption of PaE and the degradation rate for polyester films were quantitatively monitored by a positive and negative SPR signal shifts, respectively. The decrease in SPR signal and the erosion depth of amorphous poly(L-lactide) (a-PLLA) film measured by atomic force microscopy (AFM) had a linear relationship, and the weight loss was estimated from the AFM data combined with a density of a-PLLA film. Furthermore, SPR sensorgrams for various polyester films showed that degradation rate of poly(ε-caprolactone) and poly(butylene succinate-co-adipate) which contain C6 units was higher than that of other polyesters such as poly(butylene succinate) and a-PLLA. These results suggest that C6 is the preferred chain length as substrates for PaE.

  6. Spectral Characterization of RDX, ETN, PETN, TATP, HMTD, HMX, and C-4 in the Mid-Infrared Region

    Science.gov (United States)

    2014-04-01

    Plant HMTD Hexamethylene triperoxide HMX Cyclotrimethylene tetranitrate IED Improvised explosive device IR Infrared IRE Internal reflection... chromatography MIR Mid-infrared n Real refractive index PBA Poly(1,4-butylene adipate) PETN Pentaerythritol tetranitrate PIB Poly(isobutylene) PMMA...was removed from the holder, the anti-reflection coated surfaces were gently cleaned with lens paper and solvent to remove any traces of contamination

  7. Structure–property relationship of specialty elastomer–clay nanocomposites

    Indian Academy of Sciences (India)

    Anirban Ganguly; Madhuchhanda Maiti; Anil K Bhowmick

    2008-06-01

    The present work deals with the synthesis of specialty elastomer [fluoroelastomer and poly (styrene--ethylene-co-butylene--styrene (SEBS)]–clay nanocomposites and their structure–property relationship as elucidated from morphology studies by atomic force microscopy, transmission electron microscopy and X-ray diffraction and physico-mechanical properties. Due to polarity match, hydrophilic unmodified montmorillonite clay showed enhanced properties in resulting fluoroelastomer nanocomposites, while hydrophobic organo-clay showed best results in SEBS nanocomposites.

  8. Zeolites Modified Metal Cations as Catalysts in Hydrocarbon Oxidation and the Alkyl Alcohol

    OpenAIRE

    Agadadsh Makhmud Aliyev; Zumrud Abdulmutallib Shabanova; Fikret Vakhid Aliyev; Alla M. Guseynova

    2014-01-01

    The results of studies on the creation of highly metalltceolitnyh systems and the study of their catalytic activities in the oxidation of lower olefin hydrocarbons (ethylene to acetaldehyde, acetone, propylene, butylene methyl ethyl ketone); aliphatic C1-C5 alcohols to their corresponding aldehydes, ketones, carboxylic acids and carboxylic acid esters; oxidative dehydrogenation of naphthenes in the alicyclic diene hydrocarbons and the oxidative dimerization of methane to acetylene. It has bee...

  9. Development and Commercial Application of Methyl-ethyl-ketone Production Technology%甲乙酮成套技术开发及工业应用

    Institute of Scientific and Technical Information of China (English)

    刘振华; 霍稳周; 马皓; 乔凯

    2006-01-01

    A synthetic technology for the production of methyl-ethyl-ketone (MEK) is introduced, which makes use of butylene catalytic hydration to produce secondary butanol (SBA) and this is followed by dehydrogenation of SBA. By optimizing the operating conditions of a commercial unit, the running results showed that the recommended process was successful and that the catalysts had high activity, good selectivity, and long lifespan, which ensured long-term running in commercial units.

  10. Novel Zn(II) ladder-like coordination polymer constructed from designed ferrocenyl ligand

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Reaction of Zn(NO3)2.6H2O with 3-(4-carboxylphenylamino)-1-ferrocenyl-2-butylen-1-one (HL) and 4,4'-bipyridine (4,4'-bipy) in methanol solution resulted in a novel ladder-like coordination polymer {[Zn2L2(μ2-L)2(4,4'-bipy)2].MeOH}n (1). Its crystal structure, thermal and electrochemical properties axe presented.

  11. Characterization and luminescent properties of zinc–Schiff base complexes for organic white light emitting devices

    OpenAIRE

    Vandna Nishal; Devender Singh; Raman Kumar Saini; Vijeta Tanwar; Sonika Kadyan; Ritu Srivastava; Pratap Singh Kadyan

    2015-01-01

    Zinc complexes with Schiff base ligands bis(salicylidene)ethylene-1,2-diamine (salen), bis(salicylidene)propylene-1,3-diamine (salpen), bis(salicylidene)butylene-1,4-diamine (salbutene), bis(salicylidene)hexylene-1,6-diamine (salhexene), bis(salicylidene)heptylene-1,7-diamine (salheptene) were synthesized and characterized. All these metal complexes exhibited high thermal stability. The photo-physical properties of zinc complexes were investigated by taking their UV–vis absorption and photolu...

  12. Histamine homologues discriminating between two functional H3 receptor assays. Evidence for H3 receptor heterogeneity?.

    Science.gov (United States)

    Leurs, R; Kathmann, M; Vollinga, R C; Menge, W M; Schlicker, E; Timmerman, H

    1996-03-01

    We studied several histamine homologues as potential ligands for the histamine H3 receptor in two binding assays ([125l]iodophenpropit and N alpha-[3H]methylhistamine binding to rat brain cortex membranes) and two functional H3 receptor models (inhibition of the neurogenic contraction in the guinea pig jejunum and of [3H]noradrenaline release in mouse brain cortex slices). The histamine homologues acted all as competitive H3 antagonists at the guinea pig jejunum. The potency in this model and/or the affinity for N alpha-[3H]methylhistamine binding was higher for the butylene (pA2 = 7.7; pKi = 9.4) and pentylene homologue (impentamine, pA2 = 8.4; pKi = 9.1) than for the propylene, hexylene and octylene homologues (pA2 = 5.9-7.8; pKi = 6.1-7.6). In the mouse brain cortex the propylene, butylene and pentylene homologues acted as partial agonists (alpha = 0.3-0.6) and the hexylene and octylene homologues acted as antagonists. [125I]Iodophenpropit binding was displaced monophasically by the propylene, hexylene and octylene homologues and biphasically by the butylene and pentylene homologues. Biphasic displacement curves were converted to monophasic ones by 10 microM guanosine-5'-O-(3-thiotriphosphate. In conclusion, the homologue of histamine with five methylene groups is a more potent H3 receptor antagonist in the guinea pig jejunum than the other homologues tested. Furthermore, the propylene, butylene and pentylene homologues can discriminate between the two functional H3 receptor models in the guinea pig jejunum and mouse brain. These data are discussed in relation to the efficiency of receptor coupling and receptor heterogeneity.

  13. Proton transport in proton exchange membranes

    OpenAIRE

    Schmeisser, Jennifer Mary

    2007-01-01

    This work investigated several proton exchange membranes (PEMs): perfluorosulfonic acid-based polymers (Nafion®), sulfonated poly(ether ether ketone) (S-PEEK), radiation-grafted ethylenetetrafluoroethylene-grafted-poly(styrene sulfonic) acid (ETFE-g-PSSA), sulfonated trifluorostyrene-co-substituted trifluorostyrene (BAM®), sulfonated polystyrene-b-poly(ethylene-r-butylene)-b-polystyrene triblock copolymer (S-SEBS), and a series of novel photocurable polyelectrolytes. These polymer systems dif...

  14. Degradation of biodegradable plastic mulch films in soil environment by phylloplane fungi isolated from gramineous plants.

    Science.gov (United States)

    Koitabashi, Motoo; Noguchi, Masako T; Sameshima-Yamashita, Yuka; Hiradate, Syuntaro; Suzuki, Ken; Yoshida, Shigenobu; Watanabe, Takashi; Shinozaki, Yukiko; Tsushima, Seiya; Kitamoto, Hiroko K

    2012-08-02

    To improve the biodegradation of biodegradable plastic (BP) mulch films, 1227 fungal strains were isolated from plant surface (phylloplane) and evaluated for BP-degrading ability. Among them, B47-9 a strain isolated from the leaf surface of barley showed the strongest ability to degrade poly-(butylene succinate-co-butylene adipate) (PBSA) and poly-(butylene succinate) (PBS) films. The strain grew on the surface of soil-mounted BP films, produced breaks along the direction of hyphal growth indicated that it secreted a BP-degrading enzyme, and has directly contributing to accelerating the degradation of film. Treatment with the culture filtrate decomposed 91.2 wt%, 23.7 wt%, and 14.6 wt% of PBSA, PBS, and commercially available BP polymer blended mulch film, respectively, on unsterlized soil within 6 days. The PCR-DGGE analysis of the transition of soil microbial community during film degradation revealed that the process was accompanied with drastic changes in the population of soil fungi and Acantamoeba spp., as well as the growth of inoculated strain B47-9. It has a potential for application in the development of an effective method for accelerating degradation of used plastics under actual field conditions.

  15. Purification, characterization, and cloning of the gene for a biodegradable plastic-degrading enzyme from Paraphoma-related fungal strain B47-9.

    Science.gov (United States)

    Suzuki, Ken; Noguchi, Masako Tsujimoto; Shinozaki, Yukiko; Koitabashi, Motoo; Sameshima-Yamashita, Yuka; Yoshida, Shigenobu; Fujii, Takeshi; Kitamoto, Hiroko K

    2014-05-01

    Paraphoma-related fungal strain B47-9 secreted a biodegradable plastic (BP)-degrading enzyme which amounted to 68 % (w/w) of the total secreted proteins in a culture medium containing emulsified poly(butylene succinate-co-adipate) (PBSA) as sole carbon source. The gene for this enzyme was found to be composed of an open reading frame consisting of 681 nucleotides encoding 227 amino acids and two introns. Southern blot analysis showed that this gene exists as a single copy. The deduced amino acid sequence suggested that this enzyme belongs to the cutinase (E.C.3.1.1.74) family; thus, it was named P araphoma-related fungus cutinase-like enzyme (PCLE). It degraded various types of BP films, such as poly(butylene succinate), PBSA, poly(butylene adipate-co-terephthalate), poly(ε-caprolactone), and poly(DL-lactic acid). It has a molecular mass of 19.7 kDa, and an optimum pH and temperature for degradation of emulsified PBSA of 7.2 and 45 °C, respectively. Ca(2+) ion at a concentration of about 1.0 mM markedly enhanced the degradation of emulsified PBSA.

  16. Tailoring chemical and physical properties of fibrous scaffolds from block copolyesters containing ether and thio-ether linkages for skeletal differentiation of human mesenchymal stromal cells.

    Science.gov (United States)

    Chen, Honglin; Gigli, Matteo; Gualandi, Chiara; Truckenmüller, Roman; van Blitterswijk, Clemens; Lotti, Nadia; Munari, Andrea; Focarete, Maria Letizia; Moroni, Lorenzo

    2016-01-01

    Bioactive scaffolds for tissue engineering call for demands on new materials which can enhance traditional biocompatibility requirements previously considered for clinical implantation. The current commercially available thermoplastic materials, such as poly(lactic acid) (PLA), poly(glycolic acid) (PGA), poly(ε-caprolactone) (PCL) and their copolymers, have been used to fabricate scaffolds for regenerative medicine. However, these polymers have limitations including lacking of broadly tuning mechanical and degradable properties, and activation of specific cell-scaffold interactions, which limit their further application in tissue engineering. In the present study, electrospun scaffolds were successfully fabricated from a new class of block poly(butylene succinate)-based (PBS-based) copolyesters containing either butylene thiodiglycolate (BTDG) or butylene diglycolate (BDG) sequences. The polyesters displayed tunable mechanical properties and hydrolysis rate depending on the molecular architecture and on the kind of heteroatom introduced along the polymer backbone. To investigate their potential for skeletal regeneration, human mesenchymal stromal cells (hMSCs) were cultured on the scaffolds in basic, osteogenic and chondrogenic media. Our results demonstrated that PBS-based copolyesters containing thio-ether linkages (i.e. BTDG segments) were more favorable for chondrogenesis of hMSCs than those containing ether linkages (i.e. BDG sequences). In contrast, PBS-based copolyesters containing ether linkages showed enhanced mineralization. Therefore, these new functional scaffolds might hold potential for osteochondral tissue engineering applications.

  17. 不同链结构的双酚A聚碳酸酯对脂肪族聚碳酸酯结晶行为的影响%EFFECT OF BISPHENOL A POLYCARBONATE WITH DIFFERENT CHAIN STRUCTURE ON THE CRYSTALLIZATION BEHAVIOR OF ALIPHATIC POLYCARBONATE

    Institute of Scientific and Technical Information of China (English)

    宁炜; 刘琛阳; 朱文祥; 李春成; 王笃金

    2012-01-01

    脂肪族聚碳酸酯(APC)是一类可降解的高分子材料,因其生产工艺可固定温室气体的主要成分二氧化碳,这种可降解塑料得到了越来越多的关注.作为半结晶高分子材料,脂肪族聚碳酸酯的结晶性能和结晶结构对成型加工、力学性能和降解性能具有重要的影响.借助热分析(示差扫描量热仪DSC)和形态学观察(偏光显微镜POM)两种方法研究了不同链结构的双酚A型聚碳酸酯对半结晶脂肪族聚碳酸酯——聚碳酸1,4-丁二醇酯结晶动力学行为的影响.实验发现质量分数1%的双酚A聚碳酸酯的加入促进了聚碳酸1,4-丁二醇酯的成核,但不同链结构的双酚A聚碳酸酯对其晶体生长具有相反的作用,线形双酚A聚碳酸酯(PC-L)能够促进晶体生长,而支化双酚A聚碳酸酯(PC-B)则抑制晶体生长.用原子力显微镜在轻敲模式下研究了两种双酚A聚碳酸酯与APC共混物熔融状态下的相结构,发现熔体结构的不同是导致两种共混物与纯的APC相比,结晶速率呈现相反变化趋势的主要原因.%In the present investigation, the effect of the chain structure and aggregation state of bisphenol A polycarbonate ( PC) on the crystallization kinetics and morphology of the poly ( butylene carbonate) has been studied by DSC and POM. It was found that the addition of bisphenol A polycarbonate A promoted the nucleation of the poly( butylene carbonate) , while the chain structure of PC had the opposite influence on the crystal growth rate of the poly ( butylene carbonate). The linear bisphenol A polycarbonate polycarbonate accelerates the crystal growth rate of poly ( butylene carbonate) , while the long chain-branched bisphenol A polycarbonate decelerates it. The phase images of the blends of aliphatic polycarbonates and bisphenol A polycarbonate were obtained under the tapping mode by atomic force microscopy ( AFM). The linear bisphenol A polycarbonate shows isolated irregular

  18. Synthesis of thermoplastic poly(ester-olefin elastomers

    Directory of Open Access Journals (Sweden)

    Tanasijević Branka

    2004-01-01

    Full Text Available A series of thermoplastic poly(ester-olefin elastomers, based on poly(ethylene-stat-butylene, HO-PEB-OH, as the soft segment and poly (butylene terephthalate, PBT, as the hard segment, were synthesized by a catalyzed transesterification reaction in solution. The incorporation of soft hydrogenated poly(butadiene segments into the copolyester backbone was accomplished by the polycondensation of α, ω-dihydroxyl telechelic HO-PEB-OH, (PEB Mn = 3092 g/mol with 1,4-butanediol (BD and dimethyl terephthalate (DMT in the presence of a 50 wt-% high boiling solvent i.e., 1,2,4-trichlorobenzene. The molar ratio of the starting comonomers was selected to result in a constant hard to soft weight ratio of 60:40. The synthesis was optimized in terms of both the concentration of catalyst, tetra-n-butyl-titanate (Ti(OBu4, and stabilizer, N,N'-diphenyl-p-phenylenediamine (DPPD, as well as the reaction time. It was found that the optimal catalyst concentration (Ti(OBu4 for the synthesis of these thermoplastic elastomers was 1.0 mmol/mol ester and the optimal DPPD concentration was 1.0 wt-%. The extent of the reaction was followed by measuring the inherent viscosity of the reaction mixture. The effectiveness of the incorporation of the soft segments into the copolymer chains was proved by Soxhlet extraction with chloroform. The molecular structures, composition and the size of the synthesized poly(ester-butylenes were verified by 1H NMR spectroscopy, viscometry of dilute solutions and the complex dynamic melt viscosity. The thermal properties of poly(ester-olefins were investigated by differential scanning calorimetry (DSC. The degree of crystallinity was also determined by DSC. The thermal and thermo-oxidative stability were investigated by thermogravimetric analysis (TGA. The rheological properties of poly(ester-olefins were investigated by dynamic mechanical spectroscopy in the melt and solid state.

  19. Composites structures for bone tissue reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Neto, W.; Santos, João [Universidade Federal de São Carlos, Departament of Materials Engineering - Rd. Washington Luis, Km 235, 13565-905, São Carlos-SP (Brazil); Avérous, L.; Schlatter, G.; Bretas, Rosario, E-mail: bretas@ufscar.br [Université de Strasbourg, ECPM-LIPHT - 25 rue Becquerel, 67087, Strasbourg (France)

    2015-05-22

    The search for new biomaterials in the bone reconstitution field is growing continuously as humane life expectation and bone fractures increase. For this purpose, composite materials with biodegradable polymers and hydroxyapatite (HA) have been used. A composite material formed by a film, nanofibers and HA has been made. Both, the films and the non-woven mats of nanofibers were formed by nanocomposites made of butylene adipate-co-terephthalate (PBAT) and HA. The techniques used to produce the films and nanofibers were spin coating and electrospinning, respectively. The composite production and morphology were evaluated. The composite showed an adequate morphology and fibers size to be used as scaffold for cell growth.

  20. PROPERTIES OF POLYURETHANE ELASTOMERS BASED ON POLY (OXYETHYLENE-co-OXYTETRAMETHYLENE) DIOL

    Institute of Scientific and Technical Information of China (English)

    Chen-yu Su; Guang-li Zhang; Hong-zhi Zhang

    2001-01-01

    Polyurethane elastomers derived from 4,4′-methylene bis(phenyl isocyanate), butylene glycol and the low oxyethylene moiety content copolyether of tetrahydrofuran and ethylene oxide, obtained by copolymerization using heteropolyacid-ethylene oxide initiator system, were prepared. The polyurethanes exhibited an increased water absorption and much better low temperature resilience, which remained high even at a temperature of-3℃, while that of polyurethane based upon poly(tetramethylene ether) glycol of the same molecular weight, I.e. Being 2000, and molecular weight distribution, I.e. In the range of 1.4-1.5, starts to decrease dramatically at 5℃.``

  1. Enhanced propylene production in FCC by novel catalytic materials

    Energy Technology Data Exchange (ETDEWEB)

    Kelkar, C.P.; Harris, D.; Xu, M.; Fu, J. [BASF Catalyst LLC, Iselin, NJ (United States)

    2007-07-01

    Fluid catalytic cracking is expected to increasingly supply the additional incremental requirements for propylene. The most efficient route to increase propylene yield from an FCC unit is through the use of medium pore zeolites such as ZSM-5. ZSM-5 zeolite cracks near linear olefins in the gasoline range to LPG olefins such as propylene and butylenes. This paper will describe catalytic approaches to increase gasoline range olefins and the chemistry of ZSM-5 to crack those olefins. The paper will also describe novel catalytic materials designed to increase propylene. (orig.)

  2. Kinetics and Mechanism of Oxidation of Some Diols by Dihydroxydiperiodatoargentate(Ⅲ) in Alkaline Medium

    Institute of Scientific and Technical Information of China (English)

    SHAN, Jin-Huan; LI, Sheng-Min; HUO, Shu-Ying; SHEN, Shi-Gang; SUN, Han-Wen

    2006-01-01

    The kinetics of oxidation of ethylene glycol and 1,3-butylene glycol by dihydroxydiperiodatoargentate(Ⅲ) in alkaline medium have been studied by spectrophotometry in the range of 298.2-318.2 K. It is shown that the reaction was first order with respect to each reductant and Ag(Ⅲ), and kobs increased with an increase of [OH-]. A plausible mechanism of reaction involving a pre-equilibrium of adduct formation between complex and reductants was proposed, which could be applied to explain all experimental phenomena, and the activation parameters of the ratedetermining step have been also calculated.

  3. Study of the structure and the mechanical properties of dynamically cured PP/MAH-g-SEBS/epoxy blends

    Institute of Scientific and Technical Information of China (English)

    Xue Liang Jiang; Yin Xi Zhang

    2009-01-01

    A new method concerning with the simultaneous reinforcing and toughening of polypropylene (PP) was reported. Dynamical cure of the epoxy resin was successfully applied in the PP/maleic anhydride-grafted styrene--ethylene-butylene-styrene (SEBS) triblock copolymer, and the obtained blends named as dynamically cured PP/MAH-g-SEBS/epoxy blends. The stiffness and toughness of the blends are in a good balance, and MAH-g-SEBS was acted as not only an impact modifier but also a compatibilizer. The structure of the dynamically cured PP/MAH-g-SEBS/epoxy blends is the embedding of the epoxy particles by the MAH-gSEBS.

  4. Toughened carbon fibre fabric-reinforced thermoplastic composites

    OpenAIRE

    Abt, Tobias Martin; Sánchez Soto, Miguel; Maspoch Rulduà, Mª Lluïsa; Velasco Perero, José Ignacio

    2014-01-01

    Toughened carbon fibre fabric-reinforced composites were obtained by compression moulding of powder prepregs, using a modified cyclic butylene terephthalate (pCBT) matrix and a bi-directional [0°/90°] carbon fibre fabric. Modification of the pCBT matrix was done by adding small amounts of epoxy resin or isocyanates, acting as toughening agents. Homogeneous CBT/epoxy and CBT/isocyanate blends were obtained by melt blending in a lab-scale batch mixer by applying low temperatures and short proce...

  5. Modification of biodegradable polymers by radiation crosslinking technique with polyfunctional monomers

    Energy Technology Data Exchange (ETDEWEB)

    Yoshii, Fumio E-mail: yoshii@taka.jaeri.go.jp; Suhartini, Meri; Nagasawa, Naotsugu; Mitomo, Hiroshi; Kume, Tamikazu

    2003-08-01

    Poly({epsilon}-caprolactone) (PCL) and poly(butylene succinate-co-adipate) (PBSA) were electron beam-irradiated in the presence of five different polyfunctional monomers at ambient temperature. Trimethallyl isocyanurate (TMAIC) has been found to greatly enhance the radiation crosslinking of PCL and PBSA. It was pointed out that the optimum yield of gel fraction can be achieved when the polymers were irradiated at a dose of 50 kGy in the presence of 1% TMAIC. High gel fraction largely improves heat stability of PBSA, while biodegradability evaluated by soil burial test of the crosslinked polymers is slightly retarded, however they are effectively destroyed with a slightly smaller rate.

  6. Modification of biodegradable polymers by radiation crosslinking technique with polyfunctional monomers

    Science.gov (United States)

    Yoshii, Fumio; Suhartini, Meri; Nagasawa, Naotsugu; Mitomo, Hiroshi; Kume, Tamikazu

    2003-08-01

    Poly(ɛ-caprolactone) (PCL) and poly(butylene succinate-co-adipate) (PBSA) were electron beam-irradiated in the presence of five different polyfunctional monomers at ambient temperature. Trimethallyl isocyanurate (TMAIC) has been found to greatly enhance the radiation crosslinking of PCL and PBSA. It was pointed out that the optimum yield of gel fraction can be achieved when the polymers were irradiated at a dose of 50 kGy in the presence of 1% TMAIC. High gel fraction largely improves heat stability of PBSA, while biodegradability evaluated by soil burial test of the crosslinked polymers is slightly retarded, however they are effectively destroyed with a slightly smaller rate.

  7. Modifikacija PP/SAN mešanic:

    OpenAIRE

    Musil, Vojko; Radonjič, Gregor

    1995-01-01

    Properties of isotactic polypropylene (PP) can be improved with the preparation of PP blends. Polymer blend PP/SAN is immiscible and it shows a decrease in some mechanical properties but processing and some other properties can be improved. Addition of an impact modifier can also change the final properties of the PP/SAN blends. As a modifier we used poly (styrene-b-ethylene-co-butylene-b-styrene) (SEBS) triblock copolymer. Blends were prepared in the melt in a Brabender kneading chamber, coo...

  8. Flexible Composite Membranes for Selective Permeability

    Science.gov (United States)

    2006-11-01

    and physical properties of sulphonated poly(styrene ethylene/butylenes styrene), Polymer, 1991, 32, 10. DMMP VTR S -9 7- S IB S S -9 7- S IB S...is defined as moles of sulfonic acid per moles of styrene repeat unit and was determined by elemental analysis. The unsulfonated polymer was...provided by Kuraray Co., Ltd., Tsukuba research laboratories, with the reported properties : 30.84 wt% styrene, 0.95 specific gravity, Mw = 71,920 g/mol

  9. Effects of Thermal and Solvent Aging on Breakdown Voltage of TPE, PBT/PET Alloy, and PBT Insulated Low Voltage Electric Wire

    Directory of Open Access Journals (Sweden)

    Eun-Soo Park

    2013-01-01

    Full Text Available Tests were performed to evaluate the effects of thermal and solvent aging on the mechanical and dielectric breakdown properties of four types of polyester resins, namely, the insulation layer of poly(butylene terephthalat (PBT- based thermoplastic elastomer (TPE, TPE1, poly(butylene 2,6-naphthalate-based TPE (TPE2, PBT/poly(ethylene terephthalate alloy (Alloy, and PBT extruded onto a copper conductor of low voltage electric wire. The tensile specimens used in this series were prepared from the same extruded resins. The prepared electric wires and tensile specimens were thermally aged in air and in toluene, xylene, TCB, and NMP. When Alloy and PBT were thermally aged in toluene, xylene and TCB at 120°C for 6 h, the tensile properties were significantly decreased compared to TPE1 and TPE2 at the same condition. The reduction of elongation at break of Alloy was more discernible than that of PBT. This result indicated that Alloy is more affected by thermal and solvent ageing. Among them, TPE2 showed the highest breakdown voltage (BDV, and it has also the highest BDV after thermal and solvent aging.

  10. Discovery of Polyesterases from Moss-Associated Microorganisms.

    Science.gov (United States)

    Müller, Christina Andrea; Perz, Veronika; Provasnek, Christoph; Quartinello, Felice; Guebitz, Georg M; Berg, Gabriele

    2017-02-15

    The growing pollution of the environment with plastic debris is a global threat which urgently requires biotechnological solutions. Enzymatic recycling not only prevents pollution but also would allow recovery of valuable building blocks. Therefore, we explored the existence of microbial polyesterases in microbial communities associated with the Sphagnum magellanicum moss, a key species within unexploited bog ecosystems. This resulted in the identification of six novel esterases, which were isolated, cloned, and heterologously expressed in Escherichia coli The esterases were found to hydrolyze the copolyester poly(butylene adipate-co-butylene terephthalate) (PBAT) and the oligomeric model substrate bis[4-(benzoyloxy)butyl] terephthalate (BaBTaBBa). Two promising polyesterase candidates, EstB3 and EstC7, which clustered in family VIII of bacterial lipolytic enzymes, were purified and characterized using the soluble esterase substrate p-nitrophenyl butyrate (Km values of 46.5 and 3.4 μM, temperature optima of 48°C and 50°C, and pH optima of 7.0 and 8.5, respectively). In particular, EstC7 showed outstanding activity and a strong preference for hydrolysis of the aromatic ester bond in PBAT. Our study highlights the potential of plant-associated microbiomes from extreme natural ecosystems as a source for novel hydrolytic enzymes hydrolyzing polymeric compounds.

  11. An artificial neural network model for the prediction of mechanical and barrier properties of biodegradable films.

    Science.gov (United States)

    Nobrega, Marcelo Medre; Bona, Evandro; Yamashita, Fabio

    2013-10-01

    Nowadays, the production of biodegradable starch-based films is of great interest because of the growing environmental concerns regarding pollution and the need to reduce dependence on the plastics industry. A broad view of the role of different components, added to starch-based films to improve their properties, is required to guide the future development. The self-organizing maps (SOMs) provide comparisons that initially were complicated due to the large volume of the data. Furthermore, the construction of a model capable of predicting the mechanical and barrier properties of these films will accelerate the development of films with improved characteristics. The water vapor permeability (WVP) analysis using the SOM algorithm showed that the presence of glycerol is very important for films with low amounts of poly (butylene adipate co-terephthalate) and confirms the role of the equilibrium relative humidity in the determination of WVP. Considering the mechanical properties, the SOM analysis emphasizes the important role of poly (butylene adipate co-terephthalate) in thermoplastic starch based films. The properties of biodegradable films were predicted and optimized by using a multilayer perceptron coupled with a genetic algorithm, presenting a great correlation between the experimental and theoretical values with a maximum error of 24%. To improve the response of the model and to ensure the compatibility of the components more information will be necessary.

  12. Affinity purification and characterization of a biodegradable plastic-degrading enzyme from a yeast isolated from the larval midgut of a stag beetle, Aegus laevicollis.

    Science.gov (United States)

    Suzuki, Ken; Sakamoto, Hironori; Shinozaki, Yukiko; Tabata, Jun; Watanabe, Takashi; Mochizuki, Atsushi; Koitabashi, Motoo; Fujii, Takeshi; Tsushima, Seiya; Kitamoto, Hiroko K

    2013-09-01

    Two yeast strains, which have the ability to degrade biodegradable plastic films, were isolated from the larval midgut of a stag beetle, Aegus laevicollis. Both of them are most closely related to Cryptococcus magnus and could degrade biodegradable plastic (BP) films made of poly(butylene succinate) (PBS) and poly(butylene succinate-co-adipate) (PBSA) effectively. A BP-degrading enzyme was purified from the culture broth of one of the isolated strains employing a newly developed affinity purification method based on the binding action of the enzyme to the substrate (emulsified PBSA) and its subsequent degradative action toward the substrate. Partial amino acid sequences of this enzyme suggested that it belongs to the cutinase family, and thus, the enzyme was named CmCut1. It has a molecular mass of 21 kDa and a degradative activity for emulsified PBSA which was significantly enhanced by the simultaneous presence of Ca(2+) or Mg(2+) at a concentration of about 2.5 mM. Its optimal pH was 7.5, and the optimal temperature was 40 °C. It showed a broad substrate specificity for p-nitrophenyl (pNP)-fatty acid esters ranging from pNP-acetate (C2) to pNP-stearate (C18) and films of PBSA, PBS, poly(ε-caprolactone), and poly(lactic acid).

  13. Purification and characterization of a biodegradable plastic-degrading enzyme from Aspergillus oryzae.

    Science.gov (United States)

    Maeda, Hiroshi; Yamagata, Youhei; Abe, Keietsu; Hasegawa, Fumihiko; Machida, Masayuki; Ishioka, Ryoji; Gomi, Katsuya; Nakajima, Tasuku

    2005-06-01

    We used biodegradable plastics as fermentation substrates for the filamentous fungus Aspergillus oryzae. This fungus could grow under culture conditions that contained emulsified poly-(butylene succinate) (PBS) and emulsified poly-(butylene succinate-co-adipate) (PBSA) as the sole carbon source, and could digest PBS and PBSA, as indicated by clearing of the culture supernatant. We purified the PBS-degrading enzyme from the culture supernatant, and its molecular mass was determined as 21.6 kDa. The enzyme was identified as cutinase based on internal amino acid sequences. Specific activities against PBS, PBSA and poly-(lactic acid) (PLA) were determined as 0.42 U/mg, 11 U/mg and 0.067 U/mg, respectively. To obtain a better understanding of how the enzyme recognizes and hydrolyzes PBS/PBSA, we investigated the environment of the catalytic pocket, which is divided into carboxylic acid and alcohol recognition sites. The affinities for different substrates depended on the carbon chain length of the carboxylic acid in the substrate. Competitive inhibition modes were exhibited by carboxylic acids and alcohols that consisted of C4-C6 and C3-C8 chain lengths, respectively. Determination of the affinities for different chemicals indicated that the most preferred substrate for the enzyme would consist of butyric acid and n-hexanol.

  14. Catalyst Activity Comparison of Alcohols over Zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Ramasamy, Karthikeyan K.; Wang, Yong

    2013-01-01

    Alcohol transformation to transportation fuel range hydrocarbon on HZSM-5 (SiO2 / Al2O3 = 30) catalyst was studied at 360oC and 300psig. Product distributions and catalyst life were compared using methanol, ethanol, 1-propanol or 1-butanol as a feed. The catalyst life for 1-propanol and 1-butanol was more than double compared to that for methanol and ethanol. For all the alcohols studied, the product distributions (classified to paraffin, olefin, napthene, aromatic and naphthalene compounds) varied with time on stream (TOS). At 24 hours TOS, liquid product from 1-propanol and 1-butanol transformation primarily contains higher olefin compounds. The alcohol transformation process to higher hydrocarbon involves a complex set of reaction pathways such as dehydration, oligomerization, dehydrocyclization, and hydrogenation. Compared to ethylene generated from methanol and ethanol, oligomerization of propylene and butylene has a lower activation energy and can readily take place on weaker acidic sites. On the other hand, dehydrocyclization of propylene and butylene to form the cyclic compounds requires the sits with stronger acid strength. Combination of the above mentioned reasons are the primary reasons for olefin rich product generated in the later stage of the time on stream and for the extended catalyst life time for 1 propanol and 1 butanol compared to methanol and ethanol conversion over HZSM-5.

  15. Enzymatic Hydrolysis of Polyester Thin Films: Real-Time Analysis of Film Mass Changes and Dissipation Dynamics.

    Science.gov (United States)

    Zumstein, Michael Thomas; Kohler, Hans-Peter E; McNeill, Kristopher; Sander, Michael

    2016-01-05

    Cleavage of ester bonds by extracellular microbial hydrolases is considered a key step during the breakdown of biodegradable polyester materials in natural and engineered systems. Here we present a novel analytical approach for simultaneous detection of changes in the masses and rigidities of polyester thin films during enzymatic hydrolysis using a Quartz Crystal Microbalance with Dissipation monitoring (QCM-D). In experiments with poly(butylene succinate) (PBS) and the lipase of Rhizopus oryzae (RoL), we detected complete hydrolysis of PBS thin films at pH 5 and 40 °C that proceeded through soft and water-rich film intermediates. Increasing the temperature from 20 to 40 °C resulted in a larger increase of the enzymatic hydrolysis rate of PBS than of nonpolymeric dibutyl adipate. This finding was ascribed to elevated accessibility of ester bonds to the catalytic site of RoL due to increasing polyester chain mobility. When the pH of the solution was changed from 5 to 7, initial hydrolysis rates were little affected, while a softer film intermediate that lead to incomplete film hydrolysis was formed. Hydrolysis dynamics of PBS, poly(butylene adipate), poly(lactic acid), and poly(ethylene terephthalate) in assays with RoL showed distinct differences that we attribute to differences in the polyester structure.

  16. An Esterase from Anaerobic Clostridium hathewayi Can Hydrolyze Aliphatic-Aromatic Polyesters.

    Science.gov (United States)

    Perz, Veronika; Hromic, Altijana; Baumschlager, Armin; Steinkellner, Georg; Pavkov-Keller, Tea; Gruber, Karl; Bleymaier, Klaus; Zitzenbacher, Sabine; Zankel, Armin; Mayrhofer, Claudia; Sinkel, Carsten; Kueper, Ulf; Schlegel, Katharina; Ribitsch, Doris; Guebitz, Georg M

    2016-03-15

    Recently, a variety of biodegradable polymers have been developed as alternatives to recalcitrant materials. Although many studies on polyester biodegradability have focused on aerobic environments, there is much less known on biodegradation of polyesters in natural and artificial anaerobic habitats. Consequently, the potential of anaerobic biogas sludge to hydrolyze the synthetic compostable polyester PBAT (poly(butylene adipate-co-butylene terephthalate) was evaluated in this study. On the basis of reverse-phase high-performance liquid chromatography (RP-HPLC) analysis, accumulation of terephthalic acid (Ta) was observed in all anaerobic batches within the first 14 days. Thereafter, a decline of Ta was observed, which occurred presumably due to consumption by the microbial population. The esterase Chath_Est1 from the anaerobic risk 1 strain Clostridium hathewayi DSM-13479 was found to hydrolyze PBAT. Detailed characterization of this esterase including elucidation of the crystal structure was performed. The crystal structure indicates that Chath_Est1 belongs to the α/β-hydrolases family. This study gives a clear hint that also micro-organisms in anaerobic habitats can degrade manmade PBAT.

  17. Decay kinetics of benzophenone triplets and corresponding free radicals in soft and rigid polymers studied by laser flash photolysis.

    Science.gov (United States)

    Levin, Peter P; Efremkin, Alexei F; Sultimova, Natalie B; Kasparov, Valery V; Khudyakov, Igor V

    2014-01-01

    The kinetics of transients formed under photoexcitation of benzophenone (B) dissolved in three different polymers was studied by ns laser flash photolysis. These polymers were the soft rubbers poly (ethylene-co-butylene) (EB), polystyrene block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS) and hard polystyrene (PS). We monitored the decay kinetics of triplet state (3)B(*) and of ketyl radicals BH(●). We observed exponential decay of (3)B(*) and two-stage decay kinetics of BH(●) in EB. The first stage is a fast cage recombination of a radical pair (BH(●), radical of polymer R(●)). The second slow stage of BH(●) decay follows the second-order law with a relatively high rate constant, which corresponds to recombination of BH(●) in a homogeneous liquid with a viscosity of only ~0.1 P (about five times of 2-propanol viscosity). Application of a magnetic field (MF) of 0.2 T leads to deceleration of both stages of BH(●) decay in EB by approximately 20%. Decay kinetics of both transients were observed in SEBS. There was no MF effect on BH(●) decay in SEBS. We only observed (3)B(*) in PS. Decay kinetics of (3)B(*) in this case were described as polychromatic dispersive first-order kinetics. We discuss the effects of polymer structure on transient kinetics and the MF effect.

  18. Application of reactive siloxane prepolymers for the synthesis of thermoplastic poly(ester–siloxanes and poly(ester–ether–siloxanes

    Directory of Open Access Journals (Sweden)

    VESNA V. ANTIC

    2007-02-01

    Full Text Available Thermoplastic poly(ester–siloxanes (TPES and poly(ester–ether–siloxane s, (TPEES, based on poly(butylene terephthalate (PBT as the hard segment and different siloxane-prepolymers as the soft segments, were prepared. The TPES and TPEES were synthesized by catalyzed two-step transesterification from dimethyl terephthalate, (DMT, 1,4-butanediol, (BD and a siloxane-prepolymer. Incorporation of dicarboxypropyl- or disilanol-terminated poly(dimethylsiloxanes (PDMS into the polar poly(butylene terephthalate chains resulted in rather inhomogeneous TPES copolymers, which was a consequence of a prononuced phase separation of the polar and non-polar reactants during synthesis. Two concepts were employed to avoid or reduce phase separation: 1 the use of siloxane-containing triblock prepolymers with hydrophilic terminal blocks, such as ethylene oxide (EO, poly(propylene oxide (PPO or poly(caprolactone (PLC when the terminal blocks serve as a compatibilizer between the extremely non-polar PDMS and the polar DMT and BD, and 2 the use of a high-boiling solvent (1,2,4-trichlorobenzene during the first phase of the reaction. Homogeneity was significantly improved in the case of copolymers based on PCL–PDMS–PCL.

  19. Hydrolysis of synthetic polyesters by Clostridium botulinum esterases.

    Science.gov (United States)

    Perz, Veronika; Baumschlager, Armin; Bleymaier, Klaus; Zitzenbacher, Sabine; Hromic, Altijana; Steinkellner, Georg; Pairitsch, Andris; Łyskowski, Andrzej; Gruber, Karl; Sinkel, Carsten; Küper, Ulf; Ribitsch, Doris; Guebitz, Georg M

    2016-05-01

    Two novel esterases from the anaerobe Clostridium botulinum ATCC 3502 (Cbotu_EstA and Cbotu_EstB) were expressed in Escherichia coli BL21-Gold(DE3) and were found to hydrolyze the polyester poly(butylene adipate-co-butylene terephthalate) (PBAT). The active site residues (triad Ser, Asp, His) are present in both enzymes at the same location only with some amino acid variations near the active site at the surrounding of aspartate. Yet, Cbotu_EstA showed higher kcat values on para-nitrophenyl butyrate and para-nitrophenyl acetate and was considerably more active (sixfold) on PBAT. The entrance to the active site of the modeled Cbotu_EstB appears more narrowed compared to the crystal structure of Cbotu_EstA and the N-terminus is shorter which could explain its lower activity on PBAT. The Cbotu_EstA crystal structure consists of two regions that may act as movable cap domains and a zinc metal binding site.

  20. The influence of chemical composition of aliphatic-aromatic copolyesters on their properties

    Energy Technology Data Exchange (ETDEWEB)

    Wojtczak, Malgorzata; Galeski, Andrzej; Piorkowska, Ewa [Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Lodz (Poland); Dutkiewicz, Slawomir [Institute of Biopolymers and Chemical Fibres, Marii Sklodowskiej-Curie 19/27, 90-570 Lodz (Poland)

    2014-05-15

    The chain microstructure and properties of a series of aliphatic-aromatic copolyesters in a range of compositions from 10 to 100% of aromatic components were studied by examining melting and crystallization behaviors, dynamic mechanical response, morphology, wide- (WAXS) and small-angle X-ray scattering (SAXS), and tensile deformation. Chain microstructure was analyzed by {sup 1}H NMR. The results indicate that most of copolyesters used in this study have essentially random distribution of comonomers. Copolyesters with more than 30 mol% of aromatic part crystallize with a crystal structure characteristic for homopolymer poly(butylene terephthalate) (PBT). However, some of the reflections from crystal planes are shifted towards lower diffraction angles as compared to butylene terephthalate homoplymer. The phase transition temperatures decrease with increasing aliphatic content. By means of polarized light microscopy (PLM), small-angle light scattering (SALS) and SAXS, crystallization behavior of a selected aliphatic-aromatic copolyester was further explored. Selected copolyester crystallizes in the form of thin fibrous crystals, few nanometers thick, which is the main factor influencing the depression of its melting temperature.

  1. Isocyanate toughened pCBT: Reactive blending and tensile properties

    Directory of Open Access Journals (Sweden)

    T. Abt

    2013-02-01

    Full Text Available Cyclic butylene terephthalate oligomers (CBT were reacted in a ring-opening polymerization with three types of isocyanates: a bifunctional aromatic type, a bifunctional aliphatic type and a polymeric aromatic isocyanate. All reactions took place in a batch mixer. The use of 0.5 to 1 wt% isocyanate led to a dramatic increase in elongation at break of polymerized cyclic butylene terephthalate (pCBT, from 8 to above 100%. The stiffness and strength of the modified pCBT, however, were found to slightly decrease. Proton nuclear magnetic resonance (NMR analysis shows that the formation of thermally stable amide groups is the dominant chain extension reaction mechanism. Gel content measurements suggest a linear structure for samples containing bifunctional isocyanates while pCBT modified with polyfunctional isocyanate exhibited some gel formation at higher isocyanate content. Melting and crystallization temperatures as well as degree of crystallinity were found to decrease with increasing isocyanate content. No phase separation was detected by scanning electron microscopy (SEM analysis. Moreover, a high degree of polymerization is deduced due to the absence of CBT oligomer crystals.

