WorldWideScience

Sample records for solid polyol polyester

  1. Polyester Polyols from Waste PET Bottles for Polyurethane Rigid Foams

    OpenAIRE

    Evtimova, Rozeta; Lozeva, Yordanka; Schmidt, Karl-Heinz; Wotzka, Michael; Wagner, Peter; Behrendt, Gerhard

    2003-01-01

    This paper describes a modified process to produce polyester polyols from PET wastes derived from the “bottle fraction residue” of the German Dual System (DSD) [11] employing a waste oligoester condensate of the polyesterification process with the addition of some glycols of longer chain and occasional modification with further dicarboxylic acids to produce polyester polyols of a broad range of properties which are further reacted to form polyurethane or polyisocyanurate rigid foams for insul...

  2. SYNTHESIS AND CHARACTERIZATION OF BIO-BASED POLYESTER POLYOL

    Directory of Open Access Journals (Sweden)

    MİTHAT ÇELEBİ

    2016-11-01

    Full Text Available Polyurethanes are versatile polymeric materials and are usually synthesised by isocyanate reactions with polyols. Due to the variety of isocyanates and polyols, particularly polyols, polyurethanes can be easily tailored for wide applications, such as rigid and flexible foams, coatings, adhesives, and elastomers. Considerable efforts have been recently devoted to developing bio-based substitutes for petroleum-based polyuretahanes due to increasing concerns over the depletion of petroleum resources, environment, and sustainability. Polyester polyols based on aliphatic and aromatic dicarboxylic acids are one of the most important materials in polymer technologies. Large volume of plants oils are used as renewable resources to produce various chemicals which are industrially important to make soaps, cosmetic products, surfactants, lubricants, diluents, plasticizers, inks, agrochemicals, composite materials, food industry. This study introduces synthesis and properties of bio-based polyols from different renewable feedstocks including vegetable oils and derivatives. A comparison of bio-based polyol properties with their petroleum-based analogues were investigated.

  3. The catalytic microwave synthesis of biodegradable polyester polyols based on castor oil and l-lactide

    Science.gov (United States)

    Kojić, D.; Erceg, T.; Vukić, N.; Teofilović, V.; Ristić, I.; Budinski-Simendić, J.; Aleksić, V.

    2017-01-01

    Various strategies for achieving a functional poly(lactic acid) (PLA) have been developed such as ring-opening copolymerization with a functional monomer, the use of functional initiator and various post polymerization modifications. It is possible to obtain the star shaped polymer using natural oil with at least three OH groups as an initiator. It was estimated that despite of low-molecular mass of star-shaped PLA, the hydrophobic castor oil central core influenced the slow degradation rate in the case of injectable biomedical application. The star-shaped polymers with low-molecular-mass have a lower melt viscosity correlated with linear counterparts. In soft tissue reparation the polymer viscosity increases with fluid body contact and the solid implant can be formed. To ensure liquid state at injection temperature the low molar mass polymer is favorable. There is a particular size for each macromolecular chains at which chain entanglement occurs. In this work the influence of the l-lactide (LA) and the castor oil (CO) contents on the size of biodegradable branched polyester polyols was studied. The average molecular masses of synthesized polymers were estimated by GPC procedure. In sample formulations the [LA]/[CO] ratios were from to 113 to 533. Mn values for obtained polymers were from 5000 to 20000 Da. The molecular mass distribution for the resulting polymers was between 1.09 and 1.37.

  4. Magnetic Cobalt and Cobalt Oxide Nanoparticles in Hyperbranched Polyester Polyol Matrix

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    O. I. Medvedeva

    2017-01-01

    Full Text Available A series of cobalt (Co and its oxides based nanoparticles were synthesized by using hyperbranched polyester polyol Boltorn H20 as a platform and sodium borohydride as a reducing agent. UV, FT-IR, XRD, NTA, and TEM methods were employed to obtain physicochemical characteristics of the products. The average diameter of Co nanoparticles was approximately 8.2±3.4 nm. Their magnetic properties, including hysteresis loop, field-cooled, and zero field-cooled curves were investigated. The nanoparticles exhibit superparamagnetism at room temperature, accompanied by magnetic hysteresis below the blocking temperature.

  5. Preparation and properties of high storage stability polyester polyol dispersion for two-component waterborne polyurethane coating

    Science.gov (United States)

    Hao, H.; Hu, J. Q.; Wang, F.; Tu, W. P.

    2017-01-01

    A new type of polyester polyol dispersion with good storage stability was prepared based on a hydrophilic monomer 5-sodium sulfodimethyl isophthalate (5-SIPM), and frequently-used monomers such as neopentyl glycol (NPG), dimethyl terephthalate (DMT), dimethyl phthalate (DMP) and trimethylolpropane (TMP) by the transpolycondensation and polycondensation method. The polyester polyol dispersion was characterized by FTIR and GPC. The proper content of these monomers were determined by the performance of polyester dispersion: the content of TMP was 15wt%, the content of NPG was 7.5wt% and the hydrophilic monomer 5-SIPM content was 5wt%. Two-component waterborne polyurethane (2K-WPU) coatings were prepared by Bayhydur® XP2487/1 and polyester polyol dispersions, which were stored before and after at 40 ° for 6 weeks, the prepared films have no differences in drying time, adhesion, pencil hardness, gloss and chemical resistance, the result also reveals that the polyester polyol dispersion have excellent storage stability resistance.

  6. Preparation and Characterization of Waterborne Polyurethaneurea Composed of Dimer Fatty Acid Polyester Polyol

    Directory of Open Access Journals (Sweden)

    2006-01-01

    Full Text Available A series of polyurethaneurea (PUU aqueous dispersions, which were stable at ambient temperature for more than 1 year, were prepared with C 36 -dimer-fatty-acid-based polyester polyol, isophorone diisocyanate, dimethylol propionic acid, and ethylenediamine. The particle size of all these PUU (DPU aqueous dispersions ( <100 nm was less than that of comparable specimens, that is, poly-(neopentyl glycol adipate polyester-polyol-based PUU (APU aqueous dispersions, and the polydispersity index was very narrow ( ≤1.13 . The films prepared with the DPU aqueous dispersions exhibited excellent waterproof performance, such as low amount of water absorption (1.3 wt%, and good mechanical properties (hardness and tensile strength, resulting from the strong hydrogen bonding in urea carbonyl groups and the perfect ordered structure of hard segments compared with those prepared with the APU aqueous dispersions. The surface hydrophobicity of the films prepared with modified DPU aqueous dispersions, which were modified with a fluorinated polyacrylate emulsion, was excellent, as the water contact angle on the surface of such films rose up to 100. The mechanical properties of such modified DPU films were further enhanced.

  7. Hyperbranched polyester polyol plasticized tapioca starch/low density polyethylene blends

    Energy Technology Data Exchange (ETDEWEB)

    Guzman, Manuel; Giraldo, Diego; Murillo, Edwin, E-mail: edwinalbertomurillo@gmail.com [Universidad de Antioquia, Medellin (Colombia); Universidad Francisco de Paula Santander, San Jose de Cucuta (Colombia)

    2017-01-15

    n this work, low density polyethylene (LDPE)/plasticised starch (TPS) blends were prepared. The TPS employed in this study was obtained by plasticization of tapioca starch with a hyperbranched polyester polyol. Differential scanning calorimetry analysis showed that the melting temperature increased with the TPS content. The opposite effect was exhibited in the crystallization temperature and additional changes were not observed during the heating. X-ray diffraction analysis showed a reduction in intensity of the peak at Bragg’s angle 17.5°, proving a diminution on A type crystallinity with the increasing amount of LDPE. Micrographs obtained by scanning electron microscopy exhibited starch granules without destructure. TPS acted as a filler to LDPE, since the mechanical properties (Young's modulus and tensile strength) improved ostensibly. The Young' modulus and tensile strength decreased with the amount of LDPE, however, the elongation at break exhibited an opposite behavior. (author)

  8. Hyperbranched polyester polyol plasticized tapioca starch/low density polyethylene blends

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    Manuel Guzmán

    Full Text Available Abstract In this work, low density polyethylene (LDPE/plasticized starch (TPS blends were prepared. The TPS employed in this study was obtained by plasticization of tapioca starch with a hyperbranched polyester polyol. Differential scanning calorimetry analysis showed that the melting temperature increased with the TPS content. The opposite effect was exhibited in the crystallization temperature and additional changes were not observed during the heating. X-ray diffraction analysis showed a reduction in intensity of the peak at Bragg’s angle 17.5°, proving a diminution on A type crystallinity with the increasing amount of LDPE. Micrographs obtained by scanning electron microscopy exhibited starch granules without destructure. TPS acted as a filler to LDPE, since the mechanical properties (Young’s modulus and tensile strength improved ostensibly. The Young’ modulus and tensile strength decreased with the amount of LDPE, however, the elongation at break exhibited an opposite behavior.

  9. Hyperbranched polyester polyol plasticized tapioca starch/low density polyethylene blends

    International Nuclear Information System (INIS)

    Guzman, Manuel; Giraldo, Diego; Murillo, Edwin

    2017-01-01

    n this work, low density polyethylene (LDPE)/plasticised starch (TPS) blends were prepared. The TPS employed in this study was obtained by plasticization of tapioca starch with a hyperbranched polyester polyol. Differential scanning calorimetry analysis showed that the melting temperature increased with the TPS content. The opposite effect was exhibited in the crystallization temperature and additional changes were not observed during the heating. X-ray diffraction analysis showed a reduction in intensity of the peak at Bragg’s angle 17.5°, proving a diminution on A type crystallinity with the increasing amount of LDPE. Micrographs obtained by scanning electron microscopy exhibited starch granules without destructure. TPS acted as a filler to LDPE, since the mechanical properties (Young's modulus and tensile strength) improved ostensibly. The Young' modulus and tensile strength decreased with the amount of LDPE, however, the elongation at break exhibited an opposite behavior. (author)

  10. Hyperbranched polyester polyol modified with polylactic acid as a compatibilizer for plasticized tapioca starch/polylactic acid blends

    Directory of Open Access Journals (Sweden)

    Ricardo Mesias

    2018-03-01

    Full Text Available Abstract A hyperbranched polyester polyol of the second generation (HBP2 was modified with polylactic acid (HBP2-g-PLA and employed as a compatibilizer for plasticized tapioca starch (TPS/polylactic acid (PLA blends. The effect of the compatibilizer HBP2- g-PLA was evaluated in comparison to the control sample (TPS/PLA blend without HBP2-g-PLA. The torque value of the TPS/PLA blends with HBP2- g-PLA was lower than that of the control sample, while thermal stability and crystallinity followed opposite behavior. The glass transition temperature (Tg and degree of crystallinity of the TPS/PLA blends with HBP2-g-PLA decreased with increasing mass fraction of HBP2-g-PLA. By scanning electron microscopy (SEM, it was observed that the morphology of the TPS/PLA blends with HBP2-g -PLA was more homogeneous than that of the control sample, confirming that HBP2- g-PLA acted as a compatibilizer and plasticizing agent to the TPS/PLA blends. Rheological analysis of the compatibilized TPS/PLA blends indicated the presence of microstructure.

  11. Polyol accumulation by Aspergillus oryzae at low water activity in solid-state fermentation

    NARCIS (Netherlands)

    Ruijter, G.J.G.; Visser, J.; Rinzema, A.

    2004-01-01

    Polyol accumulation and metabolism were examined in Aspergillus oryzae cultured on whole wheat grains or on wheat dough as a model for solid-state culture. In solid-state fermentation (SSF), water activity (a(w)) is typically low resulting in osmotic stress. In addition to a high level of mannitol,

  12. Microbial degradation of polyurethane, polyester polyurethanes and polyether polyurethanes.

    Science.gov (United States)

    Nakajima-Kambe, T; Shigeno-Akutsu, Y; Nomura, N; Onuma, F; Nakahara, T

    1999-02-01

    Polyurethane (PUR) is a polymer derived from the condensation of polyisocyanate and polyol and it is widely used as a base material in various industries. PUR, in particular, polyester PUR, is known to be vulnerable to microbial attack. Recently, environmental pollution by plastic wastes has become a serious issue and polyester PUR had attracted attention because of its biodegradability. There are many reports on the degradation of polyester PUR by microorganisms, especially by fungi. Microbial degradation of polyester PUR is thought to be mainly due to the hydrolysis of ester bonds by esterases. Recently, polyester-PUR-degrading enzymes have been purified and their characteristics reported. Among them, a solid-polyester-PUR-degrading enzyme (PUR esterase) derived from Comamonas acidovorans TB-35 had unique characteristics. This enzyme has a hydrophobic PUR-surface-binding domain and a catalytic domain, and the surface-binding domain was considered as being essential for PUR degradation. This hydrophobic surface-binding domain is also observed in other solid-polyester-degrading enzymes such as poly(hydroxyalkanoate) (PHA) depolymerases. There was no significant homology between the amino acid sequence of PUR esterase and that of PHA depolymerases, except in the hydrophobic surface-binding region. Thus, PUR esterase and PHA depolymerase are probably different in terms of their evolutionary origin and it is possible that PUR esterases come to be classified as a new solid-polyester-degrading enzyme family.

  13. Solid-State Polymerization of Poly(Ethylene Furanoate Biobased Polyester, II: An Efficient and Facile Method to Synthesize High Molecular Weight Polyester Appropriate for Food Packaging Applications

    Directory of Open Access Journals (Sweden)

    Nejib Kasmi

    2018-04-01

    Full Text Available The goal of this study was to synthesize, through a facile strategy, high molecular weight poly(ethylene furanoate (PEF, which could be applicable in food packaging applications. The efficient method to generate PEF with high molecular weight consists of carrying out a first solid-state polycondensation under vacuum for 6 h reaction time at 205 °C for the resulting polymer from two-step melt polycondensation process, which is catalyzed by tetrabutyl titanate (TBT. A remelting step was thereafter applied for 15 min at 250 °C for the obtained polyester. Thus, the PEF sample was ground into powder, and was then crystallized for 6 h at 170 °C. This polyester is then submitted to a second solid-state polycondensation (SSP carried out at different reaction times (1, 2, 3.5, and 5 h and temperatures 190, 200, and 205 °C, under vacuum. Ultimately, a significant increase in intrinsic viscosity is observed with only 5 h reaction time at 205 °C during the second SSP being needed to obtain very high molecular weight PEF polymer greater than 1 dL/g, which sufficient for manufacturing purposes. Intrinsic viscosity (IV, carboxyl end-group content (–COOH, and thermal properties, via differential scanning calorimetry (DSC, were measured for all resultant polyesters. Thanks to the post-polymerization process, DSC results showed that the melting temperatures of the prepared PEF samples were steadily enhanced in an obvious way as a function of reaction time and temperature increase. It was revealed, as was expected for all SSP samples, that the intrinsic viscosity and the average molecular weight of PEF polyester increased with increasing SSP time and temperature, whereas the number of carboxyl end-group concentration was decreased. A simple kinetic model was also developed and used to predict the time evolution of polyesters IV, as well as the carboxyl and hydroxyl end-groups of PEF during the SSP.

  14. Radiation synthesis of polymer polyol

    International Nuclear Information System (INIS)

    Guo Jianmei; Zeng Xinmiao; Zhou Chengfei; Cao Wei; Zhai Tong; Wu Dezhen

    2010-01-01

    The polymer polyol was synthesized by γ irradiation. The properties of polymer polyol synthesized with different radiation dose were studied. The experiment result showed the radiation dose hadn't significant influence on the hydroxyl value of polymer polyol. The sample with different solid content had different hydroxyl value. When the radiation dose is between 1 to 12 kGy, the viscosity and hydroxyl value of polymer polyol were increased with the increment of radiation dose. When radiation dose is between 1 to 12 kGy, with the increment of radiation dose, viscosity of polymer polyol was rapidly increased, and the content solid of sample has few change. When radiation dose is higher than 20 kGy, the viscosity and hydroxyl value of polymer polyol have gradually increase with the increment of radiation dose. The size of polymer particles is 0.1-0.6 μm. The value of 150 mesh filter was 100%. The polymer polyol may be used as PU foam and elastomer. (authors)

  15. Sustainable coatings from bio-based, enzymatically synthesized polyesters with enhanced functionalities

    NARCIS (Netherlands)

    Gustini, L.; Lavilla, C.; Finzel, L.; Noordover, B.A.J.; Hendrix, M.M.R.M.; Koning, C.E.

    2016-01-01

    Bio-based sorbitol-containing polyester polyols were synthesized via enzymatic polycondensation. The selectivity of the biocatalyst for primary vs. secondary hydroxyl groups allowed for the preparation of close to linear renewable polyester polyols with enhanced hydroxyl functionalities, both as

  16. Effect of sucrose polyesters on crystallization rate of vegetable ghee: solid fat content study

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    Ibrahim Nasir, Mohammad

    2003-12-01

    Full Text Available Crystallization rate of partial hydrogenated blend of soybean oil and cottonseed oil used for making vegetable ghee (vanaspati was investigated, by solid fat content (SFC using pulsed nuclear magnetic resonance (p-NMR. The effects of adding sucrose fatty acid esters or sucrose polyesters (SPE on the crystallization rate of the blend fat were studied. Sucrose tetrastearate DK ester F-10 (stearate 70% - palmitate 30% was added to the fat at different concentration, namely 0.5% and 1.0%. Blank sample and sample containing 0.5% and 1.0% DK ester F-10 / (DK F-10 were chosen to measure the change in SFC at constant temperature of 15ºC for a period of 25 hr. Five determinations of SFC were taken to the fat samples during the 25 hr i.e. 2,5,9,13 and 25th hr. SFC vs. time of crystallization of the three samples showed continuous increasing in SFC in all samples during the 25 hr, with sharp increasing at the first two hours. Samples containing 0.0% and 0.5% DK F-10, showed no significant difference in SFC during the first thirteen hours, while sample containing 1.0% DK F-10, showed higher SFC than the other two samples, through out the period. The amount of SFC for 1.0% DK F-10 sample at the 13th hour is equal to the SFC of the blank (0.0% sample at the 25th hour. Melting point of the same samples increased with the increasing DK F-10 concentration in the fat samples. The results of SFC make it sure that the addition of 1.0% DK F- 10 will shorten the time required for the crystallization of vegetable ghee while the addition of 0.5% will not have significant effect.Se ha investigado, mediante el contenido en grasa sólida (SFC por resonancia magnética nuclear pulsada (p-NMR, la velocidad de cristalización de mezcla de aceite de la soja y aceite de semilla del algodón parcialmente hidrogenada utilizada en la elaboración de ghee vegetal (vanaspati. Se han estudiado los efectos de añadir ésteres de sacarosa de ácidos grasos o poliésteres de

  17. Synthesis and Characterization of Novel Polyurethanes Based on Vegetable Oils Amide and Ester Polyols

    Directory of Open Access Journals (Sweden)

    Vladimir YAKUSHIN

    2014-09-01

    Full Text Available Amide and ester type polyols were synthesized from rapeseed, sunflower and castor oils, and two types of ethanolamine (diethanolamine and triethanolamine at different molar ratio. Poly(urethane amides and polyester urethanes based on the synthesized polyols were prepared. The effect of the chemical structure of the obtained polyurethanes on density, glass transition temperature, thermal stability and mechanical properties was investigated. The influence of the content of OH groups in the synthesized polyols on the specified characteristics was estimated. It has been found that poly(urethane amides have better mechanical characteristics, but their thermal stability is lower than that of polyester urethanes. The chemical structure of the synthesized polyols and polyurethanes is qualitatively confirmed by IR-spectroscopy data. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.4532

  18. Solid-State Polymerization of Poly(ethylene furanoate Biobased Polyester, I: Effect of Catalyst Type on Molecular Weight Increase

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    Nejib Kasmi

    2017-11-01

    Full Text Available In this work, we report the synthesis of poly(ethylene furanoate (PEF, catalyzed by three different catalysts, namely, titanium (IV isopropoxide (TIS, tetrabutyltitanate (TBT, and dibutyltin (IV oxide (DBTO, via the two-stage melt polycondensation method. Solid-state polymerization (SSP was conducted at different reaction times (1, 2, 3.5, and 5 h and temperatures 190, 200, and 205 °C, under vacuum. The resultant polymers were analyzed according to their intrinsic viscosity (IV, end groups (–COOH, and thermal properties, via differential scanning calorimetry. DSC results showed that the post polymerization process was favorable to enhance the melting point of the prepared PEF samples. As was expected, the intrinsic viscosity and the average molecular weight of PEF increased with the SSP time and temperature, whereas the number of carboxyl end-groups was decreased. A simple kinetic model was also developed and used to predict the time evolution of polymers IV, as well as the carboxyl and hydroxyl content of PEF during the SSP. From both the experimental measurements and the theoretical simulation results it was proved that the presence of the TIS catalyst resulted in higher transesterification kinetic rate constants and higher reaction rates. The activation energies were not much affected by the presence of different catalysts. Finally, using DBTO as a catalyst, the polyesters produced have higher crystallinity, and as a consequence, higher number of inactive carboxyl and hydroxyl groups.

  19. Isohexide and Sorbitol-Derived, Enzymatically Synthesized Renewable Polyesters with Enhanced Tg.

    Science.gov (United States)

    Gustini, Liliana; Lavilla, Cristina; de Ilarduya, Antxon Martínez; Muñoz-Guerra, Sebastián; Koning, Cor E

    2016-10-10

    Sugar-based polyesters derived from sorbitol and isohexides were obtained via solvent-free enzymatic catalysis. Pendant hydroxyl groups, coming from the sorbitol units, were present along the polyester backbone, whereas the two isohexides, namely, isomannide and isoidide dimethyl ester monomers, were selected to introduce rigidity into the polyester chains. The feasibility of incorporating isomannide as a diol compared to the isoidide dimethyl ester as acyl-donor via lipase-catalyzed polycondensation was investigated. The presence of bicyclic units resulted in enhanced T g with respect to the parent sorbitol-containing polyester lacking isohexides. The different capability of the two isohexides to boost the thermal properties confirmed the more flexible character provided by the isoidide diester derivative. Solvent-borne coatings were prepared by cross-linking the sugar-based polyester polyols with polyisocyanates. The increased rigidity of the obtained sugar-based polyester polyols led to an enhancement in hardness of the resulting coatings.

  20. Degradation of Polyester Polyurethane by Bacterial Polyester Hydrolases

    Directory of Open Access Journals (Sweden)

    Juliane Schmidt

    2017-02-01

    Full Text Available Polyurethanes (PU are widely used synthetic polymers. The growing amount of PU used industrially has resulted in a worldwide increase of plastic wastes. The related environmental pollution as well as the limited availability of the raw materials based on petrochemicals requires novel solutions for their efficient degradation and recycling. The degradation of the polyester PU Impranil DLN by the polyester hydrolases LC cutinase (LCC, TfCut2, Tcur1278 and Tcur0390 was analyzed using a turbidimetric assay. The highest hydrolysis rates were obtained with TfCut2 and Tcur0390. TfCut2 also showed a significantly higher substrate affinity for Impranil DLN than the other three enzymes, indicated by a higher adsorption constant K. Significant weight losses of the solid thermoplastic polyester PU (TPU Elastollan B85A-10 and C85A-10 were detected as a result of the enzymatic degradation by all four polyester hydrolases. Within a reaction time of 200 h at 70 °C, LCC caused weight losses of up to 4.9% and 4.1% of Elastollan B85A-10 and C85A-10, respectively. Gel permeation chromatography confirmed a preferential degradation of the larger polymer chains. Scanning electron microscopy revealed cracks at the surface of the TPU cubes as a result of enzymatic surface erosion. Analysis by Fourier transform infrared spectroscopy indicated that the observed weight losses were a result of the cleavage of ester bonds of the polyester TPU.

  1. A review on polyols: new frontiers for health-based bakery products.

    Science.gov (United States)

    Ghosh, Soma; Sudha, M L

    2012-05-01

    Polyols or sugar alcohols, a group of reduced calorie sweeteners, are the natural and nutritive sweeteners. These are neither sugars nor alcohols; rather they are a group of low-digestible carbohydrates which can be used instead of sucrose. They occur naturally in foods and come from plant products such as fruit and berries. They are used in food as sweeteners and bulking agents. Polyols have slightly reduced sweetness and caloric values compared to sucrose. Polyols available as either in solid crystalline form or syrups are emerging as a sugar replacer as well as a sugar substitute. Low sugar or low calorie is a top ranked market trend for bakery sector. Polyols offer the baker a versatile range of ingredients to boost the available portfolio of products. They would provide the functional benefits to bakery goods when the sugars used are replaced with polyols. This review focuses on some recent studies carried out on sucrose replacement with polyols in baked products.

  2. Biodegradation of polyester. Polyester no bunkai sei

    Energy Technology Data Exchange (ETDEWEB)

    Tokiwa, Y. (Agency of Industrial Science and Technology, Tokyo (Japan). Fermentation Research Inst.)

    1991-09-10

    Penicillium sp. 14-3 and penicillium sp. 26-1 can degrade various kinds of polyester. The results of studies made on hydrolysis of polyester by enzyme, hydrolysis of polyester by various kinds of lipase, and degradation of ester type polyurethane by microbes and lipase are introduced. For the improvement of physical properties of aliphatic polyester, aromatic-aliphatic polyester copolymers (CPE) have been synthesized to study the biodegradability. Copolymer in which a number of polyamide (nylon) are alternately introduced (CPAE) to aliphatic polyester has been developed. The result of studies made on the degradability of a blended body of PCL and natural high polymer, and on the collapsibility by lipase of high polymer materials including aliphatic polyamide are introduced. 26 refs., 5 figs., 1 tab.