  2. 高效液相色谱在葡萄糖加氢裂解中的应用%The Application of HPLC in Glucose Hydrogenation Cracking

    Institute of Scientific and Technical Information of China (English)

    罗文杰; 闫锁; 陈世鑫; 陆启明; 仵闫闫

    2012-01-01

    Taking glucose as raw material,with catalysts,the reaction liguid contained 1,2-propanediol,propylene glycol,glycols,2,3-butylene glycol,1,2-butylene glycol,1,4-butylene glycol(be called binary alcohol,sorbic alcohol,third three alcohol,formic acid for short hereinafter) stopping,(be called restructuring share for short under) acetic acid salt,lactate and others,was got through hydrogenation crauking Adopting Aminex HPX-87H Lon exclusion colour spectrum post,0.006 mol/L sulfuric acid as mobile under flow rate of 0.5 mL/min,by the differential refractive power chemistry detector checks,be able to separate binary alcohol in reaction liquid as well as restructuring share was complete,assume and a linearity without exception within certain mass thickness range.The coefficient of recovery owing method binary alcohol and restructuring share in analysing reaction liquid was 97%~103%.The method was able to determine middle binary reaction liquid alcohol and the contents re-organizing share speedy and accurately.%对于以葡萄糖为原料,在催化剂的作用下,通过加氢裂解得到含有1,2-丙二醇、乙二醇、2,3-丁二醇、1,2-丁二醇、1,4-丁二醇(以下简称二元醇)、山梨醇、丙三醇、甲酸盐、乙酸盐、乳酸盐以及其他未知物(以下简称重组份)的反应液,采用AminexHPX-87H Lon exclusion色谱柱,以0.006 mol/L的硫酸作为流动相,在流速0.5 mL/min的流量下,经示差折光化学检测器检测,能够将反应液中的二元醇以及重组份完全分离,且均在一定质量浓度范围内呈线性[1]。该方法分析反应液中的二元醇及重组份的回收率在97%~103%之间。本方法能够快速、精确测定反应液中二元醇与重组份的含量。

  3. 催化剂对二元醇伯仲羟基氨酯化反应的影响%Effect of the Catalyst on the Urethane Reaction Selectivity of Different Hydroxyl in Diol

    Institute of Scientific and Technical Information of China (English)

    王顺平; 杨鹏飞; 赵超; 李俊英; 李天铎

    2012-01-01

    The urethane reaction of 1,2-propylene glycol or 1,3-butylene glycol with phenyl isocyanate was investigated with toluene,butyl acetate or N,N-dimethylformamide as solvents and trimethylamine(TEA) or 1,4-Diazabicyclooctane(DABCO) as catalyst,respectively.A comparative research between the primary and secondary hydroxyl groups in diol was done.It showed that the reactivity difference between the two hydroxyl groups was affected by amine catalyst.The reactivity difference of hydroxyl groups in 1,2-propylene glycol was nearly 11 when TEA was used as catalyst and toluene was used as solvent.When reacting with phenyl isocyanate at the same condition,1,3-butylene glycol showed similar rate constants compared with 1,2-propylene glycol,the reactivity difference of primary and secondary hydroxyl group in 1,3-butylene glycol was also very similar to 1,2-propylene glycol.%分别以甲苯、乙酸丁酯和N,N-二甲基甲酰胺作溶剂,以三乙胺(TEA)、1,4-二氮杂二环[2.2.2]辛烷(DABCO)作催化剂,进行1,2-丙二醇、1,3-丁二醇与苯基异氰酸酯的反应。用在线红外光谱监测反应过程,研究了二元醇中不同类型羟基的反应活性。结果表明,催化剂能够扩大伯羟基与仲羟基的反应活性差异。以甲苯作溶剂、TEA作催化剂时,1,2-丙二醇中伯羟基与仲羟基的活性差异最大,可达11倍左右。在相同条件下与苯基异氰酸酯反应时,1,2-丙二醇、1,3-丁二醇的反应速率相近,两者伯羟基与仲羟基的活性差异也相近。

  4. Clinical Observation of Magnesium Isoglycyrrhizinate and Polyene Phosphatidyl Choline Combined Ranitidine Acid Ademetionine Treatment of Hyperbilirubinemia in Chronic Hepatitis B Patients (46 Cases)%异甘草酸镁、多烯磷脂酰胆碱联合丁二酸腺苷蛋氨酸治疗慢性乙型肝炎高胆红素血症46例临床观察

    Institute of Scientific and Technical Information of China (English)

    王淑萍; 明全; 黄娟丽

    2015-01-01

    Objective To observe dif erent glycyr hizic acid magnesium,polyene phosphatidyl choline joint butylene adenosine methionine high blood bilirubin in patients with chronic hepatitis B clinical curative ef ect.Methods Choose 89 cases of patients with chronic hepatitis b high blood bilirubin,randomly divided into treatment group and control group,treatment group was given dif erent glycyr hizic acid magnesium,polyene phosphatidyl choline and butylene adenosine methionine treatment,the control group with dif erent glycyrrhizic acid magnesium,polyene phosphatidyl choline treatment.Results In the two groups after treatment in patients with liver before treatment were significantly decreased each index;Compared the two groups before and after treatment,clinical symptoms improved significantly.Conclusion Dif erent glycyr hizic acid magnesium joint polyene phosphatidyl choline and butylene adenosine methionine joint return yel ow ef ect is bet er.%目的观察异甘草酸镁、多烯磷脂酰胆碱联合丁二腺苷蛋氨酸治疗慢性乙型肝炎高胆红素血症的临床疗效。方法选择慢性乙型肝炎高胆红素血症患者89例,随机分为治疗组、对照组,治疗组给予异甘草酸镁、多烯磷脂酰胆碱及丁二腺苷蛋氨酸治疗,对照组以异甘草酸镁、多烯磷脂酰胆碱治疗。结果治疗后两组患者肝功能各指标较治疗前均明显下降;两组治疗前后比较,临床症状改善明显。结论异甘草酸镁联合多烯磷脂酰胆碱与丁二腺苷蛋氨酸联合退黄效果则更佳。

  5. Lipase-catalyzed synthesis of aliphatic polyesters via copolymerization of lactone, dialkyl diester, and diol.

    Science.gov (United States)

    Jiang, Zhaozhong

    2008-11-01

    Candida antarctica lipase (CALB) has been successfully used as catalyst for copolymerization of dialkyl diester with diol and lactone to form aliphatic polyesters. The polymerization reactions were performed using a two stage process: first stage oligomerization under low vacuum followed by second stage polymerization under high vacuum. Use of the two-stage process is required to obtain products with high molecular weights at high yields for the following reasons: (i) the first stage reaction ensures that the monomer loss via evaporation is minimized to maintain 1:1 diester to diol stoichiometric ratio, and the monomers are converted to nonvolatile oligomers; (ii) use of high vacuum during the second stage accelerates equilibrium transesterification reactions to transform the oligomers to high molecular weight polymers. Thus, terpolymers of omega-pentadecalactone (PDL), diethyl succinate (DES), and 1,4-butanediol (BD) with a M w of whole product (nonfractionated) up to 77000 and M w/ M n between 1.7 and 4.0 were synthesized in high yields (e.g., 95% isolated yield). A desirable reaction temperature for the copolymerizations was found to be around 95 degrees C. At 1:1:1 PDL/DES/BD monomer molar ratio, the resultant terpolymers contained equal moles of PDL, succinate, and butylene repeat units in the polymer chains. (1)H and (13)C NMR analyses were used to determine the polyester microstructures. The synthesized PDL-DES-BD terpolymers possessed near random structures with all possible combinations of PDL, succinate, and butylene units via ester linkages in the polymer backbone. Furthermore, thermal stability and crystallinity of a pure PDL-DES-BD terpolymer with 1:1:1 PDL to succinate to butylene unit ratio and M w of 85400 were studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The copolyester was found to be a semicrystalline material with a T g of -34 degrees C and a T m of 64 degrees C, which degrades in a single weight loss

  6. Degradation of PBS-Based Copolymers and Impact on the Growth of Winter Wheat%PBS基共聚物的降解性及其对冬小麦生长影响的研究

    Institute of Scientific and Technical Information of China (English)

    苏康宇; 张敏; 安雨; 马永清

    2011-01-01

    为了研究聚丁二酸丁二醇酯(PBS)基共聚物的降解性能及其对冬小麦生长的影响,笔者将冬小麦分别播种在混有等量PBS,改性共聚物聚丁二酸丁二醇酯/丁二酸己二醇酯(PBS-co-HS),聚丁二酸丁二醇酯/己二酸丁二醇酯(PBS-co-BA)的聚合物碎片的土壤中,研究聚合物在土壤中的降解,及其持续降解过程中的降解中间体、降解产物对冬小麦种子发芽及生长的影响.结果表明,在相同条件下的陕西(填)土中,共聚物比PBS显示出更好的生物降解性能;聚合物处理对冬小麦的发芽率、株高没有影响,但有利于植株生物量的提高.因此,可生物降解材料PBS、PBS-co-HS和PBS-co-BA的降解及其降解产物对目前土壤环境中植物的生长暂时没有影响.%In order to study the degradation of PBS-based copolymer and impact on the growth of winter wheat, seeds of winter wheat were sowed and cultivated in a soil blended with polymers, such as PBS, poly (butylene succinate)-co-(hexane succinate) (PBS-co-HS) and poly (butylene succinate)-co-(butylene adipate) (PBS-co-BA). The degradation of polymers, the impact of the degradation intermediates and degradation products of polymers on the winter wheat seed germination and the growth had been investigated. The results showed that the degradation of copolymers proceeded faster than that of PBS under the same conditions of Shaanxi soil, different soil treatments with polymer did not affect the germination rate of winter wheat, stem height, but enhanced the plant biomass. These results suggested that investigated polymeric materials as well as the products of their degradation possibly at present temporarily in the soil do not affect plant growth.

  7. Using glycerol produced from biodiesel as a plasticiser in extruded biodegradable films

    Directory of Open Access Journals (Sweden)

    Ana Paula Bilck

    2015-08-01

    Full Text Available AbstractThe demand for renewably sourced biodegradable materials has increased the need to produce materials that combine appropriate functional properties at competitive costs. Thermoplastic starch and polyester blends are an interesting alternative to current materials due to the low cost of starch and the functional properties and processability of the resulting blends. Producing thermoplastic starch (TPS requires using a plasticiser at concentrations between 20 and 30%wt (in relation to starch. Glycerol is the most common plasticiser due to its high plasticising capacity and thermal stability at processing temperatures. The objective of this study was to evaluate glycerol waste from the biodiesel industry, with different degrees of purification, as plasticisers for TPS / poly (butylene adipate-co-terephthalate (PBAT blends. Different purities of glycerol produced films with similar mechanical, optical and barrier properties to those made with purified glycerol (99.7%. Therefore, crude glycerol is a renewable alternative plasticiser that reduces the cost of plasticisation by 6-fold.

  8. 重油催化裂解汽柴油二次裂解性能研究%Secondary Cracking of Gasoline and Diesel from Heavy Oil Catalytic Pyrolysis

    Institute of Scientific and Technical Information of China (English)

    刘植昌; 孟祥海; 徐春明; 高金森

    2007-01-01

    This paper investigated the secondary cracking of gasoline and diesel from the catalytic pyrolysis of Daqing atmospheric residue on catalyst CEP-1 in a fluidized bed reactor.The results show that the secondary cracking reactivity of gasoline and diesel is poor, and the yield of total light olefins is only about 10% (by mass).As reaction temperature increases, ethylene yield increases, butylene yield decreases, and propylene yield shows a maximum.The optimal reaction temperature is about 670 ℃ for the production of light olefins.With the enhancement of catalyst-to-oil mass ratio and steam-to-oil mass ratio, the yields of light olefins increase to some extent.About 6.30% of the mass of total aromatic rings is converted by secondary cracking, indicating that aromatic hydrocarbons are not easy to undergo ring-opening reactions under the present experimental conditions.

  9. Zeolites Modified Metal Cations as Catalysts in Hydrocarbon Oxidation and the Alkyl Alcohol

    Directory of Open Access Journals (Sweden)

    Agadadsh Makhmud Aliyev

    2014-09-01

    Full Text Available The results of studies on the creation of highly metalltceolitnyh systems and the study of their catalytic activities in the oxidation of lower olefin hydrocarbons (ethylene to acetaldehyde, acetone, propylene, butylene methyl ethyl ketone; aliphatic C1-C5 alcohols to their corresponding aldehydes, ketones, carboxylic acids and carboxylic acid esters; oxidative dehydrogenation of naphthenes in the alicyclic diene hydrocarbons and the oxidative dimerization of methane to acetylene. It has been established that the selectivity of these catalysts determined optimal combination of metal components with the acidity and the structure of the zeolite. Selected highly effective catalysts for the reactions studied. Based on the results of experimental studies of the kinetics of the reactions of oxidation of lower olefin hydrocarbons and aliphatic alcohols, the oxidative dehydrogenation of naphthenes and oxidative coupling of methane on the synthesized catalysts are represented by their probable stepwise mechanism and kinetic models developed reactions.

  10. Partial Discharge Degradation of Several Biodegradable Polymers

    Science.gov (United States)

    Fuse, Norikazu; Fujita, Shinjiro; Hirai, Naoshi; Tanaka, Toshikatsu; Kozako, Masahiro; Kohtoh, Masanori; Okabe, Shigemitsu; Ohki, Yoshimichi

    Partial discharge (PD) resistance was examined by applying a constant voltage for four kinds of biodegradable polymers, i.e. poly-L-lactic acid (PLLA), polyethylene terephthalate succinate (PETS), poly ε-caprolactone butylene succinate (PCL-BS), and polybutylene succinate (PBS), and the results were compared with those of low density polyethylene (LDPE) and crosslinked low density polyethylene (XLPE). The PD resistance is determined by the erosion depth and the surface roughness caused by PDs, and is ranked as LDPE ≅ XLPE > PLLA ≅ PETS > PBS > PCL-BS. This means that the sample with a lower permittivity has better PD resistance. Furthermore, observations of the sample surface by a polarization microscope and a laser confocal one reveal that crystalline regions with spherulites are more resistant to PDs than amorphous regions. Therefore, good PD resistance can be achieved by the sample with a high crystallinity and a low permittivity.

  11. A Probe into Process for Maximization of Low-carbon Oleifns via Co-processing of Methanol and Heavy Oil

    Institute of Scientific and Technical Information of China (English)

    Song Baomei

    2013-01-01

    From the viewpoint of process speciifcs and thermodynamics, this article has put forward a route for maximiza-tion of low-carbon oleifns via co-processing of methanol and heavy oil. Catalytic cracking experiments on co-processing of methanol and heavy oil at different ratios in a ifxed lfuidized bed reactor had been conducted. Test results have revealed that when 12.5%of methanol was blended to the heavy oil a good products distribution and relatively higher yield of low-carbon oleifns could be obtained. The overall yield of low-carbon oleifns could reach 50.16%, with the yield of ethylene, propylene and butylene equating to 5.47%, 28.93%and 15.76%, respectively.

  12. Determination of constituents of essential oil from Angelica sinensis by gas chromatography-mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    WU Ming-jian; SUN Xian-jun; DAI Yuan-hui; GUO Fang-qiu; HUANG Lan-fang; LIANG Yi-zeng

    2005-01-01

    Gas chromatography-mass spectrometry (GC-MS) coupled with chemometric resolution upon two-dimensional data was employed to analyze the constituents of essential oils of Angelica sinensis. Constituents in essential oils of Angelica sinensis root were identified by GC-MS with the help of subwindow factor analysis (SFA) method resolving two-dimensional original data into mass spectra and chromatograms. 76 of 97 separated constituents in essential oil of Angelica sinensis root were identified and quantified, and they account for about 91.36% of the total content. The results show that ligustilide, butylene phthalide, 2-methoxy-4-vinylphenol, carvacrol, allo-ocimene,2,6,6-trimethylbicyclo-[3,1,1]hept-2-ene are the main constituents in essential oil of Angelica sinensis root.

  13. 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...... a viscoclastic rubber to a plastic fluid and from a plastic fluid to a viscoelastic liquid are shifted to more elevated temperatures when silica is added to the triblock copolymer gel. (C) 2004 Elsevier Ltd. All rights reserved....

  14. Study on reformulation of fluid catalytic cracking gasoline and increasing production of light olefins

    Institute of Scientific and Technical Information of China (English)

    Pingxiang YAN; Xianghai MENG; Jinsen GAO; Chunmin XU; Zhiyu SUI

    2008-01-01

    The effects of reaction temperature, mass ratio of catalyst to oil, space velocity, and mass ratio of water to oil on the product distribution, the yields of light olefins (light olefins including ethylene, propylene and butylene) and the composition of the fluid catalytic cracking (FCC) gasoline upgraded over the self-made catalyst GL in a confined fluidized bed reactor were investigated. The experimental results showed that FCC gasoline was obviously reformulated under appropriate reaction con-ditions. The olefins (olefins with C atom number above 4) content of FCC gasoline was markedly reduced, and the aromatics content and octane number were increased. The upgraded gasoline met the new standard of gasoline, and meanwhile, higher yields of light olefins were obtained. Furthermore, higher reaction temperature, higher mass ratio of catalyst to oil, higher mass ratio of water to oil, and lower space velocity were found to be beneficial to FCC gasoline reformulation and light olefins production.

  15. Mechanical Properties and Morphology of the Clay/Waterborne Polyurethane Nanocomposite

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yongcheng; WANG Junwei; ZHAO Yuhua; KANG maoqing; WANG Xinkui

    2006-01-01

    Stable clay/waterborne polyurethane nanocompostie dispersions were synthesized by sulfonated poly ( butylene adipate ) diol , 4,4-diphenylmethane diisocyanate , dimethyl propionic acid, 1,4-butanediol, triethyl anine and clay-water dispersion through a route named prepolymer acetone mixing progress. The reinforced mechanical properties and thermal resistance of films casting from it were examined by dynamic mechanical analyses (DMA), thermogravimetric analyses (TGA) and tensile tests. Furthermore, the morphology of these nanocompostie films and dispersions were observed by transmission electron microscopy (TEM), scanning electron microscopy( SEM), wide-angle X-ray diffraction analyses( WXRD ). The experimental results reveal that the clay could be predominantly dispersed in the pristine polymer forming nanocomposties, and evidendy enhanced the tensile properties and modulus of it. Additionally, the best-reinforced effect could occur when the clay content was near 1 wt% .

  16. Study of Low Temperature Fuel Cells Thin Films Morphology by GISAXS

    Science.gov (United States)

    Irita, Tomomi; Russell, Thomas

    2007-03-01

    Grazing incidence small angle x-ray scattering experiments were performed on thin films of Nafion solutions as a function of time as the solvent, methanol/water, evaporated. The development and orientation of the structure and morphology in the thin films, at the free surface and in the bulk of the film, was characterized by the scattering below and above the critical angle. The scattering profiles indicated that Nafion thin morphology was strongly influenced by the conformations of Nafion molecules in the solutions. In addition, the morphology in thin films of sulfonated block copolymers of polystyrene-b-poly(ethylene-o-butylene)-b-polystyrene, an alternative material for fuel cell applications, was characterized by GISAXS and scanning force microscopy using different solvents and under an applied electric field. Both the solvents used and the applied field was found to markedly influence the orientation of the ion conducting domains in the films.

  17. Luminescence-Based Spectroelectrochemical Sensor for [Tc(dmpe)3]2+/+ (dmpe = 1,2-bis(dimethylphosphino)ethane) within a Charge-Selective Polymer Film

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Sayandev; Del Negro, Andrew S.; Edwards, Matthew K.; Bryan, Samuel A.; Kaval, Necati; Pantelic, Nebojsa; Morris, Laura K.; Heineman, W. R.; Seliskar, Carl J.

    2011-03-01

    A spectroelectrochemical sensor consisting of an indium tin oxide (ITO) optically transparent electrode (OTE) coated with a thin film of sulfonated polystyrene-blockpoly(ethylene-ran-butylene)-block-polystyrene (SSEBS) was developed for [Tc(dmpe)3]+.. [Tc(dmpe)3]+ preconcentrated by ion-exchange into the SSEBS film after 20 min exposure to aqueous [Tc(dmpe)3]+ solution, resulting in a 14-fold increase in cathodic peak current compared to a bare OTE. Colorless [Tc(dmpe)3]+ was reversibly oxidized to colored [Tc(dmpe)3]2+ by cyclic voltammetry. Detection of [Tc(dmpe)3]2+ was accomplished by electrochemically cycling the complex between non-emissive [Tc(dmpe)3]+ and emissive [Tc(dmpe)3]2+ and monitoring the modulated emission (λexc = 532 nm; λem = 660 nm). The sensor gave a linear response over the range of 0.16 to 340.0 µM.

  18. A comparative study of effect of compatibilization agent on untreated and ultrasonically treated waste ground rubber tire and polyolefin blends

    Directory of Open Access Journals (Sweden)

    Jin Kuk Kim

    2006-12-01

    Full Text Available The development of thermoplastic elastomer blends from waste tire powder and two polyolefins, Viz. maleic anhydride grafted polypropylene and LDPE, was studied. The polymer blends were processed using a twin-screw extruder equipped with a well-designed screw configuration. The blends studied contained a dispersed phase of waste rubber powder obtained from waste tire in a thermoplastic matrix. The effect of ultrasonic treatment on the rubber powder was compared. Contrary to our expectation, ultrasonically treated samples gave poor mechanical properties compared to untreated samples. Significant improvement in the mechanical properties was obtained with the addition of maleic anhydride-grafted styrene-ethylene-butylene-styrene (SEBS-g-MA as a compatibilizer in treated and untreated waste tire powder / polyolefin blends.

  19. Effects of SEBS-g-MAH on the properties of injection moulded poly(lactic acid/nano-calcium carbonate composites

    Directory of Open Access Journals (Sweden)

    W. S. Chow

    2012-06-01

    Full Text Available Poly(lactic acid/nano-precipitated calcium carbonate (PLA/NPCC composites toughened with maleated styrene-ethylene/butylene-styrene (SEBS-g-MAH were prepared by melt-compounding on a co-rotating twin-screw extruder followed by injection moulding. The mechanical properties of the PLA nanocomposites were characterized by tensile, flexural and impact tests, while their morphology were investigated using transmission electron microscopy (TEM. The thermal properties of the composites were examined with differential scanning calorimeter (DSC and thermogravimetric analyzer (TGA. The elongation at break and impact strength of the PLA/NPCC nanocomposites increased significantly after addition of SEBS-g-MAH. Both nano-dispersed NPCC and small NPCC clusters were found in PLA matrix. Also, some SEBS-g-MAH encapsulated NPCC can be observed. Thermal stability of PLA/NPCC was enhanced prominently by the addition of SEBS-g-MAH.

  20. Biodegradable polyester-based eco-composites containing hemp fibers modified with macrocyclic oligomers

    Science.gov (United States)

    Conzatti, Lucia; Utzeri, Roberto; Hodge, Philip; Stagnaro, Paola

    2016-05-01

    An original compatibilizing pathway for hemp fibers/poly(1,4-butylene adipate-co-terephtalate) (PBAT) eco-composites was explored exploiting the capability of macrocyclic oligomers (MCOs), obtained by cyclodepolymerization (CDP) of PBAT at high dilution, of being re-converted into linear chains by entropically-driven ring-opening polymerization (ED-ROP) that occurs simply heating the MCOS in the bulk. CDP reaction of PBAT was carried out varying solvent, catalyst and reaction time. Selected MCOs were used to adjust the conditions of the ED-ROP reaction. The best experimental conditions were then adopted to modify hemp fibers. Eco-composites based on PBAT and hemp fibers as obtained or modified with PBAT macrocyclics or oligomers were prepared by different process strategies. The best fiber-PBAT compatibility was observed when the fibers were modified with PBAT oligomers before incorporation in the polyester matrix.

  1. Evaluation of biodegradable plastics for rubber seedling applications

    Science.gov (United States)

    Mansor, Mohd Khairulniza; Dayang Habibah A. I., H.; Kamal, Mazlina Mustafa

    2015-08-01

    The main negative consequence of conventional plastics in agriculture is related to handling the wastes plasticand the associated environmental impact. Hence, a study of different types of potentially biodegradable plastics used for nursery applications have been evaluated on its mechanical,water absorption propertiesand Fourier transform infra-red (FTIR) spectroscopy. Supplied samples from different companies were designated as SF, CF and CO. Most of the polybags exhibited mechanical properties quite similar to the conventional plastics (polybag LDPE). CO polybag which is based on PVA however had extensively higher tensile strength and water absorption properties. FTIR study revealed a characteristics absorbance of conventional plastic, SF, CF and CO biodegradable polybag are associated with polyethylene, poly(butylene adipate-co-terephthalate) (PBAT), polyethylene and polyvinyl alcohol (PVA) structures respectively.

  2. A new method for the evaluation of biodegradable plastic using coated cellulose paper.

    Science.gov (United States)

    Lim, Hyun-A; Raku, Takao; Tokiwa, Yutaka

    2004-09-16

    A highly sensitive analytical method for evaluation of poly(L-lactide) (PLA), poly(epsilon-caprolactone) (PCL), poly(beta-hydroxybutyrate) (PHB), and poly(butylene succinate) (PBS) degradability was developed using coated cellulose paper, prepared by penetration and adhesion of these plastics into/onto the cellulose paper. Enzymatic degradability of the obtained plastic coated papers was evaluated using various commercial proteases and lipases. PLA coated paper was highly susceptible to subtilisin and mammalian enzymes, alpha-chymotrypsin, elastase and trypsin. To our knowledge, this is the first report on the degradation of PLA coated paper using subtilisin and mammalian enzymes. Almost all lipase preparations degraded PCL and PHB coated papers but not PBS coated paper. The biodegradability of plastic coated paper was greater than that of plastic powder. The penetration of plastic into cellulose paper by coating improved the plastic degradability, and can be regulated easily.

  3. Synthesis of readily recyclable biobased plastics by Diels-Alder reaction.

    Science.gov (United States)

    Ishida, Kazuki; Yoshie, Naoko

    2008-10-08

    Readily recyclable biobased plastics were designed and synthesized utilizing the thermally reversible DA reaction. Furyl-telechelic poly(butylene succinate) prepolymers (PBSF(2)) were extended with bis- and tris-maleimide linkers (M(2) and M(3)) by the DA reaction in the bulk state to produce linear and network polymers, respectively. The DA reaction was able to proceed at 25-80 degrees C, at which crystalline domains of PBSF(2) were present. In the linear polymer system, the molecular weight in the reaction equilibrium was dependent on the chain length of the prepolymer, but almost independent of the reaction temperature. The cycle of DA and retro-DA reactions was repeatable with no prepolymer deterioration.

  4. Influence of carbonyl iron particle coating with silica on the properties of magnetorheological elastomers

    Science.gov (United States)

    Małecki, P.; Królewicz, M.; Hiptmair, F.; Krzak, J.; Kaleta, J.; Major, Z.; Pigłowski, J.

    2016-10-01

    In this paper, the influence of encapsulating carbonyl iron particles with various silica coatings on the properties of magnetorheological elastomers (MREs) was investigated. A soft styrene-ethylene-butylene-styrene thermoplastic elastomer was used as the composite’s polymer matrix. Spherical carbonyl iron powder (CIP) acted as the ferromagnetic filler. In order to improve the metal-polymer interaction, carbonyl iron particles were coated with two types of single and six types of double silica layers. The first layer was created through a TMOS or TEOS hydrolysis whereas the second one was composed of organosilanes. The mechanical properties of MREs containing 38.5 vol% of CIP were analysed under dynamic loading conditions. To investigate the magnetorheological effect in these composites, a 430 mT magnetic field, generated by an array of permanent magnets, was applied during testing. The results revealed that the magnetomechanical response of the MREs differs substantially, depending on the kind of particle coating.

  5. Significant Breakthrough in Industrial Test of the "Methanol to Olefins" Process Developed by Dalian Institute of Chemical Physics, Chinese Academy of Sciences

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ A process of "Methanol or Dimethylether to Olefins" developed by Dalian Institute of Chemical Physics (DICP), designated as the DMTO process, has attained great success in industrial scaling up testing. DICP, by collaborating with the Xinxing Coal Chemical Co., Ltd. of Shaanxi Province and the Luoyang Petrochemical Engineering Co. of the SINOPEC Group, operated successfully a 50t(methanol)/d unit for the conversion of methanol to lower olefins, with a methanol conversion of close to 100%, and a selectivity to lower olefins(ethylene, propylene and butylenes) of higher than 90%. On 23rd August, the industrial test project has passed a state appraisal. The experts of the Appraisal Group, headed by Prof.

  6. Biodegradable starch-based films containing saturated fatty acids: thermal, infrared and raman spectroscopic characterization

    Directory of Open Access Journals (Sweden)

    Marcelo M. Nobrega

    Full Text Available Biodegradable films of thermoplastic starch and poly (butylene adipate co-terephthalate (PBAT containing fatty acids were characterized thermally and with infrared and Raman spectroscopies. The symmetrical character of the benzene ring in PBAT provided a means to illustrate the difference between these spectroscopic techniques, because a band appeared in the Raman spectrum but not in the infrared. The thermal analysis showed three degradation stages related to fatty acids, starch and PBAT. The incorporation of saturated fatty acids with different molecular mass (caproic, lauric and stearic did not change the nature of the chemical bonds among the components in the blends of starch, PBAT and glycerol, according to the thermal analysis, infrared and Raman spectroscopies.

  7. Synthesis and Drug Release Properties of Thermosensitive Poly(N-vinylacetamide-co-vinylacctate) Hydrogels

    Institute of Scientific and Technical Information of China (English)

    YANG Li-he; CHU Hong; CHEN Ming-qing; HU Na; ZHAO Yi-fan

    2011-01-01

    Thermosensitive poly[N-vinylacetamide-co-vinylacetate][P(NVA-co-VAc)] hydrogels were prepared via free radical copolymerization from hydrophilic NVA and hydrophobic VAc in the presence of butylenes-bis (N-vinylacetamide)(Bis-NVA) as crosslinker. Scanning electron microscopy(SEM) images reveal that the as-prepared hydrogels were of three-dimensional network with irregular cave structure. The prepared hydrogels with more NVA in the feed swelled faster and the swelling ratio of the hydrogels gradually decreased with temperature increasing from 10 ℃ to 60 ℃. The dynamic swelling studies indicate that the swelling process of the hydrogels was controlled by diffusion of water molecules considered as Fickian-controlled case. The adsorption amount of model drug, sodium salicylate(SS) was higher in the hydrogels containing more NVA units, whose corresponding release could reach equilibrium in about 6 h.

  8. Bionanohybrid based on bioplastic and surface-functionalized carbon nanotubes.

    Science.gov (United States)

    Singh, Ravina; Ray, Suprakas Sinha

    2010-12-01

    A bionanohybrid consisting of biodegradable/biocompatible poly(butylene succinate) (PBS) and surface-oxidized carbon nanotubes (o-CNTs) was prepared via melt-mixing method. The inherent properties of PBS were concurrently improved by the incorporation of a small amount of o-CNTs. For example, at room temperature, elongation at break increased from approximately 21.2% for pure PBS to approximately 55.1% for the nanohybrid and an increase of about approximately 150% in the value of toughness with moderate improvement in tensile modulus and strength. The dynamic mechanical properties of PBS also increased significantly after nanocomposite formation with o-CNTs. Electron microscopy and Raman spectroscopy were used to investigate the mechanical properties and improvement mechanism of surface-functionalized o-CNTs containing PBS nanohybrid.

  9. Complementary study of molecular dynamics and domain sizes in heterogenous nanocomposites PBT/DA-C{sub 60} and PBT/TCNEO-C{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Woźniak-Braszak, A., E-mail: abraszak@amu.edu.pl; Baranowski, M.; Jurga, K.; Hołderna-Natkaniec, K. [High Pressure Physics Division, Department of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland); Jurga, J. [Polymer Processing Division, Institute of Materials Technology, Poznań University of Technology, Piotrowo 3, 61-138 Poznan (Poland); Brycki, B. [Laboratory of Microbiocides Chemistry, Department of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznan (Poland); Mikuli, E. [Department of Chemistry, Jagiellonian University, Ingardena Street 9, Krakow (Poland)

    2014-05-28

    A comprehensive study of molecular dynamics and structure in new heterogenous nanocomposites based on poly(butylene terephthalate) and nanoparticles C{sub 60} modified by n-decylamine or tetracyanoethylene oxide has been performed. The domain structure of new nanocomposites has been investigated by Fourier transform infrared spectroscopy, wide-angle X-ray scattering, and differential scanning calorimetry techniques. Solid-state {sup 1}H NMR techniques were used to study molecular dynamics and domain sizes in new nanocomposites. Information about the electronic properties of these nanocomposites was obtained by means of electron paramagnetic resonance method. It was shown that the structure and molecular dynamics of new nanocomposites were strongly dependent on the properties and concentration of fullerene derivates.

  10. Ammonium Y zeolite applied as a thermochemolysis reagent for identification of polyethers and polyesters.

    Science.gov (United States)

    Blazsó, Marianne; Bozi, János

    2013-01-04

    A potential thermochemolysis reagent has been tested for the pyrolysis gas chromatographic identification of polyether, polyester and polyether- or polyester-based thermoplastic polyurethane. The main advantage of ammonium Y zeolite over liquid reagents is that it does not react prior to pyrolysis, and its reactions have no incomplete products. The procedure of the thermochemolysis is as simple as running a pyrolysis-GC/MS analysis sampling a powder mixture of roughly equal mass of polymer and ammonium Y zeolite. The GC/MS chromatograms obtained show that the products of thermochemolysis are specific to the diol and dicarboxylic units of the polymer. It was observed that ethanal or 1,4-dioxane forms from ethylene oxide components of polyethers and polyesters, tetrahydrofuran from butylene oxide units, hexanedinitrile from adipate groups, and benzodinitrile from terephthalate groups.

  11. Lignin-based cement fluid loss control additive

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, P.

    1990-05-22

    This patent describes a hydraulic cement slurry composition. It comprises: a hydraulic cement, and the following expressed as parts by weight per 100 parts of the hydraulic cement, water from about 25 to 105 parts, and from abut 0.5 to 2.5 parts of a compound selected from the group consisting of a sulfonated lignin and a sulfomethylated lignin, wherein the lignin has been sequentially crosslinked by reacting the lignin with a member of the group consisting of formaldehyde and epichlorohydrin and alkoxylated with between about 2 to about 6 moles of a compound selected from the group consisting of ethylene oxide, propylene oxide, butylene oxide and a combination thereof per 1000 g of the lignin.

  12. One-pot synthesis of linear- and three-arm star-tetrablock quarterpolymers via sequential metal-free ring-opening polymerization using a "catalyst switch" strategy

    KAUST Repository

    Zhao, Junpeng

    2014-08-06

    A "catalyst switch" strategy has been used to sequentially polymerize four different heterocyclic monomers. In the first step, epoxides (1,2-butylene oxide and ethylene oxide) were successively polymerized from a monohydroxy or trihydroxy initiator in the presence of a strong phosphazene base promoter (t-BuP4). Then, an excess of diphenyl phosphate (DPP) was introduced, followed by addition and polymerization of a cyclic carbonate (trimethylene carbonate) and a cyclic ester (δ-valerolactone or ε-caprolactone). DPP acted as both neutralizer of the phosphazenium alkoxide (polyether chain end) and activator of the cyclic carbonate/ester. Using this method, linear- and star-tetrablock quarterpolymers were prepared in one pot. This work is emphasizing the strength of the previously developed catalyst switch strategy for the facile metal-free synthesis of complex macromolecular architectures. © 2014 Wiley Periodicals, Inc.

  13. A "catalyst switch" Strategy for the sequential metal-free polymerization of epoxides and cyclic Esters/Carbonate

    KAUST Repository

    Zhao, Junpeng

    2014-06-24

    A "catalyst switch" strategy was used to synthesize well-defined polyether-polyester/polycarbonate block copolymers. Epoxides (ethylene oxide and/or 1,2-butylene oxide) were first polymerized from a monoalcohol in the presence of a strong phosphazene base promoter (t-BuP4). Then an excess of diphenyl phosphate (DPP) was introduced, followed by the addition and polymerization of a cyclic ester (ε-caprolactone or δ-valerolactone) or a cyclic carbonate (trimethylene carbonate), where DPP acted as both the neutralizer of phosphazenium alkoxide (polyether chain end) and the activator of cyclic ester/carbonate. This work has provided a one-pot sequential polymerization method for the metal-free synthesis of block copolymers from monomers which are suited for different types of organic catalysts. © 2014 American Chemical Society.

  14. Effects of P content in a P/HZSM-5 catalyst on the conversion of ethanol to hydrocarbons

    Institute of Scientific and Technical Information of China (English)

    Jiangyin Lu; Yancong Liu

    2011-01-01

    A series of P/HZSM-5 catalysts prepared by impregnation method were used for ethanol conversion to lower olefins.The catalysts were characterized by X-ray diffraction(XRD),NH3-temperature-programmed desorption(NH3-TPD)and N2 adsorption-desorption measurements.It was found that the P/HZSM-5 catalysts showed high activity and selectivity toward light olefins.The selectivities of propylene and butylene can be improved with the introduction of phosphorus(P).When the content of P reached 3.0 wt%,more than 18.9% propylene in the gaseous products was obtained over the P/HZSM-5 catalyst at 450 ℃.The introduction of P modified the strong Br()nsted acid sites of the original HZSM-5 catalysts and P/HZSM-5 catalysts could resist coke formation and showed good stability.

  15. Nanofiber Anisotropic Conductive Films (ACF) for Ultra-Fine-Pitch Chip-on-Glass (COG) Interconnections

    Science.gov (United States)

    Lee, Sang-Hoon; Kim, Tae-Wan; Suk, Kyung-Lim; Paik, Kyung-Wook

    2015-11-01

    Nanofiber anisotropic conductive films (ACF) were invented, by adapting nanofiber technology to ACF materials, to overcome the limitations of ultra-fine-pitch interconnection packaging, i.e. shorts and open circuits as a result of the narrow space between bumps and electrodes. For nanofiber ACF, poly(vinylidene fluoride) (PVDF) and poly(butylene succinate) (PBS) polymers were used as nanofiber polymer materials. For PVDF and PBS nanofiber ACF, conductive particles of diameter 3.5 μm were incorporated into nanofibers by electrospinning. In ultra-fine-pitch chip-on-glass assembly, insulation was significantly improved by using nanofiber ACF, because nanofibers inside the ACF suppressed the mobility of conductive particles, preventing them from flowing out during the bonding process. Capture of conductive particles was increased from 31% (conventional ACF) to 65%, and stable electrical properties and reliability were achieved by use of nanofiber ACF.

  16. Absorbance-based spectroelectrochemical sensor for [Re(dmpe)3]+ (dmpe = dimethylphosphinoethane)

    Energy Technology Data Exchange (ETDEWEB)

    Morris, Laura K; Seliskar, Carl J; Heineman, William R; Del Negro, Andrew S; Bryan, Samuel A

    2009-10-01

    A spectroelectrochemical sensor was developed for [Re(dmpe)3]+ as a non radioactive analog for [Tc(dmpe)3]+. The sensor consists of an optically transparent electrode (OTE) coated with a thin film of sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SSEBS). Colorless [Re(dmpe)3]+ was reversibly oxidized to [Re(dmpe)3]2+ (λmax = 530 nm). [Re(dmpe)3]+ preconcentrated by ion-exchange into the SSEBS film, resulting in a 20-fold increase in peak current compared to a bare OTE after 1 h of exposure to aqueous [Re(dmpe)3]+ solution. Detection of [Re(dmpe)3]+ at concentrations down to 2 x 10 6 M was accomplished by electrochemical modulation of the complex and monitoring absorbance by attenuated total reflectance (ATR).

  17. Thermoplastic starch/polyester films: effects of extrusion process and poly (lactic acid) addition.

    Science.gov (United States)

    Shirai, Marianne Ayumi; Olivato, Juliana Bonametti; Garcia, Patrícia Salomão; Müller, Carmen Maria Olivera; Grossmann, Maria Victória Eiras; Yamashita, Fabio

    2013-10-01

    Biodegradable films were produced using the blown extrusion method from blends that contained cassava thermoplastic starch (TPS), poly(butylene adipate-co-terephthalate) (PBAT) and poly(lactic acid) (PLA) with two different extrusion processes. The choice of extrusion process did not have a significant effect on the mechanical properties, water vapor permeability (WVP) or viscoelasticity of the films, but the addition of PLA decreased the elongation, blow-up ratio (BUR) and opacity and increased the elastic modulus, tensile strength and viscoelastic parameters of the films. The films with 20% PLA exhibited a lower WVP due to the hydrophobic nature of this polymer. Morphological analyses revealed the incompatibility between the polymers used.

  18. Application of radiation technology to develop green tea leaf as a natural resource for the cosmetic industry

    Science.gov (United States)

    Byun, Myung Woo; Jo, Cheorun; Lee, Ju Woon; Jo, Sung Kee; Kim, Kwan Soo

    2004-09-01

    The irradiation of natural resources such as green tea leaf, persimmon leaf, licorice root and stolon or Lonicera japonica improved the color of the extract, resulting in a higher applicability without any adverse change to the beneficial functions such as the inhibitory effects of oxidation, melanin hyperpigmentation on the skin, and others. To investigate the application of irradiated natural resources for a real cosmetic composition, the physiological activities of irradiated green tea leaf extract powder dissolved in butylene glycol and ethanol were compared to a commercial green tea extract product. Furthermore, a cream lotion was manufactured using the powder and the physiological activities were compared. Results showed that the irradiation of the green tea leaf extract and the freeze-dried powder from the extract had the same physiological activities as the commercial product in a cosmetic composition.

  19. From waste molecules to consumer products : upgrader and refinery off-gases processing on the rise in Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Bentein, J.

    2010-10-15

    Only two companies process off-gases from bitumen upgraders in Alberta: Williams Energy Canada and Aux Sable Canada LP. Their projects, one at the Suncor plant north of Fort McMurray and the other at the Scotford complex near Edmonton, are designed to convert the streams into value-added petrochemical and fuel feedstock. In 2002, Williams built a cryogenic liquids extraction unit at the Suncor plant and a fractioning and distribution facility near Redwater, Alberta, which processes off-gases into liquid propane, propylene, condensates, butane, and butylenes. An expansion to the Redwater processing plant will allow for the upgrading of butane and butylene components as well as octane. Williams wants to build extraction units at two upgraders near Fort McMurray and is working with the Alberta Government to attract a petrochemical plant to Alberta that can process propylene, which must be exported at present. Aux Sable will process off-gases to produce hydrogen, ethane, and a propane-plus mix. Processing off-gases substantially reduces carbon dioxide and sulfur dioxide emissions from upgraders. Off-gas has the potential to be a new feedstock supply for the petrochemical industry in Alberta. The volumes processed by Williams are olephenic, whereas the volumes processed by Aux Sable are paraffinic, but both companies take molecules that would otherwise become atmospheric carbon dioxide and turn them into plastic for consumer goods. The off-gas projects are being driven by market forces without government incentives. Low natural gas prices have made it economical for upgraders to use more gas and sell off-gases for value-added use. 1 fig.

  20. Hybrid ion-exchange membranes for fuel cells and separation processes

    Science.gov (United States)

    Fernández-Carretero, F. J.; Compañ, V.; Riande, E.

    This work reports the preparation and characterization of hybrid membranes cast from dispersions of inorganic fillers in sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene solutions. Silica gel, SBA-15 and sepiolite, all of them functionalized with phenylsulfonic acid groups, were used as fillers. For comparative purposes, the performance of composite membranes cast from dispersions of functionalized inorganic fillers in Nafion ® solutions was investigated. Inspection of the texture of the membranes by using SEM techniques shows that the fillers are better dispersed in sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene than in Nafion ®. The value of the water uptake for the membranes prepared from the former polyelectrolyte is in most cases at least three times that measured for hybrid Nafion ® membranes. The conductivity of the membranes was measured at 80 °C by impedance spectroscopy obtaining values of 3.44, 6.90 and 3.54 S m -1 for the hybrid membranes based on the triblock copolymer containing functionalized silica gel, SBA-15 and sepiolite fillers, respectively. These results compare very favourably with those obtained at 80 °C for Nafion ® hybrid membranes containing silica gel, SBA-15 and sepiolite, all of them fuctionalized with phenylsulfonic acid groups, whose conductivities are, 2.84, 6.75 and 3.31 S m -1, respectively. Resistance measurements carried out under controlled humidity conditions show that the conductivity of sulfonated triblock copolymer membranes containing functionalized SBA-15 filler undergoes a rather sharp increase when they are conditioned under an atmosphere of 75%, or larger, relative humidity.

  1. Amphiphilic surface active triblock copolymers with mixed hydrophobic and hydrophilic side chains for tuned marine fouling-release properties.

    Science.gov (United States)

    Park, Daewon; Weinman, Craig J; Finlay, John A; Fletcher, Benjamin R; Paik, Marvin Y; Sundaram, Harihara S; Dimitriou, Michael D; Sohn, Karen E; Callow, Maureen E; Callow, James A; Handlin, Dale L; Willis, Carl L; Fischer, Daniel A; Kramer, Edward J; Ober, Christopher K

    2010-06-15

    Two series of amphiphilic triblock surface active block copolymers (SABCs) were prepared through chemical modification of two polystyrene-block-poly(ethylene-ran-butylene)-block-polyisoprene ABC triblock copolymer precursors. The methyl ether of poly(ethylene glycol) [M(n) approximately 550 g/mol (PEG550)] and a semifluorinated alcohol (CF(3)(CF(2))(9)(CH(2))(10)OH) [F10H10] were attached at different molar ratios to impart both hydrophobic and hydrophilic groups to the isoprene segment. Coatings on glass slides consisting of a thin layer of the amphiphilic SABC deposited on a thicker layer of an ABA polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene thermoplastic elastomer were prepared for biofouling assays with algae. Dynamic water contact angle analysis, X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) measurements were utilized to characterize the surfaces. Clear differences in surface structure were realized as the composition of attached side chains was varied. In biofouling assays, the settlement (attachment) of zoospores of the green alga Ulva was higher for surfaces incorporating a large proportion of the hydrophobic F10H10 side chains, while surfaces with a large proportion of the PEG550 side chains inhibited settlement. The trend in attachment strength of sporelings (young plants) of Ulva did not show such an obvious pattern. However, amphiphilic SABCs incorporating a mixture of PEG550 and F10H10 side chains performed the best. The number of cells of the diatom Navicula attached after exposure to flow decreased as the content of PEG550 to F10H10 side chains increased.

  2. Hybrid ion-exchange membranes for fuel cells and separation processes

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Carretero, F.J.; Compan, V. [Departamento de Termodinamica Aplicada, ETSII, Universidad Politecnica de Valencia, 46020 Valencia (Spain); Riande, E. [Instituto de Ciencia y Tecnologia de Polimeros (CSIC), 28006 Madrid (Spain)

    2007-11-08

    This work reports the preparation and characterization of hybrid membranes cast from dispersions of inorganic fillers in sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene solutions. Silica gel, SBA-15 and sepiolite, all of them functionalized with phenylsulfonic acid groups, were used as fillers. For comparative purposes, the performance of composite membranes cast from dispersions of functionalized inorganic fillers in Nafion {sup registered} solutions was investigated. Inspection of the texture of the membranes by using SEM techniques shows that the fillers are better dispersed in sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene than in Nafion {sup registered}. The value of the water uptake for the membranes prepared from the former polyelectrolyte is in most cases at least three times that measured for hybrid Nafion {sup registered} membranes. The conductivity of the membranes was measured at 80 C by impedance spectroscopy obtaining values of 3.44, 6.90 and 3.54 S m{sup -1} for the hybrid membranes based on the triblock copolymer containing functionalized silica gel, SBA-15 and sepiolite fillers, respectively. These results compare very favourably with those obtained at 80 C for Nafion {sup registered} hybrid membranes containing silica gel, SBA-15 and sepiolite, all of them fuctionalized with phenylsulfonic acid groups, whose conductivities are, 2.84, 6.75 and 3.31 S m{sup -1}, respectively. Resistance measurements carried out under controlled humidity conditions show that the conductivity of sulfonated triblock copolymer membranes containing functionalized SBA-15 filler undergoes a rather sharp increase when they are conditioned under an atmosphere of 75%, or larger, relative humidity. (author)

  3. C4烃在FAU、BEA、LTL型分子筛中吸附的蒙特卡罗研究%Monte Carlo Investigation into C4 Hydrocarbon Adsorption in FAU,BEA and LTL Zeolites

    Institute of Scientific and Technical Information of China (English)

    翟冬; 赵亮; 潘惠芳; 赵震; 段爱军; 高金森; 陈玉

    2011-01-01

    应用蒙特卡罗(MC)模拟方法研究了1,3-丁二烯、1-丁烯、正丁烷三种C4烃在FAU、BEA、LTL三种分子筛中的吸附行为.模拟分别得到了298 K时这些C4烃的纯组分在分子筛中的吸附等温线、吸附质分布和吸附热-结果表明,在饱和吸附状态下这些C4烃在FAU分子筛中的吸附量最大,在BEA分子筛中的吸附量居中,在LTL分子筛中的吸附量最少.对于同一种分子筛来说,正丁烷在其中的等量吸附热最大,1-丁烯居中,1,3-丁二烯最小.对于同一种C4烃来说,它在LTL分子筛中的吸附热与在BEA分子筛中的吸附热相近,并且高于在FAU分子筛中的吸附热.还模拟了543 K、2.0 MPa时这些C4烃的三元混合组分在分子筛中的吸附,发现正丁烷的吸附量占的比例最大,1-丁烯居中,1,3-丁二烯最少.%The adsorption of 1,3-butadiene, 1-butylene, and n-butane in FAU, BEA, and LTL zeolites was investigated by Monte Carlo (MC) simulations. The adsorption isotherms, distribution of adsorbates, and isosteric heat of the C4 hydrocarbons in the zeolites at 298 K were obtained by simulation. The results show that the amount of C4 hydrocarbon saturated adsorption in FAU was the highest, in BEA it was the second highest, and in LTL it was the lowest. For the same zeolite, the isosteric heat of n-butane was the largest, 1-butylene the second largest, and 1,3-butadiene was the lowest. For the same C4 hydrocarbon,the isosteric heat in LTL was almost the same as that in BEA. The isosteric heat in FAU was the lowest.The adsorption of C4 hydrocarbon mixtures onto the zeolites at 543 K, 2.0 MPa was also simulated. In these mixtures the amount of n-butane adsorption was the highest, 1-butylene the second highest, and 1,3-butadiene the lowest.

  4. Morphological Structure and Properties of PLA/PBAT/PLA-g-MAH Biodegradable Composites%PLA/PBAT/PLA-g-MAH可生物降解复合材料的形态结构与性能分析

    Institute of Scientific and Technical Information of China (English)

    周志斌; 刘跃军; 谭海英

    2016-01-01

    Poly(lactic acid)-graft-maleic anhydride (PLA-g-MAH) prepared by melt blending was used to compatiblize poly(lactic acid)/poly(butylene adipate-co-butylene terephthalate) (PLA/PBAT) blends. The structure and properties of PLA/PBAT/PLA-g-MAH composites were investigated by fourier transform infrared spectroscopy (FTIR), scanning elec-tron microscope (SEM), universal testing machine, pendulum impact tester, differential scanning calorimeter (DSC) and the hydrolysis of alkaline solution. SEM results showed that the phase interface became blurry between PLA and PBAT in PLA/PBAT blends with compatibilizer PLA-g-MAH, indicated that the PLA-g-MAH had certain compatibilized effect on PLA/PBAT blends. The incorporation of PLA-g-MAH resulted in a slight decrease of tensile strength and flexural strength compared with pure PLA, but improved impact strength and elongation at break about 17 times compared with pure PLA with added PLA-g-MAH. Moreover, the adding of PLA-g-MAH improved the biodegradability of PLA/PBAT blend.%通过熔融共混法制备马来酸酐接枝聚乳酸(PLA-g-MAH)用于改善聚乳酸/聚己二酸-对苯二甲酸丁二酯共混物(PLA/PBAT)的相容性,并对复合材料的形态结构、力学性能和生物降解性能进行研究。SEM结果显示,添加增容剂PLA-g-MAH后,PLA/PBAT共混物两相间的界面明显变得模糊,说明PLA-g-MAH对共混物有一定的增容作用;增容剂PLA-g-MAH的加入,使复合材料的拉伸强度和弯曲强度相比于纯PLA略有下降,但其冲击强度有一定程度的提高,断裂伸长率有显著提高,比纯PLA 的断裂伸长率提高了约17倍,表现出良好的力学性能;另外,PLA-g-MAH的加入提高了共混物的生物降解性能。

  5. Estudio del comportamiento mecánico de gelés físicos termorreversibles obtenidos a partir de copolímeros tribloques de PS-b-poli(etileno/butileno-PS en un disolvente selectivo del bloque central

    Directory of Open Access Journals (Sweden)

    Hernáez, E.

    2001-04-01

    Full Text Available The thermoreversible gelation of three triblock copolymers polystyrene-bpoly( ethylene/butylene-b-polystyrene, with different molar mass and a similar chemical composition, in n-octane was studied. The solvent is selective for the middle poly(ethylene/butylene block of the copolymers. The influence of the molar mass of the three copolymers on the gelation and on the mechanical properties of the gels was analysed. The sol-gel transition temperatures, Tgel, have been determined and they increase with the copolymer concentration and the copolymer molar mass. On the other hand, the mechanical properties of the different gels were examined through oscillatory shear and compressive stress relaxation measurements. The concentration dependence of the elastic storage modulus, G’, for the three copolymer studied fit a sole straight line in a doublelogarithmic scale and its slope (2.22 is close to that expected for systems in good solvents (2.25. As the temperature is near to the sol-gel transition temperature, the elastic modulus are smaller and the relaxation rates are higher.

    Se ha estudiado la influencia del peso molecular del copolímero en la formación de geles físicos termoreversibles de copolímeros tribloque de la forma poliestireno-b-poli(etileno/butileno-b-poliestireno (SEBS en n-octano y en sus propiedades mecánicas. Se ha determinado la temperatura de formación de los geles, Tgel, concluyendo que éstas aumentan con la concentración y el peso molecular del copolímero. Por otra parte, se han medido las propiedades mecánicas de los geles empleando ensayos de torsión y relajación de tensión, en función de la concentración de copolímero. La dependencia doble logarítmica del módulo G' con la concentración de copolímero para los tres SEBS se ajusta a una línea recta de pendiente 2,22, próxima a la predicha para geles preparados químicamente (2,25. Cuanto más próxima está la temperatura de medida

  6. CO2-Philic polymer membrane with extremely high separation performance

    KAUST Repository

    Yave, Wilfredo

    2010-01-12

    Polymeric membranes are attractive for CO2 separation and concentration from different gas streams because of their versatility and energy efficiency; they can compete with, and they may even replace, traditional absorption processes. Here we describe a simple and powerful method for developing nanostructured and CO2-philic polymer membranes for CO2 separation. A poly(ethylene oxide)-poly(butylene terephthalate) multiblock copolymer is used as membrane material. Smart additives such as polyethylene glycol dibutyl ether are incorporated as spacers or fillers for producing nanostructured materials. The addition of these specific additives produces CO2-philic membranes and increases the CO2 permeability (750 barrer) up to five-fold without the loss of selectivity. The membranes present outstanding performance for CO2 separation, and the measured CO2 flux is extremely high ( > 2 m3 m -2 h-1 bar-1) with selectivity over H2 and N2 of 10 and 40, respectively, making them attractive for CO 2 capture. © 2009 American Chemical Society.

  7. Colloidal Gold Nanoclusters Spiked Silica Fillers in Mixed Matrix Coatings: Simultaneous Detection and Inhibition of Healthcare-Associated Infections

    KAUST Repository

    Alsaiari, Shahad K.

    2017-01-25

    Healthcare-associated infections (HAIs) are the infections that patients get while receiving medical treatment in a medical facility with bacterial HAIs being the most common. Silver and gold nanoparticles (NPs) have been successfully employed as antibacterial motifs; however, NPs leaching in addition to poor dispersion and overall reproducibility are major hurdles to further product development. In this study, the authors design and fabricate a smart antibacterial mixed-matrix membrane coating comprising colloidal lysozyme-templated gold nanoclusters as nanofillers in poly(ethylene oxide)/poly(butylene terephthalate) amphiphilic polymer matrix. Mesoporous silica nanoparticles-lysozyme functionalized gold nanoclusters disperse homogenously within the polymer matrix with no phase separation and zero NPs leaching. This mixed-matrix coating can successfully sense and inhibit bacterial contamination via a controlled release mechanism that is only triggered by bacteria. The system is coated on a common radiographic dental imaging device (photostimulable phosphor plate) that is prone to oral bacteria contamination. Variation and eventually disappearance of the red fluorescence surface under UV light signals bacterial infection. Kanamycin, an antimicrobial agent, is controllably released to instantly inhibit bacterial growth. Interestingly, the quality of the images obtained with these coated surfaces is the same as uncoated surfaces and thus the safe application of such smart coatings can be expanded to include other medical devices without compromising their utility.

  8. Hybrid organotin and tin oxide-based thin films processed from alkynylorganotins: synthesis, characterization, and gas sensing properties.

    Science.gov (United States)

    Renard, Laetitia; Brötz, Joachim; Fuess, Hartmut; Gurlo, Aleksander; Riedel, Ralf; Toupance, Thierry

    2014-10-08

    Hydrolysis-condensation of bis(triprop-1-ynylstannyl)butylene led to nanostructured bridged polystannoxane films yielding tin dioxide thin layers upon UV-treatment or annealing in air. According to Fourier transform infrared (FTIR) spectroscopy, contact angle measurements, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and scanning electron microscopy (SEM) data, the films were composed of a network of aggregated "pseudo-particles", as calcination at 600 °C is required to form cassiterite nanocrystalline SnO2 particles. In the presence of reductive gases such as H2 and CO, these films gave rise to highly sensitive, reversible, and reproducible responses. The best selectivity toward H2 was reached at 150 °C with the hybrid thin films that do not show any response to CO at 20-200 °C. On the other hand, the SnO2 films prepared at 600 °C are more sensitive to H2 than to CO with best operating temperature in the 300-350 °C range. This organometallic approach provides an entirely new class of gas-sensing materials based on a class II organic-inorganic hybrid layer, along with a new way to include organic functionality in gas sensing metal oxides.

  9. BLEND MEMBRANES FOR DIRECT METHANOL AND PROTON EXCHANGE MEMBRANE FUEL CELLS

    Institute of Scientific and Technical Information of China (English)

    Perurnal Bhavani; Dharmalingam Sangeetha

    2012-01-01

    Sulphonated polystyrene ethylene butylene polystyrene (SPSEBS) prepared with 35% sulphonation was found to be highly elastic and enlarged up to 300%-400% of its initial length.It absorbed over 110% of water by weight.A major drawback of this membrane is its poor mechanical properties which are not adequate for use as polymer electrolytes in fuel cells.To overcome this,SPSEBS was blended with poly(vinylidene fluoride) (PVDF),a hydrophobic polymer.The blend membranes showed better mechanical properties than the base polymer.The effect of PVDF content on water uptake,ion exchange capacity and proton conductivity of the blend membranes was investigated.This paper presents the results of recent studies applied to develop an optimized in-house membrane electrode assembly (MEA) preparation technique combining catalyst ink spraying and assembly hot pressing.Easy steps were chosen in this preparation technique in order to simplify the method,aiming at cost reduction.The open circuit voltage for the cell with SPSEBS is 0.980 V which is higher compared to that of the cell with Nafion 117 (0.790 V).From this study,it is concluded that a polymer electrolyte membrane suitable for proton exchange membrane fuel cell (PEMFC) and direct methanol fuel cell (DMFC) application can be obtained by blending SPSEBS and PVDF in appropriate proportions.The methanol permeability and selectivity showed a strong influence on DMFC performance.

  10. Starch/polyester films: simultaneous optimisation of the properties for the production of biodegradable plastic bags

    Directory of Open Access Journals (Sweden)

    J. B. Olivato

    2013-01-01

    Full Text Available Blends of starch/polyester have been of great interest in the development of biodegradable packaging. A method based on multiple responses optimisation (Desirability was used to evaluate the properties of tensile strength, perforation force, elongation and seal strength of cassava starch/poly(butylene adipate-co-terephthalate (PBAT blown films produced via a one-step reactive extrusion using tartaric acid (TA as a compatibiliser. Maximum results for all the properties were set as more desirable, with an optimal formulation being obtained which contained (55:45 starch/PBAT (88.2 wt. (%, glycerol (11.0 wt. (% and TA (0.8 wt. (%. Biodegradable plastic bags were produced using the film with this formulation, and analysed according to the standard method of the Associação Brasileira de Normas Técnicas (ABNT. The bags exhibited a 45% failure rate in free-falling dart impact tests, a 10% of failure rate in dynamic load tests and no failure in static load tests. These results meet the specifications set by the standard. Thus, the biodegradable plastic bags fabricated with an optimised formulation could be useful as an alternative to those made from non-biodegradable materials if the nominal capacity declared for this material is considered.

  11. Development of an active biodegradable film containing tocopherol and avocado peel extract

    Directory of Open Access Journals (Sweden)

    J.C.F. Fidelis

    2015-12-01

    Full Text Available Thermoplastic starch (TPS films and poly(butylene adipate co-terephthalate (PBAT (60/40 m/m containing TOCO-70 (tocopherol/soybean oil 70/30 m/m and avocado peel extract (ExA were produced using blown film extrusion. The formulations of the 5 films (FC/F1/F2/F3 and F4 were established through mixture design with constraints maintaining constant PBAT and TPS proportion, and varying the antioxidant concentrations. Adding antioxidants reduced the water vapour permeability (Kw of the films, with formulation F2 presenting higher decrease in relationto FC, 77.8%. The presence of ExA improved the mechanical properties of the films. The production of the films was determined to be viable after they presented good processability in a pilotextruder, as well as mechanical properties appropriate to production and utilization in industry.The presence of ExA and TOCO 70 provided the films with antioxidant activity; their application as active packaging requires further studies.

  12. Fluorinated Amphiphilic Polymers and Their Blends for Fouling-Release Applications: The Benefits of a Triblock Copolymer Surface

    KAUST Repository

    Sundaram, Harihara S.

    2011-09-28

    Surface active triblock copolymers (SABC) with mixed polyethylene glycol (PEG) and two different semifluorinated alcohol side chains, one longer than the other, were blended with a soft thermoplastic elastomer (TPE), polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS). The surface composition of these blends was probed by X-ray photoelectron spectroscopy (XPS) and near edge X-ray absorption fine structure (NEXAFS) spectroscopy. The surface reconstruction of the coatings in water was monitored qualitatively by dynamic water contact angles in air as well as air bubble contact angle measurements in water. By blending the SABC with SEBS, we minimize the amount of the SABC used while achieving a surface that is not greatly different in composition from the pure SABC. The 15 wt % blends of the SABC with long fluoroalkyl side chains showed a composition close to that of the pure SABC while the SABC with shorter perfluoroakyl side chains did not. These differences in surface composition were reflected in the fouling-release performance of the blends for the algae, Ulva and Navicula. © 2011 American Chemical Society.

  13. Preparation and Characterization of Polycarbonate Modified Multiple-walled Carbon Nanotubes

    Institute of Scientific and Technical Information of China (English)

    YU Jin-Gang; HUANG Ke-Long; LIU Su-Qin; TANG Jin-Chun

    2008-01-01

    To prepare polymer/carbon nanotube composites, polycarbonate was chosen to modify multiple-walled carbon nanotubes. Poly[(propylene oxide)-(carbon dioxide)-(ε-caprolactone)], poly(butylene-co-ε-caprolactone carbonate),and poly[(propylene oxide)-co-(carbon dioxide)-co-(maleic anhydride)] were the polycarbonates which were used to modify multiple-walled carbon nanotubes, but only soluble poly[(propylene oxide)-(carbon dioxide)-(ε-caprolactone)] modified multiple-walled carbon nanotubes could be obtained. Thermogravimetric analysis clearly indicated that more polycarbonates were attached to soluble poly[(propylene oxide)-(carbon dioxide)-(ε-caprolactone)] modified multiple-walled carbon nanotubes. The formation of surface functional groups and changes of nanotube structures and morphology were monitored by infrared spectroscopy, scanning electron microscopy and transmission electron microscopy, respectively. Because of their solubility and bioactive moieties,poly[(propylene oxide)-(carbon dioxide)-(ε-caprolactone)] modified multiple-walled carbon nanotubes may find their potential use in drug delivery.

  14. Superiorly Plasticized PVC/PBSA Blends through Crotonic and Acrylic Acid Functionalization of PVC

    Directory of Open Access Journals (Sweden)

    Arturo Salazar Avalos

    2017-03-01

    Full Text Available Superior plasticization efficiency was achieved by a grafting from functionalization of the PVC backbone. This was deduced to a synergistic effect of internal plasticization and improved intermolecular interactions between PVC and an oligomeric poly(butylene succinate-co-adipate (PBSA plasticizer. A mild grafting process for functionalization of the PVC chain by crotonic acid (CA or acrylic acid (AA was used. The formation of PVC-g-CA and PVC-g-AA was confirmed by FTIR and 1H NMR. Grafting with the seemingly similar monomers, CA and AA, resulted in different macromolecular structures. AA is easily homopolymerized and long hydrophilic poly(acrylic acid grafts are formed resulting in branched materials. Crotonic acid does not easily homopolymerize; instead, single crotonic acid units are located along the PVC chain, leading to basically linear PVC chains with pendant crotonic acid groups. The elongation of PVC-g-CA and PVC-g-AA in comparison to pure PVC were greatly increased from 6% to 128% and 167%, respectively, by the grafting reactions. Blending 20% (w/w PBSA with PVC, PVC-AA or PVC-CA further increased the elongation at break to 150%, 240% and 320%, respectively, clearly showing a significant synergistic effect in the blends with functionalized PVC. This is a clearly promising milestone towards environmentally friendly flexible PVC materials.

  15. Hybrid carbon nanotube yarn artificial muscle inspired by spider dragline silk

    Science.gov (United States)

    Chun, Kyoung-Yong; Hyeong Kim, Shi; Kyoon Shin, Min; Hoon Kwon, Cheong; Park, Jihwang; Tae Kim, Youn; Spinks, Geoffrey M.; Lima, Márcio D.; Haines, Carter S.; Baughman, Ray H.; Jeong Kim, Seon

    2014-02-01

    Torsional artificial muscles generating fast, large-angle rotation have been recently demonstrated, which exploit the helical configuration of twist-spun carbon nanotube yarns. These wax-infiltrated, electrothermally powered artificial muscles are torsionally underdamped, thereby experiencing dynamic oscillations that complicate positional control. Here, using the strategy spiders deploy to eliminate uncontrolled spinning at the end of dragline silk, we have developed ultrafast hybrid carbon nanotube yarn muscles that generated a 9,800 r.p.m. rotation without noticeable oscillation. A high-loss viscoelastic material, comprising paraffin wax and polystyrene-poly(ethylene-butylene)-polystyrene copolymer, was used as yarn guest to give an overdamped dynamic response. Using more than 10-fold decrease in mechanical stabilization time, compared with previous nanotube yarn torsional muscles, dynamic mirror positioning that is both fast and accurate is demonstrated. Scalability to provide constant volumetric torsional work capacity is demonstrated over a 10-fold change in yarn cross-sectional area, which is important for upscaled applications.

  16. A Facile Strategy to Fabricate Multishape Memory Polymers with Controllable Mechanical Properties.

    Science.gov (United States)

    Zhang, Qinglong; Hua, Wenqiang; Feng, Jiachun

    2016-08-01

    A facile blending strategy to fabricate multishape memory polymers (SMPs) with only one sort of phase transition material has been reported. In this work, olefin block copolymer (OBC) and styrene-b-(ethylene-co-butylene)-b-styrene (SEBS), which are both physically crosslinked, are blended with crystalline paraffin together. Due to the different interactions between polymer matrices and paraffin, the paraffin penetrated in OBC and SEBS exhibit separated melting transitions. It is quite interesting that merely paraffin distributed in OBC also shows two distinct melting transitions with enough OBC content in composites. Therefore, excellent quadruple shape memory effect can be achieved with a maximum of three melting transitions. Furthermore, through adjusting the polymer species and content, the mechanical and rheological properties can be conveniently tuned to a great extent. Compared with the reported strategies, this simple and controllable method sheds light on rapid design of multi-SMPs using inexpensive raw materials, which greatly paves the way for multi-SMPs from laboratory to factory.

  17. Nucleation Mechanisms of Aromatic Polyesters, PET, PBT, and PEN, on Single-Wall Carbon Nanotubes: Early Nucleation Stages

    Directory of Open Access Journals (Sweden)

    Adriana Espinoza-Martínez

    2012-01-01

    Full Text Available Nucleation mechanisms of poly(ethylene terephthalate (PET, poly(butylene terephthalate (PBT, and poly(ethylene naphthalate (PEN on single-wall carbon nanotubes (SWNTs are proposed, based on experimental evidence, theoretical epitaxy analysis, and semiempirical quantum chemical calculations. In order to elucidate early nucleation stages polyester-coated nanotubes were obtained from highly diluted solutions. High-resolution transmission electron microscopy (HRTEM revealed helical morphologies for PET/SWNTs and PEN/SWNTs and the formation of lobules with different orientations for PBT/SWNTs. To explain the morphological behavior one model was proposed based on crystallographic interactions, that is, epitaxy. Theoretical epitaxy calculations indicated that epitaxy is not possible from the strict epitaxy point of view. Instead, aromatic self-assembly mechanism was proposed based on π-π interactions and the chirality of the nanotube. It was proposed that the mechanism implies two steps to produce helical or lobular morphologies with different orientations. In the first step polymer chains were approached, aligned parallel to the nanotube axis and adsorbed due to electrostatic interactions and the flexibility of the molecule. However, due to π-π interactions between the aromatic rings of the polymer and the nanotube, in the second step chains reoriented on the nanotube surface depending on the chirality of the nanotube. The mechanism was supported by semi-empirical calculations.

  18. Functional groups grafted nonwoven fabrics for blood filtration-The effects of functional groups and wettability on the adhesion of leukocyte and platelet

    Energy Technology Data Exchange (ETDEWEB)

    Yang Chao [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Cao Ye [Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu 610081 (China); Sun Kang, E-mail: ksun@sjtu.edu.cn [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Liu Jiaxin; Wang Hong [Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu 610081 (China)

    2011-01-15

    In this work, the effects of grafted functional groups and surface wettability on the adhesion of leukocyte and platelet were investigated by the method of blood filtration. The filter materials, poly(butylene terephthalate) nonwoven fabrics bearing different functional groups including hydroxyl (OH), carboxyl (COOH), sulfonic acid group (SO{sub 3}H) and zwitterionic sulfobetaine group ({sup +}N((CH{sub 3}){sub 2})(CH{sub 2}){sub 3}SO{sub 3}{sup Circled-Minus }) with controllable wettability were prepared by UV radiation grafting vinyl monomers with these functional groups. Our results emphasized that both surface functional groups and surface wettability had significant effects on the adhesion of leukocyte and platelet. In the case of filter materials with the same wettability, leukocytes adhering to filter materials decreased in the order: the surface bearing OH only > the surface bearing both OH and COOH > the surface bearing sulfobetaine group > the surface bearing SO{sub 3}H, while platelets adhering to filter materials decreased as the following order: the surface bearing SO{sub 3}H > the surface bearing both OH and COOH > the surface bearing OH only > the surface bearing sulfobetaine group. As the wettability of filter materials increased, both leukocyte and platelet adhesion to filter materials declined, except that leukocyte adhesion to the surface bearing OH only remained unchanged.

  19. Influence of Flame Retardants on the Melt Dripping Behaviour of Thermoplastic Polymers

    Directory of Open Access Journals (Sweden)

    Melissa Matzen

    2015-08-01

    Full Text Available Melt flow and dripping of the pyrolysing polymer melt can be both a benefit and a detriment during a fire. In several small-scale fire tests addressing the ignition of a defined specimen with a small ignition source, well-adjusted melt flow and dripping are usually beneficial to pass the test. The presence of flame retardants often changes the melt viscosity crucially. The influence of certain flame retardants on the dripping behaviour of four commercial polymers, poly(butylene terephthalate (PBT, polypropylene (PP, polypropylene modified with ethylene-propylene rubber (PP-EP and polyamide 6 (PA 6, is analysed based on an experimental monitoring of the mass loss due to melt dripping, drop size and drop temperature as a function of the furnace temperature applied to a rod-shaped specimen. Investigating the thermal transition (DSC, thermal and thermo-oxidative decomposition, as well as the viscosity of the polymer and collected drops completes the investigation. Different mechanisms of the flame retardants are associated with their influence on the dripping behaviour in the UL 94 test. Reduction in decomposition temperature and changed viscosity play a major role. A flow limit in flame-retarded PBT, enhanced decomposition of flame-retarded PP and PP-EP and the promotion of dripping in PA 6 are the salient features discussed.

  20. Microwell scaffolds for the extrahepatic transplantation of islets of Langerhans.

    Directory of Open Access Journals (Sweden)

    Mijke Buitinga

    Full Text Available Allogeneic islet transplantation into the liver has the potential to restore normoglycemia in patients with type 1 diabetes. However, the suboptimal microenvironment for islets in the liver is likely to be involved in the progressive islet dysfunction that is often observed post-transplantation. This study validates a novel microwell scaffold platform to be used for the extrahepatic transplantation of islet of Langerhans. Scaffolds were fabricated from either a thin polymer film or an electrospun mesh of poly(ethylene oxide terephthalate-poly(butylene terephthalate (PEOT/PBT block copolymer (composition: 4000PEOT30PBT70 and were imprinted with microwells, ∼400 µm in diameter and ∼350 µm in depth. The water contact angle and water uptake were 39±2° and 52.1±4.0 wt%, respectively. The glucose flux through electrospun scaffolds was three times higher than for thin film scaffolds, indicating enhanced nutrient diffusion. Human islets cultured in microwell scaffolds for seven days showed insulin release and insulin content comparable to those of free-floating control islets. Islet morphology and insulin and glucagon expression were maintained during culture in the microwell scaffolds. Our results indicate that the microwell scaffold platform prevents islet aggregation by confinement of individual islets in separate microwells, preserves the islet's native rounded morphology, and provides a protective environment without impairing islet functionality, making it a promising platform for use in extrahepatic islet transplantation.

  1. Polymerization of Ethylene Oxide, Propylene Oxide, and Other Alkylene Oxides: Synthesis, Novel Polymer Architectures, and Bioconjugation.

    Science.gov (United States)

    Herzberger, Jana; Niederer, Kerstin; Pohlit, Hannah; Seiwert, Jan; Worm, Matthias; Wurm, Frederik R; Frey, Holger

    2016-02-24

    The review summarizes current trends and developments in the polymerization of alkylene oxides in the last two decades since 1995, with a particular focus on the most important epoxide monomers ethylene oxide (EO), propylene oxide (PO), and butylene oxide (BO). Classical synthetic pathways, i.e., anionic polymerization, coordination polymerization, and cationic polymerization of epoxides (oxiranes), are briefly reviewed. The main focus of the review lies on more recent and in some cases metal-free methods for epoxide polymerization, i.e., the activated monomer strategy, the use of organocatalysts, such as N-heterocyclic carbenes (NHCs) and N-heterocyclic olefins (NHOs) as well as phosphazene bases. In addition, the commercially relevant double-metal cyanide (DMC) catalyst systems are discussed. Besides the synthetic progress, new types of multifunctional linear PEG (mf-PEG) and PPO structures accessible by copolymerization of EO or PO with functional epoxide comonomers are presented as well as complex branched, hyperbranched, and dendrimer like polyethers. Amphiphilic block copolymers based on PEO and PPO (Poloxamers and Pluronics) and advances in the area of PEGylation as the most important bioconjugation strategy are also summarized. With the ever growing toolbox for epoxide polymerization, a "polyether universe" may be envisaged that in its structural diversity parallels the immense variety of structural options available for polymers based on vinyl monomers with a purely carbon-based backbone.

  2. Synthesis and characterization of biodegradable aliphatic copolyesters with hydrophilic soft segments

    Directory of Open Access Journals (Sweden)

    JASNA DJONLAGIC

    2004-12-01

    Full Text Available In this study, the synthesis, structure and physical properties of two series of segmented poly(ester-ethers based on poly(butylene succinate and two different types of polyethers were investigated. The poly(ester-ethers were synthesized by transesterification reaction of dimethyl succinate, 1,4-butanediol and poly(ethylene oxide (PEO, Mn = 1000 g/mol in the first series, and poly(tetramethylene oxide (PTMO, Mn = 1000 g/mol in the second. The mass fraction of soft segments was varied between 10 and 50 mass. %. The effect of the introduction of two different polyether soft segments on the structure, thermal and rheological properties were investigated. The composition of the poly(ester-ethers, determined from their 1H-NMR spectra, showed that incorporation of soft polyether segments was successfully performed by the transesterification reaction in bulk. The molecular weight was estimated from solution viscosity measurements and complex dynamic viscosities. The thermal properties investigated by DSC indicated that the presence of soft segments lowers the melting and crystallization temperature of the hard phase, as well as the degree of crystallinity. Dynamical mechanical analysis was used to investigate the influence of composition on the rheological behavior of the segmented poly(ester-ethers. The results obtained from an enzymatic degradation test performed on some of the synthesized polymers showed that the biodegradability is enhanced with increasing hydrophilicity.

  3. Biodegradable compounds: Rheological, mechanical and thermal properties

    Science.gov (United States)

    Nobile, Maria Rossella; Lucia, G.; Santella, M.; Malinconico, M.; Cerruti, P.; Pantani, R.

    2015-12-01

    Recently great attention from industry has been focused on biodegradable polyesters derived from renewable resources. In particular, PLA has attracted great interest due to its high strength and high modulus and a good biocompatibility, however its brittleness and low heat distortion temperature (HDT) restrict its wide application. On the other hand, Poly(butylene succinate) (PBS) is a biodegradable polymer with a low tensile modulus but characterized by a high flexibility, excellent impact strength, good thermal and chemical resistance. In this work the two aliphatic biodegradable polyesters PBS and PLA were selected with the aim to obtain a biodegradable material for the industry of plastic cups and plates. PBS was also blended with a thermoplastic starch. Talc was also added to the compounds because of its low cost and its effectiveness in increasing the modulus and the HDT of polymers. The compounds were obtained by melt compounding in a single screw extruder and the rheological, mechanical and thermal properties were investigated. The properties of the two compounds were compared and it was found that the values of the tensile modulus and elongation at break measured for the PBS/PLA/Talc compound make it interesting for the production of disposable plates and cups. In terms of thermal resistance the compounds have HDTs high enough to contain hot food or beverages. The PLA/PBS/Talc compound can be, then, considered as biodegradable substitute for polystyrene for the production of disposable plates and cups for hot food and beverages.

  4. Fabrication and characterization of thermoplastic elastomer dry adhesives with high strength and low contamination.

    Science.gov (United States)

    Bin Khaled, Walid; Sameoto, Dan

    2014-05-14

    Polydimethylsiloxane (PDMS) and polyurethane elastomers have commonly been used to manufacture mushroom shaped gecko-inspired dry adhesives with high normal adhesion strength. However, the thermosetting nature of these two materials severely limits the commercial viability of their manufacturing due to long curing times and high material costs. In this work, we introduce poly(styrene-ethylene/butylene-styrene) (SEBS) thermoplastic elastomers as an alternative for the manufacture of mushroom shaped dry adhesives with both directional and nondirectional performance. These materials are attractive for their potential to be less contaminating via oligomer transfer than thermoset elastomers, as well as being more suited to mass manufacturing. Low material transfer properties are attractive for adhesives that could potentially be used in cleanroom environments for microscale assembly and handling in which device contamination is a serious concern. We characterized a thermoplastic elastomer in terms of oligomer transfer using X-ray photoelectron spectroscopy and found that the SEBS transfers negligible amounts of its own oligomers, during contact with a gold-coated silicon surface, which may be representative of the metallic bond pads found in micro-electro-mechanical systems devices. We also demonstrate the fabrication of mushroom shaped isotropic and anisotropic adhesive fibers with two different SEBS elastomer grades using thermocompression molding and characterize the adhesives in terms of their shear-enhanced normal adhesion strength. The overall adhesion of one of the thermoplastic elastomer adhesives was found to be stronger or comparable to their polyurethane counterparts with identical dimensions.

  5. Temperature- and pH-sensitive wearable materials for monitoring foot ulcers

    Science.gov (United States)

    Salvo, Pietro; Calisi, Nicola; Melai, Bernardo; Dini, Valentina; Paoletti, Clara; Lomonaco, Tommaso; Pucci, Andrea; Di Francesco, Fabio; Piaggesi, Alberto; Romanelli, Marco

    2017-01-01

    Foot ulcers account for 15% of comorbidities associated with diabetes. Presently, no device allows the status of foot ulcers to be continuously monitored when patients are not hospitalized. In this study, we describe a temperature and a pH sensor capable of monitoring diabetic foot and venous leg ulcers developed in the frame of the seventh framework program European Union project SWAN-iCare (smart wearable and autonomous negative pressure device for wound monitoring and therapy). Temperature is measured by exploiting the variations in the electrical resistance of a nanocomposite consisting of multiwalled carbon nanotubes and poly(styrene-b-(ethylene-co-butylene)-b-styrene). The pH sensor used a graphene oxide (GO) layer that changes its electrical potential when pH changes. The temperature sensor has a sensitivity of ~85 Ω/°C in the range 25°C–50°C and a high repeatability (maximum standard deviation of 0.1% over seven repeated measurements). For a GO concentration of 4 mg/mL, the pH sensor has a sensitivity of ~42 mV/pH and high linearity (R2=0.99). PMID:28203074

  6. Performance and environmental impact of biodegradable polymers as agricultural mulching films.

    Science.gov (United States)

    Touchaleaume, François; Martin-Closas, Lluís; Angellier-Coussy, Hélène; Chevillard, Anne; Cesar, Guy; Gontard, Nathalie; Gastaldi, Emmanuelle

    2016-02-01

    In the aim of resolving environmental key issues such as irreversible soil pollution by non-biodegradable and non-recoverable polyethylene (PE) fragments, a full-scale field experiment was set up to evaluate the suitability of four biodegradable materials based on poly(butylene adipate-co-terephtalate) (PBAT) to be used as sustainable alternatives to PE for mulching application in vineyard. Initial ultimate tensile properties, functional properties during field ageing (water vapour permeability and radiometric properties), biodegradability and agronomical performance of the mulched vines (wood production and fruiting yield) were studied. In spite of their early loss of physical integrity that occurred only five months after vine planting, the four materials satisfied all the requested functional properties and led to agronomic performance as high as polyethylene. In the light of the obtained results, the mulching material lifespan was questioned in the case of long-term perennial crop such as grapevine. Taking into account their mulching efficiency and biodegradability, the four PBAT-based studied materials are proven to constitute suitable alternatives to the excessively resistant PE material.

  7. Study of cerium-promoted rhodium alumina catalyst as a steam reforming catalyst for treatment of spent solvents

    Institute of Scientific and Technical Information of China (English)

    Hee-Chul Yang; Min-Woo Lee; Ho-Sang Hwang; Jei-Kwon Moon; Dong-Yong Chung

    2014-01-01

    This study attempted to develop an appropriate catalyst used for the steam reforming of gasified spent solvents. Rh2O3/ CeO2-Al2O3 catalysts with various CeO2 loadings were prepared and heated at different temperatures of 500 and 800 ºC, and their surface properties were studied using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron mi-croscopy (TEM), temperature programmed reduction (TPR) and Brumauer-Emmett-Teller (BET) analyses. Rhodium existed in the form of Rh2O3, regardless of the sample composition as well as the heating temperature. In the tested range of cerium addition (up to 12 times the rhodium mass), no significant changes in BET surface areas and binding energy corresponding to Rh 3d5/2were observed. Instead, the addition of cerium led to a greatly enhanced dispersion of rhodium nanoparticles, and no agglomeration of rhodium was observed for samples heated even at 800 ºC. Honeycomb monolith rhodium catalysts promoted with cerium were fabricated and tested for the steam reforming of a gasified spent solvent, mainly consisting of butylene (C4H8). The test results suggested that a ce-rium-promoted rhodium catalyst could be used as an appropriate reforming catalyst for treating low-quality non-methane hydrocar-bons without the formation of coke at high temperatures of up to 900 ºC.

  8. Droplet immobilization within a polymeric organogel improves lipid bilayer durability and portability.

    Science.gov (United States)

    Venkatesan, Guru A; Sarles, Stephen A

    2016-05-24

    The droplet interface bilayer (DIB) is a promising technique for assembling lipid membrane-based materials and devices using water droplets in oil, but it has largely been limited to laboratory environments due to its liquid construction. With a vision to transform this lab-based technique into a more-durable embodiment, we investigate the use of a polymer-based organogel to encapsulate DIBs within a more-solid material matrix to improve their handling and portability. Specifically, a temperature-sensitive organogel formed from hexadecane and poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) triblock copolymer is used to replace the liquid solvent that surrounds the lipid-coated droplets to establish a novel liquid-in-gel DIB system. Through specific capacitance measurements and single-channel recordings of the pore forming peptide alamethicin, we verify that the structural and functional membrane properties are retained when DIBs are assembled within SEBS organogel. In addition, we demonstrate that organogel encapsulation offers improved handling of droplets and yields DIBs with a near 3× higher bilayer durability, as quantified by the lateral acceleration required to rupture the membrane, compared to liquid-in-liquid DIBs in oil. This encapsulated DIB system provides a barrier against contamination from the environment and offers a new material platform for supporting multilayered DIB-based devices as well as other digital microfluidic systems that feature water droplets in oil.

  9. Rheokinetic study of crosslinking of a,w-dihydroxy oligo(alkylene maleates with a trisisocyanate

    Directory of Open Access Journals (Sweden)

    NICOLAS SPASSKY

    2003-03-01

    Full Text Available The crosslinking reaction of three series of a,w-dihydroxy oligo(alkylene maleates with a trifunctional isocyanate was followed by dynamic mechanical analysis and FTIR spectroscopy. The evaluation of rheological parameters, such as storage G’ and loss modulus G", was recorded. A typical G’ versus time curve has a characteristic “S” shape, indicating autoacceleration of the crosslinking reaction. The whole curing process starting from G’ equal G" or the beginning of gelation is described by a second - order phenomenological rheokinetic equation which takes into account the autoacceleration effect, the latter being a consequence of the superposition of both the chemical reaction and phase segregation. It appears that the crosslinking reaction rate depends on the concentration of the functional groups, i.e., on the molecular weight of the polyester prepolymer and on the length of the aliphatic sequence in the repeating unit or the segmental mobility. The crosslinking rate decreases in the order: poly(octamethylene maleate > poly(hexamethylene maleate > poly(butylene maleate.

  10. Study of Syngas Conversion to Light Olefins by Response Surface Methodology

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    Hossein Atashi

    2013-01-01

    Full Text Available The effect of adding MgO to a precipitated iron-cobalt-manganese based Fischer-Tropsch synthesis (FTS catalyst was investigated via response surface methodology. The catalytic performance of the catalysts was examined in a fixed bed microreactor at a total pressure of 1–7 bar, temperature of 280–380°C, MgO content of 5–25% and using a syngas having a H2 to CO ratio equal to 2.The dependence of the activity and product distribution on MgO content, temperature, and pressure was successfully correlated via full quadratic second-order polynomial equations. The statistical analysis and response surface demonstrations indicated that MgO significantly influences the CO conversion and chain growth probability as well as ethane, propane, propylene, butylene selectivity, and alkene/alkane ratio. A strong interaction between variables was also evidenced in some cases. The decreasing effect of pressure on alkene to alkane ratio is investigated through olefin readsorption effects and CO hydrogenation kinetics. Finally, a multiobjective optimization procedure was employed to calculate the best amount of MgO content in different reactor conditions.

  11. Laser-induced breakdown spectroscopy for polymer identification.

    Science.gov (United States)

    Grégoire, Sylvain; Boudinet, Marjorie; Pelascini, Frédéric; Surma, Fabrice; Detalle, Vincent; Holl, Yves

    2011-07-01

    This study aims at differentiating several organic materials, particularly polymers, by laser induced breakdown spectroscopy. The goal is to apply this technique to the fields of polymer recycling and cultural heritage conservation. We worked with some usual polymers families: polyethylene (PE), polypropylene (PP), polyoxymethylene, (POM), poly(vinyl chloride), polytetrafluoroethylene, polyoxyethylene (POE), and polyamide for the aliphatic ones, and poly(butylene terephthalate), acrylonitrile-butadiene-styrene, polystyrene, and polycarbonate for the aromatic ones. The fourth harmonic of a Nd:YAG laser (266 nm) in ambient air at atmospheric pressure was used. A careful analysis of the C(2) Swan system (0,0) band in polymers containing no C-C (POM), few C-C (POE), or aromatic C-C linkages led us to the conclusion that the C(2) signal might be native, i.e., the result of direct ablation from the sample. With use of these results, aliphatic and aromatic polymers could be differentiated. Further data treatments, such as properly chosen line ratios, principal component analysis, and partial least squares regression, were evaluated. It was shown that many polymers could be separated, including PE and PP, despite their similar chemical structures.