  3. Application of polyester derived from biomass in petroleum asphalt cement

    Directory of Open Access Journals (Sweden)

    Fernando de Araújo

    Full Text Available Abstract This study evaluated the effects of the incorporation of a new additive to asphalt cement oil (CAP. A polyol product was obtained through the oxypropylation reaction of sugarcane bagasse. This polyol was polymerised with pyromellitic anhydride in order to obtain a polyester (BCP to test its suitability in terms of the material properties to be applied as additives. FTIR spectra of the polymerised material (BCP confirmed the occurrence of chemical modification due to the appearance of a new band at 1750 cm-1, characteristic of ester groups. The TGA data showed that the BCP product had higher thermal stability than the polyol. According to the softening point and elastic recovery tests, the incorporation of 11% and 16% w/w BCP in conventional CAP met the specifications of regulatory standards.

  4. Microwave Synthesis Of Polyols For Urethane Materials

    International Nuclear Information System (INIS)

    Zeltins, V; Cabulis, U; Abolins, A; Gaidukovs, S

    2016-01-01

    The preparation of polyurethane (PU) polyols processed with the use of microwave (MW) irradiation heating polyols is reported. The PU polyols were consisted from bio-based rapeseed oil (RO) and recycled polyethylene terephthalate (PET) components are reported. Obtained MW polyols were compared to the conventional PU polyols synthesized by traditional heating in oil bath. The polyols have the similar properties. The obtained MW assisted polyols were characterized by Fourier transform infrared spectroscopy (FT-IR) measurements. Acid number, hydroxyl value, moisture content and viscosity of the MW synthesized polyols were measured. The obtained polyols consisted from about 34% RO and 23% PET components. The advantages of the very fast reaction rate for preparation of PU polyols, by using MW instead of the conventional heating process, are shown. (paper)

  5. Bacterial cells with improved tolerance to polyols

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as diols and other polyols, and to methods of preparing and using such bacterial cells for production of polyols and other compounds.......The present invention relates to bacterial cells genetically modified to improve their tolerance to certain commodity chemicals, such as diols and other polyols, and to methods of preparing and using such bacterial cells for production of polyols and other compounds....

  6. Rheological Behavior of Bentonite-Polyester Dispersions

    Science.gov (United States)

    Abu-Jdayil, Basim; Al-Omari, Salah Addin

    2013-07-01

    The rheological behavior of a bentonite clay dispersed in unsaturated polyester was investigated. The effects of the solid content and particle size on the steady and transient rheological properties of the dispersions were studied. In addition, two types of bentonite with different Na+/Ca+2 ratio were used in this study. The Herschel-Bulkley and the Weltman models were used to describe the apparent viscosity of the bentonite-polyester composite in relation to the shear rate and shearing time. The bentonite-polyester dispersions were found to exhibit both Newtonian and non-Newtonian behavior. The transition from a Newtonian to a Bingham plastic and then to a shear-thinning material with a yield stress was found to depend on the solid concentration, the particle size, and the type of bentonite. At a low solid content, the apparent viscosity of the bentonite dispersion increased linearly with solid concentration. But a dramatic increase in the apparent viscosity beyond a solid content of 20 wt.% was observed. On the other hand, a thixotropic behavior was detected in bentonite-polyester dispersions with a high solid content and a low particle size. However, this behavior was more pronounced in dispersions with a high Na+/Ca+2 ratio.

  7. Synthesis and characterization of saturated polyester and ...

    Indian Academy of Sciences (India)

    but which can actually be used for processes, which pro- duce interesting ... ing the synthesis of saturated polyester (from GPET waste). This has been done for the .... The solid product obtained from the glycolysis of PET was bis(hydroxy ethyl ...

  8. Polyester polymer concrete overlay.

    Science.gov (United States)

    2013-01-01

    Polyester polymer concrete (PPC) was used in a trial application on a section of pavement that suffers from extensive studded tire wear. The purpose of the trial section is to determine if PPC is a possible repair strategy for this type of pavement d...

  9. Degradation of microbial polyesters.

    Science.gov (United States)

    Tokiwa, Yutaka; Calabia, Buenaventurada P

    2004-08-01

    Microbial polyhydroxyalkanoates (PHAs), one of the largest groups of thermoplastic polyesters are receiving much attention as biodegradable substitutes for non-degradable plastics. Poly(D-3-hydroxybutyrate) (PHB) is the most ubiquitous and most intensively studied PHA. Microorganisms degrading these polyesters are widely distributed in various environments. Although various PHB-degrading microorganisms and PHB depolymerases have been studied and characterized, there are still many groups of microorganisms and enzymes with varying properties awaiting various applications. Distributions of PHB-degrading microorganisms, factors affecting the biodegradability of PHB, and microbial and enzymatic degradation of PHB are discussed in this review. We also propose an application of a new isolated, thermophilic PHB-degrading microorganism, Streptomyces strain MG, for producing pure monomers of PHA and useful chemicals, including D-3-hydroxycarboxylic acids such as D-3-hydroxybutyric acid, by enzymatic degradation of PHB.

  10. Leaf-Cutter Ant Fungus Gardens Are Biphasic Mixed Microbial Bioreactors That Convert Plant Biomass to Polyols with Biotechnological Applications

    Science.gov (United States)

    Somera, Alexandre F.; Lima, Adriel M.; dos Santos-Neto, Álvaro J.; Lanças, Fernando M.

    2015-01-01

    Leaf-cutter ants use plant matter to culture the obligate mutualistic basidiomycete Leucoagaricus gongylophorus. This fungus mediates ant nutrition on plant resources. Furthermore, other microbes living in the fungus garden might also contribute to plant digestion. The fungus garden comprises a young sector with recently incorporated leaf fragments and an old sector with partially digested plant matter. Here, we show that the young and old sectors of the grass-cutter Atta bisphaerica fungus garden operate as a biphasic solid-state mixed fermenting system. An initial plant digestion phase occurred in the young sector in the fungus garden periphery, with prevailing hemicellulose and starch degradation into arabinose, mannose, xylose, and glucose. These products support fast microbial growth but were mostly converted into four polyols. Three polyols, mannitol, arabitol, and inositol, were secreted by L. gongylophorus, and a fourth polyol, sorbitol, was likely secreted by another, unidentified, microbe. A second plant digestion phase occurred in the old sector, located in the fungus garden core, comprising stocks of microbial biomass growing slowly on monosaccharides and polyols. This biphasic operation was efficient in mediating symbiotic nutrition on plant matter: the microbes, accounting for 4% of the fungus garden biomass, converted plant matter biomass into monosaccharides and polyols, which were completely consumed by the resident ants and microbes. However, when consumption was inhibited through laboratory manipulation, most of the plant polysaccharides were degraded, products rapidly accumulated, and yields could be preferentially switched between polyols and monosaccharides. This feature might be useful in biotechnology. PMID:25911490

  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. Polyester projects for India, Pakistan

    International Nuclear Information System (INIS)

    Siddiqi, R.

    1993-01-01

    India's Indo Rama Synthetics (Bombay) is planning a $186-million integrated polyester fiber and filament complex at Nagpur, Maharashtra. The complex will have annual capacities for 38,000 m.t. of polyester chips by polycondensation, 25,000 m.t. of polyester staple fiber, and 12,000 m.t. of polyester blended yarn. The company is negotiating with the main world suppliers of polycondensation technology. The first stage of the project is slated to begin production by the end of this year and be fully completed by 1994. In Pakistan, National Fibers Ltd. (PNF; Karachi) has signed a deal with Zimmer (Frankfurt) for technology, procurement, construction, and support work to expand polyester staple fiber capacity from 14,000 m.t./year to 52,000 m.t./year. The technology involves a continuous polymerization process. The project also calls for improvements to PNF's existing batch plant. It is scheduled for completion by the end of 1994. Total cost of the project is estimated at Rs1.745 billion ($70 million), out of which the foreign exchange component is Rs1.05 billion. The Islamic Development Bank (Jeddah; Saudi Arabia) has already approved a $27-million slice of the financing, while the balance of the foreign exchange loan is being arranged through suppliers credit. Local currency loans will be provided by other financial institutions in Pakistan

  13. Palm oil based polyols for acrylated polyurethane production

    International Nuclear Information System (INIS)

    Rida Tajau; Mohd Hilmi Mahmood; Mek Zah Salleh; Khairul Zaman Mohd Dahlan; Rosley Che Ismail

    2006-01-01

    Palm oil becomes important renewable resources for the production of polyols for the polyurethane manufacturing industry. The main raw materials used for the production of acrylated polyurethane are polyols, isocyanates and hydroxyl terminated acrylate compounds. In these studies, polyurethane based natural polymer (palm oil), i.e., POBUA (Palm Oil Based Urethane Acrylate) were prepared from three different types of palm oil based polyols i.e., epoxidised palm oil (EPOP), palm oil oleic acid and refined, bleached and deodorized (RBD) palm olein based polyols. The performances of these three acrylated polyurethanes when used for coatings and adhesives were determined and compared with each other. (Author)

  14. Characterization of new polyol/H+ symporters in Debaryomyces hansenii.

    Directory of Open Access Journals (Sweden)

    Iliana Pereira

    Full Text Available Debaryomyces hansenii is a halotolerant yeast that produces and assimilates a wide variety of polyols. In this work we evaluate polyol transport in D. hansenii CBS 767, detecting the occurrence of polyol/H(+ (and sugar/H(+ symporter activity, through the transient extracellular alkalinization of unbuffered starved cell suspensions. From the D. hansenii genome database, we selected nine ORFs encoding putative transporter proteins to clone in a centromeric plasmid with C-terminal GFP tagging and screened for polyol/H(+ symporters by heterologous expression in Saccharomyces cerevisiae. Five distinct D. hansenii polyol/H(+ symporters were identified and characterized, with different specificities and affinities for polyols, namely one glycerol-specific (DhStl1, one D-galactitol-specific (DhSgl1, Symporter galactitol/H(+ 1, one D-(+-chiro-inositol-specific (DhSyi1, Symporter D-(+-chiro-inositol/H(+ 1, one for D-sorbitol/D-mannitol/ribitol/D-arabitol/D-galactitol (DhSyl1, Symporter Polyols 1 and another for D-sorbitol/D-mannitol/ribitol/D-arabitol (DhSyl2, Symporter Polyols 2. This work contributed to the annotation of new yeast polyol transporters, including two specific for uncommon substrates as galactitol and D-(+-chiro-inositol.

  15. Highly reproducible polyol synthesis for silver nanocubes

    Science.gov (United States)

    Han, Hye Ji; Yu, Taekyung; Kim, Woo-Sik; Im, Sang Hyuk

    2017-07-01

    We could synthesize the Ag nanocubes highly reproducibly by conducting the polyol synthesis using HCl etchant in dark condition because the photodecomposition/photoreduction of AgCl nanoparticles formed at initial reaction stage were greatly depressed and consequently the selective self-nucleation of Ag single crystals and their selective growth reaction could be promoted. Whereas the reproducibility of the formation of Ag nanocubes were very poor when we synthesize the Ag nanocubes in light condition due to the photoreduction of AgCl to Ag.

  16. Gluconate formation and polyol metabolism in Aspergillus niger

    NARCIS (Netherlands)

    Witteveen, C.F.B.

    1993-01-01

    The capacity of A.niger to accumulate metabolites is remarkable. Under all conditions polyols accumulate in the cell and when mycelium in later developmental stages is considered, depending on the carbon source, aeration and external pH, polyols

  17. Melt dispersion of thermoplastic polystyrene in polymer polyols

    NARCIS (Netherlands)

    2009-01-01

    Polystyrene is dispersed into a polyol via a mechanical dispersion process. A stabilizer is present to stabilize the dispersed polymer particles. The stabilizer includes a copolymer of (1) from 10 to 70% by weight of a branched polyol which has a molecular weight of from 4000 to 20,000, from 0.2 to

  18. Development of curcumin liposome formulations using polyol dilution method

    Directory of Open Access Journals (Sweden)

    Lalana Kongkaneramit

    2016-12-01

    Full Text Available This study was aimed to formulate curcumin liposomes (CLs by using polyol dilution method which is advantageous for no residue of organic solvent. CLs were the mixture of hydrogenated phosphatidylcholine (PC and cholesterol (CH at the molar ratio of 9:1. Propylene glycol (PG, glycerin, and polyethylene glycol 400 (PEG-400 were used as polyol solvent. Extrusion was applied after the suspension formed. The amount of polyol and curcumin and preparing temperature were investigated. The obtained suspensions were observed for appearance, size, size distribution, zeta potential, morphology, and percentage of entrapment. The results showed that type and amount of polyol had an impact on both liposomal size and the amount of entrapped curcumin, while preparing temperature was also an important factor. However, the solubility of lipids and drug in a given polyol should be considered because of loading efficiency in the formulation.

  19. Nanocrystalline hydroxyapatite ceramics prepared by hydrolysis in polyol medium

    Science.gov (United States)

    Mechay, Abderrahmen; Feki, Hafed E. L.; Schoenstein, Fréderic; Jouini, Noureddine

    2012-07-01

    This Letter describes a new approach for the synthesis of hydroxyapatite nanoparticles, which involves precipitation and hydrolysis reactions conducted in polyol medium. In fact, ammonium-hydrogen phosphate and calcium nitrate were dissolved in polyol, and then heated at the boiling point of the polyol (ethane1, 2diol or propane1, 2diol). Besides, the phase and composition of the polycrystalline were studied by TGA/DTA, FT-IR, TEM and XRD techniques. The nanoparticles thus obtained present interesting morphological characters varying from needle to very thin platelet. Moreover, the hydroxyapatite prepared in ployol shows higher cristallinity in comparison with that obtained by other 'chimie douce' methods.

  20. Nuclear magnetic resonance structure investigations on crosslinked polyesters

    International Nuclear Information System (INIS)

    Grobelny, J.

    1999-01-01

    Styrene-crosslinked mixed polyesters derived from maleic anhydride, 2,2-di(4-hydroxypropoxyphenyl)propane, oligo(propylene oxide) and 1,2-propylene glycol were investigated by high-resolution solid-state 13 C NMR spectroscopy. The structural modifications accompanying crosslinking were characterized in terms of spin-lattice relaxation times as a function of unsaturated polyester composition. Copolymerization and crosslinking effects were individually evaluated and the latter effect was related to variations in crosslinking density associated with the chemical structure of the unsaturated prepolymer. As the crosslinking effect is suppressed, the mechanical properties undergo expected changes, e.g., impact strength is increased and modulus of elasticity in tension is decreased. (author)

  1. Polyester Apparel Cutting Waste as Insulation Material

    OpenAIRE

    Trajković, Dušan; Jordeva, Sonja; Tomovska, Elena; Zafirova, Koleta

    2017-01-01

    Polyester waste is the dominant component of the clothing industry waste stream, yet its recycling in this industry is rarely addressed. This paper proposes using polyester cutting waste as an insulation blanket for roofing and buildings’ internal walls in order to reduce environmental pollution. The designed textile structures used waste cuttings from different polyester fabrics without opening the fabric to fibre. Thermal insulation, acoustic insulation, fire resistance and biodegradation o...

  2. Synthesis of Improved Polyester Resins.

    Science.gov (United States)

    1979-07-05

    of this page) 21. No. of Pages 22. Price* Unclassified Unclassified 83 For sale by the National Technical Information Service, Springfield. Virginia...low sensitivity .... ........... 68 B2B C-scan of carbon fiber reinforced polyester Laminate #2 at high sensitivity ..... .......... 68 B3A C-scan of...right corner, but it is obscured by the delamination. Figure B2B shows the same composite at a 12 decibel increase in sensitivity. The image now shows

  3. Radiation effects on biodegradable polyesters

    International Nuclear Information System (INIS)

    Hiroshi Mitomo; Darmawan Darwis; Fumio Yoshii; Keizo Makuuchi

    1999-01-01

    Poly(3-hydroxybutyrate) [P(3HB)] and its copolymer poly(3-hydroxybutyrate-co-3hydroxyvalerate) [P(3HB-co-3HV)] are microbial biodegradable polyesters produced by many types of bacteria. Poly(butylene succinate) (PBS) and poly(E-caprolactone) (PCL) are also biodegradable synthetic polyesters which have been commercialized. These thermoplastics are expected for wide usage in environmental protection and blocompatible applications. Radiation grafting of hydrophilic monomers onto many polymers, e.g., polyethylene and polypropylene has been studied mainly for biomedical applications. In the present study, radiation-induced graft polymerization of vinyl monomers onto PHB and P(3HB-co-3HV) was carried out and improvement of their properties was studied. Changes in the properties and biodegradability were compared with the degree of grafting. Radiation-induced crosslinking of PBS and PCL which relatively show thermal and irradiation stability was also carried out to improve their thermal stability or processability. Irradiation to PBS and PCL mainly resulted in crosslinking and characterization of these crosslinked polyesters was investigated

  4. Influence of polyols on properties of bio-based polyurethanes

    Indian Academy of Sciences (India)

    resources for the preparation of polyols required for the polyurethane industry. Among the vegetable oils, cardanol a meta-substituted phenol obtained (Kumar et al 2002) from ... High ortho-multinuclear cardanol–formaldehyde resin was.

  5. Polyol concentrations in Aspergillus repens grown under salt stress.

    Science.gov (United States)

    Kelavkar, U P; Chhatpar, H S

    1993-09-01

    Na(+), K(+) and the ratio of Na(+)/K(+) were higher in cells of the halotolerant Aspergillus repens grown with 2 M NaCl than without NaCl. The osmolytes, proline, glycerol, betaine and glutamate, did not affect the Na(+)/K(+) ratio, nor the polyol content of cells under any conditions. The concentrations of polyols, consisting of glycerol, arabitol, erythritol and mannitol, changed markedly during growth, indicating that they have a crucial role in osmotic adaptation.

  6. Effect of Structure Change on Radiation Crosslinking of Unsaturated Polyesters

    International Nuclear Information System (INIS)

    Ranogajec, F.

    2006-01-01

    During the course of crosslinking of unsaturated polyesters reacting system, that was liquid prior to reaction, gels, and becomes solid. Crosslinking reaction begins to be controlled by the change of the physical state of the system at an early stage of reaction. The kinetics can not be studied by the usual kinetical methods. In-source 60 C o gamma rays induced crosslinking of unsaturated polyester with styrene was followed directly and continuously by measuring electrical conductivity change. The results of extraction analysis proved good correlation between the change of electrical conductivity and the extent of curing. The gel content was inversely proportional to conductivity and free styrene content directly proportional to conductivity. DC-electrical conductivity has shown high sensitivity toward structural changes and enabled us to detect liquid-liquid transitions in unsaturated polyester. The upper liquid-liquid transition (T l ρ) is less known transition caused by a stepwise decrease of intramolecular short-range local order that remains above the glass and lower liquid-liquid transitions. The local order is based on secondary valent interactions and is enhanced by hydrogen bonding. The linear temperature dependence of the viscosity and dc electrical conductivity of unsaturated polyesters showed a change of slope caused by the (T l ρ). Those changes were the result of the diminishing of the local order (which includes several bond lengths) caused by breaking of the intramolecular interactions. The intramolecular nature of the (T l ρ) in the polyesters under consideration was proved by its insensitivity to crosslinking and dilution with solvents. In the corresponding temperature range, DSC thermograms shoved expected endothermic changes. The structure changes related to the (T l ρ) in the investigated polyesters were determined by 1 H NMR and NIR spectroscopy. The proton NMR indicated that the stepwise change in hydrogen bonding occurred in the

  7. Production of lactic acid from C6-polyols by alkaline hydrothermal reactions

    International Nuclear Information System (INIS)

    Zhou Huazhen; Jin Fangming; Wu Bing; Cao Jianglin; Duan Xiaokun; Kishita, Atsushi

    2010-01-01

    Production of lactic acid from C6-polyols (Mannitol) under alkaline hydrothermal conditions was investigated. Experiments were performed to examine the difference in the production of lactic acid between C6-polyols and C3-polyols (glycerine), as well as C6-aldoses (glucose). Results showed that the yield of lactic acid from C6-polyols was lower than that from both glycerine and glucose. It indicated that long chain polyols might follow a different reaction pathway from that of glycerine. Further investigation is needed to clarify the reaction mechanism and improve the relatively low lactic acid acid yield from C6-polyols.

  8. Intensification of polyester synthesis by continuous reactive distillation

    NARCIS (Netherlands)

    Shah, M.R.

    2011-01-01

    The thesis starts with a brief overview of unsaturated polyesters. In particular, the usage of raw materials, the application of unsaturated polyester resins, and, the worldwide supply and demand of the unsaturated polyester resins are discussed. Unsaturated polyester is traditionally produced in a

  9. Biodegradation of Polyester Polyurethane by Endophytic Fungi▿

    Science.gov (United States)

    Russell, Jonathan R.; Huang, Jeffrey; Anand, Pria; Kucera, Kaury; Sandoval, Amanda G.; Dantzler, Kathleen W.; Hickman, DaShawn; Jee, Justin; Kimovec, Farrah M.; Koppstein, David; Marks, Daniel H.; Mittermiller, Paul A.; Núñez, Salvador Joel; Santiago, Marina; Townes, Maria A.; Vishnevetsky, Michael; Williams, Neely E.; Vargas, Mario Percy Núñez; Boulanger, Lori-Ann; Bascom-Slack, Carol; Strobel, Scott A.

    2011-01-01

    Bioremediation is an important approach to waste reduction that relies on biological processes to break down a variety of pollutants. This is made possible by the vast metabolic diversity of the microbial world. To explore this diversity for the breakdown of plastic, we screened several dozen endophytic fungi for their ability to degrade the synthetic polymer polyester polyurethane (PUR). Several organisms demonstrated the ability to efficiently degrade PUR in both solid and liquid suspensions. Particularly robust activity was observed among several isolates in the genus Pestalotiopsis, although it was not a universal feature of this genus. Two Pestalotiopsis microspora isolates were uniquely able to grow on PUR as the sole carbon source under both aerobic and anaerobic conditions. Molecular characterization of this activity suggests that a serine hydrolase is responsible for degradation of PUR. The broad distribution of activity observed and the unprecedented case of anaerobic growth using PUR as the sole carbon source suggest that endophytes are a promising source of biodiversity from which to screen for metabolic properties useful for bioremediation. PMID:21764951

  10. Rapeseed Oil as Renewable Resource for Polyol Synthesis

    Science.gov (United States)

    Stirna, Uldis; Fridrihsone, Anda; Misane, Marija; Vilsone, Dzintra

    2011-01-01

    Vegetable oils are one of the most important platform chemicals due to their accessibility, specific structure of oils and low price. Rapeseed oil (RO) polyols were prepared by amidization of RO with diethanolamine (DEA). To determine the kinetics of amidization reaction, experiments were carried out. Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), amine (NH) value was determined. Group contribution method by Fedor‵s was used to calculate solubility parameters, van der Waals volume was calculated by Askadskii. Obtained polyol‵s OH and NH value are from 304 up to 415 mg KOH/g. RO polyols synthesis meets the criteria of "green chemistry". In the present study, reaction of RO amidization with DEA was investigated, as well as optimum conditions for polyol synthesis was established to obtain polyols for polyurethane production. Calculations of solubility parameter and cohesion energy density were calculated, as RO polyols will be used as side chains in polymers, and solubility parameter will be used to explain properties of polymers.

  11. Castor Oil-Based Biodegradable Polyesters.

    Science.gov (United States)

    Kunduru, Konda Reddy; Basu, Arijit; Haim Zada, Moran; Domb, Abraham J

    2015-09-14

    This Review compiles the synthesis, physical properties, and biomedical applications for the polyesters based on castor oil and ricinoleic acid. Castor oil has been known for its medicinal value since ancient times. It contains ∼90% ricinoleic acid, which enables direct chemical transformation into polyesters without interference of other fatty acids. The presence of ricinoleic acid (hydroxyl containing fatty acid) enables synthesis of various polyester/anhydrides. In addition, castor oil contains a cis-double bond that can be hydrogenated, oxidized, halogenated, and polymerized. Castor oil is obtained pure in large quantities from natural sources; it is safe and biocompatible.

  12. Polystyrene/Hyperbranched Polyester Blends and Reactive Polystyrene/Hyperbranched Polyester Blends

    National Research Council Canada - National Science Library

    Mulkern, Thomas

    1999-01-01

    .... In this work, the incorporation of HBPs in thermoplastic blends was investigated. Several volume fractions of hydroxyl functionalized hyperbranched polyesters were melt blended with nonreactive polystyrene (PS...

  13. 40 CFR Table 4 to Subpart Ppp of... - Known Organic HAP From Polyether Polyol Products

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Known Organic HAP From Polyether Polyol... CATEGORIES National Emission Standards for Hazardous Air Pollutant Emissions for Polyether Polyols Production Pt. 63, Subpt. PPP, Table 4 Table 4 to Subpart PPP of Part 63—Known Organic HAP From Polyether Polyol...

  14. Production of polyol oils from soybean oil by Pseudomonas aeruginosa E03-12.

    Science.gov (United States)

    Soy-polyols are important starting materials for the manufacture of polymers such as polyurethane. We have been trying to develop a bioprocess for the production of polyol oils directly from soybean oil. We reported earlier the polyol products produced from soybean oil by Acinetobacter haemolyticus ...

  15. Melt dispersion of thermoplastic polystyrene in polymer polyols

    OpenAIRE

    2009-01-01

    Polystyrene is dispersed into a polyol via a mechanical dispersion process. A stabilizer is present to stabilize the dispersed polymer particles. The stabilizer includes a copolymer of (1) from 10 to 70% by weight of a branched polyol which has a molecular weight of from 4000 to 20,000, from 0.2 to about 1.2 polymerizable ethylenically unsaturated groups per molecule and from about 3 to about 8 hydroxyl groups per molecule with (2) from 30 to 90% by weight of styrene or a mixture of styrene a...

  16. Polystyrene/Hyperbranched Polyester Blends and Reactive Polystyrene/Hyperbranched Polyester Blends

    National Research Council Canada - National Science Library

    Mulkern, Thomas

    1999-01-01

    Newly developed hyperbranched polyols (HBP) possess a highly branched three-dimensional structure and a high density of functional end groups relative to conventional linear or branched polymer molecules...

  17. Catalytic routes and oxidation mechanisms in photoreforming of polyols

    Energy Technology Data Exchange (ETDEWEB)

    Sanwald, Kai E.; Berto, Tobias F.; Eisenreich, Wolfgang; Gutiérrez, Oliver Y.; Lercher, Johannes A.

    2016-12-01

    Photocatalytic reforming of biomass-derived oxygenates leads to H2 generation and evolution of CO2 via parallel formation of organic intermediates through anodic oxidations on a Rh/TiO2 photocatalyst. The reaction pathways and kinetics in the photoreforming of C3–C6 polyols were explored. Polyols are converted via direct and indirect hole transfer pathways resulting in (i) oxidative rupture of C–C bonds, (ii) oxidation to a-oxygen functionalized aldoses and ketoses (carbonyl group formation) and (iii) light-driven dehydration. Direct hole transfer to chemisorbed oxygenates on terminal Ti(IV)-OH groups, generating alkoxy-radicals that undergo ß-C–C-cleavage, is proposed for the oxidative C–C rupture. Carbonyl group formation and dehydration are attributed to indirect hole transfer at surface lattice oxygen sites [Ti_ _ _O_ _ _Ti] followed by the generation of carbon-centered radicals. Polyol chain length impacts the contribution of the oxidation mechanisms favoring the C–C bond cleavage (internal preferred over terminal) as the dominant pathway with higher polyol carbon number.

  18. Rapeseed oil as feedstock for high functionality polyol synthesis

    Czech Academy of Sciences Publication Activity Database

    Kirpluks, M.; Kalnbunde, D.; Walterová, Zuzana; Cabulis, U.

    2017-01-01

    Roč. 5, 3-4 (2017), s. 258-270 ISSN 2164-6325 Institutional support: RVO:61389013 Keywords : polyols * polyurethane foams * renewable raw materials Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 0.812, year: 2016

  19. Synthesis and characterization of polyesters from renewable cardol ...

    African Journals Online (AJOL)

    Bulletin of the Chemical Society of Ethiopia ... The preparation and thermal characteristics of new polyesters from cardol, a renewable monomer ... All prepared polyesters were insoluble in common laboratory solvents at room temperature.

  20. Propagation of polarized light through azobenzene polyester films

    DEFF Research Database (Denmark)

    Nedelchev, L; Matharu, A; Nikolova, Ludmila

    2002-01-01

    When elliptically polarized light of appropriate wavelength Corresponding to trans-cis-trans isomerisation process is incident on thin films of azobenzene polyesters, a helical structure is induced. We investigate the propagation of the exciting light beam (self-induced) as well as a probe light...... beam outside the absorption band through the polyester films. Investigations are carried out in one amorphous and one liquid crystalline polyester. We show that amorphous polyester after irradiation behaves like classical helical material....

  1. 40 CFR 721.8082 - Polyester polyurethane acrylate.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polyester polyurethane acrylate. 721... Substances § 721.8082 Polyester polyurethane acrylate. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as polyester polyurethane acrylate...

  2. (Citric acid–co–polycaprolactone triol) polyester

    Science.gov (United States)

    Thomas, Lynda V.; Nair, Prabha D.

    2011-01-01

    Tissue engineering holds enormous challenges for materials science, wherein the ideal scaffold to be used is expected to be biocompatible, biodegradable and possess mechanical and physical properties that are suitable for target application. In this context, we have prepared degradable polyesters in different ratios by a simple polycondensation technique with citric acid and polycaprolactone triol. Differential scanning calorimetry indicated that the materials were amorphous based the absence of a crystalline melting peak and the presence of a glass transition temperature below 37°C. These polyesters were found to be hydrophilic and could be tailor-made into tubes and films. Porosity could also be introduced by addition of porogens. All the materials were non-cytotoxic in an in vitro cytotoxicity assay and may degrade via hydrolysis to non-toxic degradation products. These polyesters have potential implications in the field of soft tissue engineering on account of their similarity of properties. PMID:23507730

  3. Holographic recording in thiophene-based polyester

    DEFF Research Database (Denmark)

    Matharu, Avtar Singh; Chambers-Asman, David; Jeeva, Shehzad

    2008-01-01

    The synthesis and optical data storage properties of a side-chain thiophene-phenyl azopolyester ThPhAzoP.ol is reported. The polyester is derived from diphenyl tetradecanedioate and a thiophenebased liquid crystalline diol which exhibits a short-lived enantiotropic SmA phase (Cryst 177.7 SmA 180.......4 I). The polyester ThPhAzoPol exhibits amorphous (Tg, 78.6 DC), crystalline and liquid crystalline character as evidenced by differential scanning calorimetry and thermal polarising microscopy. A grainy texture, which is thermally reversible, with increasing birefringence on cooling from...... the isotropic melt is observed. The polyester is amenable to optical data storage, showing efficient induced anisotropy, which is stable at room temperature. Polarisation gratings can be inscribed using orthogonally.linear and circularly polarised light to good effect (>10/0) and surface relief gratings...

  4. Characterization and Growth Mechanism of Nickel Nanowires Resulting from Reduction of Nickel Formate in Polyol Medium

    Directory of Open Access Journals (Sweden)

    Olga A. Logutenko

    2016-01-01

    Full Text Available Nickel linear nanostructures were synthesized by reduction of nickel formate with hydrazine hydrate in ethylene glycol medium in the absence of any surfactants or capping agents for direction of the particles growth. The effect of the synthesis conditions such as temperature, reduction time, type of polyol, and nickel formate concentration on the reduction products was studied. The size and morphology of the nickel nanowires were characterized by X-ray diffraction, scanning, and transmission electron microscopy. It was shown that the nickel nanocrystallites were wire-shaped with a face-center-cubic phase. Ethylene glycol was found to play a crucial role in the formation of the nickel nanowires. The possible growth processes of the wire-shaped particles taking place at 110 and 130°C are discussed. It was shown that, under certain synthesis conditions, nickel nanowires grow on the surface of the crystals of the solid intermediate of nickel with hydrazine hydrate.

  5. Study of compounds emitted during thermo-oxidative decomposition of polyester fabrics

    Directory of Open Access Journals (Sweden)

    Dzięcioł Małgorzata

    2016-03-01

    Full Text Available Compounds emitted during thermo-oxidative decomposition of three commercial polyester fabrics for indoor outfit and decorations (upholstery, curtains were studied. The experiments were carried out in a flow tubular furnace at 600°C in an air atmosphere. During decomposition process the complex mixtures of volatile and solid compounds were emitted. The main volatile products were carbon oxides, benzene, acetaldehyde, vinyl benzoate and acetophe-none. The emitted solid compounds consisted mainly of aromatic carboxylic acids and its derivatives, among which the greatest part took terephthalic acid, monovinyl terephthalate and benzoic acid. The small amounts of polycyclic aromatic hydrocarbons were also emitted. The emission profiles of the tested polyester fabrics were similar. The presence of toxic compounds indicates the possibility of serious hazard for people during fire.

  6. Mechanical and Physical Properties of Polyester Polymer Concrete Using Recycled Aggregates from Concrete Sleepers

    OpenAIRE

    Carrión, F.; Montalban Domingo, Maria Laura; Real Herráiz, Julia Irene; Real, T.

    2014-01-01

    Currently, reuse of solid waste from disused infrastructures is an important environmental issue to study. In this research, polymer concrete was developed by mixing orthophthalic unsaturated polyester resin, artificial microfillers (calcium carbonate) and waste aggregates (basalt and limestone) coming from the recycling process of concrete sleepers. The variation of the mechanical and physical properties of the polymer concrete (compressive strenght, flexural strength, modulus of elasticity,...

  7. The Abrasive Wear Resistance of the Segmented Linear Polyurethane Elastomers Based on a Variety of Polyols as Soft Segments

    Directory of Open Access Journals (Sweden)

    Konrad Kwiatkowski

    2017-12-01

    Full Text Available The presented results make an original contribution to the development of knowledge on the prediction and/or modeling of the abrasive wear properties of polyurethanes. A series of segmented linear polyurethane elastomers (PUR—In which the hard segments consist of 4,4′-methylene bis(phenylisocyanate and 1,4-butanodiol, whilst polyether, polycarbonate, or polyester polyols constitute the soft segments—Were synthesized and characterized. The hardness and wear performance as functions of the variable chemical composition of polyurethane elastomers were evaluated in order to define the relationship between studied factors. The microstructure was characterized in detail, including analysis of the hydrogen bonding by Fourier transformed infrared (FT-IR spectroscopy and the phase structure by X-ray scattering (WAXS and differential scanning calorimetry (DSC methods. The presented studies provide the key features of the polymer composition affecting the abrasive resistance as well as attempts to explain the origin of the differences in the polyurethane elastomers’ performance.

  8. Micro-thermal analysis of polyester coatings

    NARCIS (Netherlands)

    Fischer, H.R.

    2010-01-01

    The application and suitability of micro-thermal analysis to detect changes in the chemical and physical properties of coating due to ageing and especially photo-degradation is demonstrated using a model polyester coating based on neopentyl glycol isophthalic acid. The changes in chemical structure

  9. Photoinduced Deformation of Azobenzene Polyester Films

    DEFF Research Database (Denmark)

    Bublitz, D.; Helgert, M.; Fleck, B.

    2000-01-01

    We investigate two types of azobenzene side-chain polyesters which have shown opposite behaviour in light-induced surface grating formation experiments. Thin films of these polymers prepared on a water surface undergo opposite changes of shape under the influence of polarized light. We propose...

  10. Carboxylated Polyurethanes Containing Hyperbranched Polyester Soft Segments

    Directory of Open Access Journals (Sweden)

    Žigon, M.

    2006-09-01

    Full Text Available hyperbranched polyester soft segments (HB PU with functional carboxylic groups in order to enable the preparation of stable HB PU dispersions. Carboxylated hyperbranched polyurethanes were synthesized using a hyperbranched polyester based on 2,2-bis(methylolpropionic acid of the fourth pseudo-generation (Boltorn H40 and hexamethylene (HDI or isophorone diisocyanate (IPDI. The reactivity of hyperbranched polyester with HDI was lower than expected, possibly due to the presence of less reactive hydroxyl groups in the linear repeat units. A gel was formed at mole ratios rNCO/OH = 1:2 or 1:4. The synthesis of HB PU was performed with partly esterified hyperbranched polyester with lowered hydroxyl functionality. The carboxyl groups were incorporated in the HB PU backbone by reaction of residual hydroxyl groups with cis-1,2-cyclohexanedicarboxylic anhydride. HB PU aqueous dispersions were stable at least for two months, although their films were brittle. The tensile strength and Young's modulus of blends of linear and HB PU decreased with increasing content of HB PU whereas elongation at break remained nearly constant, which was explained in terms of looser chain packing due to more open tree-like hyperbranched structures.

  11. Effects of monohydric alcohols and polyols on the thermal stability of a protein

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Shota [Graduate School of Energy Science, Kyoto University, Uji, Kyoto 611-0011 (Japan); Kinoshita, Masahiro, E-mail: kinoshit@iae.kyoto-u.ac.jp [Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011 (Japan)

    2016-03-28

    The thermal stability of a protein is lowered by the addition of a monohydric alcohol, and this effect becomes larger as the size of hydrophobic group in an alcohol molecule increases. By contrast, it is enhanced by the addition of a polyol possessing two or more hydroxyl groups per molecule, and this effect becomes larger as the number of hydroxyl groups increases. Here, we show that all of these experimental observations can be reproduced even in a quantitative sense by rigid-body models focused on the entropic effect originating from the translational displacement of solvent molecules. The solvent is either pure water or water-cosolvent solution. Three monohydric alcohols and five polyols are considered as cosolvents. In the rigid-body models, a protein is a fused hard spheres accounting for the polyatomic structure in the atomic detail, and the solvent is formed by hard spheres or a binary mixture of hard spheres with different diameters. The effective diameter of cosolvent molecules and the packing fractions of water and cosolvent, which are crucially important parameters, are carefully estimated using the experimental data of properties such as the density of solid crystal of cosolvent, parameters in the pertinent cosolvent-cosolvent interaction potential, and density of water-cosolvent solution. We employ the morphometric approach combined with the integral equation theory, which is best suited to the physical interpretation of the calculation result. It is argued that the degree of solvent crowding in the bulk is the key factor. When it is made more serious by the cosolvent addition, the solvent-entropy gain upon protein folding is magnified, leading to the enhanced thermal stability. When it is made less serious, the opposite is true. The mechanism of the effects of monohydric alcohols and polyols is physically the same as that of sugars. However, when the rigid-body models are employed for the effect of urea, its addition is predicted to enhance the

  12. Effect of polyols on the native structure of {alpha}-chymotrypsin: A comparable study

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Awanish; Attri, Pankaj [Department of Chemistry, University of Delhi, Delhi - 110 007 (India); Venkatesu, Pannuru, E-mail: venkatesup@hotmail.com [Department of Chemistry, University of Delhi, Delhi - 110 007 (India)

    2012-05-20

    Highlights: Black-Right-Pointing-Pointer We have studied stability of {alpha}-chymotrypsin in polyols. Black-Right-Pointing-Pointer We have performed DSC, CD and fluorescence spectroscopy. Black-Right-Pointing-Pointer Our {Delta}G{sub u} of CT in polyol increase as polyol concentration increases. Black-Right-Pointing-Pointer All polyols acted as enhancers for CT stability. Black-Right-Pointing-Pointer Our results show that trehalose is strong stabilizer. - The influence of polyols on the structure and stability of {alpha}-chymotrypsin (CT) have been explored by using differential scanning calorimeter (DSC), circular dichroism (CD) and fluorescence spectroscopy. We have predicted the thermodynamic folding properties (transition temperature (T{sub m}), enthalpy change ({Delta}H), heat capacity change ({Delta}C{sub p}) and Gibbs free energy change ({Delta}G{sub u}) from DSC to understand the clear picture of folding studies of CT. All polyols (trehalose, sucrose, sorbitol, and glycerol) acted as enhancers for CT stability, with varying efficacies and efficiencies. The DSC, CD and fluorescence spectral analysis clearly showed the ability of polyols to protect the native structural conformation of enzyme and preventing the unfolding which occurs in the aqueous media. These results explicitly explain that stabilizing polyols are preferentially excluded from the surface of CT, since water has a higher tendency toward favourable interactions with functional groups of the CT than with polyols.

  13. Influences of the Ratio of Polyol and MDI on the Acoustic Parameters of Polyurethane

    Science.gov (United States)

    Wang, Yonghua; Liu, Zheming; Wu, Haiquan; Zhang, Chengchun; Yu, Huadong; Ren, Luquan; Ichchou, Mohamed

    2018-05-01

    In this paper, the influence of different ratio of polyol and MDI on the absorption coefficient and acoustic parameters of polyurethane was studied. Ratio of 100:40 and 100:45 show the best sound absorption performance, and the change trend of transmission loss and sound absorption coefficient are opposite. The flow resistance increased with the increasing of the ratio of polyol and MDI, the greater the flow resistance, the worse the high frequency sound absorption property of the polyurethane. When the ratio of polyol and MDI keep 100:45, the minimum porosity of sample, the polyurethane porosity increase with the ratio of polyol and MDI increase.

  14. Simulation on the Performance of a Driven Fan Made by Polyester/Epoxy interpenetrate polymer network (IPN)

    Science.gov (United States)

    Fahrul Hassan, Mohd; Jamri, Azmil; Nawawi, Azli; Zaini Yunos, Muhamad; Fauzi Ahmad, Md; Adzila, Sharifah; Nasrull Abdol Rahman, Mohd

    2017-08-01

    The main purpose of this study is to investigate the performance of a driven fan design made by Polyester/Epoxy interpenetrate polymer network (IPN) material that specifically used for turbocharger compressor. Polyester/Epoxy IPN is polymer plastics that was used as replacements for traditional polymers and has been widely used in a variety of applications because of their limitless conformations. Simulation based on several parameters which are air pressure, air velocity and air temperature have been carried out for a driven fan design performance of two different materials, aluminum alloy (existing driven fan design) and Polyester/Epoxy IPN using SolidWorks Flow Simulation software. Results from both simulations were analyzed and compared where both materials show similar performance in terms of air pressure and air velocity due to similar geometric and dimension, but Polyester/Epoxy IPN produces lower air temperature than aluminum alloy. This study shows a preliminary result of the potential Polyester/Epoxy IPN to be used as a driven fan design material. In the future, further studies will be conducted on detail simulation and experimental analysis.

  15. Bio-based liquid crystalline polyesters

    Science.gov (United States)

    Wilsens, Carolus; Rastogi, Sanjay; Dutch Collaboration

    2013-03-01

    The reported thin-film polymerization has been used as a screening method in order to find bio-based liquid crystalline polyesters with convenient melting temperatures for melt-processing purposes. An in depth study of the structural, morphological and chemical changes occurring during the ongoing polycondensation reactions of these polymers have been performed. Structural and conformational changes during polymerization for different compositions have been followed by time resolved X-ray and Infrared spectroscopy. In this study, bio-based monomers such as vanillic acid and 2,5-furandicarboxylic acid are successfully incorporated in liquid crystalline polyesters and it is shown that bio-based liquid crystalline polymers with high aromatic content and convenient processing temperatures can be synthesized. Special thanks to the Dutch Polymer Institute for financial support

  16. Synthesis of hyper branched polyol from palm oil oleic acid

    International Nuclear Information System (INIS)

    Mek Zah Salleh; Mohd Hilmi Mahmood

    2010-01-01

    Hyper branched polyol from oleic acid of palm oil has been synthesized by a two-step reaction. Dipentaerythritol was initially reacted with 2, 2-bis (hydroxymethyl) propionic acid in a solution medium aided by p-toluene sulfonic acid as a catalyst. This mixture was then used as core and reacted with the oleic acid. Optimization parameters such as processing temperature and reaction time, and chemical analysis (for example OHV, AV, FTIR, NMR and GPC) of the macromolecule synthesized is presented in this paper. (author)

  17. Influence of rice straw-based polyols on the morphology, thermal ...

    African Journals Online (AJOL)

    replacement of rice straw-based polyols produced closed cell structures suitable for insulation material as revealed in Scanning electron microscope images. Higher percentage of rice straw-based polyols replacement will trigger cell wall structure rapturing that will deteriorate the properties of polyurethane foam.

  18. Production of polyol oils from soybean oil by bioprocess and Philippines edible medicinal wild mushrooms

    Science.gov (United States)

    We have been trying to develop a bioprocess for the production of polyol oils directly from soybean oil. We reported earlier the polyol products produced from soybean oil by Acinetobacter haemolyticus A01-35 (NRRL B-59985) (Hou and Lin, 2013). The objective of this study is to identify the chemical ...

  19. Mechanical and Physical Properties of Polyester Polymer Concrete Using Recycled Aggregates from Concrete Sleepers

    Directory of Open Access Journals (Sweden)

    Francisco Carrión

    2014-01-01

    Full Text Available Currently, reuse of solid waste from disused infrastructures is an important environmental issue to study. In this research, polymer concrete was developed by mixing orthophthalic unsaturated polyester resin, artificial microfillers (calcium carbonate, and waste aggregates (basalt and limestone coming from the recycling process of concrete sleepers. The variation of the mechanical and physical properties of the polymer concrete (compressive strength, flexural strength, modulus of elasticity, density, and water absorption was analyzed based on the modification of different variables: nature of the recycled aggregates, resin contents (11 wt%, 12 wt%, and 13 wt%, and particle-size distributions of microfillers used. The results show the influence of these variables on mechanical performance of polymer concrete. Compressive and flexural strength of recycled polymer concrete were improved by increasing amount of polyester resin and by optimizing the particle-size distribution of the microfillers. Besides, the results show the feasibility of developing a polymer concrete with excellent mechanical behavior.

  20. Mechanical and physical properties of polyester polymer concrete using recycled aggregates from concrete sleepers.

    Science.gov (United States)

    Carrión, Francisco; Montalbán, Laura; Real, Julia I; Real, Teresa

    2014-01-01

    Currently, reuse of solid waste from disused infrastructures is an important environmental issue to study. In this research, polymer concrete was developed by mixing orthophthalic unsaturated polyester resin, artificial microfillers (calcium carbonate), and waste aggregates (basalt and limestone) coming from the recycling process of concrete sleepers. The variation of the mechanical and physical properties of the polymer concrete (compressive strength, flexural strength, modulus of elasticity, density, and water absorption) was analyzed based on the modification of different variables: nature of the recycled aggregates, resin contents (11 wt%, 12 wt%, and 13 wt%), and particle-size distributions of microfillers used. The results show the influence of these variables on mechanical performance of polymer concrete. Compressive and flexural strength of recycled polymer concrete were improved by increasing amount of polyester resin and by optimizing the particle-size distribution of the microfillers. Besides, the results show the feasibility of developing a polymer concrete with excellent mechanical behavior.

  1. Komposit Hibrid Polyester Berpenguat Serbuk Batang Dan Serat Sabut Kelapa

    OpenAIRE

    Lumintang, Romels C. A; Soenoko, Rudy; Wahyudi, Slamet

    2011-01-01

    Sawdust coconut trunks of palm trees and fiber coconut coir are two waste materials from the processing of coconuts and coconut tree trunks sawmill waste are plentiful materials can be utilized for producing composites using polyester resins. Both each properties materials as follow polyester resin: liquid in the open air conditions, sawdust coconut and coconut coir fiber properties is lightweight and fragile nature of the polyester adhesive used as a binder (binder) between fiber coconut coi...

  2. Polarisation-sensitive optical elements in azobenzene polyesters and peptides

    DEFF Research Database (Denmark)

    Ramanujam, P.S.; Dam-Hansen, Carsten; Berg, Rolf Henrik

    2006-01-01

    In this article, we describe fabrication of polarisation holographic optical elements in azobenzene polyesters. Both liquid crystalline and amorphous side-chain polyesters have been utilised. Diffractive optical elements such as lenses and gratings that are sensitive to the polarisation...... of the incident light have been fabricated with polarisation holography. Computer-generated optical elements and patterns have also been written with a single polarised laser beam. Recording of polarisation defects enabling easy visualisation is also shown to be feasible in azobenzene polyesters....

  3. Side-chain liquid crystalline polyesters for optical information storage

    DEFF Research Database (Denmark)

    Ramanujam, P.S.; Holme, Christian; Hvilsted, Søren

    1996-01-01

    and holographic storage in one particular polyester are described in detail and polarized Fourier transform infrared spectroscopic data complementing the optical data are presented. Optical and atomic force microscope investigations point to a laser-induced aggregation as responsible for permanent optical storage.......Azobenzene side-chain liquid crystalline polyester structures suitable for permanent optical storage are described. The synthesis and characterization of the polyesters together with differential scanning calorimetry and X-ray investigations are discussed. Optical anisotropic investigations...

  4. The radiation chemistry of symmetric aliphatic polyesters

    International Nuclear Information System (INIS)

    Babanalbandi, A.; Hill, D.J.T.; Pomery, P.J.; Whittaker, A.K.

    1996-01-01

    Full text: Naturally occurring, symmetric polyesters, including polyglycolic acid, polylactic acid and polyhydroxybutyrate, have found biomedical applications in areas as diverse as the controlled release of pharmaceuticals and the manufacture of surgical sutures. As biomedical products, the materials require sterilization by high energy radiation. This has provided the motivation for the present work. D'Alelio et al. have reported that linear, asymmetric polyesters undergo scission on irradiation, but that branched polyesters containing a methyl group in the diol segments undergo crosslinking. However, for the symmetric polyhydroxybutyrate, Carswell-Pomerantz et al. have reported that only scission occurs on radiolysis, with the evolution of CO and CO 2 as a result of the loss of ester linkages. These workers also found that G(CO + CO 2 ) was approximately equal to G(S) for this polyester. By contrast, Collett et al. have reported that G(S) = 1.26 and G(X) = 0.53 for polylactic acid, which indicates that the polymer undergoes nett crosslinking on radiolysis to form a gel. They have also reported that poly(lactic-co-glycolic acid) should form a gel on radiolysis, since G(S) = 1.66 and G(X) = 0.65 for a 1:1 copolymer composition. In the present work the radiolysis of polylactic acid and poly(lactic-co-glycolic acid) have been reinvestigated in order to resolve the differences between the work of Collett et al. and that of Carswell-Pomerantz et al. In these studies, ESR has been used to study the radicals formed, GPC has been used to investigate scission and crosslinking, GC has been used to study the small molecule volatile products and NMR spectroscopy has been used to identify and measure the new chemical structures formed in the polymers

  5. Novel organometallic aromatic polyester based on ferrocene

    Institute of Scientific and Technical Information of China (English)

    Wei

    2010-01-01

    A novel polyester containing ferrocenyl was prepared by low-temperature interface polycondensation of 1,1'-ferrocenedi-carboxylic acid chloride with 4-(4-hydroxyphenyl)-2,3-phthalazin-l-one(DHPZ), which is a twisted non-coplanar heterocyclic bisphenol-like monomer. The newly generated polymer was evaluated based on characterization of its solubility, viscosity measurements, elemental analysis, FTIR spectroscopy, differential scanning calorimetric and thermogravimetric studies.

  6. Water-based binary polyol process for the controllable synthesis of silver nanoparticles inhibiting human and foodborne pathogenic bacteria

    Science.gov (United States)

    The polyol process is a widely used strategy for producing nanoparticles from various reducible metallic precursors; however it requires a bulk polyol liquid reaction with additional protective agents at high temperatures. Here, we report a water-based binary polyol process using low concentrations ...