  12. Morphology and Mechanical Properties of Nylon 6/PBT Blends Compatibilized with Styrene/Maleic Anhydride Copolymer

    Institute of Scientific and Technical Information of China (English)

    QIN Shu-hao; YU Jie; ZHENG Qiang; HE Min; ZHU Hong

    2007-01-01

    The mechanical properties and dynamic mechanical properties of blends composed of Nylon 6 and poly( butylenes terephthalate) (PBT), with styrene/maleic anhydride(SMA) as compatibilizer, were studied. The observation on the morphologies of the etched surfaces of the cryogenically fractured specimens via scanning electron microscopy(SEM)demonstrated that in the compatibilized Nylon 6/PBT blends, there exists a finer and more uniform dispersion induced by thein-situ interfacial chemical reactions during the preparation than that in the corresponding uncompatibilized blends. On the other hand, the overall mechanical properties of the compatibilized blends could be remarkably improved compared with those of the uncompatibilized ones. Moreover, increasing the amount of the compatibilizer SMA leads to a more efficient dispersion of the PBT phase in Nylon 6/PBT blends. Furthermore, there exists an optimum level of SMA added to achieve the maximum mechanical properties. As far as the mechanism of this reactive compatibilization is concerned, the enhanced interfacial adhesion is necessary to obtain improved dispersion, stable phase morphology, and better mechanical properties.

  13. Magneto-dielectric properties of polymer-Fe{sub 3}O{sub 4} nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ta-I; Brown, Rene N.C. [Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742 (United States); Kempel, Leo C. [Department of Electrical and Computer Engineering, Michigan State University, East Lansing, MI 48824 (United States); Kofinas, Peter [Fischell Department of Bioengineering, University of Maryland, 1120 Jeong H. Kim Building, College Park, MD 20742 (United States)], E-mail: kofinas@umd.edu

    2008-11-15

    The aim of this research is to elucidate the size effect of magnetic nanoparticles on the resultant magneto-dielectric properties of polymer nanocomposites at radio frequencies. The block copolymer of [styrene-b-ethylene/butylene-b-styrene] (SEBS) was utilized as a matrix for the templating of magnetic nanoparticles. Surfactant-modified iron oxide (Fe{sub 3}O{sub 4}) nanoparticles of various sizes were successfully synthesized by a seed-mediated growth method. The surfactant prevented Fe{sub 3}O{sub 4} aggregation and provided compatibility with the polymer matrix. The nucleation and growth of Fe{sub 3}O{sub 4} nanoparticles was controlled by changing the concentration ratio of surfactant to iron-precursor. The free iron ions present during synthesis are the major factor contributing to the growth of larger particles. The Fe{sub 3}O{sub 4} nanoparticle critical size for superparamagnetic to ferrimagnetic transition was determined to be near 30 nm at room temperature. The dielectric permittivity ({epsilon}{sub r}) of the polymer composite increased with increasing amount of Fe{sub 3}O{sub 4} doping, and was not influenced by nanoparticle size. However, the magnetic permeability ({mu}{sub r}) of the composites was significantly influenced by the size of Fe{sub 3}O{sub 4} nanoparticles templated within the block copolymer matrix due to thermal energy fluctuations from the nanoparticle surroundings.

  14. Binary Mixed Homopolymer Brushes Tethered to Cellulose Nanocrystals: A Step Towards Compatibilized Polyester Blends.

    Science.gov (United States)

    Mincheva, Rosica; Jasmani, Latifah; Josse, Thomas; Paint, Yoann; Raquez, Jena-Marie; Gerbaux, Pascal; Eyley, Samuel; Thielemans, Wim; Dubois, Philippe

    2016-09-12

    This article reports on the successful preparation and characterization of cellulose nanocrystals (CNCs) surface-modified with polylactide (PLA) and poly(butylene succinate) (PBS) binary mixed homopolymer brushes. Their synthesis was designed as a three-step procedure combining polyester synthesis and surface-modification of CNCs with simultaneous polyester grafting via a heterogeneous copper(I)-catalyzed azide-alkyne cycloaddition reaction. For comparison, single homopolymer brushes tethered to CNCs (PLLA-g-CNC and PBSBDEMPAM-g-CNC) were obtained applying the same procedure. The hairy nanoparticles were characterized in terms of chemical composition and thermal properties. Spectroscopic analyses suggested "rippled" microphase separation of both immiscible homopolyesters in the mixed brushes, while others showed impeded homopolyester crystallization after surface-grafting. A synergistic relationship between the polyesters and CNCs was also suggested, i.e., the polyester grafting increases the CNC thermal resistance, while CNC presence imparts char formation. The as-obtained binary homopolymer brushes tethered to nanoparticles makes these surface-modified cellulosic nanomaterials attractive as compatibilization/reinforcement agents for PLA/PBS blends.

  15. Biodegradation of poly(ε-caprolactone) (PCL) by a new Penicillium oxalicum strain DSYD05-1.

    Science.gov (United States)

    Li, Fan; Yu, Dan; Lin, Xiumei; Liu, Dongbo; Xia, Hongmei; Chen, Shan

    2012-10-01

    In this study, fungi isolated from soil were screened for their ability to form clear zones on agar plates with emulsified poly(ε-caprolactone) (PCL). The most active strain, designated as DSYD05, was identified as Penicillium oxalicum on the basis of morphological characteristics and phylogenetic analysis. Mutant DSYD05-1, obtained by ultraviolet-light mutagenesis from strain DSYD05, was more effective in PCL degradation. In liquid cultures of the mutant strain with PCL emulsion, DSYD05-1 showed the highest PCL-degrading activity after 4 days of cultivation. The products of PCL degradation were analysed by mass spectrometry; the results indicated that 6-hydroxyhexanoic acid was produced and assimilated during cultivation. The degradation of PCL film by DSYD05-1 was observed by scanning electron microscopy, and was indicative of a three-stage degradation process. The degradation of amorphous parts of the film preceded that of the crystalline center and then the peripheral crystalline regions. In addition, DSYD05-1 showed a wide range of substrate specificity, with capability to degrade PCL, poly(β-hydroxybutyrate), and poly(butylene succinate), but not poly(lactic acid), indicating that the strain could have potential for application in the treatment or recycling of bio-plastic wastes.

  16. Reduction of Noise from Disc Brake Systems Using Composite Friction Materials Containing Thermoplastic Elastomers (TPEs)

    Science.gov (United States)

    Masoomi, Mohsen; Katbab, Ali Asghar; Nazockdast, Hossein

    2006-09-01

    Attempts have been made for the first time to prepare a friction material with the characteristic of thermal sensitive modulus, by the inclusion of thermoplastic elastomers (TPE) as viscoelastic polymeric materials into the formulation in order to the increase the damping behavior of the cured friction material. Styrene butadiene styrene (SBS), styrene ethylene butylene styrene (SEBS) and nitrile rubber/polyvinyl chloride (NBR/PVC) blend system were used as TPE materials. In order to evaluate the viscoelastic parameters such as loss factor (tan δ) and storage modulus (E‧) for the friction material, dynamic mechanical analyzer (DMA) were used. Natural frequencies and mode shapes of friction material and brake disc were determined by modal analysis. However, NBR/PVC and SEBS were found to be much more effective in damping behavior. The results from this comparative study suggest that the damping characteristics of commercial friction materials can be strongly affected by the TPE ingredients. This investigation also confirmed that the specimens with high TPE content had low noise propensity.

  17. Shape Memory Properties of PBS-Silica Hybrids

    Directory of Open Access Journals (Sweden)

    Katia Paderni

    2014-01-01

    Full Text Available A series of novel Si–O–Si crosslinked organic/inorganic hybrid semi-crystalline polymers with shape memory properties was prepared from alkoxysilane-terminated poly(butylene succinate (PBS by water-induced silane crosslinking under organic solvent-free and catalyst-free conditions. The hydrolyzation and condensation of alkoxysilane end groups allowed for the generation of silica-like crosslinking points between the polymeric chains, acting not only as chemical net-points, but also as inorganic filler for a reinforcement effect. The resulting networks were characterized using differential scanning calorimetry (DSC, thermogravimetric analysis (TGA, dynamic-mechanical analysis (DMA and tensile and shape memory tests to gain insight into the relationship between the polymeric structure, the morphology and the properties. By controlling the molecular weight of the PBS precursor, a fine tuning of the crosslinking density and the inorganic content of the resulting network was possible, leading to different thermal, mechanical and shape memory properties. Thanks to their suitable morphology consisting of crystalline domains, which represent the molecular switches between the temporary and permanent shapes, and chemical net-points, which permit the shape recovery, the synthesized materials showed good shape memory characteristics, being able to fix a significant portion of the applied strain in a temporary shape and to restore their original shape above their melting temperature.

  18. The formation of standing cylinders in block copolymer films by irreversibly adsorbed polymer layers on substrates

    Science.gov (United States)

    Shang, Jun; Jiang, Naisheng; Endoh, Maya; Koga, Tadanori

    2013-03-01

    Block copolymers offer a simple and effective route to produce standing cylindrical nanostructures with regularity on the order of 10-100 nm, the length scale that is desirable for many advanced applications. However, these formations have been especially troublesome due to the fact that preferential interactions between one of the blocks and the surfaces will induce parallel alignment of the cylinders in order to minimize interfacial and surface energy. Here we introduce an alternative simple method utilizing an irreversibly adsorbed polymer layer (a ``Guiselin'' brush) as a neutral ``substrate'' formed on solid substrates for the arrangement of standing cylindrical nanostructures. The effect of polymer adsorbed layer on the long range ordering of asymmetric cylinder forming poly(styrene-block-ethylene/butylene-block-styrene) (SEBS) triblock copolymer thin films were investigated by using a combination of grazing incidence small angle x-ray scattering and atomic force microscopy techniques. We found that the SEBS, which forms cylinders lying parallel to the surface when prepared on silicon substrates, show standing cylindrical structures on selected Guiselin brush layers after prolong thermal annealing. The details will be discussed in the presentation. We acknowledges the financial support from NSF Grant No. CMMI-084626

  19. A comparative study of Pt/C cathodes in Sn 0.9In 0.1P 2O 7 and H 3PO 4 ionomers for high-temperature proton exchange membrane fuel cells

    Science.gov (United States)

    Jin, Y. C.; Okada, M.; Hibino, T.

    New Pt/C cathodes with many reaction sites for the oxygen reduction reaction as well as high tolerance to Pt corrosion have been designed for high-temperature proton exchange membrane fuel cells (PEMFCs), wherein a composite mixture of Sn 0.9In 0.1P 2O 7 (SIPO) and sulfonated polystyrene-b-poly(ethylene/butylene)-b-polystyrene (sSEBS) functioned as an ionomer. The microstructure of the Pt-SIPO-sSEBS/C cathode was characterized by homogeneous distribution of the ionomer over the catalyst layer and close contact between the ionomer and the Pt/C powder. As a result, the activation and concentration overpotentials of the Pt-SIPO-sSEBS/C cathode between 100 and 200 °C were lower than those of an H 3PO 4-impregnated Pt/C cathode, which suggests that the present ionomer can avoid poisoning of Pt by phosphate anions and the limitation of gas diffusion through the catalyst layer. Moreover, agglomeration of Pt in the Pt-SIPO-sSEBS/C cathode was not observed during a durability test at 150 °C for 6 days, although it was significant in the Pt-H 3PO 4/C cathode. Therefore, it is concluded that the Pt-SIPO-sSEBS/C electrode is a very promising cathode candidate for high-temperature PEMFCs.

  20. Assessing a Spectroelectrochemical Sensor's Performance for Detecting [Ru(bpy)3]2+ in Natural and Treated Water

    Energy Technology Data Exchange (ETDEWEB)

    Abu, Eme A.; Bryan, Samuel A.; Seliskar, Carl J.; Heineman, William R.

    2012-07-01

    A spectroelectrochemical sensor that combines three modes of selectivity in a single device was evaluated in natural and treated water samples using tris-(2,2’-bipyridyl) ruthenium(II) dichloride hexahydrate, [Ru(bpy)3]2+, as a model analyte. The sensor was an optically transparent indium tin oxide (ITO) electrode coated with a thin film of partially sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SSEBS). As the potential of the ITO electrode was cycled from +0.7 to +1.3 V, the analyte changed from the colored [Ru(bpy)3]2+ complex to colorless [Ru(bpy)3]3+ complex and the change in absorbance at 450 nm was used as the optical signal for quantification. Calibration curves were obtained for [Ru(bpy)3]2+ in natural well water, river water and treated tap water with detection limits of 108, 139 and 264 nM, respectively. A standard addition method was developed to determine an *unknown* spike addition concentration of [Ru(bpy)3]2+ in well water. The spectroelectrochemical sensor determined the concentration of [Ru(bpy)3]2+ spiked into a sample of Hanford well water to be 0.39*0.03 mM versus the actual concentration of 0.40 mM.

  1. Synthesis and Characterizations of Poly(trimethylene terephthalate-b-poly(tetramethylene glycol Copolymers

    Directory of Open Access Journals (Sweden)

    Feng Liu

    2013-01-01

    Full Text Available A series of poly(trimethylene terephthalate-b-poly(tetramethylene glycol (PTT-PTMEG copolymers were synthesized by two-step melt-polycondensation. The copolymers were characterized by using Fourier transform infrared spectroscopy (FTIR, 1H NMR spectroscopy, rheometer, differential scanning calorimetry (DSC, polarized optical microscopy (POM, thermal gravimetric analysis (TGA, and mechanical properties. The results suggest that by increasing the flexible PTMEG contents from 0% to 60 wt%, the copolymers show decreased glass transition temperatures, melting points, melt-crystallization temperatures, hardness, tensile strength, thermostability, and smaller spherulites dimensions; however it has much increased impact strength and elongation at breaking point. Compared with commercial poly(butylene terephthalate (PBT-type TPEE with 25 mol% flexible segments, PTT-type TPEE having 25 mol% flexible segments has a lower glass transition temperature, melting point, crystallization temperature, and much lower tensile strength although it has a much higher impact strength than that of PBT-type TPEE, and it is not suitably used as a commercial TPEE.

  2. Wetting of Hydrophilic Electrospun Mats Produced by Blending SEBS with PEO-PPO-PEO Copolymers of Different Molecular Weight.

    Science.gov (United States)

    Kurusu, Rafael S; Demarquette, Nicole R

    2016-02-23

    The interaction of electrospun mats with water is critical for many possible applications, and the water contact angle on the surface is the parameter usually measured to characterize wetting. Although useful for hydrophobic surfaces, this approach is limited for hydrophilic mats, where wicking also has to be considered. In this case, it is still unclear how the fiber surface chemical composition and morphology will affect the wetting behavior of electrospun mats. In this work, wetting was studied with different hydrophilic membranes produced by blending thermoplastic elastomer poly(styrene)-b-poly(ethylene-butylene)-b-poly(styrene) (SEBS) with amphiphilic poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO) molecules. Three different types of PEO-PPO-PEO, with different molar masses, PEO content, and physical form were used. The effect of these differences on the wetting behavior of the electrospun mats was evaluated by contact angle goniometry, wicking measurements, and different imaging techniques. X-ray photoelectron spectroscopy was used to characterize the surface chemical composition. The smaller molecules quickly saturated the surface at low concentrations, making the mats hydrophilic. The sheath of PEO-PPO-PEO also resulted in fast absorption of water, when comparing the saturated and nonsaturated surfaces. Longer PEO chain-ends seemed to hinder complete segregation and also led to a higher activation time when in contact with water. Liquid PEO-PPO-PEO was easily leached by water.

  3. Phase morphological study on SEBS compatibilized PS/LDPE blends

    Directory of Open Access Journals (Sweden)

    Chatchai Kunyawut

    2014-09-01

    Full Text Available The co-continuous phase morphology of polystyrene (PS/low density polyethylene (LDPE blends compatibilized with poly(styrene-block-ethylene/butylene-block-styrene triblock copolymers (SEBS with varying molecular weights has been investigated. The blend samples were prepared in a mini-twin screw extruder. The barrel length and diameter are 224 and 16 mm, respectively. The diameter of the capillary die is 1 mm. The concentration of the blends was 70/30 wt% of PS/LDPE while that of the SEBS used was 5 wt% of the blend. The mixing temperatures used were 180, 250, and 280o C, and a screw speed of 60 rpm. The morphology of the blends was investigated using an AFM technique. Average droplet diameters of the blend samples were determined using an OM technique. The co-continuous morphology has not been obtained in all the blends, although the mixing temperature used is as high as 280o C. The experimental results indicated that the model prediction of the co-continuous morphology proposed by Willemse and co-worker was not applicable to the blend systems studied. Only droplet-type dispersion was observed. This is considered to arise from the processing conditions and the mixing device used. The blend compatibilized with the high molecular weight SEBS had higher dispersed phase size than that of the blend compatibilized with the medium and low molecular weight SEBSs. This behaviour is likely to arise from coalescence during melt processing.

  4. Study and development of nanocomposites PBT/bentonite clay treated by ionizing radiation: preparation and characterization; Estudo e desenvolvimento de nanocompositos PBT/argila bentonita tratados por radiacao ionizante: preparacao e caracterizacao

    Energy Technology Data Exchange (ETDEWEB)

    Sartori, Mariana do Nascimento

    2014-07-01

    This work describes the preparation and characterization of composites based on poly (butylene terephthalate) - PBT and brazilian modified clay prepared by the melt intercalation. PBT nanocomposites with 3 and 5 % by weight of organically modified clay, by the addition of a quaternary ammonium salt, were prepared by extrusion using a twin-screw extruder machine. After the extrusion process, the materials were injected to obtain specimens tests samples for the characterization tests. Part of the specimens samples were irradiated using an electron beam accelerator with 1.5 MeV at room temperature in the presence of air. Samples of pure PBT and irradiated and non-irradiated nanocomposites were characterized by mechanical tests of tensile, flexural and impact, heat distortion temperature (HDT), X - ray diffraction (XRD), scanning electron microscopy (SEM), melt flow index (MFI) thermogravimetry (TG) and differential scanning calorimetry (DSC) and the correlation between the properties was discussed. The results showed that the addition of clay, in both percentages, promoted an increase greater than 50 % in tensile strength at break and a gain of around 35% in heat distortion temperature when compared to the pure polymer. The treatment with ionizing radiation of electron beam at the doses used in this study showed no significant changes in material properties. (author)

  5. Mechanical and thermal properties of PP/PBT blends compatibilized with triblock thermoplastic elastomer

    Directory of Open Access Journals (Sweden)

    Ignaczak Wojciech

    2015-09-01

    Full Text Available A linear triblock copolymer, poly(styrene-b-etylene/butylene-b-styrene(SEBS thermoplastic elastomer (TPE grafted with maleic anhydride was used for compatibilization of PP/PBT blends. PP/PBT blends of different mass ratios 60/40, 50/50, 40/60 were mixed with 2.5, 5.0 and 7.5 wt.% of SEBS copolymer in a twin screw extruder. Differential scanning calorimetry and dynamic mechanical analysis were performed to define the phase structure of PP/PBT blends. TPE with a rubbery mid-block shifted the glass transition of PP/PBT blend towards lower temperatures, and significant decrease the crystallization temperature of a crystalline phase of PP component was observed. The influence of the amount of compatibilizer and the blend composition on the mechanical properties (tensile and flexural strengths, toughness and moduli was determined. Addition of 5 wt.% of a triblock TPE led to a three-fold increase of PP/PBT toughness. A significant increase of impact properties was observed for all materials compatibilized with the highest amount of SEBS copolymer.

  6. Investigation of Thermal and Thermomechanical Properties of Biodegradable PLA/PBSA Composites Processed via Supercritical Fluid-Assisted Foam Injection Molding

    Directory of Open Access Journals (Sweden)

    Sai Aditya Pradeep

    2017-01-01

    Full Text Available Bio-based polymer foams have been gaining immense attention in recent years due to their positive contribution towards reducing the global carbon footprint, lightweighting, and enhancing sustainability. Currently, polylactic acid (PLA remains the most abundant commercially consumed biopolymer, but suffers from major drawbacks such as slow crystallization rate and poor melt processability. However, blending of PLA with a secondary polymer would enhance the crystallization rate and the thermal properties based on their compatibility. This study investigates the physical and compatibilized blends of PLA/poly (butylene succinate-co-adipate (PBSA processed via supercritical fluid-assisted (ScF injection molding technology using nitrogen (N2 as a facile physical blowing agent. Furthermore, this study aims at understanding the effect of blending and ScF foaming of PLA/PBSA on crystallinity, melting, and viscoelastic behavior. Results show that compatibilization, upon addition of triphenyl phosphite (TPP, led to an increase in molecular weight and a shift in melting temperature. Additionally, the glass transition temperature (Tg obtained from the tanδ curve was observed to be in agreement with the Tg value predicted by the Gordon–Taylor equation, further confirming the compatibility of PLA and PBSA. The compatibilization of ScF-foamed PLA–PBSA was found to have an increased crystallinity and storage modulus compared to their physically foamed counterparts.

  7. 阻燃SEBS热塑性弹性体研究进展%Advance on research of flame retardant for SEBS thermoplastic elastomer

    Institute of Scientific and Technical Information of China (English)

    谭逸伦; 彭治汉

    2013-01-01

    Styrene-b-ethylene-co-butylene-b-styrene triblock copolymers(SEBS) was a high performance thermoplastic elastomer,which has a wide developmental prospects,but its flammable defect limited the application.The recent research on flame retardant SEBS was presented in this paper.The kinds of flame-retardant system applied in SEBS,the mechanism of the flame retardant,existing problems and countermeasures were introduced.%苯乙烯-乙烯丁烯共聚物-苯乙烯三嵌段共聚物(SEBS)是一种性能优异的热塑性弹性体,具有广泛的发展前景,但存在易燃的缺陷,限制了其应用领域.本文综述了近年来国内外阻燃SEBS的应用研究进展,主要介绍了应用于阻燃SEBS的阻燃体系、阻燃机理和存在的问题及其解决方法.

  8. Excimer laser pretreatment and metallization of polymers

    Science.gov (United States)

    Horn, H.; Beil, S.; Wesner, D. A.; Weichenhain, R.; Kreutz, E. W.

    1999-05-01

    Metal/polymer adhesion is a crucial factor of many applications in microelectronic or microsystem technologies. It depends on chemical and structural properties of the interface, often involving just a few atomic layers. Adhesion can be influenced by various pretreatments prior to metal deposition, e.g. thermal treatment, chemical etching or exposure to reactive plasmas. Irradiation with pulsed UV-laser radiation and or UV-excimer lamps can also affect adhesion and offers several technical advantages, among them area selective pretreatment and subsequent metallization. The pretreatment of polymer surfaces by UV-radiation is investigated as an alternative technique to common wet chemical, plasma or other pretreatment methods. Chemical and morphological changes in the polymer surface are investigated with poly(butylene terephthalate) (PBT) as a model substance, containing UV-absorbing (aromatic) chromophoric groups. Chemical changes in the surface are investigated via X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR). Analysis of the morphological changes in the polymer surface is done via optical microscopy and scanning electron microscopy (SEM). The metallization of polymers pretreated by excimer laser radiation is performed via electroless plating of nickel followed by electrolytically deposited copper. The influence of excimer laser irradiation of the polymer on the adhesion of the metal overlayers is measured by tape and peel tests.

  9. Triblock Copolymers with Grafted Fluorine-Free Amphiphilic Non-Ionic Side Chains for Antifouling and Fouling-Release Applications

    Energy Technology Data Exchange (ETDEWEB)

    Y Cho; H Sundaram; C Weinman; M Paik; M Dimitriou; J Finlay; M Callow; J Callow; E Kramer; C Ober

    2011-12-31

    Fluorine-free, amphiphilic, nonionic surface active block copolymers (SABCs) were synthesized through chemical modification of a polystyrene-block-poly(ethylene-ran-butylene)-block-polyisoprene triblock copolymer precursor with selected amphiphilic nonionic Brij and other surfactants. Amphiphilicity was imparted by a hydrophobic aliphatic group combined with a hydrophilic poly(ethylene glycol) (PEG) group-containing moiety. The surfaces were characterized by dynamic water contact angle, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and near edge X-ray absorption fine structure (NEXAFS) analysis. In biofouling assays, settlement (attachment) of both spores of the green alga Ulva and cells of the diatom Navicula on SABCs modified with Brij nonionic side chains was significantly reduced relative to a PDMS standard, with a nonionic surfactant combining a PEG group and an aliphatic moiety demonstrating the best performance. Additionally, a fouling-release assay using sporelings (young plants) of Ulva and Navicula suggested that the SABC derived from nonionic Brij side chains also out-performed PDMS as a fouling-release material. Good antifouling and fouling-release properties were not demonstrated for the other two amphiphilic surfaces derived from silicone and aromatic group containing nonionic surfactants included in this study. The results suggest that small differences in chemical surface functionality impart more significant changes with respect to the antifouling settlement and fouling-release performance of materials than overall wettability behavior.

  10. Engineering Biodegradable Flame Retardant Wood-Plastic Composites

    Science.gov (United States)

    Zhang, Linxi

    Wood-plastic composites (WPCs), which are produced by blending wood and polymer materials, have attracted increasing attentions in market and industry due to the low cost and excellent performance. In this research, we have successfully engineered WPC by melt blending Polylactic Acid (PLA) and Poly(butylene adipate-co-terphthalate) (PBAT) with recycled wood flour. The thermal property and flammability of the composite are significantly improved by introducing flame retardant agent resorcinol bis(biphenyl phosphate) (RDP). The mechanical and morphological properties are also investigated via multiple techniques. The results show that wood material has increased toughness and impact resistance of the PLA/PBAT polymer matrix. SEM images have confirmed that PLA and PBAT are immiscible, but the incompatibility is reduced by the addition of wood. RDP is initially dispersed in the blends evenly. It migrates to the surface of the sample after flame application, and serves as a barrier between the fire and underlying polymers and wood mixture. It is well proved in the research that RDP is an efficient flame retardant agent in the WPC system.

  11. Enhancement of Biodegradable Plastic-degrading Enzyme Production from Paraphoma-like Fungus, Strain B47-9.

    Science.gov (United States)

    Sameshima-Yamashita, Yuka; Koitabashi, Motoo; Tsuchiya, Wataru; Suzuki, Ken; Watanabe, Takashi; Shinozaki, Yukiko; Yamamoto-Tamura, Kimiko; Yamazaki, Toshimasa; Kitamoto, Hiroko

    2016-01-01

    To improve the productivity of Paraphoma-like fungal strain B47-9 for biodegradable plastic (BP)-degrading enzyme (PCLE), the optimal concentration of emulsified poly(butylene succinate-co-adipate) (PBSA) in the medium was determined. Emulsified PBSA was consumed as a sole carbon source and an inducer of PCLE production by strain B47-9. Among the various concentrations of emulsified PBSA [0.09-0.9% (w/v)] used in flask cultivation, 0.27% yielded the maximum enzyme activity within a short cultivation period. To evaluate the residual concentration of emulsified PBSA in culture, emulsified PBSA in aliquots of culture supernatant was digested in vitro, and the concentration of released monomerised succinic acid was determined. Regardless of the initial concentration of emulsified PBSA in medium, PCLE activity was detected after residual succinic acid decreased below 0.04 mg/mL in culture broth. Jarfermentation was performed at a 0.27% PBSA concentration. Among the various airflow rates tested, 1 LPM resulted in a PCLE production rate of 1.0 U/mL/day. The enzyme activity in the resulting culture filtrate (4.2 U/2 mL) was shown to degrade commercial BP films (1 × 1 cm, 20 µm thickness) within 8 hours.

  12. Luminescence-based spectroelectrochemical sensor for [Tc(dmpe)3]2+/+ (dmpe = 1,2-bis(dimethylphosphino)ethane) within a charge-selective polymer film.

    Science.gov (United States)

    Chatterjee, Sayandev; Del Negro, Andrew S; Edwards, Matthew K; Bryan, Samuel A; Kaval, Necati; Pantelic, Nebojsa; Morris, Laura K; Heineman, William R; Seliskar, Carl J

    2011-03-01

    A spectroelectrochemical sensor consisting of an indium tin oxide (ITO) optically transparent electrode (OTE) coated with a thin film of partially sulfonated polystyrene-blockpoly(ethylene-ran-butylene)-block-polystyrene (SSEBS) was developed for [Tc(dmpe)(3)](+) (dmpe = 1,2-bis(dimethylphosphino)ethane). [Tc(dmpe)(3)](+) was preconcentrated by ion-exchange into the SSEBS film after a 20 min exposure to aqueous [Tc(dmpe)(3)](+) solution, resulting in a 14-fold increase in cathodic peak current compared to a bare OTE. Colorless [Tc(dmpe)(3)](+) was reversibly oxidized to colored [Tc(dmpe)(3)](2+) by cyclic voltammetry. Detection of [Tc(dmpe)(3)](2+) was accomplished through emission spectroscopy by electrochemically oxidizing the complex from nonemissive [Tc(dmpe)(3)](+) to emissive [Tc(dmpe)(3)](2+). The working principle of the sensor consisted of electrochemically cycling between nonemissive [Tc(dmpe)(3)](+) and emissive [Tc(dmpe)(3)](2+) and monitoring the modulated emission (λ(exc) = 532 nm; λ(em) = 660 nm). The sensor gave a linear response over the concentration range of 0.16-340.0 μM of [Tc(dmpe)(3)](2+/+) in aqueous phase with a detection limit of 24 nM.

  13. Preparation and characterization of biodegradable aliphatic-aromatic copolyesters/nano-SiO_2 hybrids via in situ melt polycondensation

    Institute of Scientific and Technical Information of China (English)

    Yan Zhang; Bing Tao Wang; Zheng Hong Guo; Jie Chen; Zheng Ping Fang

    2009-01-01

    In situ melt polycondensation was proposed to prepare biodegradable aliphatic-aromatic copolyesters/nano-SiO_2 hybrids based on terephthalic acid (TPA), poly(L-lactic acid) oligomer (OLLA), 1,4-butanediol (BDO) and nano-SiO_2. TEM and FT-IR characterizations confirmed that TPA, OLLA and BDO copolymerized to obtain biodegradable copolyesters, poly(butylene terephthalate-co-lactate) (PBTL), and the abundant hydroxyl groups on the surface of nano-SiO_2 provided potential sites for in situ grafting with the simultaneous resulted PBTL. The nano-SiO_2 particles were chemically wrapped with PBTL to form PBTL/nano-SiO2 hybrids. Due to the good dispersion and interfacial adhesion of nano-SiO_2 particles with the copolyester matrix, the tensile strength and the Young's modulus increased from 5.4 and 5.6 Mpa for neat PBTL to 16 and 390 Mpa for PBTL/nano-SiO_2 hybrids with 5 wt.% nano-SiO_2, respectively. The mechanical properties of PBTL/nano-SiO_2 hybrids were substantially improved.

  14. Sustainable Engineering and Improved Recycling of PET for High-Value Applications: Transforming Linear PET to Lightly Branched PET with a Novel, Scalable Process

    Science.gov (United States)

    Pierre, Cynthia; Torkelson, John

    2009-03-01

    A major challenge for the most effective recycling of poly(ethylene terephthalate) concerns the fact that initial melt processing of PET into a product leads to substantial degradation of molecular weight. Thus, recycled PET has insufficient melt viscosity for reuse in high-value applications such as melt-blowing of PET bottles. Academic and industrial research has tried to remedy this situation by synthesis and use of ``chain extenders'' that can lead to branched PET (with higher melt viscosity than the linear recycled PET) via condensation reactions with functional groups on the PET. Here we show that simple processing of PET via solid-state shear pulverization (SSSP) leads to enhanced PET melt viscosity without need for chemical additives. We hypothesize that this branching results from low levels of chain scission accompanying SSSP, leading to formation of polymeric radicals that participate in chain transfer and combination reactions with other PET chains and thereby to in situ branch formation. The pulverized PET exhibits vastly enhanced crystallization kinetics, eliminating the need to employ cold crystallization to achieve maximum PET crystallinity. Results of SSSP processing of PET will be compared to results obtained with poly(butylene terephthalate).

  15. Effects of electron-beam irradation on some structural properties of granulated polymer blends

    Science.gov (United States)

    Żenkiewicz, Marian; Czupryńska, Joanna; Polański, Julian; Karasiewicz, Tomasz; Engelgard, Włodzimierz

    2008-02-01

    The aim of this article was to show the effects of the electron radiation dose and presence of a compatibiliser on the peak melting temperature ( Tpm) of the crystalline phase, crystallinity ( Xc), and melt flow rate (MFR) of granulated blends of low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET) as well as of blends of LDPE, HDPE, and PP. The purpose of applying the high-energy electron radiation with doses up to 300 kGy and of adding a compatibiliser was to enhance mechanical properties of the studied blends and, at the same time, to investigate the possibility of using this technique in the processes of recycling polymeric materials. As the compatibilisers, the styrene-ethylene/butylene-styrene elastomer grafted with maleic anhydride (SEBS- g-MA) and trimethylol propane trimethacrylate (TMPTA) were utilised; they were added at the amounts of 5, 10, and 15 wt% and 1, 2, and 3 wt%, respectively. The enhancement of mechanical properties was accompanied by the following effects, discussed in this article: (i) a decrease in the peak melting temperature upon the electron radiation for the crystalline phase of LDPE, HDPE, and PP that constituted the studied granulated blends and (ii) changes in MFR upon both the electron radiation and the addition of compatibilisers.

  16. Modification of Biodegradable Polyesters Using Electron Beam

    Directory of Open Access Journals (Sweden)

    M. Suhartini

    2013-12-01

    Full Text Available Poly(4-Hydroxybutirat P4HB, Poly(butylene succinate-co-adipate PBSA and Poly(-caprolactone PCL were electron beam (EB-irradiated. Poly(4-Hydroxybutirat was irradiated without any polyfunctional monomers (PFM. While PBSA and PCL were irradiated in the presence of polyfunctional monomers such as Trimethallyl isocyanurate (TMAIC, Polyethyleneglycol dimethacrylate (2G, 4G, Trimethylolpropane trimethacrylate (TMPT and Tetramethylolmethane tetraacrylate (A-TMMT at ambient temperature. Aim of the study is to improve the properties of biodegradable polyester. It was pointed out that crosslinking yield of P4HB (6.39% gel was formed at dose of 90 kGy irradiated in vacuum conditions. Radiation degradation promoted, when P4HB was irradiated in air. The optimum crosslinking yield of PCL and PBSA respectively, were formed in the presence of 1% TMAIC at dose of 50 kGy. The biodegradability of the crosslinked PBSA evaluated by soil burial test is slightly retarded by increasing crosslinking yields.

  17. The effect of multifunctional monomers/oligomers Additives on electron beam radiation crosslinking of poly (styrene-block-isoprene/butadiene-block-styrene) (SIBS)

    Science.gov (United States)

    Wu, Jinping; Soucek, Mark D.

    2016-02-01

    The effect of multifunctional monomers or oligomers (MFM/O) additives on electron beam (E-beam) radiation induced crosslinking of poly (styrene-block-isoprene/butadiene-block-styrene) (SIBS) was studied. Ten types of MFM/O were investigated, including trimethylolpropane trimethacrylate (TMPTMA), trimethylolpropane triacrylate (TMPTA), triallyl cyanurate (TAC), polybutadiene diacrylate (PB-diacrylate), ethylene glycol dimethylacrylate (EGDMA), butylene glycol dimethacrylate (BGDMA), 1,2-polybutadiene. The effects of MFM/O concentration and E-beam radiation dose on properties of SIBS were studied including tensile strength, elongation-at-break, modulus, gel content, equilibrium swelling and crosslink density. TMPTA significantly improved the tensile modulus and crosslink density of SIBS. SIBS with TMPTMA and TMTPMA with inhibitor showed a 50% increase in tensile strength. The solubility of MFM/O in SIBS was also investigated by a selective swelling method. The MFM/O were found to be soluble in both phases of SIBS. The viscosity of SIBS with methacrylate type MFM/O was stable at 200 °C.

  18. Construction of 3D micropatterned surfaces with wormlike and superhydrophilic PEG brushes to detect dysfunctional cells.

    Science.gov (United States)

    Hou, Jianwen; Shi, Qiang; Ye, Wei; Fan, Qunfu; Shi, Hengchong; Wong, Shing-Chung; Xu, Xiaodong; Yin, Jinghua

    2014-12-10

    Detection of dysfunctional and apoptotic cells plays an important role in clinical diagnosis and therapy. To develop a portable and user-friendly platform for dysfunctional and aging cell detection, we present a facile method to construct 3D patterns on the surface of styrene-b-(ethylene-co-butylene)-b-styrene elastomer (SEBS) with poly(ethylene glycol) brushes. Normal red blood cells (RBCs) and lysed RBCs (dysfunctional cells) are used as model cells. The strategy is based on the fact that poly(ethylene glycol) brushes tend to interact with phosphatidylserine, which is in the inner leaflet of normal cell membranes but becomes exposed in abnormal or apoptotic cell membranes. We demonstrate that varied patterned surfaces can be obtained by selectively patterning atom transfer radical polymerization (ATRP) initiators on the SEBS surface via an aqueous-based method and growing PEG brushes through surface-initiated atom transfer radical polymerization. The relatively high initiator density and polymerization temperature facilitate formation of PEG brushes in high density, which gives brushes worm-like morphology and superhydrophilic property; the tendency of dysfunctional cells adhered on the patterned surfaces is completely different from well-defined arrays of normal cells on the patterned surfaces, providing a facile method to detect dysfunctional cells effectively. The PEG-patterned surfaces are also applicable to detect apoptotic HeLa cells. The simplicity and easy handling of the described technique shows the potential application in microdiagnostic devices.

  19. Maximizing light olefins production in fluid catalytic cracking (FCC) units; Maximizacao de olefinas leves em unidades de craqueamento catalitico fluido

    Energy Technology Data Exchange (ETDEWEB)

    Pimenta, Ricardo D.M.; Pinho, Andrea de Rezende [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2004-07-01

    The Fluid Catalytic Cracking (FCC) process is widely spread over the ten PETROBRAS refineries in its thirteen industrial units. The importance of the FCC process resides on its high gasoline output, being the main supplier of this important product to the system. Additionally, FCC process is the main source of light hydrocarbons in the LPG range, including light olefins. The increasing demand for ethylene, propylene and butylenes was encouraging to concentrate the research efforts on studies about alternatives for the traditional FCC process. In the present work, the proposals from main licensors (UOP, KBR, Stone and Webster) for a light-olefins-driven FCC process (Petrochemical FCC) will be compared. Furthermore, the catalytic route for light olefins production in FCC units is also described. An additive based on ZSM- 5 zeolite, which is produced following a PETROBRAS proprietary technology, is being largely applied into the catalyst inventories of all FCC units. An analysis of different scenarios was performed to estimate the maximum potential of light olefins production from the highest possible ZSM-5 additive usage. More specifically for the case of ethylene, which production is also boosted by the same type of additive, studies are being conducted with the objective of recovering it from a C2 stream using specific units to do the splitting (UPGR). The search for increasing light olefins production in the refining processes is in line with PETROBRAS strategic plan which targeted for the company a more intense activity in the Brazilian petrochemical market (author)

  20. Effect of Organic Tin Compounds on Electric Properties of Model Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Podolak, M.; Engel, G.; Man, D. [Inst. of Physics, Opole Univ., Opole (Poland)

    2006-05-15

    The objective of the present work was to investigate the effect of selected organic tin compounds and potassium chloride (used as a reference substance) on the trans-membrane electric voltage and electric resistance of model membranes, the latter being nitrocellulose filters impregnated with butylene ester of lauric acid. The increasing KCl concentration (in the measurement chambers) caused a rapid rise of the negative trans-membrane voltage, whose value stabilized afterwards. In the case of (C{sub 3}H{sub 7}){sub 3}SnCl an abrupt maximum of the negative voltage was observed followed by a monotonic drop to zero. In the case of highest concentrations of this compound the voltages, after having reached zero, changed their polarization to the opposite. Within the range of small concentrations two slight voltage maxima were observed. Non-ionic tin compounds like (CH{sub 3}){sub 4}Sn and (C{sub 2}H{sub 5}){sub 4}Sn had an insignificant influence on the electric properties of the studied membranes. (orig.)

  1. Interaction of the organic tin chloride with the liquid model membranes

    Energy Technology Data Exchange (ETDEWEB)

    Podolak, M; Engel, G; Man, D [Institute of Physics, Opole University, Oleska 48, 45-052 Opole (Poland)

    2007-08-15

    The objective of the work was to investigate the effect of organic tin chloride (C{sub 3}H{sub 7}){sub 3}SnCl on the electric parameters of membranes in the form of filters of the company Synpor (Czech Republic) impregnated with various fatty acids, dissolved with carbon tetrachloride (CCl{sub 4}). Three carboxylic acids were used in the study: palmitic, arachidic and oleic, and dissolvent of the acids (CCl{sub 4}) as well as butylene ester of lauric acid. In all cases, introduction of tin chloride of constant concentration amounting to 0.15 mM to the measurement chamber resulted in induction of membrane voltage. In case of pure lauric acid and CCl{sub 4}, the voltage reached the maximum value and then decreased to a certain constant value. In the case of all acids dissolved in CCl{sub 4}, the voltage increased only up to a certain constant value. Voltage drop (below the value) was observed after application of appropriately high concentration of tin chloride, in case of membranes impregnated with the mixture of lauric acid ester with CCl{sub 4} and palmitic acid with CCl{sub 4}. The study also demonstrated that electrical resistance of membranes impregnated with carboxylic acid increased in the presence of tin chloride and decreased in case of membranes impregnated with lauric acid ester. However, electric capacities of membranes did not significant change.

  2. Interaction of the organic tin chloride with the liquid model membranes

    Science.gov (United States)

    Podolak, M.; Engel, G.; Man, D.

    2007-08-01

    The objective of the work was to investigate the effect of organic tin chloride (C3H7)3SnCl on the electric parameters of membranes in the form of filters of the company Synpor (Czech Republic) impregnated with various fatty acids, dissolved with carbon tetrachloride (CCl4). Three carboxylic acids were used in the study: palmitic, arachidic and oleic, and dissolvent of the acids (CCl4) as well as butylene ester of lauric acid. In all cases, introduction of tin chloride of constant concentration amounting to 0.15 mM to the measurement chamber resulted in induction of membrane voltage. In case of pure lauric acid and CCl4, the voltage reached the maximum value and then decreased to a certain constant value. In the case of all acids dissolved in CCl4, the voltage increased only up to a certain constant value. Voltage drop (below the value) was observed after application of appropriately high concentration of tin chloride, in case of membranes impregnated with the mixture of lauric acid ester with CCl4 and palmitic acid with CCl4. The study also demonstrated that electrical resistance of membranes impregnated with carboxylic acid increased in the presence of tin chloride and decreased in case of membranes impregnated with lauric acid ester. However, electric capacities of membranes did not significant change.

  3. An open source image processing method to quantitatively assess tissue growth after non-invasive magnetic resonance imaging in human bone marrow stromal cell seeded 3D polymeric scaffolds.

    Science.gov (United States)

    Leferink, Anne M; Fratila, Raluca M; Koenrades, Maaike A; van Blitterswijk, Clemens A; Velders, Aldrik; Moroni, Lorenzo

    2014-01-01

    Monitoring extracellular matrix (ECM) components is one of the key methods used to determine tissue quality in three-dimensional (3D) scaffolds for regenerative medicine and clinical purposes. This is even more important when multipotent human bone marrow stromal cells (hMSCs) are used, as it could offer a method to understand in real time the dynamics of stromal cell differentiation and eventually steer it into the desired lineage. Magnetic Resonance Imaging (MRI) is a promising tool to overcome the challenge of a limited transparency in opaque 3D scaffolds. Technical limitations of MRI involve non-uniform background intensity leading to fluctuating background signals and therewith complicating quantifications on the retrieved images. We present a post-imaging processing sequence that is able to correct for this non-uniform background intensity. To test the processing sequence we investigated the use of MRI for in vitro monitoring of tissue growth in three-dimensional poly(ethylene oxide terephthalate)-poly(butylene terephthalate) (PEOT/PBT) scaffolds. Results showed that MRI, without the need to use contrast agents, is a promising non-invasive tool to quantitatively monitor ECM production and cell distribution during in vitro culture in 3D porous tissue engineered constructs.

  4. An open source image processing method to quantitatively assess tissue growth after non-invasive magnetic resonance imaging in human bone marrow stromal cell seeded 3D polymeric scaffolds.

    Directory of Open Access Journals (Sweden)

    Anne M Leferink

    Full Text Available Monitoring extracellular matrix (ECM components is one of the key methods used to determine tissue quality in three-dimensional (3D scaffolds for regenerative medicine and clinical purposes. This is even more important when multipotent human bone marrow stromal cells (hMSCs are used, as it could offer a method to understand in real time the dynamics of stromal cell differentiation and eventually steer it into the desired lineage. Magnetic Resonance Imaging (MRI is a promising tool to overcome the challenge of a limited transparency in opaque 3D scaffolds. Technical limitations of MRI involve non-uniform background intensity leading to fluctuating background signals and therewith complicating quantifications on the retrieved images. We present a post-imaging processing sequence that is able to correct for this non-uniform background intensity. To test the processing sequence we investigated the use of MRI for in vitro monitoring of tissue growth in three-dimensional poly(ethylene oxide terephthalate-poly(butylene terephthalate (PEOT/PBT scaffolds. Results showed that MRI, without the need to use contrast agents, is a promising non-invasive tool to quantitatively monitor ECM production and cell distribution during in vitro culture in 3D porous tissue engineered constructs.