  7. Effect of lignin derivatives in the bio-polyols from microwave liquefied bamboo on the properties of polyurethane foams

    Science.gov (United States)

    Jiulong Xie; Jinqiu Qi; Chung-Yun Hse; Todd F. Shupe

    2014-01-01

    Bamboo residues were subjected to a microwave-assisted liquefaction process for the production of crude bio-polyols (CBP). The fractionated bio-polyols (FBP) were obtained by the removal of lignin derivatives from the crude bio-polyols (CBP) using a simple method. Polyurethane (PU) foams were successfully prepared from both CBP and FBP. The object of this study was to...

  8. Lanthanide-IMAC enrichment of carbohydrates and polyols.

    Science.gov (United States)

    Schemeth, Dieter; Rainer, Matthias; Messner, Christoph B; Rode, Bernd M; Bonn, Günther K

    2014-03-01

    In this study a new type of immobilized metal ion affinity chromatography resin for the enrichment of carbohydrates and polyols was synthesized by radical polymerization reaction of vinyl phosphonic acid and 1,4-butandiole dimethacrylate using azo-bis-isobutyronitrile as radical initiator. Interaction between the chelated trivalent lanthanide ions and negatively charged hydroxyl groups of carbohydrates and polyols was observed by applying high pH values. The new method was evaluated by single standard solutions, mixtures of standards, honey and a more complex extract of Cynara scolymus. The washing step was accomplished by acetonitrile in excess volumes. Elution of enriched carbohydrates was successfully performed with deionized water. The subsequent analysis was carried out with matrix-free laser desorption/ionization-time of flight mass spectrometry involving a TiO2 -coated steel target, especially suitable for the measurement of low-molecular-weight substances. Quantitative analysis of the sugar alcohol xylitol as well as the determination of the maximal loading capacity was performed by gas chromatography in conjunction with mass spectrometric detection after chemical derivatization. In a parallel approach quantum mechanical geometry optimizations were performed in order to compare the coordination behavior of various trivalent lanthanide ions. Copyright © 2013 John Wiley & Sons, Ltd.

  9. Synthesis of Dense and Chiral Dendritic Polyols Using Glyconanosynthon Scaffolds

    Directory of Open Access Journals (Sweden)

    Tze Chieh Shiao

    2016-04-01

    Full Text Available Most classical dendrimers are frequently built-up from identical repeating units of low valency (usually AB2 monomers. This strategy necessitates several generations to achieve a large number of surface functionalities. In addition, these typical monomers are achiral. We propose herein the use of sugar derivatives consisting of several and varied functionalities with their own individual intrinsic chirality as both scaffolds/core as well as repeating units. This approach allows the construction of chiral, dense dendrimers with a large number of surface groups at low dendrimer generations. Perpropargylated β-D-glucopyranoside, serving as an A5 core, together with various derivatives, such as 2-azidoethyl tetra-O-allyl-β-D-glucopyranoside, serving as an AB4 repeating moiety, were utilized to construct chiral dendrimers using “click chemistry” (CuAAC reaction. These were further modified by thiol-ene and thiol-yne click reactions with alcohols to provide dendritic polyols. Molecular dynamic simulation supported the assumption that the resulting polyols have a dense structure.

  10. Catalytic Deoxydehydration of Carbohydrates and Polyols to Chemicals and Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Nicholas, Kenneth M. [Univ. of Oklahoma, Norman, OK (United States)

    2016-01-15

    As the world's fossil fuel resources are being depleted and their costs increase, there is an urgent need to discover and develop new processes for the conversion of renewable, biomass resources into fuels and chemical feedstocks. Research and development in this area have been given high priority by both governmental agencies and industry. To increase the energy content and decrease the boiling points of biomass-derived carbohydrates and polyols to the useful liquid range it is necessary to chemically remove water (dehydrate) and, preferably, oxygen (deoxygenate/reduce). The poly-hydroxylic nature of carbohydrates is attractive for their use as functionalized chemical building blocks, but it presents a daunting challenge for their selective conversion to single product chemicals or fuels. The long term, practical objective of this project is to develop catalytic processes for the deoxydehydration (DODH) of biomass-derived carbohydrates and polyols to produce unsaturated alcohols and hydrocarbons of value as chemical feedstocks and fuels; DODH: polyol + reductant --(LMOx catalyst)--> unsaturate + oxidized reductant + H2O. Limited prior studies have established the viability of the DODH process with expensive phosphine reductants and rhenium-catalysts. Initial studies in the PI's laboratory have now demonstrated: 1) the moderately efficient conversion of glycols to olefins by the economical sulfite salts is catalyzed by MeReO3 and Z+ReO4-; 2) effective phosphine-based catalytic DODH of representative glycols to olefins by cheap LMoO2 complexes; and 3) computational studies (with K. Houk, UCLA) have identified several Mo-, W-, and V-oxo complexes that are likely to catalyze glycol DODH. Seeking practically useful DODH reactions of complex polyols and new understanding of the reactivity of polyoxo-metal species with biomass-oxygenates we will employ a two-pronged approach: 1) investigate experimentally the reactivity, both stoichiometric and catalytic, of

  11. Experimental Evaluation of Polyester and Epoxy–Polyester Powder Coatings in Aggressive Media

    Directory of Open Access Journals (Sweden)

    Ivan Stojanović

    2018-03-01

    Full Text Available Protective coatings are the most widely used corrosion protection method for construction materials in different environmental conditions. They isolate metals from aggressive media, making the structure more durable. Today, alongside good anti-corrosive properties, coatings need to be safe for the environment and harmless to those who apply them. The high volatile organic compound (VOC content in conventional solvent-borne coatings presents a huge ecological problem. A solution for indispensable solvent emission reduction is the application of powder coatings. This study evaluates the corrosion performance and surface morphology of polyester and epoxy–polyester powder coatings. Electrochemical impedance spectroscopy (EIS, open circuit potential (OCP measurement, salt spray chamber and humidity chamber testing followed by adhesion testing were used to investigate the protective properties of powder coatings. Scanning electron microscope (SEM with energy-dispersive X-ray spectroscopy (EDX was used to analyse the surface morphology and chemical composition, whereas the microstructure and coating uniformity were determined by optical microscope examination. The research revealed a negative influence of coating surface texture on coating thickness and consequently a lack of barrier and adhesion properties. The epoxy–polyester powder coating showed a better performance than the polyester coating. All tested coatings showed uniform structure.

  12. Air-drying paint compositions comprising carbohydrate-based polyesters and polyester preparation

    NARCIS (Netherlands)

    Oostveen, E.A.; Weijnen, J.; Haveren, van J.; Gillard, M.

    2003-01-01

    The invention relates to a polyester obtainable by transesterification or interesterification of:(i) a carbohydrate or an acyl ester thereof, (ii) an alkyl ester of a drying fatty acid, semi-drying fatty acid or mixture thereof; and (iii) an alkyl ester of a non aromatic polycarboxylic acid. The

  13. Synthesis and Characterization of Soy-Based Polyurethane Foam with Utilization of Ethylene Glycol in Polyol

    Directory of Open Access Journals (Sweden)

    Flora Elvistia Firdaus

    2014-08-01

    Full Text Available The use of vegetable oils on replacing petroleum has attracted attention of many researchers. The chemical structure of vegetable oils are different from petrochemicals, so the structure of soybean oil has to be chemicallymodified through its unsaturated fatty acid chain in triglyceride. Atwo step process was conducted for the preparationof soy-polyol in designated temperatures; 50 °C, 60 °C, and 70 °C. Ethylene glycol (EG as co-reagent was taking part in soy-polyol synthesis, and the soy-polyol was used as a sole polyol for polyurethane synthesis. Referred to the previous study, the existence of EG in polyurethane synthesis can improved physical properties of polyurethane foam. The aim of this research is using soy-derived polyol for petro-polyol replacement aligned with drop-off of petro-derived reagent; EG. One step process was applied for the foam synthesis.The ingredients for foam synthesis; soy-polyol, Toluene diisocyanate (TDI: a mixture of 2.4 and 2.6 isomers in ratio of 80:20 (TDI T-80, surfactant, and distilled water. The synergize of stoichiometry ratio of co-reagent EG to soy-epoxide with best temperature, with the absence of EG in polyurethane formula can produce an ultimate property of polyurethane foam. 

  14. Surface modification of polyester biomaterials for tissue engineering

    International Nuclear Information System (INIS)

    Jiao Yanpeng; Cui Fuzhai

    2007-01-01

    Surfaces play an important role in a biological system for most biological reactions occurring at surfaces and interfaces. The development of biomaterials for tissue engineering is to create perfect surfaces which can provoke specific cellular responses and direct new tissue regeneration. The improvement in biocompatibility of biomaterials for tissue engineering by directed surface modification is an important contribution to biomaterials development. Among many biomaterials used for tissue engineering, polyesters have been well documented for their excellent biodegradability, biocompatibility and nontoxicity. However, poor hydrophilicity and the lack of natural recognition sites on the surface of polyesters have greatly limited their further application in the tissue engineering field. Therefore, how to introduce functional groups or molecules to polyester surfaces, which ideally adjust cell/tissue biological functions, becomes more and more important. In this review, recent advances in polyester surface modification and their applications are reviewed. The development of new technologies or methods used to modify polyester surfaces for developing their biocompatibility is introduced. The results of polyester surface modifications by surface morphological modification, surface chemical group/charge modification, surface biomacromolecule modification and so on are reported in detail. Modified surface properties of polyesters directly related to in vitro/vivo biological performances are presented as well, such as protein adsorption, cell attachment and growth and tissue response. Lastly, the prospect of polyester surface modification is discussed, especially the current conception of biomimetic and molecular recognition. (topical review)

  15. Process for the production of a dianhydrohexitol based polyester

    NARCIS (Netherlands)

    2008-01-01

    Process for the production of a polyester by the polycondensation of a mixture comprising isoidide, and a dicarboxylic acid or dicarboxylic acid anhydride, wherein the reaction is performed in the melt of the monomers and wherein these monomers are not activated. The polyesters based on one or more

  16. Biobased functional polyesters for coating applications: Synthesis, characterization and application

    NARCIS (Netherlands)

    Noordover, B.A.J.; Duchateau, R.; Koning, C.E.; Benthem, van R.A.T.M.; Ming, W.; Haveren, van J.; Es, van D.S.

    2007-01-01

    Thermosetting coating systems contain polyesters as binders. A crucial property of these polymers is their functionality. During coating application, the polyesters are cross-linked in situ, which means that each polymer chain needs a sufficient no. of reactive end-groups. Renewable monomers are

  17. Purification and Properties of a Polyester Polyurethane-Degrading Enzyme from Comamonas acidovorans TB-35.

    Science.gov (United States)

    Akutsu, Y; Nakajima-Kambe, T; Nomura, N; Nakahara, T

    1998-01-01

    A polyester polyurethane (PUR)-degrading enzyme, PUR esterase, derived from Comamonas acidovorans TB-35, a bacterium that utilizes polyester PUR as the sole carbon source, was purified until it showed a single band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This enzyme was bound to the cell surface and was extracted by addition of 0.2% N,N-bis(3-d-gluconamidopropyl)deoxycholamide (deoxy-BIGCHAP). The results of gel filtration and SDS-PAGE showed that the PUR esterase was a monomer with a molecular mass of about 62,000 Da. This enzyme, which is a kind of esterase, degraded solid polyester PUR, with diethylene glycol and adipic acid released as the degradation products. The optimum pH for this enzyme was 6.5, and the optimum temperature was 45 degrees C. PUR degradation by the PUR esterase was strongly inhibited by the addition of 0.04% deoxy-BIGCHAP. On the other hand, deoxy-BIGCHAP did not inhibit the activity when p-nitrophenyl acetate, a water-soluble compound, was used as a substrate. These observations indicated that this enzyme degrades PUR in a two-step reaction: hydrophobic adsorption to the PUR surface and hydrolysis of the ester bond of PUR.

  18. Functional bio-based polyesters by enzymatic polymerization

    DEFF Research Database (Denmark)

    Daugaard, Anders Egede; Hoffmann, Christian; Andersen, Christian

    During recent years enzymatic polymerization has become increasingly popular as an alternative to classical polyesterification processes. The high regioselectivity observed for lipases permits preparation of novel polyesters with a high number of functional groups.1 This is particularly interesting...... polymerization was applied to prepare functional water soluble polyesters based on dimethyl itaconate and poly(ethyleneglycol).2 The monomer permits postfunctionalization using thiol-ene chemistry or aza-michael additions, which was used to illustrate the possibilites of preparing functional hydrogels. Hydrogels...... based on the polyesters were shown to be degradable and could be prepared either from the pure polyester or from prefunctionalized polyesters, though the thiol-ene reactions were found to be less effective. Since then a new monomer, trans-2,5-dihydroxy-3-pentenoic acid methyl ester (DPM) has been...

  19. Radiation processed composite materials of wood and elastic polyester resins

    International Nuclear Information System (INIS)

    Tapolcai, I.; Czvikovszky, T.

    1983-01-01

    The radiation polymerization of multifunctional unsaturated polyester-monomer mixtures in wood forms interpenetrating network system. The mechanical resistance (compression, abrasion, hardness, etc.) of these composite materials are generally well over the original wood, however the impact strength is almost the same or even reduced, in comparison to the wood itself. An attempt is made using elastic polyester resins to produced wood-polyester composite materials with improved modulus of elasticity and impact properties. For the impregnation of European beech wood two types of elastic unsaturated polyester resins were used. The exothermic effect of radiation copolymerization of these resins in wood has been measured and the dose rate effects as well as hardening dose was determined. Felxural strength and impact properties were examined. Elastic unsaturated polyester resins improved the impact strength of wood composite materials. (author)

  20. Reactive modification of polyesters and their blends

    Science.gov (United States)

    Wan, Chen

    2004-12-01

    As part of a broader research effort to investigate the chemical modification of polyesters by reactive processing a low molecular weight (MW) unsaturated polyester (UP) and a higher MW saturated polyester, polyethylene terephthalate (PET), alone or blended with polypropylene (PP) were melt processed in a batch mixer and continuous twin screw extruders. Modification was monitored by on-line rheology and the products were characterized primarily by off-line rheology, morphology and thermal analysis. Efforts were made to establish processing/property relationships and provide an insight of the accompanying structural changes. The overall response of the reactively modified systems was found to be strongly dependent on the component characteristics, blend composition, type and concentrations of reactive additives and processing conditions. The work concluded that UP can be effectively modified through reactive melt processing. Its melt viscosity and MW can be increased through chemical reactions between organic peroxides (POX) and chain unsaturation or between MgO and carboxyl/hydroxyl end groups. Reactive blending of PP/UP blends through peroxide modification gave finer and more uniform morphology than unreacted blends and at a given PP/UP weight ratio more thermoplastic elastomers-like rheological behavior. This is due to the continuously decreasing viscosity ratio of PP/UP towards unity by the competing reactions between POX and the blend components and formation of PP-UP copolymers which serve as in-situ compatibilizers to promote better interfacial adhesion. Kinetics of the competing reactions were analyzed through a developed model. In addition to POX concentration and mixing efficiency, rheology and morphology of UP/PP bends were significantly affected by the addition of inorganic and organic coagents. Addition of coagents such as a difunctional maleimide, MgO and/or an anhydride functionalized PP during reactive blending offers effective means for tailoring

  1. Efficiency of Osmotic Dehydration of Apples in Polyols Solutions

    Directory of Open Access Journals (Sweden)

    Joanna Cichowska

    2018-02-01

    Full Text Available The present study aimed to evaluate the influence of selected compounds from the polyol group, as well as other saccharides, on the osmotic dehydration process of apples. The following alternative solutions were examined: erythritol, xylitol, maltitol, inulin and oligofructose. Efficiency of the osmotic dehydration process was evaluated based on the kinetics of the process, and through comparison of the results obtained during the application of a sucrose solution. This innovative research utilizes alternative solutions in osmotic pretreatment, which until now, have not been commonly used in fruit processing by researchers worldwide. Results indicate that erythritol and xylitol show stronger or similar efficiency to sucrose; however, the use of inulin, as well as oligofructose, was not satisfactory due to the insufficient, small osmotic driving forces of the process, and the low values of mass transfer parameters.

  2. Efficiency of Osmotic Dehydration of Apples in Polyols Solutions.

    Science.gov (United States)

    Cichowska, Joanna; Żubernik, Joanna; Czyżewski, Jakub; Kowalska, Hanna; Witrowa-Rajchert, Dorota

    2018-02-17

    The present study aimed to evaluate the influence of selected compounds from the polyol group, as well as other saccharides, on the osmotic dehydration process of apples. The following alternative solutions were examined: erythritol, xylitol, maltitol, inulin and oligofructose. Efficiency of the osmotic dehydration process was evaluated based on the kinetics of the process, and through comparison of the results obtained during the application of a sucrose solution. This innovative research utilizes alternative solutions in osmotic pretreatment, which until now, have not been commonly used in fruit processing by researchers worldwide. Results indicate that erythritol and xylitol show stronger or similar efficiency to sucrose; however, the use of inulin, as well as oligofructose, was not satisfactory due to the insufficient, small osmotic driving forces of the process, and the low values of mass transfer parameters.

  3. Thermal Study of Polyols for the Technological Application as Plasticizers in Food Industry

    Directory of Open Access Journals (Sweden)

    Alberto Toxqui-Terán

    2018-04-01

    Full Text Available In this work is presented the complete thermal analysis of polyols by direct methods such as simultaneous thermogravimetric and differential thermal analyzer (TGA-DTA, differential scanning calorimetry (DSC, modulated DSC (MDSC, and supercooling MDSC. The different thermal events in the temperature range of 113–553 K were identified for glycerol (GL, ethylene glycol (EG, and propylene glycol (PG. Boiling temperature (TB decreased as GL > EG > PG, but increased with the heating rate. GL showed a complex thermal event at 191–199 K, identified as the glass transition temperature (Tg and devitrification temperature (Tdv, and a liquid–liquid transition (TL-L at 215–221 K was identified as the supercooling temperature. EG showed several thermal events such as Tg and Tdv at 154 K, crystallization temperature (Tc at 175 K, and melting temperature (Tm at 255 K. PG also showed a complex thermal event (Tg and Tdv at 167 K, a second devitrification at 193 K, and TL-L at 245 K. For PG, crystallization was not observed, indicating that, during the cooling, the liquid remained as an amorphous solid.

  4. Micro-thermal analysis of polyester coatings

    Science.gov (United States)

    Fischer, Hartmut R.

    2010-04-01

    The application and suitability of micro-thermal analysis to detect changes in the chemical and physical properties of coating due to ageing and especially photo-degradation is demonstrated using a model polyester coating based on neopentyl glycol isophthalic acid. The changes in chemical structure like chain scission and cross-linking are manifested by a shift of the LTA detectable Tg and by a change of the slope of the part of the LTA graph responsible for the penetration of the hot sensor into the material after passing the glass transition temperature. As such LTA is a valuable tool to have a quick look into coating surfaces and especially their ageing. The photo-degradation of polyester in air leads to the formation of a cross-linked network at a surface layer of about 3-4 μm coupled with an increase in hardness and of the glass transition temperature by ˜90 K, the effect is less drastic for a photo-degradation in a nitrogen environment. Moreover, the presence of a non-equilibrium dense surface layer with a higher Tg formed during the drying of the coating formulation and the film solidification can be shown.

  5. Protoenzymes: the case of hyperbranched polyesters

    Science.gov (United States)

    Mamajanov, Irena; Cody, George D.

    2017-11-01

    Enzymes are biopolymeric complexes that catalyse biochemical reactions and shape metabolic pathways. Enzymes usually work with small molecule cofactors that actively participate in reaction mechanisms and complex, usually globular, polymeric structures capable of specific substrate binding, encapsulation and orientation. Moreover, the globular structures of enzymes possess cavities with modulated microenvironments, facilitating the progression of reaction(s). The globular structure is ensured by long folded protein or RNA strands. Synthesis of such elaborate complexes has proven difficult under prebiotically plausible conditions. We explore here that catalysis may have been performed by alternative polymeric structures, namely hyperbranched polymers. Hyperbranched polymers are relatively complex structures that can be synthesized under prebiotically plausible conditions; their globular structure is ensured by virtue of their architecture rather than folding. In this study, we probe the ability of tertiary amine-bearing hyperbranched polyesters to form hydrophobic pockets as a reaction-promoting medium for the Kemp elimination reaction. Our results show that polyesters formed upon reaction between glycerol, triethanolamine and organic acid containing hydrophobic groups, i.e. adipic and methylsuccinic acid, are capable of increasing the rate of Kemp elimination by a factor of up to 3 over monomeric triethanolamine. This article is part of the themed issue 'Reconceptualizing the origins of life'.

  6. Characterization and Growth Mechanism of Nickel Nano wires Resulting from Reduction of Nickel Formate in Polyol Medium

    International Nuclear Information System (INIS)

    Logutenko, O.A.; Titkov, A.I.; Vorobyov, A.M.; Yukhin, Y.M.; Lyakhov, N.Z.

    2016-01-01

    Nickel linear nano structures were synthesized by reduction of nickel formate with hydrazine hydrate in ethylene glycol medium in the absence of any surfactants or capping agents for direction of the particles growth. The effect of the synthesis conditions such as temperature, reduction time, type of polyol, and nickel formate concentration on the reduction products was studied. The size and morphology of the nickel nano wires were characterized by X-ray diffraction, scanning, and transmission electron microscopy. It was shown that the nickel nano crystallites were wire-shaped with a face-center-cubic phase. Ethylene glycol was found to play a crucial role in the formation of the nickel nano wires. The possible growth processes of the wire-shaped particles taking place at 110 and 130 degree are discussed. It was shown that, under certain synthesis conditions, nickel nano wires grow on the surface of the crystals of the solid intermediate of nickel with hydrazine hydrate.

  7. Biotechnological and in situ food production of polyols by lactic acid bacteria.

    Science.gov (United States)

    Ortiz, Maria Eugenia; Bleckwedel, Juliana; Raya, Raúl R; Mozzi, Fernanda

    2013-06-01

    Polyols such as mannitol, erythritol, sorbitol, and xylitol are naturally found in fruits and vegetables and are produced by certain bacteria, fungi, yeasts, and algae. These sugar alcohols are widely used in food and pharmaceutical industries and in medicine because of their interesting physicochemical properties. In the food industry, polyols are employed as natural sweeteners applicable in light and diabetic food products. In the last decade, biotechnological production of polyols by lactic acid bacteria (LAB) has been investigated as an alternative to their current industrial production. While heterofermentative LAB may naturally produce mannitol and erythritol under certain culture conditions, sorbitol and xylitol have been only synthesized through metabolic engineering processes. This review deals with the spontaneous formation of mannitol and erythritol in fermented foods and their biotechnological production by heterofermentative LAB and briefly presented the metabolic engineering processes applied for polyol formation.

  8. Producing Lignin-Based Polyols through Microwave-Assisted Liquefaction for Rigid Polyurethane Foam Production

    Directory of Open Access Journals (Sweden)

    Bai-Liang Xue

    2015-02-01

    Full Text Available Lignin-based polyols were synthesized through microwave-assisted liquefaction under different microwave heating times (5–30 min. The liquefaction reactions were carried out using polyethylene glycol (PEG-400/glycerol as liquefying solvents and 97 wt% sulfur acid as a catalyst at 140 °C. The polyols obtained were analyzed for their yield, composition and structural characteristics using gel permeation chromatography (GPC, Fourier transform infrared (FT-IR and nuclear magnetic resonance (NMR spectra. FT-IR and NMR spectra showed that the liquefying solvents reacted with the phenol hydroxyl groups of the lignin in the liquefied product. With increasing microwave heating time, the viscosity of polyols was slightly increased and their corresponding molecular weight (MW was gradually reduced. The optimal condition at the microwave heating time (5 min ensured a high liquefaction yield (97.47% and polyol with a suitable hydroxyl number (8.628 mmol/g. Polyurethane (PU foams were prepared by polyols and methylene diphenylene diisocyanate (MDI using the one-shot method. With the isocyanate/hydroxyl group ([NCO]/[OH] ratio increasing from 0.6 to 1.0, their mechanical properties were gradually increased. This study provided some insight into the microwave-assisted liquefied lignin polyols for the production of rigid PU foam.

  9. New biobased high functionality polyols and their use in polyurethane coatings.

    Science.gov (United States)

    Pan, Xiao; Webster, Dean C

    2012-02-13

    High-functionality polyols for application in polyurethanes (PUs) were prepared by epoxide ring-opening reactions from epoxidized sucrose esters of soybean oil-epoxidized sucrose soyates-in which secondary hydroxyl groups were generated from epoxides on fatty acid chains. Ester polyols were prepared by using a base-catalyzed acid-epoxy reaction with carboxylic acids (e.g., acetic acid); ether polyols were prepared by using an acid-catalyzed alcohol-epoxy reaction with monoalcohols (e.g., methanol). The polyols were characterized by using gel permeation chromatography, FTIR spectroscopy, (1)H NMR spectroscopy, differential scanning calorimetry (DSC), and viscosity measurements. PU thermosets were prepared by using aliphatic polyisocyanates based on isophorone diisocyanate and hexamethylene diisocyanate. The properties of the PUs were studied by performing tensile testing, dynamic mechanical analysis, DSC, and thermogravimetric analysis. The properties of PU coatings on steel substrates were evaluated by using ASTM methods to determine coating hardness, adhesion, solvent resistance, and ductility. Compared to a soy triglyceride polyol, sucrose soyate polyols provide greater hardness and range of cross-link density to PU thermosets because of the unique structure of these macromolecules: well-defined compact structures with a rigid sucrose core coupled with high hydroxyl group functionality. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Actuators based on polyurethanes with different types of polyol

    Science.gov (United States)

    Lim, Hyun-Ok; Bark, Geong-Mi; Jo, Nam-Ju

    2007-07-01

    This study dealt with the electrostrictive responses of polyurethane (PU) actuators with different microphase separation structure, which was a promising candidate for a material used in polymer actuators. In order to construct PUs with different higher-order structure, we synthesized PUs with different diols; poly(neopentyl glycol adipate) (PNAD), poly(tetramethylene glycol) (PTMG), and poly(dimethyl siloxnae) (PDMS). Synthesized PU was characterized by FT-IR spectroscopy and GPC. Thermal analysis and mechanical properties of PU films were carried out with DSC and UTM, respectively. And PU actuator was formed in a monomorph type which made by carbon black electrodes on the both surfaces of PU film by spin coating method. Actuation behavior was mainly influenced on microphase separation structure and mechanical property of PU. In result, PU actuator with PNAD, polyester urethane, had the largest field-induced displacement.