  5. Biodegradable nanofibers-reinforced microfibrous composite scaffolds for bone tissue engineering.

    Science.gov (United States)

    Martins, Albino; Pinho, Elisabete D; Correlo, Vítor M; Faria, Susana; Marques, Alexandra P; Reis, Rui L; Neves, Nuno M

    2010-12-01

    Native bone extracellular matrix (ECM) is a complex hierarchical fibrous composite structure, resulting from the assembling of collagen fibrils at several length scales, ranging from the macro to the nanoscale. The combination of nanofibers within microfibers after conventional reinforcement methodologies seems to be a feasible solution to the rational design of highly functional synthetic ECM substitutes. The present work aims at the development of bone ECM inspired structures, conjugating electrospun chitosan (Cht) nanofibers within biodegradable polymeric microfibers [poly(butylene succinate)-PBS and PBS/Cht], assembled in a fiber mesh structure. The nanofibers-reinforced composite fiber mesh scaffolds were seeded with human bone marrow mesenchymal stem cells (hBMSCs) and cultured under osteogenic differentiation conditions. These nanofibers-reinforced composite scaffolds sustained ECM deposition and mineralization, mainly in the PBS/Cht-based fiber meshes, as depicted by the increased amount of calcium phosphates produced by the osteogenic differentiated hBMSCs. The osteogenic genotype of the cultured hBMSCs was confirmed by the expression of osteoblastic genes, namely Alkaline Phosphatase, Osteopontin, Bone Sialoprotein and Osteocalcin, and the transcription factors Runx2 and Osterix, all involved in different stages of the osteogenesis. These data represent the first report on the biological functionality of nanofibers-reinforced composite scaffolds, envisaging the applicability of the developed structures for bone tissue engineering.

  6. Crystallization kinetics and thermal resistance of bamboo fiber reinforced biodegradable polymer composites

    Science.gov (United States)

    Thumsorn, S.; Srisawat, N.; On, J. Wong; Pivsa-Art, S.; Hamada, H.

    2014-05-01

    Bamboo fiber reinforced biodegradable polymer composites were prepared in this study. Biodegradable poly(butylene succinate) (PBS) was blended with bamboo fiber in a twin screw extruder with varied bamboo content from 20-0wt%. PBS/bamboo fiber composites were fabricated by compression molding process. The effect of bamboo fiber contents on properties of the composites was investigated. Non-isothermal crystallization kinetic study of the composites was investigated based on Avrami equation. The kinetic parameters indicated that bamboo fiber acted as heterogeneous nucleation and enhanced crystallinity of the composites. Bamboo fiber was well dispersed on PBS matrix and good adhered with the matrix. Tensile strength of the composites slightly deceased with adding bamboo fiber. However, tensile modulus and impact strength of the composites increased when increasing bamboo fiber contents. It can be noted that bamboo fiber promoted crystallization and crystallinity of PBS in the composites. Therefore, the composites were better in impact load transferring than neat PBS, which exhibited improving on impact performance of the composites.

  7. Electron beam damage in high temperature polymers

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S. (Dayton Univ., OH (USA). Research Inst.); Adams, W.W. (Air Force Materials Lab., Wright-Patterson AFB, OH (USA))

    1990-01-01

    Electron microscopic studies of polymers are limited due to beam damage. Two concerns are the damage mechanism in a particular material, and the maximum dose for a material before damage effects are observed. From the knowledge of the dose required for damage to the polymer structure, optimum parameters for electron microscopy imaging can be determined. In the present study, electron beam damage of polymers has been quantified by monitoring changes in the diffraction intensity as a function of electron dose. The beam damage characteristics of the following polymers were studied: poly(p-phenylene benzobisthiazole) (PBZT); poly(p-phenylene benzobisoxazole) (PBO); poly(benzoxazole) (ABPBO); poly(benzimidazole) (ABPBI); poly(p-phenylene terephthalamide) (PPTA); and poly(aryl ether ether ketone) (PEEK). Previously published literature results on polyethylene (PE), polyoxymethylene (POM), nylon-6, poly(ethylene oxide) (PEO), PBZT, PPTA, PPX, iPS, poly(butylene terephthalate) (PBT), and poly(phenylene sulphide) (PPS) were reviewed. This study demonstrates the strong dependence of the electron beam resistivity of a polymer on its thermal stability/melt temperature. (author).

  8. Effects of plasticization and shear stress on phase structure development and properties of soy protein blends.

    Science.gov (United States)

    Chen, Feng; Zhang, Jinwen

    2010-11-01

    In this study, soy protein concentrate (SPC) was used as a plastic component to blend with poly(butylene adipate-co-terephthalate) (PBAT). Effects of SPC plasticization and blend composition on its deformation during mixing were studied in detail. Influence of using water as the major plasticizer and glycerol as the co-plasticizer on the deformation of the SPC phase during mixing was explored. The effect of shear stress, as affected by SPC loading level, on the phase structure of SPC in the blends was also investigated. Quantitative analysis of the aspect ratio of SPC particles was conducted by using ImageJ software, and an empirical model predicting the formation of percolated structure was applied. The experimental results and the model prediction showed a fairly good agreement. The experimental results and statistic analysis suggest that both SPC loading level and its water content prior to compounding had significant influences on development of the SPC phase structure and were correlated in determining the morphological structures of the resulting blends. Consequently, physical and mechanical properties of the blends greatly depended on the phase morphology and PBAT/SPC ratio of the blends.

  9. Phase diagrams in blends of poly(3-hydroxybutyric acid with various aliphatic polyesters

    Directory of Open Access Journals (Sweden)

    2011-07-01

    Full Text Available Phase behavior with immiscibility, miscibility, crystalline morphology, and kinetic analysis in blends of poly(3-hydroxybutyric acid (PHB with aliphatic polyesters such as poly(butylene adipate (PBA, poly(ethylene adipate (PEA, poly(trimethylene adipate (PTA, or poly(ethylene succinate (PESu, respectively, were explored mainly using differential scanning calorimeter (DSC and polarized-light optical microscopy (POM. Immiscibility phase behavior with reversible upper-critical-solution-temperature (UCST is common in the PHB/polyester blends. The polyester/polyester blend of PHB/PTA is partially miscible with no UCST in melt and amorphous glassy states within a composition range of PTA less than 50 wt%. The miscible crystalline/crystalline blend exhibits ring-banded spherulites at Tc = 50~100°C, with inter-ring spacing dependent on Tc. All immiscible or partially miscible PHB/polyester blends, by contrast, exhibit disrupted ringbanded spherulites or discrete spherical phase domains upon cooling from UCST to crystallization. The blends of PHB with all other aliphatic polyesters, such as PESu, PEA, PBA, etc. are only partially miscible or immiscible with an upper critical solution temperature (UCST at 180~221°C depending on blend composition. UCST with reversibility was verified.

  10. FADS2 function loss at the cancer hotspot 11q13 locus diverts lipid signaling precursor synthesis to unusual eicosanoid fatty acids.

    Directory of Open Access Journals (Sweden)

    Woo Jung Park

    Full Text Available BACKGROUND: Genes coding for the fatty acid desaturases (FADS1, 2, 3 localized at the cancer genomic hotspot 11q13 locus are required for the biosynthesis of 20 carbon polyunsaturated fatty acids (PUFA that are direct eicosanoid precursors. In several cancer cell lines, FADS2 encoded Δ6 and Δ8 desaturation is not functional. METHODOLOGY/PRINCIPAL FINDINGS: Analyzing MCF7 cell fatty acids with detailed structural mass spectrometry, we show that in the absence of FADS2 activity, the FADS1 product Δ5-desaturase operates to produce 5,11,14-20∶3 and 5,11,14,17-20∶4. These PUFA are missing the 8-9 double bond of the eicosanoid signaling precursors arachidonic acid (5,8,11,14-20∶4 and eicosapentaenoic acid (5,8,11,14,17-20∶5. Heterologous expression of FADS2 restores Δ6 and Δ8-desaturase activity and normal eicosanoid precursor synthesis. CONCLUSIONS/SIGNIFICANCE: The loss of FADS2-encoded activities in cancer cells shuts down normal PUFA biosynthesis, deleting the endogenous supply of eicosanoid and downstream docosanoid precursors, and replacing them with unusual butylene-interrupted fatty acids. If recapitulated in vivo, the normal eicosanoid and docosanoid cell signaling milieu would be depleted and altered due to reduction and substitution of normal substrates with unusual substrates, with unpredictable consequences for cellular communication.

  11. Study on the Synthesis Process and Performance Comparison of Aliphatic Polyester%脂肪族聚酯的合成工艺及性能比较研究∗

    Institute of Scientific and Technical Information of China (English)

    寇莹; 郭鹏; 陈红亮

    2015-01-01

    In this paper,for the poly butylene succinate,succinic acid glycol ester,succinic acid glycol ester/top adipic acid glycol ester copolymer,PLA and PCL aliphatic polyester,the synthesis process and properties of them were compared. By comparing the relationship between synthesis and material properties of aliphatic polyester,for the synthesis and modification to provide train of thought.%对聚丁二酸丁二醇酯、聚丁二酸乙二醇酯、聚丁二酸己二醇酯/己二酸己二醇酯共聚物、聚乳酸以及聚己内酯等脂肪族聚酯的合成工艺及性能进行比较,通过比较探讨合成工艺和材料性能之间的关系,得出力学性能和分子量,性能和结晶度以及降解性之间的关系,为脂肪族聚酯的合成改性及降解研究提供思路。

  12. High-Throughput Analysis of Enzymatic Hydrolysis of Biodegradable Polyesters by Monitoring Cohydrolysis of a Polyester-Embedded Fluorogenic Probe.

    Science.gov (United States)

    Zumstein, Michael Thomas; Kohler, Hans-Peter E; McNeill, Kristopher; Sander, Michael

    2017-02-14

    Biodegradable polyesters have the potential to replace nondegradable, persistent polymers in numerous applications and thereby alleviate plastic accumulation in the environment. Herein, we present an analytical approach to study enzymatic hydrolysis of polyesters, the key step in their overall biodegradation process. The approach is based on embedding fluorescein dilaurate (FDL), a fluorogenic ester substrate, into the polyester matrix and on monitoring the enzymatic cohydrolysis of FDL to fluorescein during enzymatic hydrolysis of the polyester. We validated the approach against established techniques using FDL-containing poly(butylene adipate) films and Fusarium solani cutinase (FsC). Implemented on a microplate reader platform, the FDL-based approach enabled sensitive and high-throughput analysis of the enzymatic hydrolysis of eight aliphatic polyesters by two fungal esterases (FsC and Rhizopus oryzae lipase) at different temperatures. While hydrolysis rates for both enzymes increased with decreasing differences between the polyester melting temperatures and the experimental temperatures, this trend was more pronounced for the lipase than the cutinase. These trends in rates could be ascribed to a combination of temperature-dependent polyester chain flexibility and accessibility of the enzyme active site. The work highlights the capability of the FDL-based approach to be utilized in both screening and mechanistic studies of enzymatic polyester hydrolysis.

  13. Significant Enhancement of Mechanical and Thermal Properties of Thermoplastic Polyester Elastomer by Polymer Blending and Nanoinclusion

    Directory of Open Access Journals (Sweden)

    Manwar Hussain

    2016-01-01

    Full Text Available Thermoplastic elastomer composites and nanocomposites were fabricated via melt processing technique by blending thermoplastic elastomer (TPEE with poly(butylene terephthalate (PBT thermoplastic and also by adding small amount of organo modified nanoclay and/or polytetrafluoroethylene (PTFE. We study the effect of polymer blending on the mechanical and thermal properties of TPEE blends with and without nanoparticle additions. Significant improvement was observed by blending only TPEE and virgin PBT polymers. With a small amount (0.5 wt.% of nanoclay or PTFE particles added to the TPEE composite, there was further improvement in both the mechanical and thermal properties. To study mechanical properties, flexural strength (FS, flexural modulus (FM, tensile strength (TS, and tensile elongation (TE were all investigated. Thermogravimetric analysis (TGA and differential scanning calorimetry (DSC were used to analyze the thermal properties, including the heat distortion temperature (HDT, of the composites. Scanning electron microscopy (SEM was used to observe the polymer fracture surface morphology. The dispersion of the clay and PTFE nanoparticles was confirmed by transmission electron microscopy (TEM analysis. This material is proposed for use as a baffle plate in the automotive industry, where both high HDT and high modulus are essential.

  14. Purification and Properties of an Extracellular Polyhydroxybutyrate Depolymerase from Pseudomonas mendocina DSWY0601

    Institute of Scientific and Technical Information of China (English)

    WANG Yan; LI Fan; WANG Zhan-yong; LIU Dong-bo; XIA Hong-mei; LIU Ling-fei; CHEN Shan

    2012-01-01

    An extracellular polyhydroxybutyrate(PHB) depolymerase was purified to homogeneity from the culture supematant of a PHB-degrading bacterium,Pseudomonas mendocina DSWY0601,which was isolated from brewery sewage for the ability to form clear zones on the PHB mineral agar plates.The molecular weight of the purified PHB depolymerase as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) was approximately 59800 at the optimal temperature and pH value being 50℃ and 8.5,respectively.PHB depolymerase was stable in a temperature rangc of 20--50℃ and sensitive to pH value within a pH range of 8.0--9.5.PHB depolymerase degraded poly-3-hydroxybutyrate-co-4-hydroxybutyrate(P3/4HB) and poly-3-hydroxybutyrate-co-3-hydroxyvalerate(PHBV) but did not degrade poly(lactic acid)(PLA),poly(butylene succinate)(PBS) or poly(caprolactone)(PCL).PHB depolymerase was sensitive to phenylmethylsulfonyl fluoride(PMSF),H2O2 and SDS.The main product after enzymatic degradation of PHB was indentified as 3-hydroxbutyrate monomer(3HB) by mass spectrometric analysis,suggesting that PHB depolymerase acted as an exo-type hydrolase.Analysis ofphaZpm gene reveals that PHB depolymerase is a typical denatured short-chain-length PHA(dPHAscL,PHA=polyhydroxyalkanoate)depolymerase containing catalytic domain,linker and substrate-binding domain.

  15. Association behavior of mixed triblock copoly(oxyalkylene)s (type EBE and ESE) in aqueous solution.

    Science.gov (United States)

    Ricardo, Nágila M P S; Chaibundit, Chiraphon; Yang, Zhuo; Attwood, David; Booth, Colin

    2006-01-31

    The micellization of binary mixtures of water-soluble block copolymers E(m)B(n)E(m) and E(m)S(n)E(m) in dilute solution was investigated by light-scattering methods. We use the notation E, B, and S to denote chain units derived, respectively, from ethylene oxide, butylene oxide, and styrene oxide and the subscripts to denote number-average chain lengths in chain units. Two distinct distributions of micelles were formed in solutions of a 50:50 wt % mixture of copolymers E64B20E64 and E137S18E137, which had hydrophobic blocks of similar length but very different hydrophobicity. One distribution of micelles was formed in solutions of a mixture (50:50 wt %) of copolymers E135B20E135 and E82S9E82, which had hydrophobic blocks of different length but similar hydrophobicity. In this case, the properties of the micelles formed in solutions of the mixture were very similar to those of micelles of E82S9E82 alone. This result extended to concentrated solutions, because the hard-gel boundary for the mixture proved to be very similar to that of solutions of E82S9E82 alone.

  16. Effect of organic acids as additives on the performance of thermoplastic starch/polyester blown films.

    Science.gov (United States)

    Olivato, J B; Grossmann, M V E; Bilck, A P; Yamashita, F

    2012-09-01

    The influence of citric acid (CA), malic acid (MA) and tartaric acid (TA) in starch/poly (butylene adipate co-terephthalate) blown films was evaluated by examining the barrier, structural and mechanical properties of the films. These properties were analysed in different relative humidities. Greater concentrations of TA and CA (1.5 wt%) produced films with improved tensile strength (6.8±0.3 and 6.7±0.3 MPa, respectively), reduced water vapour permeability and a more homogeneous structure. The compatibilising effect of MA was less efficient, as shown in the scanning electron microscopy (SEM) images. Changes in the relative humidity (RH) affected the elongation of the films, which reached values of 5.7±0.5 at 33% RH and increased to 312.4±89.5% at 53% RH. The FT-IR spectra showed no additional reactions caused by the incorporation of the additives, and the observed results are attributed to the esterification reactions and/or hydrolysis of the starch, producing films with interesting properties. This process represents an alternative to the use of non-biodegradable materials.

  17. Colloidal Gold Nanoclusters Spiked Silica Fillers in Mixed Matrix Coatings: Simultaneous Detection and Inhibition of Healthcare-Associated Infections.

    Science.gov (United States)

    Alsaiari, Shahad K; Hammami, Mohammed A; Croissant, Jonas G; Omar, Haneen W; Neelakanda, Pradeep; Yapici, Tahir; Peinemann, Klaus-Viktor; Khashab, Niveen M

    2017-01-25

    Healthcare-associated infections (HAIs) are the infections that patients get while receiving medical treatment in a medical facility with bacterial HAIs being the most common. Silver and gold nanoparticles (NPs) have been successfully employed as antibacterial motifs; however, NPs leaching in addition to poor dispersion and overall reproducibility are major hurdles to further product development. In this study, the authors design and fabricate a smart antibacterial mixed-matrix membrane coating comprising colloidal lysozyme-templated gold nanoclusters as nanofillers in poly(ethylene oxide)/poly(butylene terephthalate) amphiphilic polymer matrix. Mesoporous silica nanoparticles-lysozyme functionalized gold nanoclusters disperse homogenously within the polymer matrix with no phase separation and zero NPs leaching. This mixed-matrix coating can successfully sense and inhibit bacterial contamination via a controlled release mechanism that is only triggered by bacteria. The system is coated on a common radiographic dental imaging device (photostimulable phosphor plate) that is prone to oral bacteria contamination. Variation and eventually disappearance of the red fluorescence surface under UV light signals bacterial infection. Kanamycin, an antimicrobial agent, is controllably released to instantly inhibit bacterial growth. Interestingly, the quality of the images obtained with these coated surfaces is the same as uncoated surfaces and thus the safe application of such smart coatings can be expanded to include other medical devices without compromising their utility.

  18. Amphiphilic Beads as Depots for Sustained Drug Release Integrated into Fibrillar Scaffolds

    Science.gov (United States)

    Gaharwar, Akhilesh K.; Mihaila, Silvia M.; Kulkarni, Ashish A.; Patel, Alpesh; Di Luca, Andrea; Reis, Rui L.; Gomes, Manuela E.; van Blitterswijk, Clemens; Moroni, Lorenzo; Khademhosseini, Ali

    2014-01-01

    Native extracellular matrix (ECM) is a complex fibrous structure loaded with bioactive cues that affects the surrounding cells. A promising strategy to mimicking native tissue architecture for tissue engineering applications is to engineer fibrous scaffolds using electrospinning. By loading appropriate bioactive cues within these fibrous scaffolds, various cellular functions such as cell adhesion, proliferation and differentiation can be regulated. Here, we report on the encapsulation and sustained release of model hydrophobic drug (dexamethasone (Dex)) within beaded fibrillar scaffold of poly(ethylene oxide terephthalate)-poly(butylene terephthalate) (PEOT/PBT), a polyether-ester multiblock copolymer to direct differentiation of human mesenchymal stem cells (hMSCs). The amphiphilic beads act as depots for sustained drug release that is integrated into the fibrillar scaffolds. The entrapment of Dex within the beaded structure results in sustained release of drug over the period of 28 days. This is mainly attributed to the diffusion driven release of Dex from the amphiphilic electrospun scaffolds. In vitro results indicate that hMSCs cultured on Dex containing beaded fibrillar scaffolds exhibit an increase in osteogenic differentiation potential, as evidenced by increased alkaline phosphatase (ALP) activity, compared to the direct infusion of Dex in culture medium. The formation of mineralized matrix is also significantly enhanced due to the controlled Dex release from the fibrous scaffolds. This approach can be used to engineer scaffolds with appropriate chemical cues to direct tissue regeneration. PMID:24794894

  19. Isolation and screening of biopolymer-degrading microorganisms from northern Thailand.

    Science.gov (United States)

    Penkhrue, Watsana; Khanongnuch, Chartchai; Masaki, Kazuo; Pathom-Aree, Wasu; Punyodom, Winita; Lumyong, Saisamorn

    2015-09-01

    Forty agricultural soils were collected from Chiang Mai and Lampang provinces in northern Thailand. Bacteria, actinomycetes and fungi were isolated and screened for their ability to degrade polylactic acid (PLA), polycaprolactone (PCL) and poly(butylene succinate) (PBS) by the agar diffusion method. Sixty-seven actinomycetes, seven bacteria and five fungal isolates were obtained. The majority of actinomycetes were Streptomyces based on morphological characteristic, chemotaxonomy and 16S rRNA gene data. Seventy-nine microorganisms were isolated from 40 soil samples. Twenty-six isolates showed PLA-degradation (32.9 %), 44 isolates showed PBS-degradation (55.7 %) and 58 isolates showed PCL-degradation (73.4 %). Interestingly, 16 isolates (20.2 %) could degrade all three types of bioplastics used in this study. The Amycolatopsis sp. strain SCM_MK2-4 showed the highest enzyme activity for both PLA and PCL, 0.046 and 0.023 U/mL, respectively. Moreover, this strain produced protease, esterase and lipase on agar plates. Approximately, 36.7 % of the PLA film was degraded by Amycolatopsis sp. SCM_MK2-4 after 7 days of cultivation at 30 °C in culture broth.

  20. MISCIBILITY, CRYSTALLIZATION AND MECHANICAL PROPERTIES OF PPC/PBS BLENDS

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, melt blends of poly(propylene carbonate) (PPC) with poly(butylene succinate) (PBS) were characterized by dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), tensile testing, wide-angle X-ray diffraction (WAXD), polarized optical microscopy and thermogravimetric analysis (TGA). The results indicated that the glass transition temperature of PPC in the 90/10 PPC/PBS blend was decreased by about 11 K comparing with that of pure PPC. The presence of 10% PBS was partially miscible with PPC. The 90/10 PPC/PBS blend had better impact and tensile strength than those of the other PPC/PBS blends. The glass transition temperature of PPC in the 80/20, 70/30, and 60/40 PPC/PBS blends was improved by about 4.9 K, 4.2 K, and 13 K comparing with that of pure PPC, respectively; which indicated the immiscibility between PPC and PBS. The DSC results indicated that the crystallization of PBS became more difficult when the PPC content increased. The matrix of PPC hindered the crystallization process of PBS. While the content of PBS was above 20%, significant crystallization-induced phase separation was observed by polarized optical microscopy.It was found from the WAXD analysis that the crystal structure of PBS did not change, and the degree of crystallinity increased with increasing PBS content in the PPC/PBS blends.

  1. Metallic Nanoparticle Block Copoloymer Vesicles with Enhanced Optical Properties

    Directory of Open Access Journals (Sweden)

    Juan Leonardo Martinez-Hurtado

    2011-05-01

    Full Text Available The fabrication and characterization of template silver nanoshell structures and the encapsulation of gold nanoparticles using biocompatible poly(oxyethylene-poly(butylene diblock co-polymer vesicles is described in this work. These vesicles have a narrow diameter size distribution around 200 nm. Silver nanoparticles (Ø = 1–10 nm functionalized with decanethiol were successfully entrapped in the hydrophobic membrane and non-functionalized gold nanoparticles (Ø = 3.0–5.5 nm were encapsulated in the vesicle core. Transmission Electron Microscopy confirms the localisation of the particles; silver functionalized nanoparticles appear to thicken the vesicle membrane as shown with TEM image analysis. The enhancement of the optical properties is confirmed using transmission spectrophotometry; the 430 nm plasmon resonance peak of the silver nanoparticles was replaced by a broader extinction spectrum to beyond 700 nm (O.D. = 0.8. For a number density of 4.8 x 1012 mL-1 the scattering cross section was calculated to be 0.92 x 10-4 μm2 with a scattering coefficient of 0.44 mm-1. The measurements indicate scattering cross section of 3.8 x 10-5 μm2, attenuation coefficient of 0.18 mm-1 and extinction efficiency equal to 1.2 x 10-3. Stable and biocompatible block co-polymer vesicles can potentially be used as plasmon-resonant optical contrast agents for biomedical applications.

  2. The micro thermal analysis of polymers

    CERN Document Server

    Grandy, D B

    2002-01-01

    This study is concerned with the development of micro-thermal analysis as a technique for characterising heterogeneous polymers. It is divided into two main parts. In the first part, the use of miniature Wollaston wire near-field thermal probes mounted in an atomic force microscope (AFM) to carry out highly localised thermal analysis (L-TA) of amorphous and semi-crystalline polymers is investigated. Here, the temperature of the probe sensor or tip is scanned over a pre-selected temperature range while in contact with the surface of a sample. It is thereby used to heat a volume of material of the order of several cubic micrometres. The effect of the glass transition, cold crystallisation, melting and degree of crystallinity on L-TA measurements is investigated. The materials used are poly(ethylene terephthalate), polystyrene and fluorocarbon-coated poly(butylene terephthalate). The primary measurements are the micro- or localised analogues of thermomechanical analysis (L-TMA) and differential thermal analysis ...

  3. Effect of reinforcement nanoparticles addition on mechanical properties of SBS/curaua fiber composites

    Energy Technology Data Exchange (ETDEWEB)

    Borba, Patricia M. [Servico Nacional de Aprendizagem Industrial (CETEPO/SENAI/RS), Sao Leopoldo, RS (Brazil). Centro Tecnologico de Polimeros; Tedesco, Adriana [Braskem S. A., III Polo Petroquimico, Triunfo, RS (Brazil); Lenz, Denise M., E-mail: denise.lenz@gmail.com [Universidade Luterana do Brasil (ULBRA), Canoas, RS (Brazil). Programa de Pos-graduacao em Engenharia de Materiais e Processos Sustentaveis

    2014-03-15

    Composites of styrene-butadiene-styrene triblock copolymer (SBS) matrix with curauá fiber and/or a nanoparticulated mineral (montmorillonite clay - MMT) used as reinforcing agents were prepared by melt-mixing. The influence of clay addition on properties like tensile and tear strength, rebound resilience, flex fatigue life, abrasion loss, hardness and water absorption of composites with 5, 10 and 20 wt% of curauá fiber was evaluated in presence of maleic anhydride grafted styrene-(ethylene-co-butylene)-styrene triblock copolymer (MA-g-SEBS) coupling agent. Furthermore, the effect of mineral plasticizer loading on tensile strength of selected composites was investigated. The hybrid SBS composite that showed the best overall mechanical performance was composed by 2 wt% of MMT and 5 wt% of curauá fiber. Increasing fiber content up to 20 wt% resulted in a general decrease in all mechanical properties as well as incorporation of 5 wt% MMT caused a decrease in the tensile strength in all fiber contents. The hybrid composites showed clay agglomerates (tactoids) poorly dispersed that could explain the poor mechanical performance of composites at higher concentrations of curauá fiber and MMT nanoparticles. The addition of plasticizer further decreased the tensile strength while the addition of MMT nanoparticles decreased water absorption for all SBS composites. (author)

  4. Effects of different level addition of zeolite ZSM-5 additive on quality and composition of the dry gas, LPG (Liquefied Petroleum Gas) and gasoline, produced in FCC (Fluid Catalytic Cracking); Efeito dos diferentes niveis de adicao de aditivos de ZSM-5 na qualidade e composicao do gas combustivel, GLP e gasolina produzidos em FCC

    Energy Technology Data Exchange (ETDEWEB)

    Bastiani, Raquel; Pimenta, Ricardo D.M.; Almeida, Marlon B.B.; Lau, Lam Y. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2004-07-01

    The effects of the addition of different level of ZSM-5 additives on different FCC catalysts formulations have been studied on laboratory scale FST (Fluidized Simulation Test). The main objective of the present work is to perform a qualitative identification of the main parameters of FCC catalyst which affect the ZSM-5 additives performance concerning quality and composition of Dry Gas, LPG and Gasoline. The product composition of each test was analyzed by PIANO groups separated by carbon number. The effect of ZSM-5 on products composition was evaluated. The results showed that the ZSM-5 additive cracks gasoline range olefins and isoparaffins into Dry Gas and LPG, favoring the formation of ethylene, propylene and butylenes, while the absolute yield of gasoline aromatics changes little. The aromatics fraction in gasoline, MON and RON numbers in gasoline increase. The ZSM-5 effectiveness is negatively affected by high levels of rare earth on FCC catalyst (RE-USY). Higher hydrogen transfer provides lower olefins (higher than C6) formation, which are the most reactive species for ZSM-5 cracking. (author)

  5. Application of polymer nanocomposites in the nanomedicine landscape: envisaging strategies to combat implant associated infections.

    Science.gov (United States)

    Dwivedi, Poushpi; Narvi, Shahid S; Tewari, Ravi P

    2013-12-16

    This review article presents an overview of the potential biomedical application of polymer nanocomposites arising from different chemistries, compositions, and constructions. The interaction between the chosen matrix and the filler is of critical importance. The existing polymer used in the biomedical arena includes aliphatic polyesters such as polylactide (PLA), poly(ε-caprolactone) (PCL), poly(p-dioxanone) (PPDO), poly(butylenes succinate) (PBS), poly(hydroxyalkanoate)s, and natural biopolymers such as starch, cellulose, chitin, chitosan, lignin, and proteins. The nanosized fillers utilized to fabricate the nanocomposites are inorganic, organic, and metal particles such as clays, magnetites, hydroxyapatite, nanotubes chitin whiskers, lignin, cellulose, Au, Ag, Cu, etc. These nanomaterials are taking root in a variety of diverse healthcare applications in the sector of nanomedicine including the domain of medical implants and devices. Despite sterilization and aseptic procedures the use of these biomedical devices and prosthesis to improve the patient's 'quality of life' is facing a major impediment because of bacterial colonization causing nosocomial infection, together with the multi-drug-resistant 'super-bugs' posing a serious threat to its utility. This paper discusses the current efforts and key research challenges in the development of self-sterilizing nanocomposite biomaterials for potential application in this area.

  6. Biopolymer Blends Based on Poly (lactic acid: Shear and Elongation Rheology/Structure/Blowing Process Relationships

    Directory of Open Access Journals (Sweden)

    Racha Al-Itry

    2015-05-01

    Full Text Available This study was dedicated to the blown film extrusion of poly(lactic acid, which mainly presents poor shear and elongation viscosities, and its blends. In order to enhance its melt strength, two main routes were selected (i a structural modification through chain extension and branching mechanisms by adding a reactive multifunctional epoxide (named Joncryl and (ii blending with poly(butylene adipate-co-terephtalate, named PBAT in presence (or not of Joncryl. The effects of the reactive agent on the shear and elongation rheology, morphological, and interfacial properties of the blends were systematically investigated. A decrease of the interfacial tension has been also demonstrated according to the deformed drop retraction method (DDRM. Hence, the role of Joncryl as a compatibilizer was highlighted. Consequently, finer morphology of the dispersed phase was obtained. Furthermore, the impact of the two modification routes on the blown film extrusion ability of PLA has been studied. Based on the improved shear and elongational rheological properties, a great enlargement of the blowing processing window of PLA modified with Joncryl was demonstrated. Indeed, with the addition of Joncryl into PLA–PBAT blends, a reduction of the instability defects has been detected. Finally, the induced crystalline structure and the thermo-mechanical properties of blown films were shown to be improved.

  7. Preparation and application of conducting polymer/Ag/clay composite nanoparticles formed by in situ UV-induced dispersion polymerization.

    Science.gov (United States)

    Zang, Limin; Qiu, Jianhui; Yang, Chao; Sakai, Eiichi

    2016-02-03

    In this work, composite nanoparticles containing polypyrrole, silver and attapulgite (PPy/Ag/ATP) were prepared via UV-induced dispersion polymerization of pyrrole using ATP clay as a templet and silver nitrate as photoinitiator. The effects of ATP concentration on morphology, structure and electrical conductivity were studied. The obtained composite nanoparticles with an interesting beads-on-a-string morphology can be obtained in a short time (10 min), which indicates the preparation method is facile and feasible. To explore the potential applications of the prepared PPy/Ag/ATP composite nanoparticles, they were served as multifunctional filler and blended with poly(butylene succinate) (PBS) matrix to prepare biodegradable composite material. The distribution of fillers in polymer matrix and the interfacial interaction between fillers and PBS were confirmed by scanning electron microscope, elemental mapping and dynamic mechanical analysis. The well dispersed fillers in PBS matrix impart outstanding antibacterial property to the biodegradable composite material as well as enhanced storage modulus due to Ag nanoparticles and ATP clay. The biodegradable composite material also possesses modest surface resistivity (10(6)~ 10(9) Ω/◻).

  8. Development of Ultrafiltration Membrane-Separation Technology for Energy-Efficient Water Treatment and Desalination Process

    Energy Technology Data Exchange (ETDEWEB)

    Yim, Woosoon [Univ. of Nevada, Las Vegas, NV (United States); Bae, Chulsung [Rensselaer Polytechnic Inst., Troy, NY (United States)

    2016-10-28

    The growing scarcity of fresh water is a major political and economic challenge in the 21st century. Compared to thermal-based distillation technique of water production, pressure driven membrane-based water purification process, such as ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO), can offer more energy-efficient and environmentally friendly solution to clean water production. Potential applications also include removal of hazardous chemicals (i.e., arsenic, pesticides, organics) from water. Although those membrane-separation technologies have been used to produce drinking water from seawater (desalination) and non-traditional water (i.e., municipal wastewater and brackish groundwater) over the last decades, they still have problems in order to be applied in large-scale operations. Currently, a major huddle of membrane-based water purification technology for large-scale commercialization is membrane fouling and its resulting increases in pressure and energy cost of filtration process. Membrane cleaning methods, which can restore the membrane properties to some degree, usually cause irreversible damage to the membranes. Considering that electricity for creating of pressure constitutes a majority of cost (~50%) in membrane-based water purification process, the development of new nano-porous membranes that are more resistant to degradation and less subject to fouling is highly desired. Styrene-ethylene/butylene-styrene (SEBS) block copolymer is one of the best known block copolymers that induces well defined morphologies. Due to the polarity difference of aromatic styrene unit and saturated ethylene/butylene unit, these two polymer chains self-assemble each other and form different phase-separated morphologies depending on the ratios of two polymer chain lengths. Because the surface of SEBS is hydrophobic which easily causes fouling of membrane, incorporation of ionic group (e,g, sulfonate) to the polymer is necessary to reduces fouling

  9. 电渗析技术在生产生物化工醇中的应用研究%Application of Electrodialysis Technology in the Production of Polyol Chemicals

    Institute of Scientific and Technical Information of China (English)

    罗文杰; 谢鸿飞; 陆启明; 李锦; 翁东东; 王雪娟

    2014-01-01

    秸秆糖在高压氢化裂解过程中,反应产生丙二醇、乙二醇、丁二醇、丙三醇等多元醇[1],反应液中含有有机盐类,对分离单一的二元醇影响较大,后期重组分含量多,影响精馏分离操作,通过电渗析技术,能够有效的脱除多元醇反应液中的盐类,该实验通过化工分离专用离子交换膜的电渗析技术对多元醇反应液进行脱盐处理,确定了最佳的实验操作参数。实验结果表明,电渗析法对脱除生物多元醇反应液中的盐类是可行的,脱盐效果达到95%,多元醇收率达到94%。%Straw sugar pressure hydrocracking process , the reaction of propylene glycol , ethylene glycol , butylene glycol, polyhydric alcohols such as glycerin , organic salts contained in the reaction solution , the separated single diol greater impact , heavy post content and affect operation of distillation separation by electrodialysis , the polyol can effectively remove salts in the reaction solution , the experiment exchanged membrane electrodialysis polyol reaction solution was desalted by ion chemical separation professional , and the optimum operating parameters of the experiment were determined.Experimental results showed that the removal of biological electrodialysis polyhydric alcohol solution of salts was possible , desalting effect reached to 95%, and yield of 96%polyol.

  10. Interfacial Shish-kebabs Lengthened by Coupling Effect of In-situ Flexible Nanofibrils and Intense Shear Flow: Achieving Hierarchy to Conquer the Conflicts between Strength and Toughness of Polylactide.

    Science.gov (United States)

    Zhou, Sheng-Yang; Niu, Ben; Xie, Xu-Long; Ji, Xu; Zhong, Gan-Ji; Hsiao, Benjamin S; Li, Zhong-Ming

    2017-03-02

    The challenge of hitherto elaborating a feasible pathway to overcome the conflicts between strength and toughness of polylactide (PLA) still remains among academia and industry. In the current work, a unique hierarchal structure of flexible poly(butylene adipate-co-terephthalate) (PBAT) in-situ nanofibrils integrating with abundant PLA shish-kebabs as strong building block was disclosed and expresses its capability to availably conquer this dilemma. Substantially simultaneous enhancement on tensile strength, impact strength and elongation at break could be achieved up to 91.2 MPa, 14.9 KJ/m(2) and 15.7 % respectively compared with pure PLA (61.5 MPa, 4.3 KJ/m(2), and 6.2 %). Through investigating the phase (and crystalline) morphology and molecular chain behavior in PLA/PBAT system, the formation mechanism of this structure facilitated by a coupling effect of PBAT flexible phase and shear flow was definitely elucidated. The dispersed phase of PBAT would be more inclined to existing as a fibrillar form within PLA matrix benefiting from low interfacial tension. Interestingly, this phase morphology with large specific surface area changes the crystallization behavior of PLA significantly, once introducing an intense shear flow (~10(3) s(-1)), in-situ shear-formed nanofibrils of PBAT would show strong coupling effect with shear flow on PLA crystallization: they can not only induce abundant shish-kebabs of PLA at its interfaces, which possesses lengthened shish and more densely arranged kebabs; its hysteretic relaxation of PBAT phase can further retard the relaxation of PLA chains, which can well prevent the collapse of established shish. Of immense significance is this particular hierarchical-architecture composed by flexible nanofibers (PBAT) and rigid shish-kebabs (PLA) provides significant guidance for the simultaneous reinforcement and toughness of polymer materials.

  11. Mesoporous MgTa2O6 thin films with enhanced photocatalytic activity: On the interplay between crystallinity and mesostructure

    Directory of Open Access Journals (Sweden)

    Jin-Ming Wu

    2012-02-01

    Full Text Available Ordered mesoporous, crystalline MgTa2O6 thin films with a mesoscopic nanoarchitecture were synthesized by evaporation-induced self-assembly (EISA in combination with a sol–gel procedure. Utilization of novel templates, namely the block copolymers KLE (poly(ethylene-co-butylene-b-poly(ethylene oxide and PIB6000 (CH3C(CH32(CH2C(CH32107CH2C(CH32C6H4O(CH2CH2O100H, was the key to achieving a stable ordered mesoporous structure even upon crystallization of MgTa2O6 within the mesopore walls. The effect of the calcination temperature on the ability of the mesoporous films to assist the photodegradation of rhodamine B in water was studied. As a result, two maxima in the photocatalytic activity were identified in the calcination temperature range of 550–850 °C, peaking at 700 °C and 790 °C, and the origin of this was investigated by using temperature-dependent X-ray scattering. Optimal activity was obtained when the mesoporous film was heated to 790 °C; at this temperature, crystallinity was significantly high, with MgTa2O6 nanocrystals of 1.6 nm in size (averaged over all reflections, and an ordered mesoporous structure was maintained. When considering the turnover frequency of such photocatalysts, the optimized activity of the present nanoarchitectured MgTa2O6 thin film was ca. four times that of analogous anatase TiO2 films with ordered mesopores. Our study demonstrated that high crystallinity and well-developed mesoporosity have to be achieved in order to optimize the physicochemical performance of mesoporous metal-oxide films.

  12. Development of a multiplexed microfluidic proteomic reactor and its application for studying protein-protein interactions.

    Science.gov (United States)

    Tian, Ruijun; Hoa, Xuyen Dai; Lambert, Jean-Philippe; Pezacki, John Paul; Veres, Teodor; Figeys, Daniel

    2011-06-01

    Mass spectrometry-based proteomics techniques have been very successful for the identification and study of protein-protein interactions. Typically, immunopurification of protein complexes is conducted, followed by protein separation by gel electrophoresis and in-gel protein digestion, and finally, mass spectrometry is performed to identify the interacting partners. However, the manual processing of the samples is time-consuming and error-prone. Here, we developed a polymer-based microfluidic proteomic reactor aimed at the parallel analysis of minute amounts of protein samples obtained from immunoprecipitation. The design of the proteomic reactor allows for the simultaneous processing of multiple samples on the same devices. Each proteomic reactor on the device consists of SCX beads packed and restricted into a 1 cm microchannel by two integrated pillar frits. The device is fabricated using a combination of low-cost hard cyclic olefin copolymer thermoplastic and elastomeric thermoplastic materials (styrene/(ethylene/butylenes)/styrene) using rapid hot-embossing replication techniques with a polymer-based stamp. Three immunopurified protein samples are simultaneously captured, reduced, alkylated, and digested on the device within 2-3 h instead of the days required for the conventional protein-protein interaction studies. The limit of detection of the microfluidic proteomic reactor was shown to be lower than 2 ng of protein. Furthermore, the application of the microfluidic proteomic reactor was demonstrated for the simultaneous processing of the interactome of the histone variant Htz1 in wild-type yeast and in a swr1Δ yeast strain compared to an untagged control using a novel three-channel microfluidic proteomic reactor.

  13. Stable phantom materials for ultrasound and optical imaging

    Science.gov (United States)

    Cabrelli, Luciana C.; Pelissari, Pedro I. B. G. B.; Deana, Alessandro M.; Carneiro, Antonio A. O.; Pavan, Theo Z.

    2017-01-01

    Phantoms mimicking the specific properties of biological tissues are essential to fully characterize medical devices. Water-based materials are commonly used to manufacture phantoms for ultrasound and optical imaging techniques. However, these materials have disadvantages, such as easy degradation and low temporal stability. In this study, we propose an oil-based new tissue-mimicking material for ultrasound and optical imaging, with the advantage of presenting low temporal degradation. A styrene-ethylene/butylene-styrene (SEBS) copolymer in mineral oil samples was made varying the SEBS concentration between 5%-15%, and low-density polyethylene (LDPE) between 0%-9%. Acoustic properties, such as the speed of sound and the attenuation coefficient, were obtained using frequencies ranging from 1-10 MHz, and were consistent with that of soft tissues. These properties were controlled varying SEBS and LDPE concentration. To characterize the optical properties of the samples, the diffuse reflectance and transmittance were measured. Scattering and absorption coefficients ranging from 400 nm-1200 nm were calculated for each compound. SEBS gels are a translucent material presenting low optical absorption and scattering coefficients in the visible region of the spectrum, but the presence of LDPE increased the turbidity. Adding LDPE increased the absorption and scattering of the phantom materials. Ultrasound and photoacoustic images of a heterogeneous phantom made of LDPE/SEBS containing a spherical inclusion were obtained. Annatto dye was added to the inclusion to enhance the optical absorbance. The results suggest that copolymer gels are promising for ultrasound and optical imaging, making them also potentially useful for photoacoustic imaging.

  14. Effect of the Modified Fiber on the Performance of PBS Composite%秸秆纤维的改性对PBS复合材料性能的影响

    Institute of Scientific and Technical Information of China (English)

    丁芳芳; 张敏; 李成涛; 葛正浩; 梁金生

    2011-01-01

    Composite made by modified corn stalk fiber/poly butylene succinate (PBS) were prepared by hot-pressing technology, and the effect of five different modifiers such as phenylformic acid, stearic acid, silane, chitosan and acetic acid on the fiber/PBS composite was studied. Energy disperse spectroscopy, scanning electron microscopy,infrared spectroscopy and Xray diffraction were used to characterize the modified fiber and the composite. The results showed that every modifier showed some effects on the modified fiber. Compared with the different modifiers and its addition on the properties of composite,found that when the acid content was 2 % ~ 3 % ,the performance of the composite was the best.%采用改性剂改性后的玉米秸秆纤维增强聚丁二酸丁二醇酯(PBS),利用热压工艺得到了秸秆纤维/PBS复合材料;研究了苯甲酸、硬脂酸、硅烷、壳聚糖及乙酸5种改性剂对经超声波处理后的秸秆纤维/PBS复合材料性能的影响;采用EDS、SEM、FTIR及WXRD对改性前后的纤维及复合材料进行了分析.研究结果表明:5种改性剂对纤维均有改性效果,苯甲酸质量分数为2%-3%时,复合材料力学性能最优.