  11. Process development of short-chain polyols synthesis from corn stover by combination of enzymatic hydrolysis and catalytic hydrogenolysis

    Directory of Open Access Journals (Sweden)

    Zhen-Hong Fang

    2014-09-01

    Full Text Available Currently short-chain polyols such as ethanediol, propanediol, and butanediol are produced either from the petroleum feedstock or from the starch-based food crop feedstock. In this study, a combinational process of enzymatic hydrolysis with catalytic hydrogenolysis for short-chain polyols production using corn stover as feedstock was developed. The enzymatic hydrolysis of the pretreated corn stover was optimized to produce stover sugars at the minimum cost. Then the stover sugars were purified and hydrogenolyzed into polyols products catalyzed by Raney nickel catalyst. The results show that the yield of short-chain polyols from the stover sugars was comparable to that of the corn-based glucose. The present study provided an important prototype for polyols production from lignocellulose to replace the petroleum- or corn-based polyols for future industrial applications.

  12. Electrospinning of microbial polyester for cell culture

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Oh Hyeong [Department of Polymer Science and Engineering, Kumoh National Institute of Technology, 1 Yangho-dong, Gumi, Gyeongbuk 730-701 (Korea, Republic of); Lee, Ik Sang [Department of Polymer Science and Engineering, Kumoh National Institute of Technology, 1 Yangho-dong, Gumi, Gyeongbuk 730-701 (Korea, Republic of); Ko, Young-Gwang [Department of Polymer Science and Engineering, Kumoh National Institute of Technology, 1 Yangho-dong, Gumi, Gyeongbuk 730-701 (Korea, Republic of); Meng, Wan [Department of Polymer Science, Kyungpook National University, 1370 Sankyuk-dong, Buk-gu, Daegu 702-701 (Korea, Republic of); Jung, Kyung-Hye [Department of Polymer Science, Kyungpook National University, 1370 Sankyuk-dong, Buk-gu, Daegu 702-701 (Korea, Republic of); Kang, Inn-Kyu [Department of Polymer Science, Kyungpook National University, 1370 Sankyuk-dong, Buk-gu, Daegu 702-701 (Korea, Republic of); Ito, Yoshihiro [Kanagawa Academy of Science and Technology, KSP East 309, Sakado 3-2-1, Takatsu-ku, Kawasaki 213-0012 (Japan)

    2007-03-01

    Biodegradable and biocompatible poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), a copolymer of microbial polyester, was fabricated as a nanofibrous mat by electrospinning. The specific surface area and the porosity of electrospun PHBV nanofibrous mat were determined. When the mechanical properties of flat film and electrospun PHBV nanofibrous mats were investigated, both the tensile modulus and strength of electrospun PHBV were less than those of cast PHBV film. However, the elongation ratio of nanofiber mat was higher than that of the cast film. The structure of electrospun nanofibers using PHBV-trifluoroethanol solutions depended on the solution concentrations. When x-ray diffraction patterns of bulk PHBV before and after electrospinning were compared, the crystallinity of PHBV was not significantly affected by the electrospinning process. Chondrocytes adhered and grew on the electrospun PHBV nanofibrous mat better than on the cast PHBV film. Therefore, the electrospun PHBV was considered to be suitable for cell culture.

  13. Characterization of material composite marble-polyester

    Directory of Open Access Journals (Sweden)

    Corpas, F. A.

    2002-12-01

    Full Text Available In this work we characterize a new material composite, formed with a polyester and crushed white marble mixture. The final purpose is double: to obtain a material for applications sufficiently competitive after an economic viability study, increasing the yield of the main commodity, using waste marble and improving the jobs in the quarries area. From the results obtained, we deduce then that this material could be used to inside and outside adornment.

    En este trabajo, caracterizamos un nuevo material compuesto, formado con una mezcla de poliéster y de mármol blanco triturado. El propósito final es doble: por un lado obtener un material para aplicaciones lo suficientemente competitivas como para que se pueda iniciar un estudio económico de viabilidad, aumentando el rendimiento de la materia prima y mejorando las salidas laborales de las comarcas extractoras. Para la caracterización del material se ha determinado el porcentaje adecuado de poliéster. Así como las propiedades mecánicas (flexión, compresión y dureza, químicas, fatiga térmica y su influencia a la exposición solar In order to characterized of material, we have determined the suitable porcentage of polyester Also we have carried out a study of the mechanical (stretching, resistance to traction, hardeness and thermal fatigue chemicals properties and solar radiation influence. De los resultados obtenidos, este material podría ser utilizado para ornamentación tanto de interior como de exterior.

  14. Nano-biocomposites based on synthetic aliphatic polyesters and nanoclay

    CSIR Research Space (South Africa)

    Ojijo, Vincent O

    2014-05-01

    Full Text Available This article gives an overview of the recent developments in the preparation, characterisation, properties, crystallisation behaviour, and melt rheology of clay-containing composites of biodegradable synthetic aliphatic polyesters such as poly...

  15. Light scattering of thin azobenzene side-chain polyester layers

    DEFF Research Database (Denmark)

    Kerekes, Á.; Lörincz, E.; Ramanujam, P.S.

    2002-01-01

    Light scattering properties of liquid crystalline and amorphous azobenzene side-chain polyester layers used for optical data storage were examined by means of transmissive scatterometry. Comparative experiments show that the amorphous polyester has significantly lower light scattering...... characteristics than the liquid crystalline polyester. The amorphous samples have negligible polarization part orthogonal to the incident beam. the liquid crystalline samples have relative high orthogonal polarization part in light scattering, The light scattering results can be used to give a lower limit...... for the domain size in thin liquid crystalline polyester layers being responsible for the dominant light scattering. The characteristic domain Sizes obtained from the Fourier transformation of polarization microscopic Pictures confirm these values....

  16. Synthetic polyester-hydrolyzing enzymes from thermophilic actinomycetes.

    Science.gov (United States)

    Wei, Ren; Oeser, Thorsten; Zimmermann, Wolfgang

    2014-01-01

    Thermophilic actinomycetes produce enzymes capable of hydrolyzing synthetic polyesters such as polyethylene terephthalate (PET). In addition to carboxylesterases, which have hydrolytic activity predominantly against PET oligomers, esterases related to cutinases also hydrolyze synthetic polymers. The production of these enzymes by actinomycetes as well as their recombinant expression in heterologous hosts is described and their catalytic activity against polyester substrates is compared. Assays to analyze the enzymatic hydrolysis of synthetic polyesters are evaluated, and a kinetic model describing the enzymatic heterogeneous hydrolysis process is discussed. Structure-function and structure-stability relationships of actinomycete polyester hydrolases are compared based on molecular dynamics simulations and recently solved protein structures. In addition, recent progress in enhancing their activity and thermal stability by random or site-directed mutagenesis is presented. © 2014 Elsevier Inc. All rights reserved.

  17. Preparation and applications of wood-polyester composites

    International Nuclear Information System (INIS)

    Czvikovszky, T.

    1982-01-01

    Optimum processing parameters were searched for the pilot-scale production of wood-polyester composites by irradiation of resin-impregnated wood material. The radiation initiation of the following systems were examined in wood and without wood matrix: methyl methacrylate, mixture of styrene and acrylonitryle, and their combination with unsaturated polyester. In the most cases the over-all rate of the complete polymerization process in wood matrix is proportional to the square root of the initiation rate. The parameters of the radiation technology of wood-polyester composites have been determined, using 260 TBq (7 kCi) 60 Co radiation source. A pilot plant has been constructed using an underwater irradiation system of 1.85 PBq (50 kCi) 60 Co. The successful production rate of 200 kg wood-polyester composite per day, as well as the application tests have demonstrated the technical feasibility of this new structural material. (author)

  18. Tensile strength of woven yarn kenaf fiber reinforced polyester composites

    OpenAIRE

    A.E. Ismail; M.A. Che Abdul Aziz

    2015-01-01

    This paper presents the tensile strength of woven kenaf fiber reinforced polyester composites. The as-received yarn kenaf fiber is weaved and then aligned into specific fiber orientations before it is hardened with polyester resin. The composite plates are shaped according to the standard geometry and uni-axially loaded in order to investigate the tensile responses. Two important parameters are studied such as fiber orientations and number of layers. According to the results, it is shown that...

  19. Application of eco-friendly antimicrobial finish butea monosperma leaves on fabric properties of polyester and cotton/polyester

    International Nuclear Information System (INIS)

    Sadaf, S.; Saeed, M.; Kalsoom, S.; Saeed, M.

    2017-01-01

    The study was aimed to check the effect of eco-friendly antimicrobial finish on 100% polyester and 50/50 cotton/polyester woven fabrics. The leaves' extract of Butea monosperma was used as an eco-friendly antimicrobial finish. The fabric was first desized, scoured, bleached and washed then antimicrobial finish was applied by using pad dry cure method. The aesthetic, comfort and mechanical fabrics properties were checked before and after applying antimicrobial finish. Under aesthetic property stiffness and smoothness appearance was checked, under comfort related property absorbency and air permeability was checked and under mechanical property tear and tensile strength was checked. The antimicrobial finish was checked by using ASTEM E2149 Shake Flask method. The AATCC and ISO standard testing methods were used for checking fabric properties. One way ANOVA statistical test was applied for analysis of results. Antimicrobial finish has increased aesthetic (stiffness, smoothness appearance), comfort (absorbency, air permeability) and mechanical (tensile and tear strengths) properties of polyester and cotton/polyester fabrics. The antimicrobial finish was effective on both 100% polyester and 50/50 cotton/polyester fabrics up to 25 washes. This study is beneficial to medical industry, paramedical staff, sports wears, home furnishing as well as common people. (author)

  20. Polyol specificity of recombinant Arabidopsis thaliana sorbitol dehydrogenase studied by enzyme kinetics and in silico modeling

    Directory of Open Access Journals (Sweden)

    María Francisca eAguayo

    2015-02-01

    Full Text Available Polyols are enzymatically-produced plant compounds which can act as compatible solutes during periods of abiotic stress. NAD+-dependent SORBITOL DEHYDROGENASE (SDH, E.C. 1.1.1.14 from Arabidopsis thaliana L. (AtSDH is capable of oxidizing several polyols including sorbitol, ribitol and xylitol. In the present study, enzymatic assays using recombinant AtSDH demonstrated a higher specificity constant for xylitol compared to sorbitol and ribitol, all of which are C2 (S and C4 (R polyols. Enzyme activity was reduced by preincubation with ethylenediaminetetraacetic acid (EDTA, indicating a requirement for zinc ions. In humans, it has been proposed that sorbitol becomes part of a pentahedric coordination sphere of the catalytic zinc during the reaction mechanism. In order to determine the validity of this pentahedric coordination model in a plant SDH, homology modeling and Molecular Dynamics simulations of AtSDH ternary complexes with the three polyols were performed using crystal structures of human and Bemisia argentifolii (Genn. (Hemiptera: Aleyrodidae SDHs as scaffolds. The results indicate that the differences in interaction with structural water molecules correlate very well with the observed enzymatic parameters, validate the proposed pentahedric coordination of the catalytic zinc ion in a plant SDH, and provide an explanation for why AtSDH shows a preference for polyols with a chirality of C2 (S and C4 (R.

  1. Bio-Based Polyols from Seed Oils for Water-Blown Rigid Polyurethane Foam Preparation

    Directory of Open Access Journals (Sweden)

    Paweena Ekkaphan

    2016-01-01

    Full Text Available The preparation of water-blown rigid polyurethane (RPUR foams using bio-based polyols from sesame seed oil and pumpkin seed oil has been reported. Polyols synthesis involved two steps, namely, hydroxylation and alcoholysis reaction. FTIR, NMR, and ESI-MS were used to monitor the process of the synthesized polyols and their physicochemical properties were determined. The resulting polyols have OH number in the range of 340–351 mg KOH/g. RPUR foams blown with water were produced from the reaction of biopolyols with commercial polymeric methylene diphenyl diisocyanate (PMDI. The proper PUR formulations can be manipulated to produce the desired material applications. These seed oil-based RPUR foams exhibited relatively high compressive strength (237.7–240.2 kPa with the density in the range of 40–45 kg/m3. Additionally, the cell foam morphology investigated by scanning electron microscope indicated that their cellular structure presented mostly polygonal closed cells. The experimental results demonstrate that these bio-based polyols can be used as an alternative starting material for RPUR production.

  2. COMPOSITE FRIEND SISAL / POLYESTER TREATED IN SURFACE

    Directory of Open Access Journals (Sweden)

    Jayna K. Dionisio Santos

    2011-09-01

    Full Text Available The use of composites in manufacturing equipment and products is taking a very important space in the industry in general. Moreover these materials have unique characteristics when analyzed separately from constituents who are part of them. However it is know that cares must be taken in their manufacture, as the use of appropriate process and the composition of each element, in addition to adherence fiber / matrix, which is a major factor in obtaining of the final mechanical strength of the product. One should also take into account whether the composites are environmentally friendly. For this reason, in this work, a composite partially ecological was made, using as reinforcement, a sisal woven and, as matrix, the polyester resin. Seeking to improve the adherence fiber / matrix, a treatment in sisal woven was performed with aqueous solution of sodium hydroxide (NaOH at a concentration of 3%. The composite subjected to this treatment presented, in bending test, a better mechanical performance, with an increase of 27% in the flexion strength and of 54% in maximum strain, but there was a reduction of about 15% in its flexural modulus.

  3. An Undergraduate Experiment in Polyester (PET) Synthesis

    Science.gov (United States)

    Cammidge, Andrew N.

    1999-02-01

    The most important polyester manufactured industrially is PET (polyethyleneterephthalate). We describe an experiment that conveniently mimics the industrial synthesis in the undergraduate laboratory. The first step of the reaction is a base-catalyzed transesterification between ethane diol and dimethylterephthalate. Methanol is distilled off to drive the reaction to completion. Excess ethane diol is employed to suppress formation of higher oligomers. The intermediate (bis-(2-hydroxyethyl)terephthalate) is isolated by crystallization and filtration and characterized by 1H NMR spectroscopy. In the second step the monomer is heated (with and without acid catalyst) to form polymer. Samples are removed at intervals and their physical properties are recorded as they cool. These properties are used to qualitatively monitor polymerization. This experiment reinforces some fundamental chemical concepts and introduces the students to new laboratory procedures. The students perform a distillation and apply their knowledge of the reaction equilibrium to calculate the volume of distillate (methanol) expected. The reversible nature of esterification reactions is emphasized during the polymerization step (acid-catalyzed), where the process is driven towards polymer formation by the removal (evaporation) of ethane diol.

  4. Characterization of polyurethane based on polyol synthesized from glycerol and hexamethylene diisocyanate

    International Nuclear Information System (INIS)

    Carvalho, Sabrina M.; Weber, Vanessa; Silva, Tailu N.; Barreto, Pedro L.M.

    2009-01-01

    A new polyol based on glycerol was synthesized and used in the production of polyurethane by reaction with hexamethylene diisocyanate. The polyol was characterized by nuclear magnetic resonance spectroscopy (NMR) and Fourier transform-infrared spectroscopy (FTIR). The polyurethane produced was characterized by FTIR, thermogravimetry (TG), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The polyol was shown to be reactive with hexamethylene diisocyanate, as the FTIR spectrum showed no free isocyanate groups and identified the presence of group -C=O of urethane groups. Analysis by DSC showed that the sample of polyurethane has a glass transition temperature around -8.53 deg C and SEM micrographs showed fracture and surface continuous and not broken. The thermogravimetric analysis showed that the polyurethane produced has a high thermal stability with a temperature of maximum degradation around 430 deg C. (author)

  5. Identification of molecular species of polyol oils produced from soybean oil by Pseudomonas aeruginosa e03-12 nrrl b-59991

    Science.gov (United States)

    The objective of this study is to develop a bioprocess for the production of polyol oils directly from soybean oil. We reported earlier methods for microbial screening and production of polyol oils from soybean oil (Hou and Lin, 2013). The polyol oil produced by Acinetobacter haemolyticus A01-35 (NR...

  6. Interior microelectrolysis oxidation of polyester wastewater and its treatment technology

    Energy Technology Data Exchange (ETDEWEB)

    Yang Xiaoyi, E-mail: yangxiaoyi@buaa.edu.cn [Department of Thermal Energy Engineering, BeiHang University, Beijing 100191 (China)

    2009-09-30

    This paper has investigated the effects of interior microelectrolysis pretreatment on polyester wastewater treatment and analyzed its mechanism on COD and surfactant removal. The efficiency of interior microelectrolysis is mainly influenced by solution pH, aeration and reaction time. Contaminants can be removed not only by redox reaction and flocculation in the result of ferrous and ferric hydroxides but also by electrophoresis under electric fields created by electron flow. pH confirms the chemical states of surfactants, Fe(II)/Fe(III) ratio and the redox potential, and thus influences the effects of electrophoresis, flocculation and redox action on contaminant removal. Anaerobic and aerobic batch tests were performed to study the degradation of polyester wastewater. The results imply that interior microelectrolysis and anaerobic pretreatment are lacking of effectiveness if applied individually in treating polyester wastewater in spite of their individual advantages. The interior microelectrolysis-anaerobic-aerobic process was investigated to treat polyester wastewater with comparison with interior microelectrolysis-aerobic process and anaerobic-aerobic process. High COD removal efficiencies have been gotten by the combination of interior microelectrolysis with anaerobic technology and aerobic technology. The results also imply that only biological treatment was less effective in polyester wastewater treatment.

  7. Interior microelectrolysis oxidation of polyester wastewater and its treatment technology

    International Nuclear Information System (INIS)

    Yang Xiaoyi

    2009-01-01

    This paper has investigated the effects of interior microelectrolysis pretreatment on polyester wastewater treatment and analyzed its mechanism on COD and surfactant removal. The efficiency of interior microelectrolysis is mainly influenced by solution pH, aeration and reaction time. Contaminants can be removed not only by redox reaction and flocculation in the result of ferrous and ferric hydroxides but also by electrophoresis under electric fields created by electron flow. pH confirms the chemical states of surfactants, Fe(II)/Fe(III) ratio and the redox potential, and thus influences the effects of electrophoresis, flocculation and redox action on contaminant removal. Anaerobic and aerobic batch tests were performed to study the degradation of polyester wastewater. The results imply that interior microelectrolysis and anaerobic pretreatment are lacking of effectiveness if applied individually in treating polyester wastewater in spite of their individual advantages. The interior microelectrolysis-anaerobic-aerobic process was investigated to treat polyester wastewater with comparison with interior microelectrolysis-aerobic process and anaerobic-aerobic process. High COD removal efficiencies have been gotten by the combination of interior microelectrolysis with anaerobic technology and aerobic technology. The results also imply that only biological treatment was less effective in polyester wastewater treatment.

  8. Wettability and Impact Performance of Wood Veneer/Polyester Composites

    Directory of Open Access Journals (Sweden)

    Shayesteh Haghdan

    2015-07-01

    Full Text Available Fiber-reinforced thermosetting composites have been of interest since the 1940s due to their ease of use in processing, fast curing times, and high specific stiffness and strength. While the use of plant fibers in a polyester matrix has been thoroughly studied, only limited information is available regarding using wood as reinforcement. In this study, composites of thin wood veneer and a polyester matrix were made and the difficulties in the lamination and curing processes were investigated. Sheets of Douglas fir, maple, and oak veneers using a catalyzed polyester resin were assembled as unidirectional, balanced, and unbalanced cross-ply laminates. These were compared to control specimens using glass fiber as reinforcement. The impact properties of the samples, with respect to the laminate thicknesses, were characterized using a drop-weight impact tester. The wettability and surface roughness of unsanded and sanded wood veneers were also investigated. Results showed that Douglas fir cross-ply laminates had an impact energy equivalent to glass fiber laminates, making them an interesting alternative to synthetic fiber composites. Wood/polyester laminates absorbed a considerable amount of energy through a higher number of fracture modes. The balanced lay-up limited twisting of the wood/polyester composites. The lowest contact angle and highest wettability were observed in unsanded Douglas fir veneers.

  9. Interior microelectrolysis oxidation of polyester wastewater and its treatment technology.

    Science.gov (United States)

    Yang, Xiaoyi

    2009-09-30

    This paper has investigated the effects of interior microelectrolysis pretreatment on polyester wastewater treatment and analyzed its mechanism on COD and surfactant removal. The efficiency of interior microelectrolysis is mainly influenced by solution pH, aeration and reaction time. Contaminants can be removed not only by redox reaction and flocculation in the result of ferrous and ferric hydroxides but also by electrophoresis under electric fields created by electron flow. pH confirms the chemical states of surfactants, Fe(II)/Fe(III) ratio and the redox potential, and thus influences the effects of electrophoresis, flocculation and redox action on contaminant removal. Anaerobic and aerobic batch tests were performed to study the degradation of polyester wastewater. The results imply that interior microelectrolysis and anaerobic pretreatment are lacking of effectiveness if applied individually in treating polyester wastewater in spite of their individual advantages. The interior microelectrolysis-anaerobic-aerobic process was investigated to treat polyester wastewater with comparison with interior microelectrolysis-aerobic process and anaerobic-aerobic process. High COD removal efficiencies have been gotten by the combination of interior microelectrolysis with anaerobic technology and aerobic technology. The results also imply that only biological treatment was less effective in polyester wastewater treatment.

  10. Aliphatic polyesters for medical imaging and theranostic applications.

    Science.gov (United States)

    Nottelet, Benjamin; Darcos, Vincent; Coudane, Jean

    2015-11-01

    Medical imaging is a cornerstone of modern medicine. In that context the development of innovative imaging systems combining biomaterials and contrast agents (CAs)/imaging probes (IPs) for improved diagnostic and theranostic applications focuses intense research efforts. In particular, the classical aliphatic (co)polyesters poly(lactide) (PLA), poly(lactide-co-glycolide) (PLGA) and poly(ɛ-caprolactone) (PCL), attract much attention due to their long track record in the medical field. This review aims therefore at providing a state-of-the-art of polyester-based imaging systems. In a first section a rapid description of the various imaging modalities, including magnetic resonance imaging (MRI), optical imaging, computed tomography (CT), ultrasound (US) and radionuclide imaging (SPECT, PET) will be given. Then, the two main strategies used to combine the CAs/IPs and the polyesters will be discussed. In more detail we will first present the strategies relying on CAs/IPs encapsulation in nanoparticles, micelles, dendrimers or capsules. We will then present chemical modifications of polyesters backbones and/or polyester surfaces to yield macromolecular imaging agents. Finally, opportunities offered by these innovative systems will be illustrated with some recent examples in the fields of cell labeling, diagnostic or theranostic applications and medical devices. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Direct synthesis of L1 type Fe-Pt nanoparticles using microwave-polyol method

    International Nuclear Information System (INIS)

    Minami, Rumiko; Kitamoto, Yoshitaka; Chikata, Tsukasa; Kato, Shunsaku

    2005-01-01

    We report the synthesis of Fe-Pt nanoparticles with microwave irradiation during polyol-reduction reaction. Chemically ordered Fe-Pt nanoparticles with L1 structure are fabricated at 250 deg. C using a microwave-polyol method without any post-synthesis treatments. Moessbauer analyses reveal the nanoparticles have partially ordered L1 structure. The partially ordered Fe-Pt nanoparticles exhibit coercivity of 3.4 kOe, saturation magnetization of 49 emu/g, and anisotropy field of 83 kOe at room temperature

  12. Study of the properties of poly(ester urethanes) following ionizing irradiation

    International Nuclear Information System (INIS)

    Kornacka, A.M.; Przybytniak, G.

    2006-01-01

    Copolymers of polyurethanes and polyesters were found unsuitable for long-term implants because of fast hydrolysis of the ester soft segments. On the other hand, such properties make them valuable as gradually degradable biomaterial that might be used as scaffolds for tissue engineering. The elastomeric polyurethanes are known to be radiation stable materials in sterilizing dose. Nevertheless, if additional components appear in the system, e.g. segments of polyesters, then the influence of irradiation is poorly recognized. In presented paper it has been shown that ionizing radiation induces solid state reorganization of the segmented domains, leading to migration of soft segments towards the surface and to grow of hydrophobic properties. Obtained results confirmed that the urethane segments were more resistant towards ionizing irradiation and the presence of ester units facilitated generation of free radicals. It was also found that in poly(ε-caprolactane)diol (PCL) segments ionizing radiation induces radicals that are able to introduce cross-linking in macromolecules, and consequently reduce ability to biodegradation

  13. Azobenzene Polyesters Used as Gate‐Like Scaffolds in Nanoscopic Hybrid Systems

    DEFF Research Database (Denmark)

    Bernardos, Andrea; Mondragón, Laura; Javakhishvili, Irakli

    2012-01-01

    inside the mesopores. Two solid materials, Rh‐PAzo8‐S and Rh‐PAzo6‐S, containing two closely related polymers, PAzo8 and PAzo6, in the pore outlets have been prepared. Materials Rh‐PAzo8‐S and Rh‐PAzo6‐S showed an almost zero release in water due to steric hindrance imposed by the presence of anchored...... bulky polyesters, whereas a large delivery of the cargo was observed in the presence of an esterase enzyme due to the progressive hydrolysis of polyester chains. Moreover, nanoparticles Rh‐PAzo8‐S and Rh‐PAzo6‐S were used to study the controlled release of the dye in intracellular media. Nanoparticles...... were not toxic for HeLa cells and endocytosis‐mediated cell internalisation was confirmed by confocal microscopy. Furthermore, the possible use of capped materials as a drug‐delivery system was demonstrated by the preparation of a new mesoporous silica nanoparticle functionalised with PAzo6 and loaded...