  15. Influence of the chelator structures on the stability of Re and Tc tricarbonyl complexes with iminodiacetic acid tridentate ligands: a computational study.

    Science.gov (United States)

    Hernández-Valdés, Daniel; Rodríguez-Riera, Zalua; Díaz-García, Alicia; Benoist, Eric; Jáuregui-Haza, Ulises

    2016-08-01

    The development of novel radiopharmaceuticals for nuclear medicine based on M(CO)3 (M = Tc, Re) complexes has attracted great attention. The versatility of this core and the easy production of the fac-[M(CO)3(H2O)3](+) precursor could explain this interest. The main characteristics of these tricarbonyl complexes are the high substitution stability of the three CO ligands and the corresponding lability of the coordinated water molecules, yielding, via easy exchange of a variety of bi- and tridentate ligands, complexes xof very high kinetic stability. Here, a computational study of different tricarbonyl complexes of Re(I) and Tc(I) was performed using density functional theory. The solvent effect was simulated using the polarizable continuum model. These structures were used as a starting point to investigate the relative stabilities of tricarbonyl complexes with various tridentate ligands. These complexes included an iminodiacetic acid unit for tridentate coordination to the fac-[M(CO)3](+) moiety (M = Re, Tc), an aromatic ring system bearing a functional group (-NO2, -NH2, and -Cl) as a linking site model, and a tethering moiety (a methylene, ethylene, propylene butylene, or pentylene bridge) between the linking and coordinating sites. The optimized complexes showed geometries comparable to those inferred from X-ray data. In general, the Re complexes were more stable than the corresponding Tc complexes. Furthermore, using NH2 as the functional group, a medium length carbon chain, and ortho substitution increased complex stability. All of the bonds involving the metal center presented a closed shell interaction with dative or covalent character, and the strength of these bonds decreased in the sequence Tc-CO > Tc-O > Tc-N.

  16. Cobalt carbide nanoprisms for direct production of lower olefins from syngas.

    Science.gov (United States)

    Zhong, Liangshu; Yu, Fei; An, Yunlei; Zhao, Yonghui; Sun, Yuhan; Li, Zhengjia; Lin, Tiejun; Lin, Yanjun; Qi, Xingzhen; Dai, Yuanyuan; Gu, Lin; Hu, Jinsong; Jin, Shifeng; Shen, Qun; Wang, Hui

    2016-10-06

    Lower olefins-generally referring to ethylene, propylene and butylene-are basic carbon-based building blocks that are widely used in the chemical industry, and are traditionally produced through thermal or catalytic cracking of a range of hydrocarbon feedstocks, such as naphtha, gas oil, condensates and light alkanes. With the rapid depletion of the limited petroleum reserves that serve as the source of these hydrocarbons, there is an urgent need for processes that can produce lower olefins from alternative feedstocks. The 'Fischer-Tropsch to olefins' (FTO) process has long offered a way of producing lower olefins directly from syngas-a mixture of hydrogen and carbon monoxide that is readily derived from coal, biomass and natural gas. But the hydrocarbons obtained with the FTO process typically follow the so-called Anderson-Schulz-Flory distribution, which is characterized by a maximum C2-C4 hydrocarbon fraction of about 56.7 per cent and an undesired methane fraction of about 29.2 per cent (refs 1, 10, 11, 12). Here we show that, under mild reaction conditions, cobalt carbide quadrangular nanoprisms catalyse the FTO conversion of syngas with high selectivity for the production of lower olefins (constituting around 60.8 per cent of the carbon products), while generating little methane (about 5.0 per cent), with the ratio of desired unsaturated hydrocarbons to less valuable saturated hydrocarbons amongst the C2-C4 products being as high as 30. Detailed catalyst characterization during the initial reaction stage and theoretical calculations indicate that preferentially exposed {101} and {020} facets play a pivotal role during syngas conversion, in that they favour olefin production and inhibit methane formation, and thereby render cobalt carbide nanoprisms a promising new catalyst system for directly converting syngas into lower olefins.

  17. Cyclization Phenomena in the Sol-Gel Polymerization of a,w-Bis(triethoxysilyl)alkanes and Incorporation of the Cyclic Structures into Network Silsesquioxane Polymers

    Energy Technology Data Exchange (ETDEWEB)

    Alam, T.M.; Carpenter, J.P.; Dorhout, P.K.; Greaves, J.; Loy, D.A.; Shaltout, R.; Shea, K.J.; Small, J.H.

    1999-01-04

    Intramolecular cyclizations during acid-catalyzed, sol-gel polymerizations of ct,co- bis(tietioxysilyl)aWmes substintidly lengtien gelties formonomers witietiylene- (l), propylene- (2), and butylene-(3)-bridging groups. These cyclizations reactions were found, using mass spectrometry and %i NMR spectroscopy, to lead preferentially to monomeric and dimeric products based on six and seven membered disilsesquioxane rings. 1,2- Bis(triethoxysilyl)ethane (1) reacts under acidic conditions to give a bicyclic drier (5) that is composed of two annelated seven membered rings. Under the same conditions, 1,3- bis(triethoxysilyl)propane (2), 1,4-bis(triethoxysilyl)butane (3), and z-1,4- bis(triethoxysilyl)but-2-ene (10) undergo an intramolecular condensation reaction to give the six membemd and seven membered cyclic disilsesquioxanes 6, 7, and 11. Subsequently, these cyclic monomers slowly react to form the tricyclic dirners 8,9 and 12. With NaOH as polymerization catalyst these cyclic silsesquioxanes readily ~aeted to afford gels that were shown by CP MAS z%i NMR and infr=d spectroscopes to retain some cyclic structures. Comparison of the porosity and microstructwe of xerogels prepared from the cyclic monomers 6 and 7 with gels prepared directly from their acyclic precursors 2 and 3, indicate that the final pore structure of the xerogels is markedly dependent on the nature of the precursor. In addition, despite the fact that the monomeric cyclic disilsesquioxane species can not be isolated from 1-3 under basic conditions due to their rapid rate of gelation, spectroscopic techniques also detected the presence of the cyclic structures in the resulting polymeric gels.

  18. 玻纤增强阻燃PBT长期弯曲蠕变行为预测%Long-term Flexural Creep Behavior Prediction of GF-reinforced Flame Retardant PBT

    Institute of Scientific and Technical Information of China (English)

    陈大华; 吴博; 雷彩红

    2011-01-01

    The short term creep data of glass-fiber reinforced flame retardant poly (butylene terephthalate) (PBT-RG301) was studied under different stress using universal testing machine. The long term creep behavior was predicted based on time-stress superposition (TSS) principle, Burgers model and Findley power law. It was found that using TSS principle, the creep value up to 104 h could be predicted. Within experimental time of 4 000 s, the predicted results from Burgers model and Findley power law were in good agreement with the experimental results. The strain values under long time of 10 000h predicted based on Burgers model were far larger than those based on TSS principle and Findley power law, which was further proved by experimental results within 14 h.%采用万能电子拉力机测试了不同应力下玻纤增强阻燃PBT(PBT-RG301)的短期蠕变数据,并采用时间应力等效原理、Burgers模型以及Findley指数定律预测了长期蠕变行为.结果发现:依据时间应力等效原理可预测10000h后体系的蠕变数值,在4000s实验时间内Burgers模型和Findley指数定律均可很好的拟合实验结果,但Burgers模型预测的长期蠕变数据高于Findley指数定律和时间应力等效原理预测数值,实验时间14h的跟踪数据也证实了该结果.

  19. Influence of processing sequence on the tribological properties of VGCF-X/PA6/SEBS composites

    Science.gov (United States)

    Osada, Yu; Nishitani, Yosuke; Kitano, Takeshi

    2016-03-01

    In order to develop the new tribomaterials for mechanical sliding parts with sufficient balance of mechanical and tribological properties, we investigated the influence of processing sequence on the tribological properties of the ternary nanocomposites: the polymer blends of polyamide 6 (PA6) and styrene-ethylene/butylene-styrene copolymer (SEBS) filled with vapor grown carbon fiber (VGCF-X), which is one of carbon nanofiber (CNF) and has 15nm diameter and 3μm length. Five different processing sequences: (1) VGCF-X, PA6 and SEBS were mixed simultaneously (Process A), (2) Re-mixing (Second compounding) of the materials prepared by Process A (Process AR),(3) SEBS was blended with PA6 (PA6/SEBS blends) and then these blends were mixed with VGCF-X (Process B), (4) VGCF-X was mixed with PA6 (VGCF-X/PA6 composites) and then these composites were blended with SEBS (Process C), and (5) VGCF-X were mixed with SEBS (VGCF-X/SEBS composites) and then these composites were blended with PA6 (Process D) were attempted for preparing of the ternary nanocomposites (VGCF-X/PA6/SEBS composites). These ternary polymer nanocomposites were extruded by a twin screw extruder and injection-molded. Their tribological properties were evaluated by using a ring-on-plate type sliding wear tester under dry condition. The tribological properties such as the frictional coefficient and the specific wear rate were influenced by the processing sequence. These results may be attributed to the change of internal structure formation, which is a dispersibility of SEBS particle and VGCF-X in ternary nanocomposites (VGCF-X/PA6/SEBS) by different processing sequences. In particular, the processing sequences of AR, B and D, which are those of re-mixing of VGCF-X, have a good dispersibility of VGCF-X for the improvement of tribological properties.

  20. Six-month clinical outcomes of Firebird 2TM sirolimus-eluting stent implantation in real-world patients with coronary artery diseases

    Institute of Scientific and Technical Information of China (English)

    GE Jun-bo; ZHANG Feng; QIAN Ju-ying; GE Lei; LIU Xue-bo; ZHOU Jun

    2011-01-01

    Background The Firebird 2TM sirolimus-eluting stent (Firebird 2 stent) is a second-generation sirolimus-eluting stent which has a cobalt-chromium alloy stent platform, a brand new bracket structure, and two layers of styrene-butylenes-styrene polymer coatings with better biocompatibility. The Firebird 2TM cObalt-Chromium alloy sirolimus-elUting Stent registry (FOCUS registry) aimed to evaluate the safety and efficacy of the Firebird 2 stent in patients with coronary artery disease in daily practice.Methods The FOCUS registry is a prospective, non-randomized, international multi-center, single-arm clinical registry.Between March 2009 and February 2010, 5084 patients receiving at least 1 Firebird 2 stent during daily clinical practice at 83 medical centers were enrolled.Results Of the 5084 patients enrolled in the registry, 5077 and 5058 were respectively available for 30 days and 6 months follow-up. The 30-day rate of major adverse cardiac events (MACE) was 1.20%, including 13 cardiac deaths, 46 non-fatal myocardial infarction (MI), and 6 target vessel revascularization (TVR). At 6 months follow-up, the rate of MACE was 1.80%. There were 32 cardiac deaths, 48 non-fatal MI, and 15 TVR. According to the Academic Research Consortium definition, definite/probable stent thrombosis (ST) occurred in 0.43% (22/5058) of patients, including 8 cases of acute ST, 11 subacute ST, and 3 late ST.Conclusion The Firebird 2 stent showed the promising efficacy and safety at 30 days and 6 months in a real-world population of patients with coronary artery diseases.

  1. Temperature-dependent absorption cross-section measurements of 1-butene (1-C4H8) in VUV and IR

    KAUST Repository

    Es-sebbar, Et-touhami

    2013-01-01

    Vacuum ultraviolet (VUV) and infrared (IR) absorption cross-section measurements of 1-butene (1-C4H8; CH2=CHCH2CH3; Butylene) are reported over the temperature range of 296-529K. The VUV measurements are performed between 115 and 205nm using synchrotron radiation as a tunable VUV light source. Fourier Transform Infrared (FTIR) spectroscopy is employed to measure absorption cross-section and band strengths in the IR region between 1.54 and 25μm (~6500-400cm-1). The measured room-temperature VUV and IR absorption cross-sections are compared with available literature data and are found to be in good agreement. The oscillator strength for the electronic transition (A1A\\'→X1A\\') around 150-205nm is determined to be 0.32±0.01.The gas temperature has a strong effect on both VUV and IR spectra. Measurements made in the VUV region show that the peak value of the band cross-section decreases and the background continuum increases with increasing gas temperature. This behavior is due to a change in the rotational and vibrational population distribution of 1-butene molecule. Similar changes in rotational population are observed in the IR spectra. Moreover, variation of the IR spectra with temperature is used to measure the enthalpy difference between syn and skew conformations of 1-butene and is found to be 0.24±0.03. kcal/mol, which is in excellent agreement with values reported in the literature. The measurements reported in this work will provide the much-needed spectroscopic information for the development of high-temperature quantitative diagnostics in combustion applications and validation of atmospheric chemistry models of extra-solar planets. © 2012 Elsevier Ltd.

  2. Functional analysis of FarA transcription factor in the regulation of the genes encoding lipolytic enzymes and hydrophobic surface binding protein for the degradation of biodegradable plastics in Aspergillus oryzae.

    Science.gov (United States)

    Garrido, Sharon Marie; Kitamoto, Noriyuki; Watanabe, Akira; Shintani, Takahiro; Gomi, Katsuya

    2012-05-01

    FarA is a Zn(II)(2)Cys(6) transcription factor which upregulates genes required for growth on fatty acids in filamentous fungi like Aspergillus nidulans. FarA is also highly similar to the cutinase transcription factor CTF1α of Fusarium solani which binds to the cutinase gene promoter in this plant pathogen. This study determines whether FarA transcriptional factor also works in the regulation of genes responsible for the production of cutinase for the degradation of a biodegradable plastic, poly-(butylene succinate-co-adipate) (PBSA), in Aspergillus oryzae. The wild-type and the farA gene disruption strains were grown in minimal agar medium with emulsified PBSA, and the wild-type showed clear zone around the colonies while the disruptants did not. Western blot analysis revealed that the cutinase protein CutL1 and a hydrophobic surface binding protein such as HsbA were produced by the wild-type but not by the disruptants. In addition, the expressions of cutL1, triacylglycerol lipase (tglA), and mono- and di-acylglycerol lipase (mdlB) genes as well as the hsbA gene were significantly lower in the disruptants compared to the wild-type. These results indicated that the FarA transcriptional factor would be implicated in the expression of cutL1 and hsbA genes that are required for the degradation of PBSA as well as lipolytic genes such as mdlB and tglA for lipid hydrolysis.

  3. Extremely supercharged proteins in mass spectrometry: profiling the pH of electrospray generated droplets, narrowing charge state distributions, and increasing ion fragmentation.

    Science.gov (United States)

    Zenaidee, Muhammad A; Donald, William A

    2015-03-21

    The effects of 12 acids, 4 solvents, and 8 low-volatility additives that increase analyte charging (i.e., superchargers) on the charge state distributions (CSDs) of protein ions in ESI-MS were investigated. We discovered that (i) relatively low concentrations [5% (v/v)] of 1,2-butylene carbonate (and 4-vinyl-1,3-dioxolan-2-one) can be added to ESI solutions to form higher charge states of cytochrome c and myoglobin ions than by using more traditional additives (e.g., propylene carbonate, sulfolane, or m-nitrobenzyl alcohol) under these conditions and (ii) the width of CSDs narrow as the effectiveness of superchargers increase, which concentrates protein ions into fewer detection channels. The use of strong acids (pKa values 0) results in significantly higher protein ion charging, less acid adduction, and narrower CSDs, indicating that protein ion supercharging in ESI can be significantly limited by the binding of conjugate base anions of acids that neutralize charge sites and broaden CSDs. The extent of protein charging as a function of acid identity (HA) does not strongly correlate with gas-phase proton transfer data (i.e., gas-phase basicity and proton affinity values for HA and A(-)), solution-phase protein secondary structures (as determined by circular dichroism spectroscopy), and/or acid molecule volatility data. For protein-denaturing solutions, these data were used to infer that the "effective" pH of ESI generated droplets near the moment of ion formation can be ∼0, which is ca. 1 to 3 pH units lower than the pH of the solutions prior to ESI. Electron capture dissociation (ECD) of [ubiquitin, 17H](17+) resulted in the identification of 223 cleavages, 74 of 75 inter-residue sites, and 92% ECD fragmentation efficiency, which correspond to highest of these values that have been obtained by ECD of a single isolated charge state of ubiquitin.

  4. Promoting fertilizer use via controlled release of a bacteria-encapsulated film bag.

    Science.gov (United States)

    Wu, Chin-San

    2010-05-26

    A phosphate-solubilizing bacterium ( Burkholderia cepacia isolate) encapsulated in maleic anhydride (MA) grafted onto poly(butylene succinate adipate) (PBSA) and then combined with starch as film bag material (PBSA-g-MA/starch) incubated in a saline solution required approximately 20 days to deplete the starch in the film bags. Thereafter, the cell concentration in the saline solution increased significantly because of the release of cells from the severely destroyed film bags and also their growth by use of depolymerized PBSA-g-MA fragments as a substrate. The incubation proceeded for 60 days, by which time the PBSA-g-MA/starch composite had suffered a >80% weight loss. For practical application, effectiveness of the above-mentioned film bags was demonstrated because it could improve the absorbability of a fertilizer for plants and promote the growth of plants. As a result, it can avoid the accumulation of the phosphate in excess fertilizer that lead to the phenomenon of poor soils. These results demonstrate that PBSA-g-MA/starch can be used to encapsulate cells of an indigenous phosphate-solubilizing bacterium ( B. cepacia isolate) to form a controlled release of bacteria-encapsulated film bag (BEFB). The B. cepacia isolate was able to degrade the film bags material, causing cell release. Biodegradability of the film bags depended upon the type of material used, because the PBSA film bags were also degraded but to a lesser degree. The addition of starch made the film bags more biodegradable. The decrease in intrinsic viscosity was also higher for the starch composite, suggesting a strong connection between the biodegradability and these characteristics. The results suggest that the release of fertilizer-promoted bacteria might be controllable via a suitable film bag material formulation. In addition, this work adopted live bacteria to promote the absorption of phosphate, which is superior to the phosphate used in the traditional way.

  5. Progress in Industrialization of Biobased Materials%生物基材料产业化进展

    Institute of Scientific and Technical Information of China (English)

    谭天伟; 苏海佳; 杨晶

    2012-01-01

    在全球石油资源供给日趋紧张,环保问题日益突出,对低碳经济发展需求日益迫切的情势下,以可再生资源为基础的生物基材料迅速发展成为必然趋势。综述了目前国内外生物基材料产业化的最新进展,系统介绍和总结了乳酸、1,3-丙二醇、聚乳酸、聚丁二酸丁二醇酯、聚羟基脂肪酸酯、透明质酸、大豆蛋白、聚天冬氨酸、木塑复合材料等几种生物基材料产业化最新结果。对比了美国、日本和欧洲等国家生物基材料产业状况,分析了生物基材料产业化的发展趋势及前景。%The latest progress in industrialization of biobased materials was reviewed. The new results of industrialization of several representative biobased materials such as lactic acid, 1, 3-propanediol, poly ( lactic acid) , poly ( butylene succinate) , poly (hydroxyalkanoate) , hyaluronic acid, Xanthan Gum, polyaspartic acid, and wood-plastic composed ma- terials were systematically introduced and summarized. The industrialization situations in US, Japan and Europe were compared. Furthermore, the possible development trend and future were discussed.

  6. Preparation and properties of polystyrene encapsulated paraffin wax as possible phase change material in a polypropylene matrix

    Energy Technology Data Exchange (ETDEWEB)

    Mochane, M.J. [Department of Chemistry, University of the Free State (Qwaqwa Campus), Phuthaditjhaba (South Africa); Luyt, A.S., E-mail: LuytAS@qwa.ufs.ac.za [Department of Chemistry, University of the Free State (Qwaqwa Campus), Phuthaditjhaba (South Africa)

    2012-09-20

    Highlights: Black-Right-Pointing-Pointer Polystyrene microcapsules containing about 30 wt% soft paraffin wax were successfully prepared. Black-Right-Pointing-Pointer The presence of microcapsules in polypropylene influenced the morphology and properties of the matrix. Black-Right-Pointing-Pointer The SEBS modifier had little influence on the interaction between polypropylene and microcapsules. - Abstract: The study deals with the preparation and characterization of polystyrene (PS) capsules containing Fischer-Tropsch paraffin wax (PS:wax) as phase change material (PCM) for thermal energy storage embedded in a polypropylene (PP) matrix. Blends of PP/PS:wax were prepared without and with polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS) as a modifier. The influence of PS:wax microcapsules on the morphology, as well as thermal and mechanical properties of the PP was investigated. The scanning electron microscopy (SEM) images of the microencapsulated PCM show that the capsules were grouped in irregular spherical agglomerates of size 16-24 {mu}m. However, after melt-blending with PP smaller, perfectly spherical microcapsules were well dispersed in the PP matrix. There was fairly good interaction between the microcapsules and the matrix, even in the absence of SEBS modification. The FTIR spectrum of the microcapsules is almost exactly the same as that of polystyrene, which indicates that the microcapsules were mostly intact and that the FTIR only detected the polystyrene shell. The amount of wax in the PS:wax microcapsules was determined as 20-30% by weight. An increase in PS:wax content resulted in a decrease in the melting peak temperatures of PP. The thermal stability of the blends decreased with an increase in PS:wax microcapsules content as a consequence of the lower thermal stability of both the wax and PS. There was a drop in storage modulus with increasing PS:wax microcapsules content.

  7. 汽车炸弹作用下球罐动力学响应的模拟研究%Simulation Research on Dynamic Response of Speherical Tank Effected on Car Bomb

    Institute of Scientific and Technical Information of China (English)

    冯伟涛; 方向; 谢立军; 刘金川; 陈刊

    2011-01-01

    The numerical simulation on dynamic response of spherical tank effeeted on the car bomb was researched. The ANSYS/LS-DYNA software was used to calculate the relationship among equivalent stress, dispalcement and time on a 5 000 m butylene spherical tank body when a 1 600 kg TNT car bomb exploded. The simulation results show that the metamorphosis of the spherical tank happens earlier and the effective stress and displacement is bigger when the spherical tank closer to the explosion center,then the damage on tank body is more obvious. So,on the effect of the car bombs, the partial damage is very likely to happen on the spherical tank, therefore, it is necessary to adopt some protection measures mound the spherical tanks.%针对球形储罐在汽车炸弹作用下的动力学响应进行了数值模拟研究.采用ANSYS/LS-DYNA软件模拟计算了装药量为1 600 kg TNT汽车炸弹爆炸后在1 m、5 m和10 m距离内5000m3丁烯球罐罐体上的等效应力和位移随时间的变化关系.模拟结果表明,炸药边界距离球罐距离越近,罐体发生变形的时间越早,观察点的应力和位移值越大,汽车炸弹对罐体的破坏作用越明显.因此,在汽车炸弹作用下,球罐极有可能发生局部破坏,有必要在罐区周围采取一定的防护措施.

  8. Glyceryl monooleyl ether-based liquid crystalline nanoparticles as a transdermal delivery system of flurbiprofen: characterization and in vitro transport.

    Science.gov (United States)

    Uchino, Tomonobu; Murata, Akiko; Miyazaki, Yasunori; Oka, Toshihiko; Kagawa, Yoshiyuki

    2015-01-01

    Liquid crystalline nanoparticles (LCNs) were prepared using glyceryl monooleyl ether (GME) by the modified film rehydration method. Hydrogenated lecithin (HL), 1,3-butylene glycol (1,3-BG), and Poloxamer 407 were used as additives. The prepared LCN formulations were evaluated based on particle size, small-angle X-ray diffraction (SAXS) analysis, (1)H- and (19)F-NMR spectra, and in vitro skin permeation across Yucatan micropig skin. The composition (weight percent) of the LCN formulations were GME-HL-1,3-BG (4 : 1 : 15), 4% GME-based LCN and GME-HL-1,3-BG (8 : 1 : 15), 8% GME-based LCN and their mean particle sizes were 130-175 nm. Flurbiprofen 5 and 10 mg was loaded into 4% GME-based LCN and 8% GME-based LCN systems, respectively. The results of SAXS and NMR suggested that both flurbiprofen-loaded formulations consist of particles with reverse type hexagonal phase (formation of hexosome) and flurbiprofen molecules were localized in the lipid domain through interaction of flurbiprofen with the lipid components. Flurbiprofen transport from the LCN systems across the Yucatan micropig skin was increased compared to flurbiprofen in citric buffer (pH=3.0). The 8% GME-based LCN systems was superior to the 4% GME-based LCN for flurbiprofen transport. Since the internal hexagonal phase in the 8% GME-based LCN systems had a higher degree of order compared to the 4% GME-based LCN in SAXS patterns, the 8% GME-based LCN system had a larger surface area, which might influence flurbiprofen permeation. These results indicated that the GME-based LCN system is effective in improving the skin permeation of flurbiprofen across the skin.

  9. Additive manufactured polymeric 3D scaffolds with tailored surface topography influence mesenchymal stromal cells activity.

    Science.gov (United States)

    Neves, Sara C; Mota, Carlos; Longoni, Alessia; Barrias, Cristina C; Granja, Pedro L; Moroni, Lorenzo

    2016-05-24

    Additive manufactured three-dimensional (3D) scaffolds with tailored surface topography constitute a clear advantage in tissue regeneration strategies to steer cell behavior. 3D fibrous scaffolds of poly(ethylene oxide terephthalate)/poly(butylene terephthalate) block copolymer presenting different fiber surface features were successfully fabricated by additive manufacturing combined with wet-spinning, in a single step, without any post-processing. The optimization of the processing parameters, mainly driven by different solvent/non-solvent combinations, led to four distinct scaffold types, with average surface roughness values ranging from 0.071 ± 0.012 μm to 1.950 ± 0.553 μm, average pore sizes in the x- and y-axis between 351.1 ± 33.6 μm and 396.1 ± 32.3 μm, in the z-axis between 36.5 ± 5.3 μm and 70.7 ± 8.8 μm, average fiber diameters between 69.4 ± 6.1 μm and 99.0 ± 9.4 μm, and porosity values ranging from 60.2 ± 0.8% to 71.7 ± 2.6%. Human mesenchymal stromal cells (hMSCs) cultured on these scaffolds adhered, proliferated, and produced endogenous extracellular matrix. The effect of surface roughness and topography on hMSCs differentiation was more evident for cells seeded at lower density, where the percentage of cells in direct contact with the surface was higher compared to more densely seeded scaffolds. Under osteogenic conditions, lower surface roughness values (0.227 ± 0.035 μm) had a synergistic effect on hMSCs behavior, while chondrogenesis was favored on rougher surfaces (1.950 ± 0.553 μm).

  10. Label-free Raman monitoring of extracellular matrix formation in three-dimensional polymeric scaffolds.

    Science.gov (United States)

    Kunstar, Aliz; Leferink, Anne M; Okagbare, Paul I; Morris, Michael D; Roessler, Blake J; Otto, Cees; Karperien, Marcel; van Blitterswijk, Clemens A; Moroni, Lorenzo; van Apeldoorn, Aart A

    2013-09-06

    Monitoring extracellular matrix (ECM) components is one of the key methods used to determine tissue quality in three-dimensional scaffolds for regenerative medicine and clinical purposes. Raman spectroscopy can be used for non-invasive sensing of cellular and ECM biochemistry. We have investigated the use of conventional (confocal and semiconfocal) Raman microspectroscopy and fibre-optic Raman spectroscopy for in vitro monitoring of ECM formation in three-dimensional poly(ethylene oxide terephthalate)-poly(butylene terephthalate) (PEOT/PBT) scaffolds. Chondrocyte-seeded PEOT/PBT scaffolds were analysed for ECM formation by Raman microspectroscopy, biochemical analysis, histology and scanning electron microscopy. ECM deposition in these scaffolds was successfully detected by biochemical and histological analysis and by label-free non-destructive Raman microspectroscopy. In the spectra collected by the conventional Raman set-ups, the Raman bands at 937 and at 1062 cm(-1) which, respectively, correspond to collagen and sulfated glycosaminoglycans could be used as Raman markers for ECM formation in scaffolds. Collagen synthesis was found to be different in single chondrocyte-seeded scaffolds when compared with microaggregate-seeded samples. Normalized band-area ratios for collagen content of single cell-seeded samples gradually decreased during a 21-day culture period, whereas collagen content of the microaggregate-seeded samples significantly increased during this period. Moreover, a fibre-optic Raman set-up allowed for the collection of Raman spectra from multiple pores inside scaffolds in parallel. These fibre-optic measurements could give a representative average of the ECM Raman signal present in tissue-engineered constructs. Results in this study provide proof-of-principle that Raman microspectroscopy is a promising non-invasive tool to monitor ECM production and remodelling in three-dimensional porous cartilage tissue-engineered constructs.

  11. Design of biphasic polymeric 3-dimensional fiber deposited scaffolds for cartilage tissue engineering applications.

    Science.gov (United States)

    Moroni, L; Hendriks, J A A; Schotel, R; de Wijn, J R; van Blitterswijk, C A

    2007-02-01

    This report describes a novel system to create rapid prototyped 3-dimensional (3D) fibrous scaffolds with a shell-core fiber architecture in which the core polymer supplies the mechanical properties and the shell polymer acts as a coating providing the desired physicochemical surface properties. Poly[(ethylene oxide) terephthalate-co-poly(butylene) terephthalate] (PEOT/PBT) 3D fiber deposited (3DF) scaffolds were fabricated and examined for articular cartilage tissue regeneration. The shell polymer contained a higher molecular weight of the initial poly(ethylene glycol) (PEG) segments used in the copolymerization and a higher weight percentage of the PEOT domains compared with the core polymer. The 3DF scaffolds entirely produced with the shell or with the core polymers were also considered. After 3 weeks of culture, scaffolds were homogeneously filled with cartilage tissue, as assessed by scanning electron microscopy. Although comparable amounts of entrapped chondrocytes and of extracellular matrix formation were found for all analyzed scaffolds, chondrocytes maintained their rounded shape and aggregated during the culture period on shell-core 3DF scaffolds, suggesting a proper cell differentiation into articular cartilage. This finding was also observed in the 3DF scaffolds fabricated with the shell composition only. In contrast, cells spread and attached on scaffolds made simply with the core polymer, implying a lower degree of differentiation into articular cartilaginous tissue. Furthermore, the shell-core scaffolds displayed an improved dynamic stiffness as a result of a "prestress" action of the shell polymer on the core one. In addition, the dynamic stiffness of the constructs increased compared with the stiffness of the bare scaffolds before culture. These findings suggest that shell-core 3DF PEOT/PBT scaffolds with desired mechanical and surface properties are a promising solution for improved cartilage tissue engineering.

  12. Interfacing polymeric scaffolds with primary pancreatic ductal adenocarcinoma cells to develop 3D cancer models.

    Science.gov (United States)

    Ricci, Claudio; Mota, Carlos; Moscato, Stefania; D'Alessandro, Delfo; Ugel, Stefano; Sartoris, Silvia; Bronte, Vincenzo; Boggi, Ugo; Campani, Daniela; Funel, Niccola; Moroni, Lorenzo; Danti, Serena

    2014-01-01

    We analyzed the interactions between human primary cells from pancreatic ductal adenocarcinoma (PDAC) and polymeric scaffolds to develop 3D cancer models useful for mimicking the biology of this tumor. Three scaffold types based on two biocompatible polymeric formulations, such as poly(vinyl alcohol)/gelatin (PVA/G) mixture and poly(ethylene oxide terephthalate)/poly(butylene terephthalate) (PEOT/PBT) copolymer, were obtained via different techniques, namely, emulsion and freeze-drying, compression molding followed by salt leaching, and electrospinning. In this way, primary PDAC cells interfaced with different pore topographies, such as sponge-like pores of different shape and size or nanofiber interspaces. The aim of this study was to investigate the influence played by the scaffold architecture over cancerous cell growth and function. In all scaffolds, primary PDAC cells showed good viability and synthesized tumor-specific metalloproteinases (MMPs) such as MMP-2, and MMP-9. However, only sponge-like pores, obtained via emulsion-based and salt leaching-based techniques allowed for an organized cellular aggregation very similar to the native PDAC morphological structure. Differently, these cell clusters were not observed on PEOT/PBT electrospun scaffolds. MMP-2 and MMP-9, as active enzymes, resulted to be increased in PVA/G and PEOT/PBT sponges, respectively. These findings suggested that spongy scaffolds supported the generation of pancreatic tumor models with enhanced aggressiveness. In conclusion, primary PDAC cells showed diverse behaviors while interacting with different scaffold types that can be potentially exploited to create stage-specific pancreatic cancer models likely to provide new knowledge on the modulation and drug susceptibility of MMPs.

  13. 热处理对PBST纤维聚集态结构和力学性能的影响%Development of Aggregation Structure and Mechanical Properties of PBST Fibers Subjected to Heat-Setting Treatment

    Institute of Scientific and Technical Information of China (English)

    高佳佳; 李发学; 俞建勇

    2012-01-01

    将生物可降解高分子材料聚丁二酸丁二醇-共-对苯二甲酸丁二醇酯(PBST)纤维在不同温度、牵伸倍数和热定型时间下热处理后,分别用差示扫描量热仪(DSC)、热台偏光显微镜(POM)、强力仪等测试其聚集态结构和力学性能的变化.研究结果表明,在热处理条件下,PBST纤维的聚集态结构和力学性能随着牵伸倍数、热处理温度和热处理时间的变化而变化,纤维聚集态结构的变化是纤维力学性能变化的内在原因.%Biodegradable poly(butylene succiante-co-terephthalate) (PBST) fibers were heat-setting under different temperatures, different drawing ratios and different heat-setting time. The development of aggregation structure and mechanical properties of PBST fibers before and after heat-setting were investigated by tensile test, differential scanning calorimeter (DSC) and polarizing optical microscopy (POM) measurement. Research results indicate that the aggregation structure and mechanical properties of PBST fibers changes with the drawing ratio, the heat-setting temperatures and time, and corresponding changes of aggregation structure agree with the development of mechanical properties.

  14. Heat Treatment of Polylactide-based Ternary Blends%聚乳酸基三元共混物的热处理

    Institute of Scientific and Technical Information of China (English)

    宋庆林; 桂宗彦; 程树军; 陆冲

    2012-01-01

    Three different kinds of heat treatment methods were applied to the blends of poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate)(PBAT)/poly(propylene carbonate) (PPC). The blends were characterized with wide angle X-ray diffraction, differential scanning calorimetry, polarized optical microscopy, and scanning electron microscope, and the effects of the heat treatment process on the structures and properties of the blends were studied. The results show that: the crystallization of PLA in the blends promotes and the water vapour barrier property enhances after been annealed. The vapour barrier property of blends treated with first quenched and then annealed is better than that of blends treated with direct annealing.%采用3种热处理过程对聚乳酸(PLA)、聚(己二酸-对苯二甲酸丁二酯)(PBAT)和聚丙撑碳酸酯(PPC)的共混物进行了热处理.采用广角X射线衍射仪、差示扫描食热仪、偏光显微镜和扫描电子显微镜等对共混物进行了表征,研究了热处理过程对共混物结构和性能的影响.结果表明:退火处理促进了共混物中PLA的结晶,提高了共混物的水蒸气阻隔性;先淬火再退火相对于直接退火处理,共混物的水蒸气阻隔性较好.

  15. Conductivity of microfibrillar polymer-polymer composites with CNT-loaded microfibrils or compatibilizer: A comparative study

    Directory of Open Access Journals (Sweden)

    S. Fakirov

    2013-07-01

    Full Text Available Conductive polymer composites have wide ranging applications, but when they are produced by conventional melt blending, high conductive filler loadings are normally required, hindering their processability and reducing mechanical properties. In this study, two types of polymer-polymer composites were studied: i microfibrillar composites (MFC of polypropylene (PP and 5 wt% carbon nanotube (CNT loaded poly(butylene terephthalate (PBT as reinforcement, and ii maleic anhydride-grafted polypropylene (PP-g-MA compatibilizer, loaded with 5 wt% CNTs introduced into an MFC of PP and poly(ethylene terephthalate (PET in concentrations of 5 and 10 wt%. For the compatibilized composite type, PP and PET were melt-blended, cold-drawn and pelletized, followed by dry-mixing with PP-g-MA/CNT, re-extrusion at 200°C, and cold-drawing. The drawn blends produced were compression moulded to produce sheets with MFC structure. Using scanning electron microscopy, CNTs coated with PP-g-MA could be observed at the interface between PP matrix and PET microfibrils in the compatibilized blends. The volume resistivities tested by four-point test method were: 2.87•108 and 9.93•107 Ω•cm for the 66.5/28.5/5 and 63/27/10 (by wt% PP/PET/(PP-g-MA/CNT blends, corresponding to total CNT loadings (in the composites of 0.07 vol% (0.24 wt% and 0.14 vol% (0.46 wt%, respectively. For the non-compatibilized MFC types based on PP/(PBT/CNT with higher and lower melt flow grades of PP, the resistivities of 70/(95/5 blends were 1.9•106 and 1.5•107 Ω•cm, respectively, corresponding to a total filler loading (in the composite of 0.44 vol% (1.5 wt% in both MFCs.

  16. Fabrication of biodegradable polyurethane microspheres by a facile and green process.

    Science.gov (United States)

    Lin, Cheng-Yen; Hsu, Shan-hui

    2015-05-01

    Two different compositions of water-based biodegradable polyurethane (PU) in the form of homogeneous nanoparticles (NPs) were synthesized using biodegradable polyesters as the soft segment. The first PU (PU01) was based on poly(ε-caprolactone) (PCL) diol and the second PU (PU02) was based on 40% PCL diol and 60% polyethylene butylene adipate diol. The PU NP dispersions with different solid contents were sprayed into liquid nitrogen and resuspended in water to generate elastic microspheres (50-60 µm) with different nanoporosities. In vitro degradation analysis revealed that microspheres of PU02 (i.e., PU02 MS) degraded faster than those of PU01 (PU01 MS). Methylene blue was encapsulated during microsphere formation and the release was investigated. Microspheres made from a lower content (10%) of PU02 dispersion (i.e., PU02 MS_10) showed a greater burst release of methylene blue in 6 h, whereas those made from a higher content (30%) of PU01 dispersion (i.e., PU01 MS_30) revealed a prolonged release with a significantly lower burst release. Biocompatibility evaluation using L929 fibroblasts demonstrated that cells were attached and proliferated on microspheres after 24 h. On the other hand, microspheres may further self-assemble into films and scaffolds. Surface modification of microspheres by chitosan may modify the self-assembly behavior of microspheres. Microspheres could be stacked to form scaffolds with different macroporosities. Fibroblasts were successfully seeded and grown in the microsphere-stacked scaffolds. We concluded that the biodegradable and elastic microspheres may be facilely produced from a green and sustainable process with potential applications in drug release and three-dimensional cell culture.

  17. 基于流程模拟器和列队竞争算法的蒸馏优化设计%Optimization design of distillation process based on process simulator and line-up competition algorithm

    Institute of Scientific and Technical Information of China (English)

    李振华; 林子雄; 罗艳玲; 张宇; 鄢烈祥; 史彬

    2013-01-01

    An optimal method for distillation process design was proposed based on the process simulator and the line up competition algorithm (LCA).Taking the minimal total cost as the objective function,a non-convex mixed-integer nonlinear programming model for the optimization design of distillation process was set up,in which the distillation sequence and heat integration were considered.The simulation of distillation process and the optimal search by LCA were alternately implemented until the optimal solution was acquired.The method proposed was applied to the optimal design of separating 1-butylene from C4 mixture.The optimal distillation sequence and heat integration process structure as well as the optimal design and the operating parameters of each column were obtained.%文章提出了基于流程模拟器与列队竞争算法的蒸馏过程优化设计方法.以总费用最少为目标函数,建立了蒸馏过程优化设计的混合整数非线性规划模型,其中考虑了蒸馏序列和热集成情况.流程模拟器对蒸馏过程的模拟与列队竞争算法的优化搜索交替进行,迭代计算直到收敛到最优解.将文中提出的方法应用于从C4混合物中分离1-丁烯的蒸馏过程优化设计,得到了最优的蒸馏序列和热集成流程结构,以及各塔的最优设计与操作参数.

  18. Bare and Polymer-Coated Indium Tin Oxide as Working Electrodes for Manganese Cathodic Stripping Voltammetry.

    Science.gov (United States)

    Rusinek, Cory A; Bange, Adam; Warren, Mercedes; Kang, Wenjing; Nahan, Keaton; Papautsky, Ian; Heineman, William R

    2016-04-19

    Though an essential metal in the body, manganese (Mn) has a number of health implications when found in excess that are magnified by chronic exposure. These health complications include neurotoxicity, memory loss, infertility in males, and development of a neurologic psychiatric disorder, manganism. Thus, trace detection in environmental samples is increasingly important. Few electrode materials are able to reach the negative reductive potential of Mn required for anodic stripping voltammetry (ASV), so cathodic stripping voltammetry (CSV) has been shown to be a viable alternative. We demonstrate Mn CSV using an indium tin oxide (ITO) working electrode both bare and coated with a sulfonated charge selective polymer film, polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene-sulfonate (SSEBS). ITO itself proved to be an excellent electrode material for Mn CSV, achieving a calculated detection limit of 5 nM (0.3 ppb) with a deposition time of 3 min. Coating the ITO with the SSEBS polymer was found to increase the sensitivity and lower the detection limit to 1 nM (0.06 ppb). This polymer modified electrode offers excellent selectivity for Mn as no interferences were observed from other metal ions tested (Zn(2+), Cd(2+), Pb(2+), In(3+), Sb(3+), Al(3+), Ba(2+), Co(2+), Cu(2+), Ni(3+), Bi(3+), and Sn(2+)) except Fe(2+), which was found to interfere with the analytical signal for Mn(2+) at a ratio 20:1 (Fe(2+)/Mn(2+)). The applicability of this procedure to the analysis of tap, river, and pond water samples was demonstrated. This simple, sensitive analytical method using ITO and SSEBS-ITO could be applied to a number of electroactive transition metals detectable by CSV.

  19. Enhancement of the optical properties of a new radiochromic dosimeter based on aliphatic-aromatic biodegradable polymers

    Energy Technology Data Exchange (ETDEWEB)

    Schimitberger, Thiago, E-mail: tschimitberger@ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Escola de Engenharia. Departamento de Engenharia Nuclear; Faria, Luiz O., E-mail: farialo@cdtn.br [Centro de desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    The development of a dosimeter that is of low cost, easy to process without dependence on expensive complex instruments and environment friendly is a challenging in irradiation quality control. Recently, an aliphatic-aromatic biodegradable polymer has been proposed as radiochromic dosimeter. The dosimeter is based on biodegradable poly(butylene adipate-co-terephthalate) copolymers (PBAT). In order to improve the photoluminescence (PL) properties of PBAT, increasing its range of applicability (50 kGy to 1000 kGy), this work investigates the influence of solution concentration in the dose response. Films with thickness of c.a. 80 μm were produce by wirebar coating, a simple deposition method for preparing large areas of organic films at low cost. The irradiation of samples was performed at room temperature using a Co-60 source at dose rate of 20 kGy/h. The films were exposed to doses ranging from 501 kGy to 1000 kGy. A 405 nm LED light source was used to excite the films. The USB2000 spectrometer made by Ocean Optics was used to collect the emission spectra of the luminescent films. The photoluminescent intensity captured by the spectrometer present linear radiation dose dependence. The maximum PL for the film sample made from a 0.05 g.mL{sup -1} solution is 1.5 (a.u.) while it is about 3.5 (a.u.) for a film sample made from a 0.2 mg.mL{sup -1} solution, when irradiated with 1000 kGy. These results indicate that PBAT films have great potential to be used as a high gamma dose radiochromic dosimeter over a wide dose range, expanding its applicability for different radiations process. (author)

  20. Synthesis of polymer materials by low energy electron beam. IV. EB-polymerized urethane-acrylate, -methacrylate and -acrylamide

    Science.gov (United States)

    Ando, Masayuki; Uryu, Toshiyuki

    The structure and properties before and after electron beam (EB) irradiation were investigated using urethane prepolymers with different terminal groups of 2-hydroxyethyl acrylate (HEA), 2-hydroxyethyl methacrylate (HEMA) and N-hydroxymethyl acrylamide (HMAAm). The prepolymers were synthesized by reaction of HEA, HEMA and HMAAm with the isocyanate-capped intermediate, which was obtained by reaction of poly(butylene adipate)diol (PBAD) with 4,4'-diphenylmethane diisocyanate. The resulting urethane-acrylate (UA-251M), -methacrylate (UMA-251M) and -acrylamide (UNAA-251M) had the crystallinity arising from PBAD moieties, and UA-251M and UMA-251M had higher crystallinity than UNAA-251M. IR results indicated that UNAA-251M was larger in the fraction of free NH stretching absorption than UA-251M and UMA-251M regardless of the number of NH group per a molecule. Accordingly, it was assumed that the difference in crystallinity was attributed to the polarity of terminal group. Hence, the rate of gel formation for UA-251M and UMA-251M was higher than that of UNAA-251M. The crystallinity based on PBAD of the prepolymers was remained also after EB irradiation. Spherulitic texture was observed on the EB-polymerized gel film surfaces for UA-251M and UMA-251M, while it was almost destroyed for UNAA-251M. Mechanical properties of UA-251M and UMA-251M gel films were much superior to those of UNAA-251M gel film according to the phase structure. Especially, UMA-251M gel film represented most excellent mechanical properties. Schematic models of the phase structure for UA-251M, UMA-251M and UNAA-251M were suggested from all experimental results.

  1. Preparation of Heat Conduction Polyurethane Pouring Adhesive%导热聚氨酯灌封胶的研制

    Institute of Scientific and Technical Information of China (English)

    安佳丽; 周正发; 王洁玲; 吕洪香; 徐卫兵

    2012-01-01

    Based on polyoxypropylene ( PPG ) , 1,4-butylene-glycol ( BDO) , trimethylolpropane ( TMP) , iso-phorone diisocyanate(IPDI) , alumina powder was chosen as the heat conduction filler, the heat conduction polyurethane (PU) pouring adhesive was synthesized. The effects of the Al2O3 filler content and the polyol species on the thermal conductivity and mechanical properties were researched. The results indicated that Al2O3 powder in the Al2O3/PU composities increased from 0 to 80% , the thermal conductivity increased from 0.08 W/(m·K) to 0. 76 W/(m·K) , which was 9 times than pure polyurethane. The results of SEM showed that Al2O3 particle was better dispersed in this system.%以聚醚210、聚醚305、1,4-丁二醇、三羟甲基丙烷为原料,氧化铝(Al2O3)为导热填料,与异佛尔酮二异氰酸酯反应合成导热聚氨酯灌封胶.研究Al2O3用量、催化剂和聚醚多元醇的种类对灌封胶性能的影响.结果表明,当Al2O3的质量分数从0增加到80%时,灌封胶的导热系数从0.08 W/(m·K)增加到0.76 W/(m·K),是纯聚氨酯灌封胶的9倍多.SEM测试表明,Al2O3在体系中有着较好的分散性.

  2. Proton exchange membranes based on PVDF/SEBS blends

    Energy Technology Data Exchange (ETDEWEB)

    Mokrini, A.; Huneault, M.A. [Industrial Materials Institute, National Research Council of Canada, 75 de Mortagne Blvd., Boucherville, Que. (Canada J4B 6Y4)

    2006-03-09

    Proton-conductive polymer membranes are used as an electrolyte in the so-called proton exchange membrane fuel cells. Current commercially available membranes are perfluorosulfonic acid polymers, a class of high-cost ionomers. This paper examines the potential of polymer blends, namely those of styrene-(ethylene-butylene)-styrene block copolymer (SEBS) and polyvinylidene fluoride (PVDF), in the proton exchange membrane application. SEBS/PVDF blends were prepared by twin-screw extrusion and the membranes were formed by calendering. SEBS is a phase-segregated material where the polystyrene blocks can be selectively functionalized offering high ionic conductivity, while PVDF insures good dimensional stability and chemical resistance to the films. Proton conductivity of the films was obtained by solid-state grafting of sulfonic acid moieties. The obtained membranes were characterized in terms of conductivity, ionic exchange capacity and water uptake. In addition, the membranes were characterized in terms of morphology, microstructure and thermo-mechanical properties to establish the blends morphology-property relationships. Modification of interfacial properties between SEBS and PVDF was found to be a key to optimize the blends performance. Addition of a methyl methacrylate-butyl acrylate-methyl methacrylate block copolymer (MMA-BA-MMA) was found to compatibilize the blend by reducing the segregation scale and improving the blend homogeneity. Mechanical resistance of the membranes was also improved through the addition of this compatibilizer. As little as 2wt.% compatibilizer was sufficient for complete interfacial coverage and lead to improved mechanical properties. Compatibilized blend membranes also showed higher conductivities, 1.9x10{sup -2} to 5.5x10{sup -3}Scm{sup -1}, and improved water management. (author)

  3. Proton exchange membranes based on PVDF/SEBS blends

    Science.gov (United States)

    Mokrini, A.; Huneault, M. A.

    Proton-conductive polymer membranes are used as an electrolyte in the so-called proton exchange membrane fuel cells. Current commercially available membranes are perfluorosulfonic acid polymers, a class of high-cost ionomers. This paper examines the potential of polymer blends, namely those of styrene-(ethylene-butylene)-styrene block copolymer (SEBS) and polyvinylidene fluoride (PVDF), in the proton exchange membrane application. SEBS/PVDF blends were prepared by twin-screw extrusion and the membranes were formed by calendering. SEBS is a phase-segregated material where the polystyrene blocks can be selectively functionalized offering high ionic conductivity, while PVDF insures good dimensional stability and chemical resistance to the films. Proton conductivity of the films was obtained by solid-state grafting of sulfonic acid moieties. The obtained membranes were characterized in terms of conductivity, ionic exchange capacity and water uptake. In addition, the membranes were characterized in terms of morphology, microstructure and thermo-mechanical properties to establish the blends morphology-property relationships. Modification of interfacial properties between SEBS and PVDF was found to be a key to optimize the blends performance. Addition of a methyl methacrylate-butyl acrylate-methyl methacrylate block copolymer (MMA-BA-MMA) was found to compatibilize the blend by reducing the segregation scale and improving the blend homogeneity. Mechanical resistance of the membranes was also improved through the addition of this compatibilizer. As little as 2 wt.% compatibilizer was sufficient for complete interfacial coverage and lead to improved mechanical properties. Compatibilized blend membranes also showed higher conductivities, 1.9 × 10 -2 to 5.5 × 10 -3 S cm -1, and improved water management.

  4. Biodegradable polyesters based on succinic acid

    Directory of Open Access Journals (Sweden)

    Nikolić Marija S.

    2003-01-01

    Full Text Available Two series of aliphatic polyesters based on succinic acid were synthesized by copolymerization with adipic acid for the first series of saturated polyesters, and with fumaric acid for the second series. Polyesters were prepared starting from the corresponding dimethyl esters and 1,4-butanediol by melt transesterification in the presence of a highly effective catalyst tetra-n-butyl-titanate, Ti(0Bu4. The molecular structure and composition of the copolyesters was determined by 1H NMR spectroscopy. The effect of copolymer composition on the physical and thermal properties of these random polyesters were investigated using differential scanning calorimetry. The degree of crystallinity was determined by DSC and wide angle X-ray. The degrees of crystallinity of the saturated and unsaturated copolyesters were generally reduced with respect to poly(butylene succinate, PBS. The melting temperatures of the saturated polyesters were lower, while the melting temperatures of the unsaturated copolyesters were higher than the melting temperature of PBS. The biodegradability of the polyesters was investigated by enzymatic degradation tests. The enzymatic degradation tests were performed in a buffer solution with Candida cylindracea lipase and for the unsaturated polyesters with Rhizopus arrhizus lipase. The extent of biodegradation was quantified as the weight loss of polyester films. Also the surface of the polyester films after degradation was observed using optical microscopy. It could be concluded that the biodegradability depended strongly on the degree of crystallinity, but also on the flexibility of the chain backbone. The highest biodegradation was observed for copolyesters containing 50 mol.% of adipic acid units, and in the series of unsaturated polyesters for copolyesters containing 5 and 10 mol.% of fumarate units. Although the degree of crystallinity of the unsaturated polyesters decreased slightly with increasing unsaturation, the biodegradation

  5. Control of enzymatic degradation of biodegradable polymers by treatment with biosurfactants, mannosylerythritol lipids, derived from Pseudozyma spp. yeast strains.

    Science.gov (United States)

    Fukuoka, Tokuma; Shinozaki, Yukiko; Tsuchiya, Wataru; Suzuki, Ken; Watanabe, Takashi; Yamazaki, Toshimasa; Kitamoto, Dai; Kitamoto, Hiroko

    2016-02-01

    Cutinase-like esterase from the yeasts Pseudozyma antarctica (PaE) shows strong degradation activity in an agricultural biodegradable plastic (BP) model of mulch films composed of poly(butylene succinate-co-adipate) (PBSA). P. antarctica is known to abundantly produce a glycolipid biosurfactant, mannosylerythritol lipid (MEL). Here, the effects of MEL on PaE-catalyzed degradation of BPs were investigated. Based on PBSA dispersion solution, the degradation of PBSA particles by PaE was inhibited in the presence of MEL. MEL behavior on BP substrates was monitored by surface plasmon resonance (SPR) using a sensor chip coated with polymer films. The positive SPR signal shift indicated that MEL readily adsorbed and spread onto the surface of a BP film. The amount of BP degradation by PaE was monitored based on the negative SPR signal shift and was decreased 1.7-fold by MEL pretreatment. Furthermore, the shape of PBSA mulch films in PaE-containing solution was maintained with MEL pretreatment, whereas untreated films were almost completely degraded and dissolved. These results suggest that MEL covering the surface of BP film inhibits adsorption of PaE and PaE-catalyzed degradation of BPs. We applied the above results to control the microbial degradation of BP mulch films. MEL pretreatment significantly inhibited BP mulch film degradation by both PaE solution and BP-degradable microorganism. Moreover, the degradation of these films was recovered after removal of the coated MEL by ethanol treatment. These results demonstrate that the biodegradation of BP films can be readily and reversibly controlled by a physical approach using MEL.

  6. Study on Isothermal Crystallization Kinetics of the Calcium Sulfate Whisker/PBS Blends%硫酸钙晶须/PBS共混物等温结晶动力学研究

    Institute of Scientific and Technical Information of China (English)

    杨海; 张宁; 卢翔; 瞿金平

    2013-01-01

    用差示扫描量热仪(DSC)测试了硫酸钙晶须/聚丁二酸丁二醇酯(PBS)共混物的等温结量过程.采用Hoffm-weeks方程拟合的方法得到了4种配比的硫酸钙晶须/PBS共混物的平衡熔点,并根据实验数据拟合出描述硫酸钙晶须/PBS共混物等温结晶过程的Avrami方程.结果表明:共混物的平衡熔点随着硫酸钙晶须含量的提高而降低;硫酸钙晶须的加入,对PBS的成核机理和生长方式没有明显的影响;等温结晶温度不影响共混物的结晶机理,但会影响结晶速率,等温结晶温度越高,结晶速率越慢.%The isothermal crystallization process of calcium sulfate whisker/poly(butylene succinate) (PBS) blends was observed by differential scanning calorimetry (DSC). The equilibrium melting points of the calcium sulfate whisker/PBS blends was obtained by using Hoffm-weeks equation fitting method, and the equilibrium melting point of blends decreased with the increase of calcium sulfate whisker content. The isothermal crystallization process was described by the classic Avrami equation. The Avrami equation was fitted by experimental data. The results show that: the calcium sulfate whisker has no significant effect on the mechanism of nucleation of the PBS, the isothermal crystallization temperature (Tc) can't affect the mechanism of crystallization of the blend, but it can affect the rate of crystallization; the higher Tc is, the slower the rate of crystallization is.

  7. Efeito da adição de diferentes copolímeros em blendas HDPE/HIPS pós-consumo: morfologia de fases e propriedades térmicas The effect of different block copolymers on post consumer HDPE/HIPS Blends: phase morphology and thermal properties

    Directory of Open Access Journals (Sweden)

    Igor S. B. Perez

    2008-09-01

    Full Text Available Blendas de poliolefinas/HIPS têm sido exploradas para obter filmes especiais com determinadas propriedades desejadas, tornando imperativo desenvolver vários estudos para um melhor conhecimento do comportamento desses materiais. Neste trabalho, efeitos da adição dos copolímeros comerciais de estireno-butadieno multibloco (SBS e de estireno-(etileno-co-butileno-estireno (SEBS tribloco linear em blendas pós-consumo de HDPE e HIPS são reportados. A diminuição nas dimensões da microfase dispersa, aliada à rugosidade superficial da fase HDPE após extração seletiva do HIPS, independentemente de a fase matriz ser HIPS ou HDPE, mostraram mais eficiência do SEBS como modificador interfacial de tensão ou como surfactante entre os diferentes domínios quando comparado com o SBS. Os resultados das caracterizações térmicas, por exemplo, menor Tm e menor grau de cristalinidade do HDPE, e maior Tg do poliestireno na presença de SEBS corroboraram esta conclusão, como será discutido posteriormente.Blending of post-consumer polyolefins/HIPS has been exploited for obtaining special films with a desired set of properties, which has required studies to understand the behavior of these materials. In this work the effects of commercial multiblock styrene-butadiene (SBS and linear triblock styrene-(ethylene-co-butylene-styrene (SEBS copolymers in blends of post-consumer high density polyethylene (HDPE and HIPS are reported. Thermal properties and phase morphology were comparatively analyzed for the additives aiming at verifying possible correlations between them. Decreased dimensions of the minor micro phase along with HDPE surface roughness after HIPS selective extraction, independently of the matrix being HIPS or HDPE, showed better effectiveness for SEBS as interfacial tension modifier or as surfactant at the different domains interface when compared with SBS. The results of thermal characterizations, e.g. lower HDPE melting temperature, lower

  8. Synthesis, properties and applications of bio-based materials

    Science.gov (United States)

    Srinivasan, Madhusudhan

    Bio-based feedstock have become very significant as they offer a value proposition in terms of carbon balance and also in terms of endowing biodegradability where needed. Thus a lot of attention is being given to the modification such feedstock for different applications. Soybean oil is one such feedstock. The oil is a triglyceride ester composed of different fatty acids, which are common to other plant oils. Thus soybean oil serves as a platform for plant oils, as modifications of this oil, can in theory be extended to cover other plant oils. Methyl oleate was used as a model fatty acid ester, to synthesize hydroxyesters with ethylene glycol via a two stage oxidative cleavage of the double bonds. Ozone was chosen as the oxidant due to its many advantages. The first stage involved oxidation of the double bond to aldehydes, ozonides and acetals, which were subsequently converted to hydroxyesters (hydroxy values of 220 - 270) in near quantitative yield by treatment with Oxone. This method could be extended to soybean oil to make "polyols" which could find applications in resin syntheses. Silylation was employed as another platform to functionalize soybean oil and fatty acid methyl esters with a reactive silane (vinyltrimethoxy silane). This simple modification produced materials that are cured by atmospheric moisture and are useful as coatings. The silylation was controlled by varying the grafting time, cure temperature and the concentration of the silane. Products with gel content as high as 90% could be achieved. The coating exhibited good adhesion to metal, glass, concrete and paper. Steel panels coated with these coatings exhibited good stability against corrosion in high humidity conditions and moderate stability against a salt spray. The silylation was also successfully utilized to improve the tensile strength of the blend of biodegradable polyester, poly (butylene adipate-co-terephthalate) with talc. A reactive extrusion process was employed to graft vinyl

  9. 'Remote' adiabatic photoinduced deprotonation and aggregate formation of amphiphilic N-alkyl-N-methyl-3-(pyren-1-yl)propan-1-ammonium chloride salts.

    Science.gov (United States)

    Abraham, Shibu; Weiss, Richard G

    2011-11-30

    The absorption and emission properties of a series of amphiphilic N-alkyl-N-methyl-3-(pyren-1-yl)propan-1-ammonium chloride salts were investigated in solvents of different polarities and over a wide concentration range. For example, at 10(-5) M concentrations in tetrahydrofuran (THF), salts with at least one N-H bond exhibited broad, structureless emissions even though time-correlated single photon counting (TCSPC) experiments indicated negligible static or dynamic intermolecular interactions. Salts with a butylene spacer or lacking an N-H bond showed no discernible structureless emission; their emission spectra were dominated by the normal monomeric fluorescence of a pyrenyl group and the TCSPC histograms could be interpreted on the basis of intramolecular photophysics. The broad, structureless emission is attributed to an unprecedented, rapid, adiabatic proton-transfer to the medium, followed by the formation of an intramolecular exciplex consisting of amine and pyrenyl groups. The proposed mechanism involves excitation of a ground-state conformer of the salts in which the ammonium group sits over the pyrenyl ring due to electrostatic stabilization. At higher concentrations, with longer N-alkyl groups, or in selected solvents, electronic excitation of the salts led to dynamic and static excimeric emissions. For example, whereas the emission spectrum of 10(-3) M N-hexyl-N-methyl-3-(pyren-1-yl)propan-1-ammonium chloride in THF consisted of comparable amounts of monomeric and excimeric emission, the emission from 10(-5) M N-dodecyl-N-methyl-3-(pyren-1-yl)propan-1-ammonium chloride in 1:9 (v:v) ethanol/water solutions was dominated by excimeric emission, and discrete particles near micrometer size were discernible from confocal microscopy and dynamic light scattering experiments. Comparison of the static and dynamic emission characteristics of the particles and of the neat solid of N-dodecyl-N-methyl-3-(pyren-1-yl)propan-1-ammonium chloride indicate that molecular

  10. Effect of anti-inflamentation extracts from Korean traditional medicinal herb

    Directory of Open Access Journals (Sweden)

    Zhang Xiaowan

    2014-09-01

    Full Text Available Five Mix Plant Extracts according to different extraction solvents were assessed for its cell viability and anti-inflammatory activity by in vitro methods. The single plant extract was extracted with 70% ethanol(EtOH and the mix plants(C.kousa, R.multiflora, T.nucifera, M.basjoo and S.glabra were extracted with EtOH 30%, 70%; Butylene Glycol(BG 30%, 70%; Propylene Glycol(PG 30%, 70%; Distilled Water(D.W. Cell viability was measured using the Micro culture tetrazolium (MTT assay method and Human fibroblast cells, CCD 1102 KERTr were used. The plant extracts with the maximum concentration that none toxic to the cells were evaluated for anti-inflammatory activity. Anti-inflammatory activity was evaluated using lipoxygenase inhibition assay method. A dose response curve was plotted to determine the IC50 values. Results showed that, at the 5 kinds of single plant extracts by 70% EtOH extraction solvent, it showed the IC50 was 280ug/ml of S1, 370ug/ml of S2, 380ug/ml of S3, 170ug/ml of S4 and 190ug/ml of S5. At the mix plant extracts by 7 kinds of extraction solvents (70%, 30% EtOH; 70%, 30% BG; 70%, 30% PG; D.W, it showed the IC50 was 140ug/ml of M E70, 140ug/ml of M E30, 120ug/ml of M BG70, 110ug/ml of M BG30, 120ug/ml of M PG70, 136ug/ml of M PG30 and 120ug/ml of M D.W. From the results, it is concluded that when these five plants mixed before extraction, it will extract more active ingredients with anti-inflammatory effects. Further study we will analyzing plants effective single compound using high performance liquid chromatography (HPLC profiling and progressing the experiments in vivo.

  11. Geochemical Features of Shale Hydrocarbons of the Central Part of Volga-Ural Oil and Gas Province

    Science.gov (United States)

    Nosova, Fidania F.; Pronin, Nikita V.; Plotnikova, Irina N.; Nosova, Julia G.

    2014-05-01

    heterogeneity in the composition of organic matter, which varies from sapropel to sapropel - humus. The study of adsorbed gases show the following: all samples have increased, high and abnormally high concentration of selected gases. Their common characteristic is that the gases are heavy, fatty, and have low methane content and hydrocarbons of unsaturated series (ethylene, propylene and butylene). Heavy hydrocarbons of saturated series are dominating, their share is changing irregularly in the homologous series . There is a relation between silica and organic matter content, the amount of organic matter and adsorbed gas, the presence of lube fraction and isotopic composition.

  12. STUDY ON INTENSIFYING THE PROCESS OF SHENGLI VACUUM RESIDUE THERMAL CRACKING%胜利减压渣油强化热转化过程的研究

    Institute of Scientific and Technical Information of China (English)

    马力; 侯焕娣; 王子军

    2012-01-01

    在实验室小型评价装置上考察复合型增液剂L对胜利减压渣油热转化反应的影响.研究结果表明,增液剂L使热转化液体产物收率增加、焦炭和干气产率降低.增加的液体产物主要是蜡油馏分,其组成主要是3环以上的多环芳烃,说明增液剂可促进残渣油和重质生成油分子多环芳烃结构的烷基侧链和多环芳烃结构之间桥链的断裂,使3~4环的多环芳烃能够及时从反应器逸出而成为液体产品.气体产物中C3、C4烃收率增加,C1、C2烃收率减少,表明增液剂L改变了原料烃的热裂化方式.%The thermal cracking of Shengli vacuum residue using a complex additive L to intensify liquid yield was studied by a lab-scale evaluation device. Test results demonstrate that using additive L, the liquid yield of thermal cracking can be increased, coke and dry gas yields decrease. The increased liquid product is mainly VGO fraction composed of more than 3-ring aromatic hydrocarbons, which indicates that the presence of additive L accelerates the cracking of alkyl side chains of polycyclic aromatics, as well as the bridge chains connected polycyclic rings, and furthermore, the obtained 3—4 rings aromatics can be escaped from the reaction system in time to form liquid product. Gas composition data show that in the gas product, the contents of methane, ethane and ethylene decrease, the contents of propane, propylene, butane and butylenes increase, which indicates that the presence of additive L may change the reaction pathway of hydrocarbons thermal cracking.

  13. Defeating anisotropy in material extrusion 3D printing via materials development

    Science.gov (United States)

    Torrado Perez, Angel Ramon

    ABS, UHMWPE (Ultra High Molecular Weight Polyethylene) and SEBS (Styrene Ethylene Butylene Styrene) were further examined due to the potential they demonstrated as low anisotropic materials in terms of strength. Also, the geometrical influence of different standard tensile specimens was studied. The development of materials that lead to lowered anisotropy on the strength of 3D printed parts has been successfully demonstrated, and alternative methodologies for the evaluation of anisotropic characteristics has been proposed as well. The present work shows the beginning to a better understanding of the mechanics taking place during the fusion of deposited material in MEAM.

  14. Study on Synthesis and Properties of Biodegradable Aqueous Polyurethane%可降解水性聚氨酯的合成及其性能研究

    Institute of Scientific and Technical Information of China (English)

    梁飞; 杨颖; 余蕾; 贾敏

    2012-01-01

    以L-赖氨酸二异氰酸酯为硬段,聚ε-己内酯二元醇(PCL)为软段采用两步法合成了无毒、可生物降解型水性聚氨酯,研究了R值、扩链剂用量以及预聚温度对乳液及涂膜性能的影响.结果表明,当R值为1.5、扩链剂1,4-丁二醇用量为4%、预聚温度为80℃时所合成的水性聚氨酯乳液性能最优.力学性能测试表明其具有良好的机械性能,拉伸强度可达46.5 MPa;80 d后水解降解质量损失达42%,说明所制备的聚氨酯具有可降解性,是一种具有广泛应用前景的生物医用材料.%Taking L - lysine diisocyanate as hard segment,polycaprolactone glycol (PCL) as soft segment,a non -toxic and biodegradable aqueous polyurethane was prepared using a two step process. The influence of R value,amount of chain extendel 1,4- butylene glycol and prepolymerization temperature on the properties of waterborne polyurethane emulsion and the film were studied. It is showed that when the R value was 1. 5 ,the amount of BDO 4% and the reaction temperature 80 ℃ ,the product prepared was best. The mechanical property tests showed good mechanical properties,tensile strength up to 46. 5 MPa and the mass loss of hydrolytic degradation after 80 days was 42% . The polyurethane prepared have biodegradabili-ty,which showed a good prospects as a biological medical material.

  15. VOCs Speciation From Steam Boiler Stacks of Industries Located in Naucalpan

    Science.gov (United States)

    Mejia, G. M.; Tejeda, D. D.; Bremauntz, M. P.; Valdez, A.; Montufar, P. C.; Martinez, M. A.; Sierra, M. J.; Gonzalez, C. A.

    2007-05-01

    Results of VOCs speciation from industrial steam boiler stacks located in Naucalpan are presented and discussed. This municipality is located north of the Metropolitan Zone of the Valley of Mexico (MZVM). Speciation of VOCs is important to generate information about sources of pollution, to update emission inventories, to study the dynamics of pollutants in the atmosphere, and to estimate possible risks of population exposure. This information is valuable for decision making on air pollution control strategies. Samples from 35 steam boilers form industries burning Diesel, LPG, or CNG were taken using the US-EPA Method 18. Selected samples from the use of different fuels were analyzed using gas chromatography and flame ionization detection (GC-FID) according to US-EPA protocol TO-14. The VOCs analyzed included alkanes of 9 carbons or less, alkenes of 7 carbons or less and aromatics (families of benzene). The results show consistency on the VOCs detected on Diesel samples. The main compounds found were 1- Butene+iButylene, m/p-Xylene, Ethane, Propene, Propane, Acetylene, 2Me-1Butene, and Toluene. The average concentrations of these compounds were in the range of 130 to 385 ppbC. The results of LPG samples did not show a definite pattern of VOCs, although light components predominate and, in some samples, Toluene and Xylene. These last components were not expected for industries reporting the use of LPG, perhaps due to the use of a combination of fuels and mistakes in the reports of fuel used at the time of sampling. The analysis of CNG samples show predominance of light VOCs, in the range of 90 to 300 ppbC. As in the case of LPG, some aromatics showed high concentrations in some samples analyzed perhaps due to the use of different fuels in the boiler. The results of this study are the first results of VOCs speciation obtained form exhaust gases from stacks of Mexican industries. The data reported are valuable to analyze emission inventories of VOCs and to better

  16. Water-enhanced solvation of organics

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.H.

    1993-07-01

    Water-enhanced solvation (WES) was explored for Lewis acid solutes in Lewis base organic solvents, to develop cheap extract regeneration processes. WES for solid solutes was determined from ratios of solubilities of solutes in water-sat. and low-water solvent; both were determined from solid-liquid equilibrium. Vapor-headspace analysis was used to determine solute activity coefficients as function of organic phase water concentration. WES magnitudes of volatile solutes were normalized, set equal to slope of log {gamma}{sub s} vs x{sub w}/x{sub s} curve. From graph shape {Delta}(log {gamma}{sub s}) represents relative change in solute activity coefficient. Solutes investigated by vapor-headspace analysis were acetic acid, propionic acid, ethanol, 1,2-propylene glycol, 2,3-butylene glycol. Monocarboxylic acids had largest decrease in activity coefficient with water addition followed by glycols and alcohols. Propionic acid in cyclohexanone showed greatest water-enhancement {Delta} (log {gamma}{sub acid})/{Delta}(x{sub w}/x{sub acid}) = {minus}0.25. In methylcyclohexanone, the decrease of the activity coefficient of propionic acid was {minus}0.19. Activity coefficient of propionic acid in methylcyclohexanone stopped decreasing once the water reached a 2:1 water to acid mole ratio, implying a stoichiometric relation between water, ketone, and acid. Except for 2,3-butanediol, activity coefficients of the solutes studied decreased monotonically with water content. Activity coefficient curves of ethanol, 1,2-propanediol and 2,3-butanediol did not level off at large water/solute mole ratio. Solutes investigated by solid-liquid equilibrium were citric acid, gallic acid, phenol, xylenols, 2-naphthol. Saturation concentration of citric acid in anhydrous butyl acetate increased from 0.0009 to 0.087 mol/L after 1.3 % (g/g) water co-dissolved into organic phase. Effect of water-enhanced solvation for citric acid is very large but very small for phenol and its derivatives.

  17. High density polyethylene (HDPE)/poly(ethylene terephthalate) (PET) polymer blend studies related to recycling co-mingled plastics

    Science.gov (United States)

    Tsai, Pang-Yen

    Polymer blends of virgin high density polyethylene (HDPE) and poly(ethylene terephthalate) (PET) were studied as an attempt to relate the microstructure to the mechanical properties of the blends. The virgin blends were prepared by extrusion and then injection molded into specimens for characterization. Two of the virgin blends were tested for possible compatibilization using a styrene-ethylene-butylene-styrene (SEBS) block copolymer. In addition, six blends of post-consumer resins (PCRs) of HDPE and PET were included in this work for comparison. The moduli of the virgin blends showed positive deviation from those expected from the rule of mixtures. The synergism of the composite moduli can be explained partly by a Poisson's effect. Yield strengths of the blends molded at low injection chamber temperatures (200sp°, 230sp°, and 250sp°C) followed the rule of mixtures well, because PET filaments found in the composites had very high length to diameter ratios. When the injection chamber temperature was above the PET melting point (˜254sp°C), PET filaments were found to break down into particles, and the yield strengths of the blends coincided with the values expected from the inverse rule of mixtures. Impact strengths of the virgin blends were much less than that of a HDPE homopolymer due to poor interfacial bonding between HDPE and PET. Compatibilization appeared to be advantageous since it dramatically improved the impact strength of the virgin blends. SEM micrographs of impact fractured surfaces revealed that the improved adhesion from compatibilization and the presence of numerous uniaxially aligned PET filaments in the HDPE substrate can account for the significant increases in fracture resistance of the compatibilized blends. Mechanical performance of the PCRs was inferior to that of the virgin blends. Aside from polymer degradation and contamination due to repeated processing and handling, absence of PET filaments and interfacial bonding could be

  18. Processing and characterization of solid and microcellular biobased and biodegradable PHBV-based polymer blends and composites

    Science.gov (United States)

    Javadi, Alireza

    Petroleum-based polymers have made a significant contribution to human society due to their extraordinary adaptability and processability. However, due to the wide-spread application of plastics over the past few decades, there are growing concerns over depleting fossil resources and the undesirable environmental impact of plastics. Most of the petroleum-based plastics are non-biodegradable and thus will be disposed in landfills. Inappropriate disposal of plastics may also become a potential threat to the environment. Many approaches, such as efficient plastics waste management and replacing petroleum-based plastics with biodegradable materials obtained from renewable resources, have been put forth to overcome these problems. Plastics waste management is at its beginning stages of development which is also more expensive than expected. Thus, there is a growing interest in developing sustainable biobased and biodegradable materials produced from renewable resources such as plants and crops, which can offer comparable performance with additional advantages, such as biodegradability, biocompatibility, and reducing the carbon footprint. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is one of the most promising biobased and biodegradable polymers, In fact many petroleum based polymers such as poly(propylene) (PP) can be potentially replaced by PHBV because of the similarity in their properties. Despite PHBV's attractive properties, there are many drawbacks such as high cost, brittleness, and thermal instability, which hamper the widespread usage of this specific polymer. The goals of this study are to investigate various strategies to address these drawbacks, including blending with other biodegradable polymers such as poly (butylene adipate-coterephthalate) (PBAT) or fillers (e.g., coir fiber, recycled wood fiber, and nanofillers) and use of novel processing technologies such as microcellular injection molding technique. Microcellular injection molding technique

  19. Final report on the safety assessment of Arnica montana extract and Arnica montana.

    Science.gov (United States)

    2001-01-01

    Arnica Montana Extract is an extract of dried flowerheads of the plant, Arnica montana. Arnica Montana is a generic term used to describe a plant material derived from the dried flowers, roots, or rhizomes of A. montana. Common names for A. montana include leopard's bane, mountain tobacco, mountain snuff, and wolf's bane. Two techniques for preparing Arnica Montana Extract are hydroalcoholic maceration and gentle disintegration in soybean oil. Propylene glycol and butylene glycol extractions were also reported. The composition of these extracts can include fatty acids, especially palmitic, linoleic, myristic, and linolenic acids, essential oil, triterpenic alcohols, sesquiterpene lactones, sugars, phytosterols, phenol acids, tannins, choline, inulin, phulin, arnicin, flavonoids, carotenoids, coumarins, and heavy metals. The components present in these extracts are dependent on where the plant is grown. Arnica Montana Extract was reported to be used in almost 100 cosmetic formulations across a wide range of product types, whereas Arnica Montana was reported only once. Extractions of Arnica Montana were tested and found not toxic in acute toxicity tests in rabbits, mice, and rats; they were not irritating, sensitizing, or phototoxic to mouse or guinea pig skin; and they did not produce significant ocular irritation. In an Ames test, an extract of A. montana was mutagenic, possibly related to the flavenoid content of the extract. No carcinogenicity or reproductive/developmental toxicity data were available. Clinical tests of extractions failed to elicit irritation or sensitization, yet Arnica dermatitis, a delayed type IV allergy, is reported in individuals who handle arnica flowers and may be caused by sesquiterpene lactones found in the flowers. Ingestion of A. montana-containing products has induced severe gastroenteritis, nervousness, accelerated heart rate, muscular weakness, and death. Absent any basis for concluding that data on one member of a botanical

  20. PBS/EVOH共混物制备与性能研究%Preparation and Properties of Polybutylene Succinate/Ethylene-Vinyl Alcohol Blends

    Institute of Scientific and Technical Information of China (English)

    赵芸芳

    2012-01-01

    利用熔融共混法制备了综合性能优良的聚丁二酸丁二醇酯/乙烯-乙烯醇共聚物( PBS/EVOH)共混物,并通过扫描电子显微镜、傅立叶转变红外光谱( FTIR)仪、万能试验机以及差示扫描量热分析仪分别研究了共混体系的微观形态、两相间的作用情况、力学性能以及热性能.结果表明,共混体系为两相“海-岛”结构,分散相以“球状”均匀地分布于连续相中,且两相界面结合比较好;FTIR结果证实了PBS与EVOH之间存在强烈的氢键作用,且氢键作用降低了PBS结晶度,从而可以加快PBS的降解过程.PBS/EVOH共混物可用于制造可降解的包装薄膜材料.%Poly butylenes succinate / ethyTene-vinyl alcohol ( PBS / EVOH ) blends were prepared by melt blending.The morphology, interaction between two phase, mechanical and thermal properties of the composites were investigated via scanning electron microscopy ( SEM X fourier transform infrared chromatograph ( FTIR )> universal testing machine and differential scanning calorimetry ( DSC) respectively.The result showed that the composite was two-phase "sea-island" structure, the interaction between the sphere dispersed phase and continuous phase was good.FTIR analysis verified the existence of H-bonding between PBS and EVOH, and H-bonding reduced the crystallization of PBS, so accelerated the degradation of PBS.PBS / EVOH blends could be used to make biodegradable packing film.

  1. 油溶性聚醚的制备及其抗氧化性能考察%PREARATION AND ANTIOXIDANT CHARACTERISTICS OF OIL-SOLUCLE POLYETHER

    Institute of Scientific and Technical Information of China (English)

    程亮; 李洪伟; 孔令杰; 张东恒

    2014-01-01

    以氢氧化钾作为催化剂,环氧丙烷与环氧丁烷共聚制备了分别符合黏度级别 OSP-18,OSP-46, OSP-150要求的油溶性聚醚,并通过红外光谱(IR)、核磁共振(NMR)和凝胶渗透色谱(GPC)对其进行表征。利用旋转氧弹测试方法考察了油溶性聚醚的抗氧化性能,结果表明油溶性聚醚本身的抗氧化性能较差。通过考察不同抗氧剂与油溶性聚醚的互配性,开发了α-苯胺与氨基甲酸酯组成的复合抗氧剂,该复合抗氧剂与油溶性聚醚有较好的互配性,可使油溶性聚醚的旋转氧弹时间达到1200 min,复合抗氧剂可使油溶性聚醚在不同配方体系中得到应用。%Oil-soluble polyether (OSP)was prepared by the copolymerization of propylene oxide and butylene oxide using KOH as a catalyst.The viscosity grades of the prepared oil-soluble polyether are OSP-18,OSP-46,OSP-150,respectively.The structures of the products were defined by means of infra-red spectroscopy (IR),nuclear magnetic resonance (NMR)and gel permeation chromatography (GPC). The anti-oxidation performance of OSPs were investigated by rotary oxygen bomb test method (ROBT).The results indicate that the oil-soluble polyether is poor in anti-oxidation with short induc-tion period.However,the performance of the oil-soluble polyether is greatly improved by addition of the composite antioxidant,composed of α-aniline (AOA-4 )and carbamate (AOL-1 ). The ROBT can reach to 1 200 minutes.The performance of this composite antioxidant makes OSP the best application in different formulations.

  2. Study on Impact of Modified Wheat Straw Fibers on PBS Composites Properties%改性小麦秸秆纤维对PBS复合材料性能的影响研究

    Institute of Scientific and Technical Information of China (English)

    强琪; 张敏; 徐丹; 邱建辉

    2012-01-01

    Wheat straw fiber was treated by NaOH,on this basis,the Na 2 S 2 O 4 and coupling agents (KH550,KH560) were used to modify the fiber,then the wheat straw fiber/PBS composites were prepared through the blending with poly(butylene succinate) (PBS).The effects of addition of Na2S2O4,and modification of KH550 and KH560 after NaOH treatment on the properties of the straw fiber/PBS composites were studied.Energy disperse spectroscopy (EDS) ,X-ray diffraction and SEM were used to characterize and observe the modified fibers and composites before and after modification.The results indicated that the properties of the composite would be the best when the fiber was treated by NaOH-3% Na2S2O4,compared with KH550,the mechanical properties of composite modified by KH560 could been improved more effectively,and the properties would be the best when the addition of KH560 was 2%.%采用NaOH对小麦秸秆纤维进行处理,在此基础上使用蒸煮助剂Na2S2O4和偶联剂(KH550、KH560)改性秸秆纤维,并将其分别与聚丁二酸丁二醇酯(PBS)共混,制备了秸秆纤维/PBS复合材料.研究了NaOH处理中Na2S2O4的添加以及NaOH处理后KH550、KH560的改性对复合材料性能的影响.采用EDS、WXRD和SEM对改性前后的纤维及复合材料分别进行了分析和观测.研究结果表明:NaOH同3% Na2S2O4混合处理得到的复合材料的性能最好,KH560较KH550更能有效地改善复合材料的力学性能,当KH560质量分数为2%时,复合材料的力学性能最好.

  3. Environmental effects of poly(phenylene ether) blends after long-term exposure to potable hot water

    Science.gov (United States)

    Maclean, Steven

    In recent years, engineering thermoplastic resins have been contemplated for use in a variety pressurized fluid handling components such as potable water delivery pipes, fitting and valves. In this research, rigid blends of glassy poly(phenylene ether) (PPE) polymer are studied to assess their suitability in long-term, potable, hot water environments. Three distinct PPE-based model compounds were prepared for this research: (i) a 50/50 blend of PPE and high impact polystyrene (HIPS); (ii) a 50/50 blend of PPE and HIPS with the inclusion of an anti-oxidant package and; (iii) a blend consisting of capped PPE, crystal polystyrene and styrene-ethyelene-butylene-styrene (SEBS) rubber. A fourth engineering thermoplastic, namely bisphenol-A polysulfone (PSU), was incorporated into the study as a benchmark material due to its proven reliability in hot water applications. Aging experiments were carried out for 8,000 hours in an 80°C water bath and an 80°C convection oven to characterize physical property retention and degradation mechanisms in each material. During water bath immersion, excessive, non-Fickian water diffusion occurred in both PPE/HIPS blends which led to water clustering and disc shaped microcavities on the order of 50 to 100 mum in diameter. These voids in the bulk caused appreciable losses in tensile elongation and fatigue resistance. The capped PPE/PS/SEBS blend, however, managed water uptake more effectively and its chemistry deterred water clustering. With further improvements to the formulation, such as larger rubber domains or an alternative impact modifier, the capped PPE blend may be able to offer physical property retention equal to that of PSU. With the exception of slight craze formation at sharp specimen edges during hot water immersion, the PSU material proved to be an exceptional material candidate throughout the entire experimentation. Surprisingly long-term hot water exposure did not cause gross chemical degradation in any of the materials

  4. PP/Talc/MA-SEBS复合材料的力学性能研究%The Mechanical Properties of PP/Talc/MA-SEBS Composite

    Institute of Scientific and Technical Information of China (English)

    谢晓春

    2011-01-01

    PP/Talc composites compatibilized by MA-SEBS(maleic anhydride grafted styrene-(ethylene-co-butylene)-styrene copolymer) were prepared by melt extrusion, followed by injection molding. The effects of Talc and MA-SEBS on mechanical properties of PP/Talc/MA-SEBS composites were systematically investigated. The results indicated that Talc mixing into PP could obviously improve the impact strength of PP at room temperature. After the entry of MA-SEBS to the PP/Talc composites, the impact strength increased even more. MA-SEBS acted as a toughening agent as well as a compatilizer, enhancing the toughening effect of Talc. The rigid Talc particles made the flexural strength increase markedly, and the flexural moduls go up with the increase of Talc content; and elastomer MA-SEBS got the flexural performance of composites obviously deteriorated. Talc had no bad effect on the PP tensile properties; if adding Talc and MA-SEBS at the same time,the tensile strength would go down, and tend to decrease with increasing MA-SEBS content in the composites.%选用MA-SEBS为增容剂,制备了PP/滑石粉(Talc)/MA-SEBS复合材料,研究了Talc和MA-SEBS的含量对复合材料力学性能的影响.结果表明,单纯加入一定量Talc可以明显提高PP冲击强度,再加入MA-SEBs后,复合材料的冲击强度进一步增加.MA-SEBS除了作为相容剂.也充当增韧剂.刚性粒子Talc使材料的弯曲强度明显增大,弯曲模量随Talc含量增加而增大;而弹性体MA-SEBS使材料弯曲性能明显变差.单纯加入Talc对PP的拉伸性能无负面影响;若同时加入Tak和MA-SEBS,材料的拉伸强度明显下降,且MA-SEBS含量越大降幅越大.