  14. Obtaining polyester from glycerin for synthesis of polyurethanes

    International Nuclear Information System (INIS)

    Breves, Rodolfo A.; Ghesti, Grace F.; Sales, Maria J.A.

    2014-01-01

    The use of renewable resources has been increasing, due to the development of materials that have viable applications that are environmentally friendly. In this paper, a polyester was synthesized from glycerin, with the addition of adipic acid in a molar ratio of 1: 1.5, with dilauryl tin catalyst, which was added in proportions of 1 to 3% obtained PUs from castor oil (Ricinus communis) and MDI (diphenyl methane diisocyanate). The materials were characterized by infrared spectroscopy (FTIR), nuclear magnetic resonance "1H NMR, thermogravimetry (TG) and derivative thermogravimetry (DTG). The reaction for obtaining the polyester was confirmed by FTIR, the absorption band between 1708-1730 cm"-"1 and "1H NMR, in the region 1.4 to 1.8 ppm and 2.2 to 2.6 ppm. The thermal decomposition of polyester occurred with temperature above 300 ° C. PUs showed similar thermal stability. (author)

  15. Radiation flame proofing of polyester/cotton blends

    International Nuclear Information System (INIS)

    Liepins, R.; Surles, J.R.; Morosoff, N.; Stannett, V.T.; Barker, R.H.

    1977-01-01

    Methodology has been developed for the grafting of vinyl functional organobromide and organophosphorus compounds on polyester fibers and 50/50 PET/cotton fabric. Procedures were developed for localized grafting of vinyl bromide (VBr) and diethylvinylphosphonate (DEVP) upon PET fibers. Oxygen index was used to evaluate the effect of the location of VBr and DEVP within the filament upon their flame retardance efficiencies. For the various bromine homopolymer grafts the apparent thermal stability of the graft and its flame retardance efficiency may be related to the alpha aliphatic hydrogen to bromine ratio. Using results from the polyester studies, techniques were devised for the treatment of 50/50 polyester/ cotton fabrics. Both homopolymer and copolymer grafts were evaluated but the greatest degree of success was attained using mixtures of phosphorus and bromine containing monomers. The results of these studies will be reviewed and their implications for development as commercial textile treatments discussed. (author)

  16. Properties and performance of flax yarn/thermoplastic polyester composites

    DEFF Research Database (Denmark)

    Madsen, Bo; Mehmood, Shahid

    2012-01-01

    Aiming at demonstrating the potential of unidirectional natural fiber-reinforced thermoplastic composites in structural applications, textile flax yarn/thermoplastic polyester composites with variable fiber volume fractions have been manufactured by a filament-winding process followed by a vacuum......-assisted compression molding process. The microstructure of the composites shows that the flax fiber yarns are well impregnated by the polyester matrix, and this supports the measured low porosity content of the composites. The experimental tensile modulus and ultimate tensile stress of the composites in the axial...

  17. Radiation cured polyester compositions containing metal-properties

    Science.gov (United States)

    Szalińska, H.; Pietrzak, M.; Gonerski, A.

    The subject of the studies was unsaturated polyester resin, Polimal-109 and its compositions containing acrylates of: sodium, potassium, calcium, magnesium, barium, manganese, iron, cobalt, copper and acrylic acid. Polyester resin modified with acrylic acid salts was cured with 60Co gamma radiation. Measurements of Vicat softening temperature, water absorption, creep current resistance, volume and surface resistivity, the tangent of dielectric loss angle and permittivity of radiation cured compositions were carried out. The results of the studies presented testify to the fact that the properties of cross-linked polymers alter after ionogenic compounds have been introduced into them.

  18. Radiation cured polyester compositions containing metal-properties

    International Nuclear Information System (INIS)

    Szalinska, H.; Pietrzak, M.; Gonerski, A.

    1987-01-01

    The subject of the studies was unsaturated polyester resin, Polimal-109 and its compositions containing acrylates of: sodium, potassium, calcium, magnesium, barium, manganese, iron, cobalt, copper and acrylic acid. Polyester resin modified with acrylic acid salts was cured with 60 Co gamma radiation. Measurements of Vicat softening temperature, water absorption, creep current resistance, volume and surface resistivity, the tangent of dielectric loss angle and permittivity of radiation cured compositions were carried out. The results of the studies presented testify to the fact that the properties of cross-linked polymers alter after ionogenic compounds have been introduced into them. (author)

  19. Rewritable azobenzene polyester for polarization holographic data storage

    DEFF Research Database (Denmark)

    Kerekes, A; Sajti, Sz.; Loerincz, Emoeke

    2000-01-01

    Optical storage properties of thin azobenzene side-chain polyester films were examined by polarization holographic measurements. The new amorphous polyester film is the candidate material for the purpose of rewritable holographic memory system. Temporal formation of anisotropic and topographic...... gratings was studied in case of films with and without a hard protective layer. We showed that the dominant contribution to the diffraction efficiency comes from the anisotropy in case of expositions below 1 sec even for high incident intensity. The usage of the same wavelength for writing, reading...

  20. Polyol synthesis in Aspergillus niger : influence of oxygen availability, carbon and nitrogen sources on the metabolism

    DEFF Research Database (Denmark)

    Diano, Audrey; Bekker-Jensen, S; Dynesen, Jens Østergaard

    2006-01-01

    Polyol production has been studied in Aspergillus niger under different conditions. Fermentations have been run using high concentration of glucose or xylose as carbon source and ammonium or nitrate as nitrogen source. The growth of biomass, as freely dispersed hyphae, led to an increase of medium...

  1. Molecular interactions in the betaine monohydrate-polyol deep eutectic solvents: Experimental and computational studies

    Science.gov (United States)

    Zahrina, Ida; Mulia, Kamarza; Yanuar, Arry; Nasikin, Mohammad

    2018-04-01

    DES (deep eutectic solvents) are a new class of ionic liquids that have excellent properties. The strength of interaction between molecules in the DES affects their properties and applications. In this work, the strength of molecular interactions between components in the betaine monohydrate salt and polyol (glycerol or/and propylene glycol) eutectic mixtures was studied by experimental and computational studies. The melting point and fusion enthalpy of the mixtures were measured using STA (Simultaneous Thermal Analyzer). The nature and strength of intermolecular interactions were observed by FT-IR and NMR spectroscopy. The molecular dynamics simulation was used to determine the number of H-bonds, percent occupancy, and radial distribution functions in the eutectic mixtures. The interaction between betaine monohydrate and polyol is following order: betaine monohydrate-glycerol-propylene glycol > betaine monohydrate-glycerol > betaine monohydrate-propylene glycol, where the latter is the eutectic mixture with the lowest stability, strength and extent of the hydrogen bonding interactions between component molecules. The presence of intra-molecular hydrogen bonding interactions, the inter-molecular hydrogen bonding interactions between betaine molecule and polyol, and also interactions between polyol and H2O of betaine monohydrate in the eutectic mixtures.

  2. Polyurethane foams based entirely on recycled polyols derived from natural oils

    Czech Academy of Sciences Publication Activity Database

    Horák, Pavel; Beneš, Hynek

    2015-01-01

    Roč. 60, č. 9 (2015), s. 579-585 ISSN 0032-2725 R&D Projects: GA MPO(CZ) FR-TI4/133 Institutional support: RVO:61389013 Keywords : polyurethane foam * recycled polyol * rapeseed oil Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.718, year: 2015

  3. Enzymatic synthesis of polyol seters in aqueous - organic two-phase systems

    NARCIS (Netherlands)

    Janssen, A.

    1993-01-01

    The last decade increasingly attention is paid to lipases as catalysts for synthesis of components, such as fatty acid-based surfactants, flavors, edible oil equivalents, monomers and polymers, and amides. In this thesis, the lipase-catalyzed esterification of polyols and fatty acids is

  4. Film-forming properties of castor oil polyol ester blends in elastohydrodynamic conditions

    Science.gov (United States)

    The viscosities and elastohydrodynamic (EHD) film thickness properties of binary blends of castor oil with polyol esters were determined experimentally. Predicted blend viscosity was calculated from the viscosity of the pure blend components. Measured viscosity values were closer to the values pre...

  5. The tissue and plasma concentration of polyols and sugars in sheep intrauterine growth retardation

    NARCIS (Netherlands)

    T.R.H. Regnault (Timothy); C. Teng (Cecilia); B. de Vrijer (Barbra); H.L. Galan (Henry); R.B. Wilkening (Randall); F.C. Battaglia (Frederick)

    2010-01-01

    textabstractIn an ovine model of placental insufficiency-induced intrauterine growth retardation (PI-IUGR), characterized by hypoxia, hypoglycemia and a significant reduction in fetal weight, we assessed alterations in fetal and placental polyols. Arterial maternal-fetal concentration differences of

  6. Polyols as filler-binders for disintegrating tablets prepared by direct compaction

    NARCIS (Netherlands)

    Bolhuis, Gerad K.; Rexwinkel, Erik G.; Zuurman, Klaas

    Background: Although polyols are frequently used as tablet excipients in lozenges, chewing tablets, and orodisperse tablets, special directly compressible (DC) forms are recommended as filler-binder in common disintegrating tablets. Aim: In this article, DC types of isomalt, lactitol, mannitol,

  7. Corrosion Protection Performance of Polyester-Melamine Coating with Natural Wood Fiber Using EIS Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Shin, PyongHwa; Shon, MinYoung [Pukyong National University, Busan (Korea, Republic of); Jo, DuHwan [POSCO, Gwangyang (Korea, Republic of)

    2016-04-15

    In the present study, polyester-melamine coating systems with natural wood fiber (NWF) were prepared and the effects of NWF on the corrosion protectiveness of the polyester-melamine coating were examined using EIS analysis. From the results, higher average surface roughness was observed with increase of NWF content. Water diffusivity and water uptake into the polyester-melamine coatings with NWF were much higher than that into the pure polyester-melamine coating. The decrease in the impedance modulus |Z| was associated with the localized corrosion on carbon steel, confirming that corrosion protection of the polyester-melamine coatings with NWF well agrees with its water transport behavior.

  8. Plasma treatment of polyester fabric to impart the water repellency ...

    Indian Academy of Sciences (India)

    test method 39 (1971). ... pilot production line [7]. It is found that prior .... experiment was set up for testing the absorbancy of modified polyester fabric as in case of .... New Delhi for providing the research grant under TAPTEC scheme. We are ...

  9. Modification of unsaturated polyester resins using nano-size core ...

    African Journals Online (AJOL)

    Modification of unsaturated polyester resins using nano-size core-shell particles. MO Munyati, PA Lovell. Abstract. No Abstract Available Journal of Science and Technology Special Edition 2004: 24-31. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  10. Photoinduced Circular Anisotropy in Side-Chain Azobenzene Polyesters

    DEFF Research Database (Denmark)

    Nikolova, L.; Todorov, T.; Ivanov, M.

    1997-01-01

    We report for the first time the inducing of large circular anisotropy in previously unoriented films of side-chain azobenzene polyesters on illumination with circularly polarized light at a wavelength of 488 nm. The circular dichroism and optical activity are measured simultaneously in real time...

  11. Design of Functional Polyesters for Electronic and Biological Applications

    OpenAIRE

    Nelson, Ashley Marie

    2015-01-01

    Melt polymerization and novel monomers enabled the synthesis of polyesters for electronic and biological applications. Inspiration from nature and a passion for environmental preservation instigated an emphasis on the incorporation of renewable resources into polymeric materials. Critical analysis of current research surrounding bisphenol-A replacements and ioncontaining segmented polyurethanes aided in identifying benchmark polymers, including limitations, challenges, and future needs. Struc...

  12. Highly Branched Bio-Based Unsaturated Polyesters by Enzymatic Polymerization

    Directory of Open Access Journals (Sweden)

    Hiep Dinh Nguyen

    2016-10-01

    Full Text Available A one-pot, enzyme-catalyzed bulk polymerization method for direct production of highly branched polyesters has been developed as an alternative to currently used industrial procedures. Bio-based feed components in the form of glycerol, pentaerythritol, azelaic acid, and tall oil fatty acid (TOFA were polymerized using an immobilized Candida antarctica lipase B (CALB and the potential for an enzymatic synthesis of alkyds was investigated. The developed method enables the use of both glycerol and also pentaerythritol (for the first time as the alcohol source and was found to be very robust. This allows simple variations in the molar mass and structure of the polyester without premature gelation, thus enabling easy tailoring of the branched polyester structure. The postpolymerization crosslinking of the polyesters illustrates their potential as binders in alkyds. The formed films had good UV stability, very high water contact angles of up to 141° and a glass transition temperature that could be controlled through the feed composition.

  13. Comparison of Cashew Nut Shell Liquid (CNS) Resin with Polyester ...

    African Journals Online (AJOL)

    Akorede

    cobalt amine (accelerator), methyl ethyl ketone peroxide (catalyst) to develop two sets of ... shell liquid (CNSL) resin were comparable to those developed with polyester resin. ... permit diffusion of water, this function is often not adequately ... When designed ... blades in gas turbine engines, wing leading edges and flaps.

  14. Effect of electron beam irradiation on the thermal properties of polycarbonate / polyester blend

    International Nuclear Information System (INIS)

    Zarie, K.A.

    2007-01-01

    The effect of electron beam irradiation on the thermal properties of Bayfol (polycarbonate/polyester blend) solid state nuclear track detector (SSNTD) was investigated. Non-isothermal studies were carried out using thermogravimetric analysis (TGA) and differential thermogravimetric (DTG) to obtain the activation energy of thermal decomposition for Bayfol detector. The thermogravimetric analysis (TGA) indicated that the Bayfol samples were decomposed in one main break down stage. Samples of 250 μm thickness sheets were exposed to electron beam irradiations in the dose range 20-600 KGy. The variation of melting temperatures with the electron dose was determined using differential thermal analysis (DTA). The results indicated that the electron irradiation in the dose range 200-600 KGy decreases the melting temperature of the Bayfol samples and this is most suitable for applications requiring the molding of this polymer at lower temperatures

  15. hermo-Physical and Mechanical Properties of Unsaturated Polyester /Cobalt Ferrite Composites

    Directory of Open Access Journals (Sweden)

    Lamees Salam Faiq

    2017-04-01

    Full Text Available Unsaturated polyester was used as a matrix which was filled with different percentages of cobalt ferrite using hand lay-up method. Cobalt ferrite was synthesized using solid state ceramic method with reagent of CoO and Fe2O3. Mechanical properties such tensile strength, Young's modulus and shore D hardness of the composite have been studied. All these properties have increased by 10% with increasing cobalt ferrite contents. Also the thermal properties such thermal conductivity and specific heat capacity are highly increased as the ferrite content increased, while the thermal diffusivity increased by 22 %. On the other hand dielectric strength of composite has been measured which increased by 50% by increasing the cobalt ferrite content.

  16. Dot-ELISA for the detection of anti-Cysticercus cellulosae antibodies in cerebrospinal fluid using a new solid phase (resin-treated polyester fabric and Cysticercus longicollis antigens Teste dot-ELISA para detecção de anticorpos anti-Cysticercus cellulosae em líquido cefalorraquiano utilizando um novo suporte (tecido de poliéster-resina e antígenos de Cysticercus longicollis

    Directory of Open Access Journals (Sweden)

    Adelaide José Vaz

    1996-12-01

    Full Text Available A dot-ELISA was developed for the detection of antibodies in CSF in the immunologic diagnosis of human neurocysticercosis, using antigen extracts of the membrane and scolex of Cysticercus cellulosae (M+S-Cc and, alternately, membrane (M and vesicular fluid (VF of Cysticercus longicollis (Cl covalently bound to a new solid phase consisting of polyester fabric treated with N-methylol-acrylamide resin (dot-RT. The test was performed at room temperature, with reduced incubation times and with no need for special care in the manipulation of the support. The sensitivity rates obtained were 95.1% for antigen Cc and 97.6% for antigen Cl. Specificity was 90.6% when Cc was used, and 96.9% and 100% when M-Cl and VF-Cl were used, respectively. No significant differences in titer were observed between tests carried out with homologous and heterologous antigens. The low cost and easy execution of the dot-RT test using antigen extracts of Cysticercus longicollis indicate the test for use in the immunodiagnosis of human neurocysticercosis.Foi desenvolvido o teste dot-ELISA para detecção de anticorpos em líquido cefalorraquiano (LCR no diagnóstico imunológico da neurocisticercose humana, utilizando antígenos de membrana e escólex de Cysticercus cellulosae (M+E-Cc e, alternativamente, membrana (M e líquido vesicular (LV de Cysticercus longicollis (Cl covalentemente ligados a um novo suporte constituído de tecido de poliéster-resina de N-metilol-acrilamida (dot-TR. O teste foi realizado à temperatura ambiente, com tempos de incubação reduzidos e sem necessidade de cuidados na manipulação do suporte. A sensibilidade obtida foi de 95,1% para o antígeno Cc e 97,6% para o Cl. A especificidade foi de 90,6% quando o antígeno Cc foi usado, e 96,9% e 100% para M-Cl e LV-Cl, respectivamente. Não foi observada diferença significativa entre os antígenos homólogo e heterólogo. O baixo custo e a fácil execução do teste dot-TR empregando extratos antig

  17. Dyeing of Polyester with Disperse Dyes: Part 2. Synthesis and Dyeing Characteristics of Some Azo Disperse Dyes for Polyester Fabrics

    Directory of Open Access Journals (Sweden)

    Alya M. Al-Etaibi

    2016-06-01

    Full Text Available The goal of this study was to utilize carrier for accelerating the rate of dyeing not only to enhance dyeing of polyester fabrics dyed with disperse dyes 3a,b, but also to save energy. Both the color strength expressed as dye uptake and the fastness properties of the dyed fabrics were evaluated.

  18. Polyester textile functionalization through incorporation of pH/thermo-responsive microgels. Part II: polyester functionalization and characterization

    NARCIS (Netherlands)

    Glampedaki, P.; Calvimontes, A.; Dutschk, Victoria; Warmoeskerken, Marinus

    2012-01-01

    A new approach to functionalize the surface of polyester textiles is described in this study. Functionalization was achieved by incorporating pH/temperature-responsive polyelectrolyte microgels into the textile surface layer using UV irradiation. The aim of functionalization was to regulate

  19. Assessment of the radiation resistance of some aromatic polyesters

    International Nuclear Information System (INIS)

    Choi, E.J.; Hill, D.J.T.; Kim, K.Y.

    1998-01-01

    Full text: For many applications, polyesters have more useful properties than vinyl polymers, and they can be degraded to their monomer components and recycled. In addition, aromatic polyesters are known to display a resistance to high temperatures and high-energy ionizing radiation. Recently, we have reported the γ-radiolysis for some aromatic polyesters at low radiation dose; The G-values of radical formation at 77 K were determined to be in the range 0.38∼0.46 for the polyesters of bisphenol A with fluorine substitution at isopropylidene units and in the range 0.71∼1.18 for the polyesters of halogenated bisphenol A with decamethylene segments. While the radiation sensitivities of the latter polymers were dependent on the position and content of halogen substitution, those of the former polymers were slightly dependent on these factors as assessed by the G-values at 77 K. We also have studied the radiolysis of the commercial aromatic polyesters (UP) and polycarbonate (PC). UP has been found to be more radiation stable than PC with respect to the total yield of radicals formed. The G-values for radical formation at 77K was determined to be 0.31 and 0.5 for UP and PC, respectively. In this work, we have prepared poly(ethylene-, butylene- or decalene-terephthalate)s (PET, PBT or PDT) and poly(ethylene-, buthylene- or decalene-2,6-naphthalenedicarboxylate)s (PEN, PBN or PDN) by standard melt polymerization methods, and have examined their γ-radiolysis at 77 K or room temperature, and in vacuum or air, through the applications of ESR spectroscopy and thermal analysis. Inherent viscosities of the polyesters used for the radiation studies were in the range of 0.16∼0.69 dL/g. The values of G(R) indicates that PEN-related polymers have more radiation stable than PET-related polymers and the E, B and D order is one of decreasing stability as one might expect. The significant decrease in the G(R)-values of the polyester being in the range of 0.1∼0.41 at 77 K by

  20. Influence of PVP in magnetic properties of NiSn nanoparticles prepared by polyol method

    Energy Technology Data Exchange (ETDEWEB)

    Bobadilla, L.F., E-mail: lbobadilla@iciq.es [Departamento de Quimica Inorganica e Instituto de Ciencia de Materiales, Centro mixto Universidad de Sevilla-CSIC, Av. Americo Vespucio, 41092 Sevilla (Spain); Garcia, C. [Physics Department, Bogazici University, North Campus KB 331-O, Bebek/Istambul (Turkey); Delgado, J.J. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica y Quimica Inorganica, Facultad de Ciencias, Universidad de Cadiz, Campus Rio San Pedro, E-11510 Puerto Real, Cadiz (Spain); Sanz, O. [Grupo de Ingenieria Quimica, Departamento de Quimica Aplicada, Facultad de Ciencias Quimicas, UPV/EHU, Paseo Manuel de Lardizabal, 3, 20018 San Sebastian (Spain); Romero-Sarria, F.; Centeno, M.A.; Odriozola, J.A. [Departamento de Quimica Inorganica e Instituto de Ciencia de Materiales, Centro mixto Universidad de Sevilla-CSIC, Av. Americo Vespucio, 41092 Sevilla (Spain)

    2012-11-15

    The influence of PVP on the magnetic properties of NiSn nanoparticles prepared by polyol method has been studied. NiSn nanoparticles exhibit superparamagnetic behavior although there is a ferromagnetic contribution due to particles agglomerated below the blocking temperature. The particle size is controlled by the addiction of PVP in varying amounts. The addition of PVP also favours the particles isolation, narrow the particle size distribution and decrease the interparticle interaction strength increasing the superparamagnetic contribution. - Highlights: Black-Right-Pointing-Pointer Ni{sub x}Sn{sub y} alloys nanoparticles have been prepared by polyol method. Black-Right-Pointing-Pointer NiSn nanoparticles exhibit superparamagnetic behavior. Black-Right-Pointing-Pointer The PVP addition favours the particles isolation.

  1. Oleic and Undecylenic Acids as Renewable Feedstocks in the Synthesis of Polyols and Polyurethanes

    Directory of Open Access Journals (Sweden)

    Virginia Cádiz

    2010-10-01

    Full Text Available Nowadays, the utilization of raw materials derived from renewable feedstock is in the spotlight of the chemical industry, as vegetable oils are one of the most important platform chemicals due to their universal availability, inherent biodegradability and low price. Taking into account that polyurethanes are one of the most important industrial products exhibiting versatile properties suitable for use in many fields, our research is focused on exploiting fatty acids in the preparation of biobased polyols and polyurethanes. This review is organized as a function of the nature of the final polyurethane systems; hence we describe the preparation of linear thermoplastic and crosslinked polyurethanes derived from oleic and undecylenic acids-based diols and polyols, respectively.

  2. Microwave heated polyol synthesis of carbon supported PtAuSn/C nanoparticles for ethanol electrooxidation

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Hong; Han, Kefei [School of Science, State key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Liu, Yingli; Chang, Zhaorong [College of Chemistry and Environmental Science, Henan Normal University, Xinxiang, Henan (China); Shen, Liangbo [Beijing No.4 High School, Beijing (China); Wei, Yongsheng; Guo, Zhijun (School of Science Beijing Jiaotong University Beijing P. R. China); Wang, Haijiang [Institute for Fuel Cell Innovation, National Research Council of (Canada)

    2010-04-15

    Carbon-supported PtAuSn/C nanoparticle catalyst was synthesized by a microwave-assisted polyol process. The process is a quick process that only requires a few minutes to complete. The catalyst thus obtained was characterized by transmission electron microscopy and X-ray diffraction analysis. The electrochemical performance of the catalyst, for the ethanol oxidation reaction, was also investigated. The results indicated that the PtAuSn/C catalyst was uniformly dispersed on carbon and was in the nano-size range. The electrochemical measurements indicated that PtAuSn/C nanoparticle catalyst synthesized by the microwave-assisted polyol method demonstrated a significantly higher electrochemically active area and higher catalytic activity than Pt/C for the ethanol oxidation reaction. (author)

  3. Polyol-mediated synthesis of copper indium sulphide by solvothermal process

    International Nuclear Information System (INIS)

    Gorai, S.; Chaudhuri, S.

    2005-01-01

    A simple polyol-mediated solvothermal method has been proposed to synthesize copper indium sulphide. XRD studies reveal that the products are well crystallized. SEM indicates rod-like (with different aspect ratio) and star-shaped flake-like morphology of the products. The products are also characterized by optical studies and compositional analysis (XRF). XRF results show the formation of stoichiometric and non-stoichiometric copper indium sulphides depending on the reaction conditions

  4. The influence of polyol type on cell geometry and the thermal stability of polyurethane foams

    Directory of Open Access Journals (Sweden)

    Prendžov Slobodan J.