  5. Studies in reactive extrusion processing of biodegradable polymeric materials

    Science.gov (United States)

    Balakrishnan, Sunder

    Various reaction chemistries such as Polymerization, Polymer cross-linking and Reactive grafting were investigated in twin-screw extruders. Poly (1,4-dioxan-2-one) (PPDX) was manufactured in melt by the continuous polymerization of 1,4-dioxan-2-one (PDX) monomer in a twin-screw extruder using Aluminum tri-sec butoxide (ATSB) initiator. Good and accurate control over molecular weight was obtained by controlling the ratio of monomer to initiator. A screw configuration consisting of only conveying elements was used for the polymerization. The polymerization reaction was characterized by a monomer-polymer dynamic equilibrium, above the melting temperature of the polymer, limiting the equilibrium conversion to 78-percent. Near complete (˜100-percent) conversion was obtained on co-polymerizing PDX monomer with a few mol-percent (around 8-percent) Caprolactone (CL) monomer in a twin-screw extruder using ATSB initiator. The co-polymers exhibited improved thermal stability with reduction in glass transition temperature. The extruder was modeled as an Axial Dispersed Plug Flow Reactor for the polymerization of CL monomer using Residence Time Distribution (RTD) Analysis. The model provided a good fit to the experimental RTD and conversion data. Aliphatic and aliphatic-aromatic co-polyesters, namely Polycaprolactone (PCL) and Poly butylenes (adipate-co-terephthalate) (Ecoflex) were cross-linked in a twin-screw extruder using radical initiator to form micro-gel reinforced biodegradable polyesters. Cross-linked Ecoflex was further extrusion blended with talc to form blends suitable to be blown into films. A screw configuration consisting of conveying and kneading elements was found to be effective in dispersion of the talc particles (5--10 microns) in the polyester matrix. While the rates of crystallization increased for the talc filled polyester blends, overall crystallinity reduced. Mechanical, tear and puncture properties of films made using the talc filled polyester blends

  6. Adjustment of surface chemical and physical properties with functionalized polymers to control cell adhesion

    Science.gov (United States)

    Zhou, Zhaoli

    Cell-surface interaction is crucial in many cellular functions such as movement, growth, differentiation, proliferation and survival. In the present work, we have developed several strategies to design and prepare synthetic polymeric materials with selected cues to control cell attachment. To promote neuronal cell adhesion on the surfaces, biocompatible, non-adhesive PEG-based materials were modified with neurotransmitter acetylcholine functionalities to produce hydrogels with a range of porous structures, swollen states, and mechanical strengths. Mice hippocampal cells cultured on the hydrogels showed differences in number, length of processes and exhibited different survival rates, thereby highlighting the importance of chemical composition and structure in biomaterials. Similar strategies were used to prepare polymer brushes to assess how topographical cues influence neuronal cell behaviors. The brushes were prepared using the "grown from" method through surface-initiated atom transfer radical polymerization (SI-ATRP) reactions and further patterned via UV photolithography. Protein absorption tests and hippocampal neuronal cell culture of the brush patterns showed that both protein and neuronal cells can adhere to the patterns and therefore can be guided by the patterns at certain length scales. We also prepared functional polymers to discourage attachment of undesirable cells on the surfaces. For example, we synthesized PEG-perfluorinated alkyl amphiphilic surfactants to modify polystyrene-block-poly(ethylene-ran-butylene)- block-polyisoprene (SEBI or K3) triblock copolymers for marine antifouling/fouling release surface coatings. Initial results showed that the polymer coated surfaces can facilitate removal of Ulva sporelings on the surfaces. In addition, we prepared both bioactive and dual functional biopassive/bioactive antimicrobial coatings based on SEBI polymers. Incubating the polymer coated surfaces with gram-positive bacteria (S. aureus), gram

  7. Effect of Straw Fiber Modification on Properties for Wheat Straw Fiber/PBS Composite%纤维改性对小麦秸秆纤维/PBS复合材料性能的影响

    Institute of Scientific and Technical Information of China (English)

    强琪; 张敏; 徐丹; 何文清; 宋吉青

    2013-01-01

    利用NaOH对小麦秸秆纤维进行处理,同时采用了不同的蒸煮助剂和改性剂,以改变纤维自身物理性能及其表面化学性质.将改性纤维与聚丁二酸丁二醇酯(PBS)共混,制备了秸秆纤维/PBS复合材料,并通过X射线能谱仪(EDS)、X射线衍射仪(XRD)和扫描电子显微镜(SEM)对改性前后的纤维进行了分析和观测,研究分析了助剂和改性剂对复合材料性能的影响.结果表明:秸秆纤维经NaOH/4%Na2SO3处理,以及碱处理纤维经钛酸酯偶联剂NDZ201、环氧树脂E44改性,所得纤维增强复合材料的性能较为优异.%Wheat straw fiber was treated with NaOH, meanwhile different additives and modifiers were used to alter the physical properties and surface chemical properties of wheat straw fiber, and the composites were prepared through the blending between the fibers and poly (butylene succinate) (PBS). Through analysis and observation of modified fibers by energy disperse spectroscopy (EDS), X-ray diffraction (XRD) and scanning electron microscopy (SEM), the effects of type and addition for additives and modifies on the properties of straw fiber and the straw fiber/PBS composites were studied. The results show that the property of the composite is better when the raw fiber is treated by NaOH/4%Na2SO3, and the NaOH treated fiber is modified by NOZ201 or E44.

  8. Reactivity of Benzophenone Ketyl Free Radicals in an Elongated Elastomer Film.

    Science.gov (United States)

    Levin, Peter P; Efremkin, Alexei F; Kasparov, Valery V; Khudyakov, Igor V

    2016-09-29

    The effect of polymer film elongation leading to the thinning of the film up to three times on the decay of transients was studied. Kinetics of benzophenone (B) triplet state (3)B* and ketyl free radical BH• in soft rubber poly(ethylene-co-butylene) (abbreviated as E) was investigated by nanosecond laser flash photolysis. We monitored decay kinetics of the triplet state of (3)B* and of BH• decay in the polymer cage and decay of BH• in the polymer bulk. The fast exponential decay of (3)B*(lifetime τT ≈ 200 ns) is accompanied by hydrogen atom abstraction from E with the formation of BH• and a polymer free radical R•. The decay of BH• in the polymer cage occurs during τc ≈ 1 μs. Cage recombination, in turn, was followed by a cross-termination of BH• in the polymer bulk (τb ≈ 100 μs under our conditions) and is characterized by a rate constant kb ≈ 10(8) M(-1) s(-1). We studied changes of rates of transients decay upon elongation (thinning) of E. Decay of (3)B* is practically independent of elongation of the film. Recombination of BH• in the solvent bulk occurs with a two times lower kb than in a nonelongated E. The decrease in kb is ascribed mainly to a lower fractional polymer free volume Vf in elongated E compared with that in nonelongated E. Dependencies of log10 kb versus [Formula: see text], where [Formula: see text] is the thickness of the film, turned out to be linear with a negative slope. At the same [Formula: see text] recombination proceeds slower in the elongated elastomer compared with the nonelongated elastomer. Cage effect increases twice as well due to a lower rate of radicals escape from the polymer cage in the elongated film. We observed relatively large effects of external magnetic field (B = 0.2T) on the kinetics of cage recombination and recombination in the polymer bulk. Magnetic field effect on recombination rates in the cage and in the solvent bulk does not depend on elongation.

  9. 聚乳酸的静态双向拉伸性能%Static biaxially oriented property of PLA

    Institute of Scientific and Technical Information of China (English)

    罗焯欣; 董月平

    2016-01-01

    以国产聚乳酸(PLA)和进口PLA为原料,研究其成膜加工性能以及静态拉伸工艺对薄膜性能的影响,并研究了扩链剂苯乙烯-丙烯酸甘油酯共聚物(ADR)、聚碳酸丁二酯(PBC)以及防粘连剂对PLA成膜性和力学性能的影响。结果表明:在拉伸速度为60mm/s时,易得到综合性能较好的薄膜;w(ADR)为0.2%时,可有效改善PLA薄膜的厚薄均匀性,并可提高薄膜的纵、横向拉伸强度;w(PBC)为10%时,可明显改善其成膜性,膜的厚薄均匀性及脆性;防粘连剂的加入对成膜性及薄膜性能影响不大。%The film forming ability and static stretching process of imported and domestic poly(lactic acid) (PLA)were studied in this paper. The impact of chain extender that include poly(butylene carbonate)(PBC) and styrene-acrylic glyceride(ADR)and anti-blocking agent on the forming and mechanical properties of PLA were observed as well. The results indicate that the properties of the film are the best when the oriented speed for PLA is 60 mm/s. The thickness uniformity of PLA is improved by adding chain extender ADR of 0.2% in mass fraction along with the lateral and vertical tensile strength of the film. 10% of PBC in mass fraction can enhance the film reforming ability of the film significantly as well as thickness uniformity and brittleness. Anti-blocking agent contributes little to forming ability and properties of PLA.

  10. CBT/PA6共混物等温及非等温结晶动力学%Isothermal and non-isothermal crystallization kinetics of CBT/PA6 blends

    Institute of Scientific and Technical Information of China (English)

    董红星; 赵庆晨; 佟丽莉; 刘文婧; 张进; 杨晓光; 刘立佳; 张春红; 李峻青

    2015-01-01

    利用溶液共混法制备了尼龙6( PA6)/对苯二甲酸丁二醇酯( CBT)的共混物,研究了PA6和CBT/PA6体系粘度随温度的变化、结晶形态以及等温和非等温结晶动力学. 流变结果表明,CBT的加入可以明显降低PA6的粘度. DSC结果表明:等温结晶时,加入CBT后,PA6的Avrami指数n、t1/2、tmax均降低,结晶速率G提高;非等温结晶时,共混物的Jeziorny指数n有所降低,相比于PA6,结晶速率加快. POM结果表明:CBT的加入能有效地增加PA6的成核密度. 可见CBT有望成为PA6结晶过程促进剂.%This paper studied the blends that were produced by the way of solution mixing of nylon 6 ( PA6) and cyclic butylenes terephthalate ( CBT) , the viscosity of the PA6 and CBT/PA6 blends changing with temperature, the crystalline form, and the isothermal and non-isothermal crystallization kinetics. The rheological results showed that with the addition of CBT it could significantly reduce the viscosity of PA6. The DSC results showed that in iso-thermal crystallization the Avrami indices n, t1/2, tmax of PA6 were reduced while the crystallization rate G increased as the CBT was added into the blend. In non-isothermal crystallization, the blend's Jeziorny index n was reduced and comparing with PA6 the crystallization rate was faster. Based on the studies in this paper, CBT is expected to become an accelerator, which can effectively increase nucleation density of PA6.

  11. Chemical and enzymatic catalytic routes to polyesters and oligopeptides biobased materials

    Science.gov (United States)

    Zhu, Jianhui

    My Ph.D research focuses on the synthesis and property studies of different biobased materials, including polyesters, polyurethanes and oligopeptides. The first study describes the synthesis, crystal structure and physico-mechanical properties of a bio-based polyester prepared from 2,5-furandicarboxylic acid (FDCA) and 1,4-butanediol. Melt-polycondensation experiments were conducted by a two-stage polymerization using titanium tetraisopropoxide (Ti[OiPr] 4) as catalyst. Polymerization conditions (catalyst concentration, reaction time and 2nd stage reaction temperature) were varied to optimize poly(butylene furan dicarboxylate), PBF, molecular weight. A series of PBFs with different Mw were characterized by Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Dynamic Mechanical Thermal Analysis (DMTA), X-Ray diffraction and tensile testing. Influence of molecular weight and melting/crystallization enthalpy on PBF material tensile properties was explored. Cold-drawing tensile tests at room temperature for PBF with Mw 16K to 27K showed a brittle-to-ductile transition. When Mw reaches 38K, the Young's Modulus of PBF remains above 900 MPa, and the elongation at break increases to above 1000%. The mechanical properties, thermal properties and crystal structures of PBF were similar to petroleum derived poly(butylenes terephthalate), PBT. Fiber diagrams of uniaxially stretched PBF films were collected, indexed, and the unit cell was determined as triclinic (a=4.78(3) A, b=6.03(5) A, c=12.3(1) A, alpha=110.1(2)°, beta=121.1(3)°, gamma=100.6(2)°). A crystal structure was derived from this data and final atomic coordinates are reported. We concluded that there is a close similarity of the PBF structure to PBT alpha- and beta-forms. In the second study, a biobased long chain polyester polyol (PC14-OH) was synthesized from o-hydroxytetradecanoic acid (o-HOC14) and 1,4-butanediol. The first section about polyester polyurethanes describes the synthesis

  12. 偶联剂对聚丁烯-1/碳酸钙复合材料性能的影响%Inlfuences of Coupling Agents on Properties of Polybutene-1/Calcium Carbonate Composites

    Institute of Scientific and Technical Information of China (English)

    乔辉; 王树建; 刘维松; 丁筠

    2016-01-01

    of polybutene-1 can be improved with addition of calcium carbonate modified by aluminate and compact packed tiny crystal ball is formed in matrix. Calcium carbonate modified by aluminate has better dispersion in polybutylene-1 with no obvious agglomeration and has strong interface binding capacity with poly-butylene-1,it can absorb deformation work to improve the toughness of the composite.

  13. Development of Modified Pag (Polyalkylene Glycol) High VI High Fuel Efficient Lubricant for LDV Applications

    Energy Technology Data Exchange (ETDEWEB)

    Gangopadhyay, Arup [Ford Motor Company, Dearborn, MI (United States); McWatt, D. G. [Ford Motor Company, Dearborn, MI (United States); Zdrodowski, R. J. [Ford Motor Company, Dearborn, MI (United States); Liu, Zak [Ford Motor Company, Dearborn, MI (United States); Elie, Larry [Ford Motor Company, Dearborn, MI (United States); Simko, S. J. [Ford Motor Company, Dearborn, MI (United States); Erdemir, Ali [Argonne National Lab. (ANL), Argonne, IL (United States); Ramirez, Giovanni [Argonne National Lab. (ANL), Argonne, IL (United States); Cuthbert, J. [Dow Chemical Company, Midland, MI (United States); Hock, E. D. [Dow Chemical Company, Midland, MI (United States)

    2015-09-30

    Test Procedure) metro/highway cycles. Five different PAG chemistries were selected by varying the starting alcohol, the oxide monomers (ethylene oxide, propylene oxide, or butylene oxide), capped or uncapped, homopolymer or random copolymer. All formulations contained a proprietary additive package and one which contained additional antiwear and friction modifier additives. Laboratory bench tests (Pin-on-Disk, High Frequency Reciprocating Rig (HFRR), Block-on-Ring, Mini-Traction Machine (MTM) identified formulations having friction, wear, and load carrying characteristics similar to or better than baseline GF-5 SAE 5W-20 oil. Motored valvetrain and motored piston ring friction tests showed nearly 50% friction reduction for some of the PAG formulations compared to GF-5 SAE 5W-20 oil. Motored engine tests showed up to 15% friction benefit over GF-5 SAE 5W-20 oil. It was observed that friction benefits are more related to PAG base oil chemistry than their lower viscosity compared to GF-5 SAE 5W-20 oil. Analysis of wear surfaces from laboratory bench tests and bucket tappets from motored valvetrain tests confirmed the presence of PAG molecules. The adsorption of these polar molecules is believed to be reason for friction reduction. However, the wear surfaces also had thin tribo-film derived from additive components. The tribo-film consisting of phosphates, sulfides, and molybdenum disulfide (when molybdenum additive was present) were observed for both GF-5 SAE 5W-20 and PAG fluids. However, when using PAG fluids, motored valvetrain tests showed high initial wear, which is believed to be due to delay in protective tribo-film formation. After the initial wear, the wear rate of PAG fluids was comparable to GF-5 SAE 5W-20 oil. The PAG oil containing additional antiwear and friction reducing additives showed low initial wear as expected. However, when this oil was evaluated in Sequence IVA test, it showed initially low wear comparable to GF-5 oil but wear accelerated with oil

  14. 正辛烷热裂化和催化裂化生成甲烷反应机理%Mechanism of methane formation in thermal and catalytic cracking of n-octane

    Institute of Scientific and Technical Information of China (English)

    李福超; 张久顺; 袁起民

    2014-01-01

    The thermal and catalytic cracking reactions of n-octane were carried out in a temperature range of 550~650℃ with low conversions ( x<15%) in a pulse micro-reactor over quartz and ZRP zeolite. Reaction mechanism of methane formation was analyzed. The results showed that ethylene, propylene and n-butylene were primary products and four paths contributed to methane formation in thermal cracking of n-octane. At 600 ℃, dehydrogenation of terminal C-H bond in the chain attacked by methyl radical led to methane production. Due to higher activation energy of cleavage of terminal C-C bond in octyl radical formed via dehydrogenation of central C-C bond, only methane can form at higher temperature. Protolytic cracking was predominant with relatively remarkable yield of normal paraffin in catalytic cracking of n-octane over ZRP zeolite. Methane was produced by protolytic cracking route as well. By comparison of methane formation between thermal and protolytic cracking, it revealed that methane formed through protolytic cracking below 600℃ while thermal cracking dominated the selectivity of methane at higher reaction temperatures.%采用脉冲微反装置,在反应温度为550~650℃,低转化率(小于15%)下,研究了正辛烷在石英砂和ZRP分子筛上的热裂化和催化裂化反应,分析了甲烷的生成机理。结果表明,正辛烷热裂化时,乙烯、丙烯和正丁烯是初始产物,甲烷由4种反应路径生成。当反应温度为600℃时,甲基自由基攻击碳链端部C-H键生成甲烷。中部C-H键脱氢形成的辛基自由基在端部C-C键断裂的活化能较高,仅在高温下生成甲烷。正辛烷在ZRP分子筛上主要发生质子化裂化反应,正构烷烃占有相当比重,甲烷由质子化裂化步骤生成。热裂化与质子化裂化对甲烷贡献的对比可知,当反应温度低于600℃时,甲烷由质子化裂化反应生成;在高温下,热裂化反应决定甲烷选择性。

  15. MA-SEBS对超高分子量聚乙烯/碳纳米管复合材料结晶和熔融行为的影响%Effect of MA-SEBS on crystallization and melting behavior of ultra high molecular weight polyethylene/carbon nanotube composites

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    以马来酸酐接枝SEBS (MA-SEBS)作相容剂,采用溶液共混的方法制备超高分子量聚乙烯(UHMWPE)/碳纳米管(CNTs)复合材料.熔融结晶的UHMWPE/CNT复合材料是将其熔体以20℃/分的速率降温结晶而成.采用差示扫描量热法(DSC)研究了以不同方式结晶制备的UHMWPE/CNT复合材料的结晶和熔融行为.结果表明UHMWPE/CNT复合材料中UHMWPE相在溶液态结晶比在熔融态结晶形成的晶片厚,因而表现出更高的熔点(Tm)和结晶度(Xc).随着CNTs含量增加,UHMWPE/CNT复合材料中UHMWPE相的结晶温度(Tc)趋于提高.而且MA-SEBS的加入降低了UHMWPE/CNT复合材料中UHMWPE相的Tm 和 Tc. 此外UHMWPE/CNT复合材料中UHMWPE相的结晶速率随CNTs的引入而提高; MA-SEBS起相容剂的作用,改善了CNTs在UHMWPE基体中的分散性,使UHMWPE相的结晶速率进一步提高.%Ultra-high molecular weight polyethylene (UHMWPE) is filled with carbon nano-tubes (CNTs) by solution in the presence of maleic anhydride grafted styrene-(ethylene-co-butylene)-styrene copolymer (MA-SEBS) as a compatibilizer. The UHMWPE/CNT composites crystallized in melting state were prepared at a cooling rate of 20 ℃ min-1. The melting and crystallization behaviors of UHMWPE/CNT composites were investigated by differential scanning calorimetry. The results showed that Tm and Xc of UHMWPE/CNT composites crystallized in solution state are higher than those in melting state due to the larger crystalline lamellar thickness. Tc of UHMWPE/CNT composites tends to shift to higher temperature region with increasing CNTs content in the composites. Tm and Tc of UHMWPE phase in UHMWPE/CNT composites decrease with the addition of MA-SEBS. Moreover, the crystallization rate of UHMWPE phase in UHMWPE/CNT composite is accelerated due to the introduction of CNTs. MA-SEBS acts as compatilizer, enhances the dispersion of CNTs in the UHMWPE matrix. Thereby, the crystallization rate of UHMWPE phase in UHMWPE

  16. Design of biobased and biodegradable - compostable engineered plastics based on poly(lactide)

    Science.gov (United States)

    Schneider, Jeffrey Samuelson

    Poly(lactide) (PLA) is a biobased and biodegradable - compostable plastic that is derived from renewable resources such as corn and sugar cane. It possesses excellent strength and stiffness properties and is recognized as safe for biomedical and food packaging applications. Commercially, it costs $1/lb and is now competitive with petroleum based polymers that have dominated the industry for decades. However, the material has some inherently weak properties that prevent it from certain applications - most notably, its rheological properties, brittleness, and poor high temperature performance. Cost effective modifications of the polymer to enhance these deficiencies could allow for increased applications and further its commercial growth. Multiple synthetic strategies have been developed to address PLA's performance property deficiencies. PLA typically exhibits poor melt strength and does not have the ability to strain harden, partially a result of its highly linear nature. Strain hardening and high melt strength are crucial elements of a material when producing blown films, a large untapped market for PLA. By increasing molecular weight and introducing long-chain branching into the material, these properties can be improved. Epoxy-functionalized PLA (EF-PLA) was synthesized by reacting PLA with a multifunctional epoxy polymer (MEP) using reactive extrusion processing (REX). These modified PLA polymers can function as a rheology modifier for PLA and a compatibilizer for blends with other biopolyesters. The modified PLA showed an increased melt strength and exhibited significant strain hardening, thus making it more suited for blown film applications. Blown films comprised of PLA and poly(butylene adipate-co-terephthalate) (PBAT) were produced using EF-PLA as a reactive modifier for rheological enhancement and compatibilization. This resulted in films with better processability (as seen by increased bubble stability) and improved mechanical properties, compared to a

  17. INVESTIGATION ON THE PHASE INVERSION BEHAVIOR OF WATERBORNE POLYURETHANE DURING EMULSIFICATION PROCESS%水性聚氨酯乳化过程中相转变的研究

    Institute of Scientific and Technical Information of China (English)

    鹿秀山; 郝广杰; 郭天瑛; 宋谋道; 张邦华

    2001-01-01

    本文合成了单官能团小分子物质封端的脂肪族水性聚氨酯预聚物,通过考察预聚物加水乳化过程中粘度及电导率的变化,研究了其相转变行为.实验结果表明,随着软段分子量升高,体系的相转变点后延;聚酯体系的相转变比聚醚体系的相转变发生得早;[NCO]/[OH]值越接近1,体系的粘度就越高,相转变发生所需的水含量也越高;羧基含量及中和度也会对分散体系的相转变产生影响.通过选择合适的条件,可以实现对乳化过程的优化.%Several aliphatic waterborne polyurethane prepolymers are prepared from isophorone diisocyanate,dimethylolpropanic acid,poly(butylene adipate) (PBA) and polypropylene glyco (PPG).The prepolymers are blocked with 2-methoxyethanol,followed by neutralization pendant carboxyl by triethylamine,then diluted to 50?wt% with methyl ethyl ketone,emulsified by adding deionized water under constant agitation.The principle of emulsification is explained.The aggregated structure of prepolymers in organic solvent is discussed.The prepolymer molecules with ionic groups can form segment microionic lattices.The emulsification process and phase inversion are characterized by using the variation of viscosity and conductivity.The emulsification process includes the dissociation of the segment microionic lattices and the aggregation of the hydrophobic segments.The inversion process can be clearly divided into three regions depending upon the variation of viscosity and conductivity.The experimental results show that several factors can affect the phase inversion heavily,including the molecular weight and type of soft segments,the [NCO]/[OH] ratio,carboxyl content and neutralization degree.With the increasing of the molecular weight of soft segment,the phase inversion delays.In addition,the phase inversion of PBA-based prepolymer occurs earlier than that of PPG-based prepolymer,while their soft

  18. 醚化PBS与CMC液体复合材料的相互作用%Interfacial Interaction Mechanism of Etherified PBS and CMC Liquid Composites

    Institute of Scientific and Technical Information of China (English)

    张敏; 许小玲; 宋吉青; 何文清

    2015-01-01

    采用聚乙二醇( PEG)对聚丁二酸丁二醇酯( PBS)进行醚化改性,得到醚化PBS( PEG/PBS), PEG/PBS与羧甲基纤维素(CMC)共混制备了在水相均匀分散的新型(PEG/PBS)-CMC液体复合材料。结合分子模拟技术对PEG/PBS与CMC复合材料的相互作用机理进行了研究。结果表明, PEG/PBS具有预期的化学结构和优异的水润湿性;含醚链段PEG的引入有效提高了PBS分子链的极性和柔顺性, PEG/PBS与CMC之间存在氢键作用、范德华力作用、疏水作用和吸附作用。红外光谱( FTIR )中官能团(如—OH,—OCO—,—COOH,—C—O—C—等)的吸收峰频率发生偏移;光电子能谱( XPS)中C和O元素的结合能分布转移,表明PBS及PEG/PBS与CMC的官能团之间发生了相互作用;偏光显微镜( POM)和 X射线衍射( XRD)结果表明,复合材料之间的相互作用为非共价键的结合;扫描电子显微镜( SEM)结果表明醚化改性后( PEG/PBS)-CMC复合材料间的相互作用增强,表面结合更紧密,相容性得到提高。%Poly(butylene succinate)(PBS) was etherified by polyethylene glycol(PEG), and blended with carboxymethylcellulose( CMC) . A novel liquid composite( PEG/PBS)-CMC was successfully prepared in wa-ter solution. The interaction mechanism of ( PEG/PBS)-CMC composite was investigated by molecular simula-tion. The results showed that the desired structure of PEG/PBS with good hydrophilicity was achieved. Molecular simulation displayed that the polarity and flexibility of PEG/PBS was enhanced by introducing PEG to PBS. The interactions of ( PEG/PBS)-CMC were hydrogen bonding, van der Waals, hydrophobic bond and adsorption. This results were explained by the deviation of absorption peak frequency on functional groups such as —OH, —OCO—, —COOH and —C—O—C— in Fourier transform infrared ( FTIR ) and the binding energy transfer of C and O element in X-ray photoelectron spectroseopy ( XPS ) . Non-covalent interaction existed

  19. Preparation and characterization of biodegradable polymer-coated urea%可生物降解树脂包膜尿素的研制及性能

    Institute of Scientific and Technical Information of China (English)

    王州; 张坤; 徐静; 张民

    2013-01-01

    Two kinds of biodegradable polymers, poly(propylene carbonate)(PPC) and poly(butylenes succinate) ( PBS) , were used as slow-released film for urea , and ratios of PPC/PBS in solution are adjusted in range of 12∶0-0∶12.After evaporating the solvent , the PPC/PBS membranes were obtained in various ratios .The PPC/PBS-coated slow-released urea was prepared by spouted-spraying method , nitrogen release was investigated by Ultraviolet Spectrophotometry method , and scanning electronic microscopy ( SEM ) was used to observe the structure of the coating film.The results show that the flexible and compatible membrane is the best under the ratio of 7∶5.When the weight ratio of PPC∶PBS is about 7∶5 , the composite material possesses strong film characteristic , comparable and flexible .The PPC/PBS film is found suitable to the rugged surface of urea and combined tightly with the surface of urea .The PPC/PBS coated urea shows remarkable controlling function of urea nitrogen release .These results also prove that reducing envelope time or increasing resin quality can enhance the quality of controlled release effect .%以聚碳酸亚丙酯( PPC)与聚丁二酸丁二醇酯( PBS)两种可生物降解树脂作为包膜材料,研制不同PPC/PBS组方包膜溶液,铺膜后初步确定两种材料混合的最佳比例;采用流化喷涂分别制备包膜尿素。通过分光光度法研究不同肥料的初期溶出率,采用扫描电镜观察包膜结构。结果表明,PPC与PBS的质量比在7∶5时,材料之间融合较好,质地较柔软,适合作为肥料包膜材料。实验证明此包膜材料在尿素表面能够形成细腻光滑致密的膜,可以适应尿素颗粒表面的外形轮廓而将其紧密覆盖。尿素包膜后,对尿素氮的释放有明显的控释作用,且在一定范围内,减少包膜所用时间或增加树脂用量都能增强控释效果。

  20. 食品包装材料生态化发展下的非石油基降解塑料%Non-Petroleum Based Biodegradable Plastic with the Development of Ecologicalization in Food Packaging Materials

    Institute of Scientific and Technical Information of China (English)

    戴宏民; 戴佩燕

    2015-01-01

    -toxic, non-irritating, high strength, easy process-ing and good biocompatibility. Polylactic acid is a kind of biodegradable plastic which could truly realize the dual benefits in ecology and economy with the fastest development. The biodegradable plastic comprehensive properties of butylene succinate are excellent with reasonable cost performance, so it has good application prospect in the fields of food packaging, disposable tableware, packing bottle for medicine, biomedical polymer materials, and auto parts etc. As the packing material, non-petroleum based biodegradable plastic is the inevitable trend with the focus in improving the modified technology and cost control, ensuring non-toxic and harmless to human body, emphasizing individuality, and paying attention to improving the market adoption.

  1. Development of Modified Pag (Polyalkylene Glycol) High VI High Fuel Efficient Lubricant for LDV Applications

    Energy Technology Data Exchange (ETDEWEB)

    Gangopadhyay, Arup [Ford Motor Company, Dearborn, MI (United States); McWatt, D. G. [Ford Motor Company, Dearborn, MI (United States); Zdrodowski, R. J. [Ford Motor Company, Dearborn, MI (United States); Liu, Zak [Ford Motor Company, Dearborn, MI (United States); Elie, Larry [Ford Motor Company, Dearborn, MI (United States); Simko, S. J. [Ford Motor Company, Dearborn, MI (United States); Erdemir, Ali [Argonne National Lab. (ANL), Argonne, IL (United States); Ramirez, Giovanni [Argonne National Lab. (ANL), Argonne, IL (United States); Cuthbert, J. [Dow Chemical Company, Midland, MI (United States); Hock, E. D. [Dow Chemical Company, Midland, MI (United States)

    2015-09-30

    Test Procedure) metro/highway cycles. Five different PAG chemistries were selected by varying the starting alcohol, the oxide monomers (ethylene oxide, propylene oxide, or butylene oxide), capped or uncapped, homopolymer or random copolymer. All formulations contained a proprietary additive package and one which contained additional antiwear and friction modifier additives. Laboratory bench tests (Pin-on-Disk, High Frequency Reciprocating Rig (HFRR), Block-on-Ring, Mini-Traction Machine (MTM) identified formulations having friction, wear, and load carrying characteristics similar to or better than baseline GF-5 SAE 5W-20 oil. Motored valvetrain and motored piston ring friction tests showed nearly 50% friction reduction for some of the PAG formulations compared to GF-5 SAE 5W-20 oil. Motored engine tests showed up to 15% friction benefit over GF-5 SAE 5W-20 oil. It was observed that friction benefits are more related to PAG base oil chemistry than their lower viscosity compared to GF-5 SAE 5W-20 oil. Analysis of wear surfaces from laboratory bench tests and bucket tappets from motored valvetrain tests confirmed the presence of PAG molecules. The adsorption of these polar molecules is believed to be reason for friction reduction. However, the wear surfaces also had thin tribo-film derived from additive components. The tribo-film consisting of phosphates, sulfides, and molybdenum disulfide (when molybdenum additive was present) were observed for both GF-5 SAE 5W-20 and PAG fluids. However, when using PAG fluids, motored valvetrain tests showed high initial wear, which is believed to be due to delay in protective tribo-film formation. After the initial wear, the wear rate of PAG fluids was comparable to GF-5 SAE 5W-20 oil. The PAG oil containing additional antiwear and friction reducing additives showed low initial wear as expected. However, when this oil was evaluated in Sequence IVA test, it showed initially low wear comparable to GF-5 oil but wear accelerated with oil

  2. Spectroelectrochemical Sensor for Pertechnetate Applicable to Hanford and Other DOE Sites

    Energy Technology Data Exchange (ETDEWEB)

    Heineman, William R; Seliskar, Carl J; Bryan, Samuel A

    2012-09-18

    The general aim of our work funded by DOE is the design and implementation of a new sensor technology that offers unprecedented levels of specificity needed for analysis of the complex chemical mixtures found at DOE sites nationwide. The specific goal of this project was the development of a sensor for technetium (Tc) that is applicable to characterizing and monitoring the vadose zone and associated subsurface water at the Hanford Site and other DOE sites. The concept for the spectroelectrochemical sensor is innovative and represents a breakthrough in sensor technology. The sensor combines three modes of selectivity (electrochemistry, spectroscopy, and selective partitioning) into a single sensor to substantially improve selectivity. The sensor consists of a basic spectroelectrochemical configuration that we have developed under our previous DOE grants: a waveguide with an optically transparent electrode (OTE) that is coated with a thin chemically-selective film that preconcnetrates the analyte. The key to adapting this generic sensor to detect TcO4- and Tc complexes lies in the development of chemically-selective films that preconcentrate the analyte and, when necessary, chemically convert it into a complex with electrochemical and spectroscopic properties appropriate for sensing. Significant accomplishments were made in the general areas of synthesis and characterization of polymer films that efficiently preconcentrate the analyte, development and characterization of sensors and associated instrumentation, and synthesis and characterization of relevant Re and Tc complexes. Two new polymer films for the preconcentration step in the sensor were developed: partially sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SSEBS) and phosphine containing polymer films. The latter was a directed polymer film synthesis that combined the proper electrostatic properties to attract TcO4- and also incorporated a suitable ligand for covalently trapping a

  3. Localization of solid micro and nano-inclusions in heterophase bioplastic blends

    Science.gov (United States)

    Dil, Ebrahim Jalali

    Blending poly(lactic acid), PLA, with other high impact bioplastics has been introduced as an effective method for improving the toughness of PLA; however, this strategy considerably reduces the modulus and mechanical strength of PLA. The addition of solid particles is a well-known method for tuning the stiffness/toughness balance in toughened polymer matrices. Notwithstanding the significance of controlling the localization of solid inclusions in polymer blends, the literature is lacking a detailed analysis of the migration mechanisms and the effects of thermodynamic and kinetic parameters on the localization of solid particles in polymer blends. In this dissertation, the localization and migration of spherical micro- and nano-silica particles in two bioplastic blends of PLA/low density polyethylene (LDPE) and PLA/poly(butylene adipateco-terephthalate), PBAT, were studied. In the first part of this work, a detailed study on the miscibility and morphology development in the PLA/PBAT blend was carried out. The interfacial tension between PLA and PBAT was determined to be 0.6 +/- 0.15 mN/m by fitting Palierne's model on the rheological data. The miscibility of PLA/PBAT was then examined by studying the shift in the glass transition temperature (Tg) of the polymer phases at different blend compositions. The obtained results indicate a limited one-way partial miscibility of PBAT molecules in the PLA-rich phase. This partial miscibility depends significantly on the molecular weight of PBAT, which underlines its entropic nature. The morphology analysis of the blend samples revealed that the dispersed phase in PLA/PBAT blends exists in the form of fibers, even at low compositions of 1 vol.% of the dispersed phase. Finally, the co-continuity region in PLA/PBAT blends was determined using a rheological approach and it was shown that PLA/PBAT has a wide symmetric co-continuous region located between 30-40 and 60-70 vol.% of PBAT. In the second part of this project, the

  4. 1,3-丁二烯热裂解的动力学计算与模型研究%Kinetic Calculation and Modeling Study of 1,3-Butadiene Pyrolysis

    Institute of Scientific and Technical Information of China (English)

    杜鸟锋; 甯红波; 李泽荣; 张其翼; 李象远

    2016-01-01

    reactions and barrierless reactions are obtained by transition state theory and variable reaction coordinate transition state theory, respectively. The calculated rate constants in this work are in good agreement with those available from literature. Furthermore, the mechanism of Hidaka et al. is updated with replacing the calculated rate constants of reactions in this work to simulate the shock tube experiment results of 1,3-butadiene pyrolysis and the updated mechanism consists of 45 species and 224 reactions. It can be seen that the updated mechanism can improve the concentration profiles of the main products, ethylene, 1-butylene-3-acetylene, and benzene in 1,3-butadiene pyrolysis. It can also provide reliable kinetic and thermodynamic parameters to further improve the core mechanism of C0-C4 species.

  5. Spectroelectrochemical Sensor for Pertechnetate Applicable to Hanford and Other DOE Sites

    Energy Technology Data Exchange (ETDEWEB)

    Heineman, William R; Seliskar, Carl J; Bryan, Samuel A

    2012-09-18

    The general aim of our work funded by DOE is the design and implementation of a new sensor technology that offers unprecedented levels of specificity needed for analysis of the complex chemical mixtures found at DOE sites nationwide. The specific goal of this project was the development of a sensor for technetium (Tc) that is applicable to characterizing and monitoring the vadose zone and associated subsurface water at the Hanford Site and other DOE sites. The concept for the spectroelectrochemical sensor is innovative and represents a breakthrough in sensor technology. The sensor combines three modes of selectivity (electrochemistry, spectroscopy, and selective partitioning) into a single sensor to substantially improve selectivity. The sensor consists of a basic spectroelectrochemical configuration that we have developed under our previous DOE grants: a waveguide with an optically transparent electrode (OTE) that is coated with a thin chemically-selective film that preconcnetrates the analyte. The key to adapting this generic sensor to detect TcO4- and Tc complexes lies in the development of chemically-selective films that preconcentrate the analyte and, when necessary, chemically convert it into a complex with electrochemical and spectroscopic properties appropriate for sensing. Significant accomplishments were made in the general areas of synthesis and characterization of polymer films that efficiently preconcentrate the analyte, development and characterization of sensors and associated instrumentation, and synthesis and characterization of relevant Re and Tc complexes. Two new polymer films for the preconcentration step in the sensor were developed: partially sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SSEBS) and phosphine containing polymer films. The latter was a directed polymer film synthesis that combined the proper electrostatic properties to attract TcO4- and also incorporated a suitable ligand for covalently trapping a

  6. NTP Toxicology and Carcinogenesis Studies of Isobutene (CAS No. 115-11-7) in F344/N Rats and B6C3F1 Mice (Inhalation Studies).

    Science.gov (United States)

    1998-12-01

    was measured in the urine of male and female mice as an indicator of isobutene exposure at 6, 12t 6, 12,and 18 months. The amount of HIBA excreted increased with increasing exposure concentration. However, when HIBA concentration was normalized to isobutene exposure concentration, the relative amount of HIBA excreted decreased with increasing exposure concentration, implying nonlinear kinetics. Pathology Findings: The incidences of hyaline degeneration of the respiratory epithelium in all groups of exposed males and females were significantly greater than those in the chamber control groups. The incidences of hyaline degeneration of the olfactory epithelium in 2,000 and 8,000 ppm mice were greater than those in the chamber controls. GENETIC TOXICOLOGY: Isobutene was not mutagenic in any of four strains of S. typhimurium, with or without S9 metabolic activation, and no increase in the frequency of micronucleated erythrocytes was seen in peripheral blood of male or female mice treated with isobutene by inhalation for 14 weeks. CONCLUSIONS: Under the conditions of these 2-year inhalation studies, there was some evidence of carcinogenic activity of isobutene in male F344/N rats based on an increased incidence of follicular cell carcinoma of the thyroid gland. There was no evidence of carcinogenic activity of isobutene in female F344/N rats or male or female B6C3F1 mice exposed to 500, 2,000, or 8,000 ppm. Exposure to isobutene by inhalation for 2 years resulted in increased incidences and/or severities of nasal lesions including hyaline degeneration of the olfactory epithelium in male and female rats and mice and hyaline degeneration of the respiratory epithelium in male and female mice. Synonyms: Isobutylene, 2-methylpropene, liquified petroleum gas, g-butylene.

  7. 玻璃纤维增强尼龙复合材料新型增韧剂研究%Study on Novel Toughening Agent for Glass Fiber Reinforced Nylon 6

    Institute of Scientific and Technical Information of China (English)

    周旭初; 汤鑫焱; 宋克东; 胡天辉; 王文志; 黄自华

    2014-01-01

    Using maleic anhydride (MAH) grafted trans-1,4-polyisoprene (TPI-g-MAH),MAH grafted ethylene-octene copolymer(POE-g-MAH),MAH grafted ethylene-propylene-diene block copolymer (EPDM-g-MAH) and MAH grafted styrene-ethylene-butylene-styrence block copolymer (SEBS-g-MAH) as toughening agent,glass fiber (GF) with mass fraction of 15%as enhancer,a series of toughened GF reinforced nylon(PA)6 composites were prepared by twin screw extruder. The effects of the toughening agents on the mechanical properties and melt flow rate (MFR) of the toughened composites were investigated. The results show that as the content of the toughening agents increases,the tensile strength,flexural strength as well as MFR decrease but the notched impact strength increases significantly,the toughening effect of EPDM-g-MAH is the best,the effects of TPI-g-MAH and POE-g-MAH follow,and the SEBS-g-MAH is the worst of all. When the mass fraction of toughening agent is 10%,the notched impact strength of TPI-g-MAH toughened composite is the same with that of EPDM-g-MAH toughened composite,meanwhile, comparing with other toughening agent,TPI-g-MAH can minimize the decrease degrees of the tensile strength,flexural strength and MFR of the toughened composite. In summary,TPI-g-MAH has obvious toughening effect on the GF reinforced PA6 composite and gets little impact on strength and MFR,it is a new and efficient toughening agent for the GF reinforced PA6 composite.%以马来酸酐接枝反式-1,4-聚异戊二烯(TPI-g-MAH),马来酸酐接枝乙烯–辛烯共聚物(POE-g-MAH)、马来酸酐接枝三元乙丙橡胶(EPDM-g-MAH)和马来酸酐接枝氢化苯乙烯–丁二烯–苯乙烯共聚物(SEBS-g-MAH)为增韧剂,以质量分数为15%的玻璃纤维(GF)为增强剂,通过双螺杆挤出机制备了一系列增韧型GF增强尼龙(PA)6复合材料,研究了增韧剂种类及含量对复合材料力学性能和熔体流动速率(MFR)的影响。结果表明,随着增韧剂含量的增加,

  8. Phenolic resin-based porous carbons for adsorption and energy storage applications

    Science.gov (United States)

    Wickramaratne, Nilantha P.

    view. So far, carbons with high surface area and nitrogen content have been vastly studied. Also, there are several reports showing the importance of pore size towards CO2 adsorption at ambient conditions. In the case of nitrogen containing carbons, it was shown that the incorporation of nitrogen into carbon matrix is a challenging task. In chapter 3, we discussed how to improve the surface area and pore size distribution of phenolic resin-based carbons to obtain optimum CO 2 adsorption capacities at ambient conditions. The chemical and physical activation of polymer/carbon particles is used to generate necessary physical properties of the final carbons, which display unprecedented CO2 adsorption capacities at ambient conditions. Moreover, the modified Stober-like methods are used for the synthesis of nitrogen containing carbon particles. These facile synthesis methods afford highly porous nitrogen containing carbons with comparatively high CO2 adsorption capacities at ambient conditions. Chapter 4 begins with synthesis of ultra large mesoporous carbons using (ethylene oxide)38 (butylene oxide)46 (ethylene oxide) 38 triblock copolymer as a soft template and phenolic resins as the carbon precursors. Even though, there are many reports dealing with the synthesis of mesoporous silica with large pores for bio-molucular adsorption their high cost discourage them to use in industrial applications. However, cheap mesoporous carbons with large pores (>15 nm) are potential materials for bio-molecular adsorption on large scale. The first part of chapter 4 is demonstrates the synthesis of mesoporous carbons with ultra large pores for bio-molecular adsorption. Lysozyme was selected as a model biomolecule for adsorption processes. The second part of Chapter 4 is focused on functionalized polymer spheres for heavy metal ions adsorption. It is shown that the synthesis of functionalized polymer spheres can be achieved by using modified Stober method; the reacting spheres show very

  9. 胶质瘤中PIN1-Nanog相关通路表达的研究%Relation of peptidyl-prolyi isomerase 1 and Nanog expressions in human gliomas

    Institute of Scientific and Technical Information of China (English)

    倪升远; 牛朝诗; 杨洋; 张翔宇

    2015-01-01

    目的 观察肽基脯氨酰异构酶1(PIN1)、Nanog在胶质瘤组织中的表达以及PIN1抑制剂PiB对U87细胞增殖能力及PIN1、Nanog表达的影响. 方法 选取安徽医科大学附属省立医院神经外科自2013年3月至2014年8月间手术切除的84例胶质瘤和10例正常脑组织标本,免疫组化染色检测标本PIN1、Nanog蛋白的表达.体外常规培养U87胶质瘤细胞,用0.2、0.5、1.0、2.0 μg/mL PiB分别作用24、48 h,MTT检测PiB对细胞增殖的抑制作用并计算抑制率;以1.0μmol/L PiB处理U87细胞24 h为1.0 μmol/L PiB组,未经任何处理的U87细胞作为对照组,免疫荧光双染检测细胞PIN1、Nanog的表达,RT-PCR和Westem blotting分别检测细胞PIN1、Nanog mRNA和蛋白的表达. 结果 WHOⅡ级、Ⅲ级、Ⅳ级胶质瘤中PIN1、Nanog高表达率不同,差异有统计学意义(P<0.05),且胶质瘤级别越高,PIN1、Nanog高表达率越高.MTT检测显示PiB对U87细胞的增殖有抑制作用,且呈时间和剂量依赖性.与对照组比较,1.0 μmol/L PiB组PIN1、Nanog及PIN1/Nanog阳性细胞百分比降低,差异有统计学意义(P<0.05);对照组和1.0 μmol/L PiB组细胞PIN1 mRNA的表达量分别为1.82±0.03和0.94±0.20,Nanog mRNA的表达量分别为1.47±0.04和0.82±0.19,差异均有统计学意义(P<0.05);对照组和1.0 μmol/L PiB组细胞PIN1蛋白表达量分别为2.96±0.05和1.15±0.26,Nanog蛋白表达量分别为1.52±0.16和0.75±0.05,差异均有统计学意义(P<0.05). 结论 PIN1、Nanog在胶质瘤的发生发展中起重要作用,且与肿瘤的恶性程度相关.PIN1可参与调控Nanog,两者之间存在相关通路,下调PIN1-Nanog通路后,胶质瘤细胞增殖能力下降.%Objective To obsevre the peptidyl-prolyi isomerase 1 (PIN1) and Nanog expreesions in glioma tissues and the effect of PIN1 inhibitor polyiso-butylene (PiB) on their expressions and U87 cell proliferation.Methods Eighty-four glioma samples (15 with WHO graded Ⅱ,27 with WHO graded