    2006-01-01

    Full Text Available The aim of this study was to examine the influence of substituting defined amounts of polyol Voranol 3322 by polyol Voranol CP 1055 on the cell geometry and thermal stability of the synthesized flexible polyurethane foams. The influence of the amount of antipyrene on the cell geometry and their thermal stability was also investigated. The following components were used in the synthesis of the polyurethanes: a mixture of two polyols (Voranol 3322 with the hydroxyl number 47 mg KOH/g, mean molecular mass 3400 and Voranol CP 1055 with the hydroxyl number 156 mg KOH/g, mean molecular mass 1000, toluene discarnate as the isocyanate component, a combination of an organic-metallic compound and a tertiary amine as catalysts, surfactant and water as the coreactant. The thermal stability was determined by thermogravimetric analysis (in a nitrogen atmosphere. The cell geometry was analyzed by optical microscopy. Examination of the cell geometry revealed different cell shapes. The form factor as an indicator of cell deviation from spherical shape increased (more round forms were observed with increasing amount of Voranol CP 1055. The TG examination showed that specimens with 6 and 8 g of Voranol 3322 substituted by Voranol CP 1055 completely degraded at 350 °C, while foams with 10 and 12 g of Voranol 3322 substituted by Voranol CP 1055 displayed lower mass loss at higher temperatures and had residual masses of 46 % and 43 % at 600°C respectively. The addition of antipyrene in an amount of 1% (based on the amount of polyol contributed to improved thermal stability, no visible color change of the specimen tested at 210°C for 40 minutes, and to rounder cell forms. Considering the obtained results it can be concluded that an increase in the amount of Voranol CP 1055 yielded more spherically shaped cells and better thermal stability of the synthesized flexible polyurethane foams. The addition of antipyrene improves the thermal stability and the cell geometry.

  5. Characterization and Growth Mechanism of Nickel Nanowires Resulting from Reduction of Nickel Formate in Polyol Medium

    OpenAIRE

    Logutenko, Olga A.; Titkov, Alexander I.; Vorob’yov, Alexander M.; Yukhin, Yriy M.; Lyakhov, Nikolay Z.

    2016-01-01

    Nickel linear nanostructures were synthesized by reduction of nickel formate with hydrazine hydrate in ethylene glycol medium in the absence of any surfactants or capping agents for direction of the particles growth. The effect of the synthesis conditions such as temperature, reduction time, type of polyol, and nickel formate concentration on the reduction products was studied. The size and morphology of the nickel nanowires were characterized by X-ray diffraction, scanning, and transmission ...

  6. Mild and Highly Efficient Copper(I Inspired Acylation of Alcohols and Polyols

    Directory of Open Access Journals (Sweden)

    Enoch A. Mensah

    2017-01-01

    Full Text Available A new and highly efficient method mediated by tetrakis(acetonitrilecopper(I triflate for activating both simple and highly hindered anhydrides in the acylation of alcohols and polyols is described. This new acylation method is mild and mostly proceeds at room temperature with low catalyst loading. The method is versatile and has been extended to a wide variety of different alcohol substrates to afford the corresponding ester products in good to excellent yields.

  7. Radiation resistance of plastic solid

    International Nuclear Information System (INIS)

    Moriyama, Noboru; Dojiri, Shigeru; Wadachi, Yoshiki

    1985-01-01

    The radiation from nucleides contained in solidified wates have some effects on the degradation of the solidification materials. This report deals with effects of such radiation on the mechanical strength of waste-plastics composites and on the generation of gasses. It is shown that the mechanical strength of polyethylene and polyester solids will not decrease at a total absorbed dose of 10 6 rad, a dose which a low-level waste composite is expected to receive during an infinite period of time. Rather, it increases in the case of polyethylene. The amount of gas generated from degraded polyethylene is about three times as large as that from polyester, namely, about 6 l per 200 l drum can at 10 6 rad. Hydrogen accounts for about 80 % of the total gas generated from polyethylene. On the other hand, the gas from polyester solid mainly contains hydrogen, carbon dioxide, carbon monoxide and methane, with a composition greatly dependent on the type of the waste contained. It is concluded from these results that plastic materials can serve satisfactorily as for as the effects of radiation on their mechanical strength and gas generation are concerned. A more important problem still remaining to be solved is the effects of radiation on the leaching of radioactive nuclides. (Nogami, K.)

  8. Removal of Aqueous Boron by Using Complexation of Boric Acid with Polyols: A Raman Spectroscopic Study

    Energy Technology Data Exchange (ETDEWEB)

    Eom, Ki Heon; Jeong, Hui Cheol; An, Hye Young; Lim, Jun-Heok; Lee, Jea-Keun; Won, Yong Sun [Pukyong National University, Busan (Korea, Republic of)

    2015-12-15

    Boron is difficult to be removed from seawater by simple RO (reverse osmosis) membrane process, because the size of boric acid (B(OH){sub 3}), the major form of aqueous boron, is as small as the nominal pore size of RO membrane. Thus, the complexation of boric acid with polyols was suggested as an alternative way to increase the size of aqueous boron compounds and the complexation behavior was investigated with Raman spectroscopy. As a reference, the Raman peak for symmetric B-O stretching vibrational mode both in boric acid and borate ion (B(OH){sub 4}{sup -}) was selected. A Raman peak shift (877 cm{sup -1} →730 cm{sup -1}) was observed to confirm that boric acid in water is converted to borate ion as the pH increases, which is also correctly predicted by frequency calculation. Meanwhile, the Raman peak of borate ion (730 cm{sup -1}) did not appear as the pH increased when polyols were applied into aqueous solution of boric acid, suggesting that the boric acid forms complexing compounds by combining with polyols.

  9. Simple boron removal from seawater by using polyols as complexing agents: A computational mechanistic study

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min-Kyung; Eom, Ki Heon; Lim, Jun-Heok; Lee, Jea-Keun; Lee, Ju Dong; Won, Yong Sun [Pukyong National University, Busan (Korea, Republic of)

    2015-11-15

    The complexation of boric acid (B(OH){sub 3}), the primary form of aqueous boron at moderate pH, with polyols is proposed and mechanistically studied as an efficient way to improve membrane processes such as reverse osmosis (RO) for removing boron in seawater by increasing the size of aqueous boron compounds. Computational chemistry based on the density functional theory (DFT) was used to manifest the reaction pathways of the complexation of B(OH){sub 3} with various polyols such as glycerol, xylitol, and mannitol. The reaction energies were calculated as −80.6, −98.1, and −87.2 kcal/mol for glycerol, xylitol, and mannitol, respectively, indicating that xylitol is the most thermodynamically favorable for the complexation with B(OH){sub 3}. Moreover, the 1 : 2 molar ratio of B(OH)3 to polyol was found to be more favorable than the ratio of 1 : 1 for the complexation. Meanwhile, latest lab-scale actual RO experiments successfully supported our computational prediction that 2 moles of xylitol are the most effective as the complexing agent for 1 mole of B(OH){sub 3} in aqueous solution.

  10. Performance enhancement in vanadium redox flow battery using platinum-based electrocatalyst synthesized by polyol process

    International Nuclear Information System (INIS)

    Jeong, Sanghyun; Kim, Sunhoe; Kwon, Yongchai

    2013-01-01

    Sluggish reaction rate of [VO] 2+ /[VO 2 ] + redox couple is an obstacle to be addressed in vanadium redox flow battery (VRFB). To improve the slow reaction rate, Pt/C catalyst synthesized by polyol method is suggested. Its catalytic activity, reaction reversibility and charge–discharge performance are evaluated by half cell and single cell tests, while its crystal structure, particle size and particle distribution are measured by XRD and TEM. The XRD and TEM measurements show the polyol Pt/C catalyst has larger electrochemically active surface (EAS) area and smaller particle size than commercial Pt/C catalyst. When catalytic activities of all the catalysts are estimated, the Pt-included catalysts demonstrate high peak current ratio, small peak potential difference and high electron transfer rate constant, confirming that their catalytic activity and reaction reversibility are excellent. In charge–discharge performance tests, the catalysts indicate high efficiencies as well as low overpotential and internal resistance. Excellent performances of the Pt-included catalysts are attributed to positively charged Pts that serve as active sites for activating [VO] 2+ /[VO 2 ] + reaction. Indeed, adoption of the Pt-included catalysts, especially, use of the polyol Pt/C consisting of uniform and small particles helps improve performance of VRFB

  11. Synthesis and characterization of a novel bio-based resin from maleated soybean oil polyols

    Science.gov (United States)

    Li, Y. T.; Yang, L. T.; Zhang, H.

    2017-02-01

    In this paper, a novel bio-based resin was prepared by the radical copolymerization of maleated soybean oil polyols (MSBOP) and styrene (ST). Structure of the product was studied by Fourier transformation infrared spectrometer (FT-IR), and the result was found to be consistent with that of theoretical structure. Swelling experiments indicated that the crosslinking degree increased with the increase of hydroxyl value. Thermal analysis by differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TG) revealed that glass transition temperature (Tg) of the polymer increased with increasing hydroxyl values, and that its thermal stability showed a good correlation with the hydroxyl value. The tensile strength and impact strength were significantly affected by the hydroxyl value of soybean oil polyols. With increasing hydroxyl value, the tensile strength presented an increasing trend, while the impact strength showed a decreasing one. Moreover, the property of the polymer from elastomer to plastic character also depended on the functionality of the hydroxyl value of soybean oil polyols.

  12. Different catalysts for new polyols for rigid PUR-PIR foams

    Directory of Open Access Journals (Sweden)

    Liszkowska Joanna

    2015-12-01

    Full Text Available New polyols were synthesized with 2-hydroxypropane-1.2.3-tricarboxylic acid and butane-1,4-diol (1.4-BD. The synthesis was performed using different catalysts in the amount of 0.1%. Used catalyst: Tyzor TPT, tin(II acetate, sulfuric(IV acid. The fourth reaction was conducted without the use of a catalyst. The polyols’ properties were evaluated with regards to the usefulness in rigid polyurethane-polyisocyanurate (PUR-PIR foams (acid value, density, pH and solubility, FTIR spectra. Based on the research, it was evaluated that only the polyol synthesized using Tyzor TPT (E6 was useful in production of rigid PUR-PIR foams. Its hydroxyl number was 496 mgKOH/g and its viscosity was about 14 552 mPa · s. A series of five foams P6.1–P6.5 was produced with this polyol. Rigid foams test results indicated that the amount of this compound in the foam substantially affects its compressive strength, density and their retention. The foams have low brittleness values.

  13. Neutron shielding performance of water-extended polyester

    International Nuclear Information System (INIS)

    Vega Carrillo, H.R.; Manzanares-Acuna, E.; Hernandez-Davila, V.M.; Vega Carrillo, H.R.; Hernandez-Davila, V.M.; Gallego, E.; Lorente, A.

    2006-01-01

    A Monte Carlo study to determine the shielding features to neutrons of water-extended polyester (WEP) was carried out. Materials with low atomic number are predominantly used for neutron shielding because these materials effectively attenuate neutrons, mainly through elastic and inelastic collisions. In addition to neutron attenuation properties, other desirable properties for neutron shielding materials include mechanical strength, stability, low cost, and ease of handling. During the selection of materials to design a neutron shield, prompt gamma production as well as radionuclide induced by neutron activation must be considered. In this investigation the Monte Carlo method (MCNP code) was used to evaluate the performance of a water-extended polyester shield designed for the transportation, storage, and use of a 252 Cf isotopic neutron source, for comparison the calculations were extended to water shielding, the bare source in vacuum and in air. (authors)

  14. Neutron shielding performance of water-extended polyester

    International Nuclear Information System (INIS)

    Vega Carrillo, H.R.; Manzanares-Acuna, E.; Hernandez-Davila, V.M.; Vega Carrillo, H.R.; Gallegoc, E.; Lorentec, A.; Hernandez-Davila, V.M.

    2006-01-01

    A Monte Carlo study to determine the shielding features to neutrons of water-extended polyester was carried out. Materials with low atomic number are predominantly used for neutron shielding because these materials effectively attenuate neutrons, mainly through elastic and inelastic collisions. In addition to neutron attenuation properties, other desirable properties for neutron shielding materials include mechanical strength, stability, low cost, and ease of handling. During the selection of materials to design a neutron shield, prompt gamma production as well as radionuclide induced by neutron activation must be considered. In this investigation the Monte Carlo method (M.C.N.P. code) was used to evaluate the performance of a water-extended polyester shield designed for the transportation, storage, and use of a 252 Cf isotopic neutron source, for comparison the calculations were extended to water shielding, the bare source in vacuum and in air. (authors)

  15. Neutron shielding performance of water-extended polyester

    Energy Technology Data Exchange (ETDEWEB)

    Vega Carrillo, H.R.; Manzanares-Acuna, E.; Hernandez-Davila, V.M. [Zacatecas Univ. Autonoma, Nuclear Studies (Mexico); Vega Carrillo, H.R.; Hernandez-Davila, V.M. [Zacatecas Univ. Autonoma, Electric Engineering Academic Units (Mexico); Gallego, E.; Lorente, A. [Madrid Univ. Politecnica, cNuclear Engineering Department (Mexico)

    2006-07-01

    A Monte Carlo study to determine the shielding features to neutrons of water-extended polyester (WEP) was carried out. Materials with low atomic number are predominantly used for neutron shielding because these materials effectively attenuate neutrons, mainly through elastic and inelastic collisions. In addition to neutron attenuation properties, other desirable properties for neutron shielding materials include mechanical strength, stability, low cost, and ease of handling. During the selection of materials to design a neutron shield, prompt gamma production as well as radionuclide induced by neutron activation must be considered. In this investigation the Monte Carlo method (MCNP code) was used to evaluate the performance of a water-extended polyester shield designed for the transportation, storage, and use of a {sup 252}Cf isotopic neutron source, for comparison the calculations were extended to water shielding, the bare source in vacuum and in air. (authors)

  16. Tensile strength of woven yarn kenaf fiber reinforced polyester composites

    Directory of Open Access Journals (Sweden)

    A.E. Ismail

    2015-12-01

    Full Text Available This paper presents the tensile strength of woven kenaf fiber reinforced polyester composites. The as-received yarn kenaf fiber is weaved and then aligned into specific fiber orientations before it is hardened with polyester resin. The composite plates are shaped according to the standard geometry and uni-axially loaded in order to investigate the tensile responses. Two important parameters are studied such as fiber orientations and number of layers. According to the results, it is shown that fiber orientations greatly affected the ultimate tensile strength but it is not for modulus of elasticity for both types of layers. It is estimated that the reductions of both ultimate tensile strength and Young’s modulus are in the range of 27.7-30.9% and 2.4-3.7% respectively, if the inclined fibers are used with respect to the principal axis.

  17. Procedure for the fabrication of a cross-linked polyester material

    International Nuclear Information System (INIS)

    D'Alelio, G.F.

    1972-01-01

    The procedures are described for the production of a cross-linked polyester material by means of the irradiation of a radiosensitive polyester with a dose of over 0.5 megarad and under 8 megarads high energy, ionising radiation, corresponding to at least 100,000 ev. The polyester is of the telomerised diacrylpolyester type, and may be in a mixture containing about 1% of a coplymerisable aliphatic monomer, or about 30-90% of an unsaturated aliphatic alkyd resin. (JIW)

  18. Highly Branched Bio-Based Unsaturated Polyesters by Enzymatic Polymerization

    DEFF Research Database (Denmark)

    Nguyen, Hiep Dinh; Löf, David; Hvilsted, Søren

    2016-01-01

    A one-pot, enzyme-catalyzed bulk polymerization method for direct production of highly branched polyesters has been developed as an alternative to currently used industrial procedures. Bio-based feed components in the form of glycerol, pentaerythritol, azelaic acid, and tall oil fatty acid (TOFA)...... stability, very high water contact angles of up to 141° and a glass transition temperature that could be controlled through the feed composition....

  19. A study on influence of borax to polyester insulators

    OpenAIRE

    ERSOY, Aysel; KUNTMAN, Ayten

    2014-01-01

    In this study the effect of borax on polyester insulators is investigated by evaluating the tracking and erosion resistance using the inclined plane test. The test procedure follows the ASTM D2303 standard. During the test, 50 Hz current was acquired from the ground electrode allowing a sampling rate of 48000 samples per second. The effect of borax concentration on the glass transition and the degradation temperature is studied by employing differential scanning calorimetry (DSC) an...

  20. Acetalised Galactarate Polyesters: Interplay between Chemical Structure and Polymerisation Kinetics

    Directory of Open Access Journals (Sweden)

    Ionela Gavrila

    2018-02-01

    Full Text Available In spite of the progress that has made so far in the recent years regarding the synthesis of bio-based polymers and in particular polyesters, only few references address the optimisation of these new reactions with respect to conversion and reaction time. Related to this aspect, we here describe the transesterification reaction of two different acetalised galactarate esters with a model aliphatic diol, 1,6-hexanediol. The kinetics of these two apparently similar reactions is compared, with a focus on the conversion while varying the concentration of a di-butyltin oxide catalyst (DBTO, respectively, the used N2 flow-rate. During the first stage of polymerisation, the molecular weight of the end-products is more than doubled when using a 250 mL/min flow as opposed to an almost static N2 pressure. Additionally, the resulted pre-polymers are subjected to further polycondensation and the comparison between the obtained polyesters is extended to their thermal, mechanical and dielectrical characterisation. The influence of the acetal groups on the stability of the polyesters in acidic conditions concludes the study.

  1. Mechanical Characterization of Cotton Fiber/Polyester Composite Material

    Directory of Open Access Journals (Sweden)

    Altaf Hussain Rajper

    2014-04-01

    Full Text Available Development of composite from natural fiber for lower structural application is growing for long-term sustainable perspective. Cotton fiber composite material has the added advantages of high specific strength, corrosion resistance, low cost and low weight compared to glass fiber on the expense of internal components of IC engines. The primary aim of the research study is to examine the effect of the cotton fiber on mechanical properties of lower structural applications when added with the polyester resin. In this paper composite material sample has been prepared by hand Lay-Up process. A mould is locally developed in the laboratory for test sample preparation. Initially samples of polyester resin with appropriate ratio of the hardener were developed and tested. At the second stage yarns of cotton fiber were mixed with the polyester resin and sample specimens were developed and tested. Relative effect of the cotton as reinforcing agent was examined and observed that developed composite specimen possess significant improvement in mechanical properties such as tensile strength was improved as 19.78 % and modulus of elasticity was increased up to 24.81%. Through this research it was also observed that developed composite material was of ductile nature and its density decreases up to 2.6%. Results from this study were compared with relevant available advanced composite materials and found improved mechanical properties of developed composite material

  2. Effect of nanomodified polyester resin on hybrid sandwich laminates

    International Nuclear Information System (INIS)

    Anbusagar, NRR.; Giridharan, P.K.; Palanikumar, K.

    2014-01-01

    Highlights: • Effect of nanomodified polyester resin on hybrid sandwich laminates is evaluated. • The hybrid sandwich laminates are fabricated with varying wt% of nanoclay. • Flexural, impact and moisture absorbtion properties are evaluated for hybrid composites. • Scanning electron microscopy is utilized to analyze the dispersion of clay and fractured surfaces of the nanocomposites. - Abstract: Effect of nanoclay modified polyester resin on flexural, impact, hardness and water absorption properties of untreated woven jute and glass fabric hybrid sandwich laminates have been investigated experimentally. The hybrid sandwich laminates are prepared by hand lay-up manufacturing technique (HL) for investigation. All hybrid sandwich laminates are fabricated with a total of 10 layers, by varying the extreme layers and wt% of nanoclay in polyester resin so as to obtain four different combinations of hybrid sandwich laminates. For comparison of the composite with hybrid composite, jute fiber reinforced composite laminate also fabricated. X-ray diffraction (XRD) results obtained from samples with nanoclay indicated that intergallery spacing of the layered clay increases with matrix. Scanning electron microscopy (SEM) gave a morphological picture of the cross-sections and energy dispersive X-ray spectroscopy (EDS) allowed investigating the elemental composition of matrix in composites. The testing results indicated that the flexural properties are greatly increased at 4% of nanoclay loading while impact, hardness and water absorption properties are increased at 6% of nanoclay loading. A plausible explanation for high increase of properties has also been discussed

  3. Thermal Degradation Mechanism of a Thermostable Polyester Stabilized with an Open-Cage Oligomeric Silsesquioxane

    Directory of Open Access Journals (Sweden)

    Yolanda Bautista

    2017-12-01

    Full Text Available A polyester composite was prepared through the polymerization of an unsaturated ester resin with styrene and an open-cage oligomeric silsesquioxane with methacrylate groups. The effect of the open-cage oligomeric silsesquioxane on the thermal stability of the thermostable polyester was studied using both thermogravimetric analysis and differential thermal analysis. The results showed that the methacryl oligomeric silsesquioxane improved the thermal stability of the polyester. The decomposition mechanism of the polyester/oligomer silsesquioxane composite was proposed by Fourier transform infrared spectroscopy (FTIR analysis of the volatiles.

  4. Blends of polyester ionomers with polar polymers: Interactions, reactions, and compatibilization

    Science.gov (United States)

    Boykin, Timothy Lamar

    The compatibility of amorphous and semicrystalline polyester ionomers with various polar polymers (i.e., polyesters and polyamides) has been investigated for their potential use as minor component compatibilizers. The degree of compatibility (i.e., ranging from incompatible to miscible) between the polyester ionomers and the polar polymers was determined by evaluating the effect of blend composition on the melting behavior and phase behavior of binary blends. In addition, the origin of compatibility and/or incompatibility for each of the binary blends (i.e., polyamide/ionomer and polyester/ionomer) was determined by evaluating blends prepared by both solution and melt mixed methods. Subsequent to investigation of the binary blends, the effect of polyester ionomer addition on the compatibility of polyamide/polyester blends was investigated by evaluating the mechanical properties and phase morphology of ionomer compatibilized polyamide/polyester blends. Polyester ionomers (amorphous and semicrystalline) were shown to exhibit a high degree of compatibility (even miscibility) with polyamides, such as nylon 6,6 (N66). Compatibility was attributed to specific interactions between the metal counterion of the polyester ionomer and the amide groups of N66. The degree of compatibility (or miscibility) was shown to be dependent on the counterion type of the ionomer, with the highest degree exhibited by blends containing the divalent form of the polyester ionomers. Although polyester ionomers were shown to exhibit incompatibility with both poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT), increasing the time of melt processing significantly enhanced the compatibility of the polyester ionomers with both PET and PBT. The observed enhancement in compatibility was attributed to ester-ester interchange between the polyester blend components, which was confirmed by NMR spectroscopy. The addition of polyester ionomers as a minor component compatibilizer (i

  5. Stereodivergent Synthesis of 1,3-Syn-Polyol Natural Product for Stereochemical-Based Structure Activity Relationship Studies

    Science.gov (United States)

    Zheng, Jiamin

    The 1,3-syn-diol functionality is very common in many natural products. An important class containing this moiety are the 1,3-syn-polyol/pyranone natural products, which have been isolated from a variety of plant sources, and possess biological activities like plant growth inhibition as well as antifeedant, antifungal, antibacterial, and antitumor properties. The feature of this class is a 6-membered lactone where the lactoe oxygen is part of a 1,3-syn-diol motif. To pursue the 1,3-syn-polyol/pyranone natural products, an iterative hydration of polyene strategy was utilized to provide the 1,3- syn-diol functionality, and asymmetric synthetic strategies were explored to form the requisite stereochemistry. The versatility of the asymmetric approach was demonstrated in the synthesis of eupatorium pyranone and also in an ongoing project aimed at the synthesis of SIA7248. As an outgrowth of our work on the total syntheses of 1,3-syn -polyol natural products inspired a stereo-divergent synthesis of 1,3-syn-polyol natural products and their analogs for stereochemical-based structure-activity relationship (SSAR) studies. To identify the key structural factors important for the anticancer activity of the 1,3-syn-polyol/pyranones, a stereo-divergent 16-member library of pyranone/polyol congeners was designed, synthesized and tested with variations in both stereochemistry and numbers of polyol repeat units. Having access to stereochemical isomers of the biologically active natural products allowed us to design experiments that help illustrate their mechanisms of action.

  6. Separation and determination of polyurethane amine catalysts in polyether polyols by using UHPLC-Q-TOF-MS on a reversed-phase/cation-exchange mixed-mode column.

    Science.gov (United States)

    Li, Jiaxiao; Zhu, Marcel

    2018-02-01

    A simple, selective, and accurate ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry method was established and validated for the efficient separation and quantification of polyurethane amine catalysts in polyether polyols. Amine catalysts were primarily separated in polyether polyol-based sample by solid-phase extraction, and further baseline separated on a reversed-phase/cation-exchange mixed-mode column (SiELC Primesep™ 200) using 0.1% trifluoroacetic acid/acetonitrile as a mobile phase in gradient elution mode at a flow rate of 0.2 mL/min. High-resolution quadrupole time-of-flight mass spectrometry analysis in electrospray ionization positive mode allowed the identification as N,N'-bis[3-(dimethylamino)propyl]urea, N-[2-(2-dimethylaminoethoxy)ethyl]-N-methyl-1,3-propanediamine, and N,N,N',N'-tetramethyldipropylenetriamine. The method was validated and presented good linearity for all the analytes in blank matrices within the concentration range of 0.20-5.0 or 0.1-2.0 μg/mL with the correlation coefficients (R 2 ) ranging from 0.986 to 0.997. Method recovery ranged within 81-105% at all three levels (80, 100, and 120% of the original amount) with relative standard deviations of 1.0-6.2%. The limits of detection were in the range of 0.007-0.051 μg/mL. Good precision was obtained with relative standard deviation below 3.2 and 0.72% for peak area and retention time of three amines, respectively. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Characterizing the sorption of polybrominated diphenyl ethers (PBDEs) to cotton and polyester fabrics under controlled conditions

    Energy Technology Data Exchange (ETDEWEB)

    Saini, Amandeep [Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military trail, Toronto, ON M1C 1A4 (Canada); Rauert, Cassandra [School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT (United Kingdom); Simpson, Myrna J. [Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military trail, Toronto, ON M1C 1A4 (Canada); Harrad, Stuart [School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT (United Kingdom); Diamond, Miriam L., E-mail: miriam.diamond@utoronto.ca [Department of Earth Sciences, 22 Russell Street, University of Toronto, Toronto, ON M5S 3B1 (Canada); Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military trail, Toronto, ON M1C 1A4 (Canada)

    2016-09-01

    Cotton and polyester, physically and chemically different fabrics, were characterized for sorption of gas-phase polybrominated diphenyl ethers (PBDEs). Scanning electron microscopic (SEM) images and BET specific surface area (BET-SSA) analysis showed cotton's high microsurface area; NMR analysis showed richness of hexose- and aromatic-carbon in cotton and polyester, respectively. Cotton and polyester sorbed similar concentrations of gas-phase PBDEs in chamber studies, when normalized to planar surface area. However, polyester concentrations were 20–50 times greater than cotton when normalized to BET-SSA, greater than the 10 times difference in BET-SSA. The difference in sorption between cotton and polyester is hypothesized to be due to ‘dilution’ due to cotton's large BET-SSA and/or greater affinity of PBDEs for aromatic-rich polyester. Similar fabric-air area normalized distribution coefficients (K'{sub D}, 10{sup 3} to 10{sup 4} m) for cotton and polyester support air-side controlled uptake under non-equilibrium conditions. K'{sub D} values imply that 1 m{sup 2} of cotton or polyester fabrics would sorb gas-phase PBDEs present in 10{sup 3} to 10{sup 4} m{sup 3} of equivalent air volume at room temperature over one week, assuming similar air flow conditions. Sorption of PBDEs to fabrics has implications for their fate indoors and human exposure. - Highlights: • Sorption of gas-phase PBDEs by cotton and polyester fabrics • Similar sorption to cotton and polyester per unit planar surface area • Greater sorption by polyester/BET-SSA; cotton's dilution or polyester’s affinity • 1 m{sup 2} fabric sorbs PBDEs in 10{sup 3} to 10{sup 4} m{sup 3} of equivalent air volume • Clothing likely a large indoor sink of PBDEs and influence human exposure.

  8. Magnetostrictive properties of FeAl/polyester and FeAl/silicone composites

    Energy Technology Data Exchange (ETDEWEB)

    Riesgo, G. [Dpto. de Ciencias y Técnicas de la Navegación, Universidad de Oviedo, Campus universitario de Gijón, 33203 Gijón (Spain); Carrizo, J. [Dpto. de Física de la Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Elbaile, L., E-mail: elbaile@uniovi.es [Dpto. de Física de la Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Crespo, R.D. [Dpto. de Física de la Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain); Sepúlveda, R. [Dpto. de Ingeniería Mecánica y de los Materiales, Universidad de Sevilla, Isla Cartuja, 41092 Sevilla (Spain); García, J.A. [Dpto. de Física de la Universidad de Oviedo, c/ Calvo Sotelo s/n, 33007 Oviedo (Spain)

    2017-01-15

    Highlights: • Nanocrystalline powders of FeAl have been obtained from the Fe{sub 81}Al{sub 19} ribbon produced by melt spinning. • The method allows the obtainment of a FeAl solid solution from the starting process. • The microstructure and magnetic properties of the powders were investigated. • Composites with a magnetostriction of 45 ppm have been obtained. - Abstract: Ribbons of composition Fe{sub 81}Al{sub 19} obtained by the melt spinning method have been used to yield powder by mechanical milling. Using this method, a rapid nanocrystallization and a FeAl solid solution phase was obtained from the start of the process. The microstructural and magnetic properties as well as the XRD patterns of the powders were studied in function of the milling time. Grain refinement and an increase of the coercive field were the main transformations resulting from increasing the milling time. Two sets of magnetostrictive composites were produced from the 100 h-milled powder. In one of them polyester was used as matrix and in the other one silicone. In the case of the silicone composites cured in a magnetic field of 140 mT in the longitudinal direction a saturation magnetostriction as high as 45 ppm was obtained.

  9. Utilization of microbial oil obtained from crude glycerol for the production of polyol and its subsequent conversion to polyurethane foams.

    Science.gov (United States)

    Uprety, Bijaya K; Reddy, Jayanth Venkatarama; Dalli, Sai Swaroop; Rakshit, Sudip K

    2017-07-01

    We have demonstrated possible use of microbial oil in biopolymer industries. Microbial oil was produced from biodiesel based crude glycerol and subsequently converted into polyol. Fermentation of crude glycerol in a batch bioreactor using Rhodosporidium toruloides ATCC 10788 produced 18.69g/L of lipid at the end of 7days. The microbial oil was then chemically converted to polyol and characterized using FT-IR and 1 H NMR. For comparison, canola oil and palm oil were also converted into their respective polyols. The hydroxyl numbers of polyols from canola, palm and microbial oil were found to be 266.86, 222.32 and 230.30 (mgKOH/g of sample) respectively. All the polyols were further converted into rigid and semi-rigid polyurethanes (maintaining the molar -NCO/-OH ratio of 1.1) to examine their suitability in polymer applications. Conversion of microbial lipid to polyurethane foam also provides a new route for the production of polymers using biodiesel based crude glycerol. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Orthogonal protection of saccharide polyols through solvent-free one-pot sequences based on regioselective silylations

    Directory of Open Access Journals (Sweden)

    Serena Traboni

    2016-12-01

    Full Text Available tert-Butyldimethylsilyl (TBDMS and tert-butyldiphenylsilyl (TBDPS are alcohol protecting groups widely employed in organic synthesis in view of their compatibility with a wide range of conditions. Their regioselective installation on polyols generally requires lengthy reactions and the use of high boiling solvents. In the first part of this paper we demonstrate that regioselective silylation of sugar polyols can be conducted in short times with the requisite silyl chloride and a very limited excess of pyridine (2–3 equivalents. Under these conditions, that can be regarded as solvent-free conditions in view of the insolubility of the polyol substrates, the reactions are faster than in most examples reported in the literature, and can even be further accelerated with a catalytic amount of tetrabutylammonium bromide (TBAB. The strategy proved also useful for either the selective TBDMS protection of secondary alcohols or the fast per-O-trimethylsilylation of saccharide polyols. In the second part of the paper the scope of the silylation approach was significantly extended with the development of unprecedented “one-pot” and “solvent-free” sequences allowing the regioselective silylation/alkylation (or the reverse sequence of saccharide polyols in short times. The developed methodologies represent a very useful and experimentally simple tool for the straightforward access to saccharide building-blocks useful in organic synthesis.

  11. Reactive distillation: an attractive alternative for the synthesis of unsaturated polyester

    NARCIS (Netherlands)

    Shah, M.R.; Zondervan, E.; Oudshoorn, M.L.; Haan, de A.B.

    2011-01-01

    Unsaturated polyester is traditionally produced in a batch wise operating reaction vessel connected to a distillation unit. An attractive alternative for the synthesis of unsaturated polyester is a reactive distillation. To value such alternative synthesis route reliable process models need to be

  12. Prevention of primary vascular graft infection with silver-coated polyester graft in a porcine model

    DEFF Research Database (Denmark)

    Gao, H; Sandermann, J; Prag, J

    2010-01-01

    To evaluate the efficacy of a silver-coated vascular polyester graft in the prevention of graft infection after inoculation with Staphylococcus aureus in a porcine model.......To evaluate the efficacy of a silver-coated vascular polyester graft in the prevention of graft infection after inoculation with Staphylococcus aureus in a porcine model....

  13. Light-induced circular birefringence in cyanoazobenzene side-chain liquid-crystalline polyester films

    DEFF Research Database (Denmark)

    Naydenova, I; Nikolova, L; Ramanujam, P.S.

    1999-01-01

    We report the inducement of large circular birefringence (optical activity) in films of a cyanoazobenzene side-chain liquid-crystalline polyester on illumination with circularly polarized light. The polyester has no chiral groups and is initially isotropic. The induced optical rotation is up to 5...

  14. Life-cycle assessment of textiles manufacture of polyester shirt (VB)

    DEFF Research Database (Denmark)

    Othman, Samer; Peter, Oduro Justice; Hassan, Osama

    1998-01-01

    According to the EDIP (Environmental Design of Industrial Products), It is made possible to perform resource and environmental profile analysis of the 100% polyester shirt. In order to understand the true life-cycle consequences, life-cycle analysis of a typical 100% polyester shirt was carried out...

  15. 76 FR 58040 - Certain Polyester Staple Fiber From Korea and Taiwan

    Science.gov (United States)

    2011-09-19

    ... Polyester Staple Fiber From Korea and Taiwan Determination On the basis of the record \\1\\ developed in the... antidumping duty orders on certain polyester staple fiber from Korea and Taiwan would be likely to lead to continuation or recurrence of material injury to an industry in the United States within a reasonably...

  16. 76 FR 11268 - Certain Polyester Staple Fiber From Korea and Taiwan

    Science.gov (United States)

    2011-03-01

    ... Polyester Staple Fiber From Korea and Taiwan AGENCY: United States International Trade Commission. ACTION... Korea and Taiwan. SUMMARY: The Commission hereby gives notice that it has instituted reviews pursuant to... the antidumping duty orders on certain polyester staple fiber from Korea and Taiwan would be likely to...

  17. Activation of the polyol pathway may contribute to increased risk of radiocontrast agent nephrotoxicity in diabetes

    International Nuclear Information System (INIS)

    Kaplan, D.L.; Mann, P.L.; Zager, P.G.; Smith, M.A.

    1991-01-01

    The incidence of radiocontrast (RC) agent nephrotoxicity is higher in diabetic than non-diabetic patients. RC nephropathy involves both glomerular and tubular cells. The authors postulate that activation of the polyol pathway contributes to the increased susceptibility of diabetics to RC nephrotoxicity. Mesangial cells modulate GFR by altering the capillary surface area available for filtration. Toxic insult to mesangial cells can impair glomerular function. The present study was performed to determine if mesangial cells isolated from galactose fed rats, the classic model for studying the effects of polyol accumulation, demonstrate increased susceptibility to RC toxicity. A cellular model was developed to study the effects of RC agents on mesangial cells isolated from rats maintained on diets of 50% galactose (MCG) and 50% dextrin (MCD). MCG's and MCD's were plated in 96 well trays at a density of 6.25 x 10 4 cells/ml. Cells were exposed to Hypaque 90 at concentrations of 10 mM to 1 uM for 1, 2, 4 and 24 hrs. Cell viability was determined by fluorescein diacetate/propidium iodide staining. 3H-thymidine incorporation was used to determine cell proliferation rates. Hypaque 90 produced no direct cytotoxicity at any time points or concentrations tested. An increase in cell proliferation was observed 1 hr after exposure to 1 uM to 1mM Hypaque. Higher concentrations blunted cell proliferation rates. Hypaque 90 produced no direct cytotoxicity at any time points or concentrations tested. An increase in cell proliferation was observed 1 hr after exposure to 1 uM to 1mM Hypaque. Higher concentrations blunted cell proliferation. No significant effects on 3H-thymidine incorporation were observed at later time points. The effects on 3H-thymidine incorporation were more pronounced in MCG's than MCD's. Activation of the polyol pathway amplifies the proliferative response of MC to RC agents. This activation may contribute to the risk of RC nephropathy in diabetics

  18. Novel side-chain liquid crystalline polyester architecture for reversible optical storage

    DEFF Research Database (Denmark)

    Hvilsted, Søren; Andruzzi, Fulvio; Kulinna, Chrisian

    1995-01-01

    New side-chain liquid crystalline polyesters have been prepared by melt transesterification of diphenyl tetradecanedioate and a series of mesogenic 2-[omega-[4-[(4-cyanophenyl)azo]phenoxyl] alkyl]-1,3-propanediols, where the alkyl spacer is hexa-, octa-, and decamethylene in turn. The polyesters...... have molecular masses in the range 5000-89 000. Solution C-13 NMR spectroscopy has been employed to identify carbons of polyester repeat units and of both types of end groups. Polyester phases and phase transitions have been investigated in detail by polarizing optical microscopy and differential...... scanning calorimetry for the hexamethylene spacer architecture with different molecular masses. Using FTIR polarization spectroscopy, the segmental orientation in unoriented polyester films induced by argon ion laser irradiation has been followed and an irradiation-dependent order parameter...

  19. Flame Retardance and Physical Properties of Novel Cured Blends of Unsaturated Polyester and Furan Resins

    Directory of Open Access Journals (Sweden)

    Baljinder Kaur Kandola

    2015-02-01

    Full Text Available Novel blends of two furan resins with an unsaturated polyester have been prepared and cured by parallel free radical (for the unsaturated polyester and acid-catalysed crosslinking (for the furan resin to give co-cured composite materials. Although these materials have inferior physical properties, such as low Tg and low storage modulus compared with those of unsaturated polyester and furan resins alone, they show markedly improved flame retardance compared with that of the normally highly flammable unsaturated polyester. This increased flame retardance arises from a condensed phase mechanism in which the furanic component forms a semi-protective char, reducing rates of thermal degradation and total heat release and heat of combustion. The blends also burn with reduced smoke output compared with that from unsaturated polyester alone.

  20. Oleic Acid Based Polyesters of Trimethylolpropane and Pentaerythritol for Bio lubricant Application

    International Nuclear Information System (INIS)

    Hamizah Ammarah Mahmud; Nadia Salih; Jumat Salimon

    2015-01-01

    The production of polyesters based on oleic acid and trimethylolpropane (TMP) or pentaerythritol (PE) as potential bio lubricant were carried out. The esterification processes between oleic acid with TMP or PE were carried out using sulfuric acid as a catalyst. The esterification process produced high yield between 92 %-94 % w/w respectively. The formation of polyesters was confirmed using gas chromatography (GC-FID), Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR). The polyesters were analyzed for basic lubrication physicochemical properties. The results showed that polyesters of both TMP and PE having high viscosity index between 200-309, good pour points ranging from -42 to -59 degree Celsius and high flash points of 280 - 300 degree Celsius respectively. The polyesters also showed good thermal oxidative stability with TGA onset temperatures above 180 degree Celsius. In general both products are plausible to be used as bio lubricant for industrial application. (author)

  1. Investigating the role of polyols in Cladosporium fulvum during growth under hyper-osmotic stress and in planta.

    Science.gov (United States)

    Clark, Anthony J; Blissett, Kerry J; Oliver, Richard P

    2003-02-01

    The role of the large amounts of polyols accumulated by the fungal tomato pathogen, Cladosporium fulvum (syn. Fulvia fulva, Cooke) both in planta and in axenic cultures has been examined. Arabinitol and glycerol accumulated in response to hyper-osmotic stress in vitro. Mannitol levels were lower in osmo-stressed mycelium. (13)C NMR spectroscopy indicated that carbon flow from glucose to mannitol was redirected to arabinitol and glycerol in hyper-osmotic conditions. Infected tomato ( Lycopersicon esculentum Mill.) plants contained all three polyols whereas glycerol was the only polyol present in uninfected plants, suggesting that the mannitol and arabinitol were of fungal origin. Substantially higher levels of arabinitol and glycerol were present in infected plants that were subjected to a restricted watering regime compared to fully watered plants. The results suggest that a primary role of fungal arabinitol and glycerol, but not mannitol, is osmoregulation and that water acquisition is an important aspect of pathogenicity.

  2. Polyol-mediated thermolysis process for the synthesis of MgO nanoparticles and nanowires

    International Nuclear Information System (INIS)

    Subramania, A; Kumar, G Vijaya; Priya, A R Sathiya; Vasudevan, T

    2007-01-01

    The main aim of this work is to prepare MgO nanoparticles and nanowires by a novel polyol-mediated thermolysis (PMT) process. The influence of different mole concentration of magnesium acetate, polyvinyl pyrrolidone (PVP; capping agent) and ethylene glycol (EG; solvent as well as reducing agent) on the formation of nanoparticles and nanowires and the effect of calcination on the crystalline size of the samples were also examined. The resultant oxide structure, thermal behaviour, size and shape have been studied using x-ray diffraction (XRD) studies, thermal (TG/DTA) analysis and scanning electron microscopy (SEM)/transmission electron microscopy (TEM) respectively

  3. Polyol-mediated thermolysis process for the synthesis of MgO nanoparticles and nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Subramania, A; Kumar, G Vijaya; Priya, A R Sathiya; Vasudevan, T [Advanced Materials Research Lab, Department of Industrial Chemistry, Alagappa University, Karaikudi-630 003 (India)

    2007-06-06

    The main aim of this work is to prepare MgO nanoparticles and nanowires by a novel polyol-mediated thermolysis (PMT) process. The influence of different mole concentration of magnesium acetate, polyvinyl pyrrolidone (PVP; capping agent) and ethylene glycol (EG; solvent as well as reducing agent) on the formation of nanoparticles and nanowires and the effect of calcination on the crystalline size of the samples were also examined. The resultant oxide structure, thermal behaviour, size and shape have been studied using x-ray diffraction (XRD) studies, thermal (TG/DTA) analysis and scanning electron microscopy (SEM)/transmission electron microscopy (TEM) respectively.

  4. Polyol-mediated thermolysis process for the synthesis of MgO nanoparticles and nanowires

    Science.gov (United States)

    Subramania, A.; Vijaya Kumar, G.; Sathiya Priya, A. R.; Vasudevan, T.

    2007-06-01

    The main aim of this work is to prepare MgO nanoparticles and nanowires by a novel polyol-mediated thermolysis (PMT) process. The influence of different mole concentration of magnesium acetate, polyvinyl pyrrolidone (PVP; capping agent) and ethylene glycol (EG; solvent as well as reducing agent) on the formation of nanoparticles and nanowires and the effect of calcination on the crystalline size of the samples were also examined. The resultant oxide structure, thermal behaviour, size and shape have been studied using x-ray diffraction (XRD) studies, thermal (TG/DTA) analysis and scanning electron microscopy (SEM)/transmission electron microscopy (TEM) respectively.

  5. Karakterstik Serapan Suara Komposit Polyester Berpenguat Serat Tapis Kelapa

    OpenAIRE

    Astika, I Made; Dwijana, I Gusti Komang

    2016-01-01

    The purpose of this study is to investigate of sound absorption of coconut filter fiber composites. The research material made with coconut filter fiber as reinforcement and matrix resin unsaturated polyester (UPRs) type Yukalac BQTN 157 with 1% hardener types MEKPO (Methyl Ethyl Ketone Peroxide) and fiber treatment by  0,5% KMnO4. Production methods is poltrusion and the variations of fiber volume fraction are 20, 25 and 30% and fiber length are 5, 10 and 15 mm. Testing of sound absorpt...

  6. UV-irradiation effects on polyester nuclear track detector

    International Nuclear Information System (INIS)

    Agarwal, Chhavi; Kalsi, P.C.

    2010-01-01

    The effects of UV irradiation (λ=254 nm) on polyester nuclear track detector have been investigated employing bulk-etch technique, UV-visible spectrophotometry and infra-red spectrometry (FTIR). The activation energy values for bulk-etching were found to decrease with the UV-irradiation time indicating the scission of the polymer. Not much shift in the absorption edge due to UV irradiation was seen in the UV-visible spectra. FTIR studies also indicate the scission of the chemical bonds, thereby further validating the bulk-etch rate results.

  7. Atmospheric pressure H20 plasma treatment of polyester cord threads

    International Nuclear Information System (INIS)

    Simor, M.; Krump, H.; Hudec, I.; Rahel, J.; Brablec, A.; Cernak, M.

    2004-01-01

    Polyester cord threads, which are used as a reinforcing materials of rubber blend, have been treated in atmospheric-pressure H 2 0 plasma in order to enhance their adhesion to rubber. The atmospheric-pressure H 2 0 plasma was generated in an underwater diaphragm discharge. The plasma treatment resulted in approximately 100% improvement in the adhesion. Scanning electron microscopy investigation indicates that not only introduced surface polar groups but also increased surface area of the fibres due to a fibre surface roughening are responsible for the improved adhesive strength (Authors)

  8. The influence of solvent processing on polyester bioabsorbable polymers.

    Science.gov (United States)

    Manson, Joanne; Dixon, Dorian

    2012-01-01

    Solvent-based methods are commonly employed for the production of polyester-based samples and coatings in both medical device production and research. The influence of solvent casting and subsequent drying time was studied using thermal analysis, spectroscopy and weight measurement for four grades of 50 : 50 poly(lactic-co-glycolic acid) (PLGA) produced by using chloroform, dichloromethane, and acetone. The results demonstrate that solvent choice and PLGA molecular weight are critical factors in terms of solvent removal rate and maintaining sample integrity, respectively. The protocols widely employed result in high levels of residual solvent and a new protocol is presented together with solutions to commonly encountered problems.

  9. Unsaturated polyester resin composition curable with ionizing radiations

    International Nuclear Information System (INIS)

    Maruyama, Tsutomu; Murata, Koichiro.

    1971-01-01

    An unsaturated polyester resin composition curable with ionizing radiations and excellent in weather resistance is provided. The composition is obtained by reacting 10-12 moles of a polyhydric alcohol (e.g. ethylene glycol) with 10 moles of an acid mixture (25.45% by mole of endo-cis-bicyclo (2,2,1)-5-heptene-2-3-dicarboxylic acid (A), 20-40% of unsaturated dibasic acid and 15-55% of saturated dibasic acid) so that the acid value reaches 4-11. The composition is useful as coating, laminating and molding materials. As a coating material it is excellent in surface hardening property. The ionizing radiation used is preferably β-, α-rays or electron beams. In one example, and unsaturated polyester was prepared by reacting 3 moles of fumaric acid, 2 moles of phthalic anhydride, 3 moles of adipic acid 3, moles of (A), 10 moles of neopentyl glycol and 1 mole of trimethylolpropane. The resin was dissolved into a mixture of styrene, methyl methacrylate and butyl acrylate (50:8:42) and incorporated with titanium white. An ABS plate was coated with the enamel thus obtained and irradiated with electron beams (12 Mrad). In exposure test at 60 0 C, luster of the film was 92 before exposure and 83 after 30 months. In a comparative run in which (A) was not used, luster of the film decreased from 90 to 45 in 30 months. (Sakaichi, S.)

  10. Glass fibres reinforced polyester composites degradation monitoring by surface analysis

    Energy Technology Data Exchange (ETDEWEB)

    Croitoru, Catalin [“Transilvania” University of Brasov, Materials Engineering and Welding Department, Eroilor 29 Str., 500036 Brasov (Romania); Patachia, Silvia, E-mail: st.patachia@unitbv.ro [“Transilvania” University of Brasov, Product Design Environment and Mechatronics Department, Eroilor 29 Str., 500036 Brasov (Romania); Papancea, Adina [“Transilvania” University of Brasov, Product Design Environment and Mechatronics Department, Eroilor 29 Str., 500036 Brasov (Romania); Baltes, Liana; Tierean, Mircea [“Transilvania” University of Brasov, Materials Engineering and Welding Department, Eroilor 29 Str., 500036 Brasov (Romania)

    2015-12-15

    Highlights: • Glass fibre-reinforced polyester composites surface analysis by photographic method. • The composites are submitted to accelerated ageing by UV irradiation at 254 nm. • The UV irradiation promotes differences in the surface chemistry of the composites. • MB dye is differently adsorbed on surfaces with different degradation degrees. • Good correlation between the colouring degree and surface chemistry. - Abstract: The paper presents a novel method for quantification of the modifications that occur on the surface of different types of gel-coated glass fibre-reinforced polyester composites under artificial UV-ageing at 254 nm. The method implies the adsorption of an ionic dye, namely methylene blue, on the UV-aged composite, and computing the CIELab colour space parameters from the photographic image of the coloured composite's surface. The method significantly enhances the colour differences between the irradiated composites and the reference, in contrast with the non-coloured ones. The colour modifications that occur represent a good indicative of the surface degradation, alteration of surface hydrophily and roughness of the composite and are in good correlation with the ATR-FTIR spectroscopy and optical microscopy results. The proposed method is easier, faster and cheaper than the traditional ones.

  11. Complications of transvaginal silicone-coated polyester synthetic mesh sling.

    Science.gov (United States)

    Govier, F E; Kobashi, K C; Kuznetsov, D D; Comiter, C; Jones, P; Dakil, S E; James, R

    2005-10-01

    To report a premarket multicenter trial to test the feasibility of a transvaginal silicone-coated polyester synthetic mesh sling in women with anatomic incontinence. Fifty-one patients in four centers underwent transvaginal placement of a silicone-coated polyester synthetic mesh sling (American Medical Systems) during an 8-month period. Of the 51 patients, 31 were part of a prospective institutional review board-approved feasibility trial in three centers funded by American Medical Systems (group 1) and 20 underwent implantation by a single surgeon and their data were retrospectively reviewed (group 2). The studies were done concomitantly, and all slings were fixed transvaginally with bone anchors. All patients in group 1 were followed up at 4 weeks, 6 months, and 1 year (as applicable) with repeat questionnaires, physical examinations, and pad tests. In group 1, 20 patients completed 6 months of follow-up. Ten patients (32%) required a second surgical procedure at an average of 183 days (range 68 to 343) postoperatively. Eight patients (26%) had vaginal extrusion of the mesh, one (3%) required sling lysis, and one (3%) required sling removal because of infection. In group 2, 8 patients (40%) underwent sling removal for vaginal extrusion at a mean of 160 days (range 83 to 214). Transvaginally placed silicone-coated mesh slings used for the treatment of urinary incontinence demonstrated an unacceptably high vaginal extrusion rate in this study. Once identified, this study was immediately terminated, and this product was not marketed for this application in the United States.

  12. Process optimization and properties of magnetically hard cobalt carbide nanoparticles via modified polyol method

    International Nuclear Information System (INIS)

    Zamanpour, Mehdi; Bennett, Steven P.; Majidi, Leily; Chen, Yajie; Harris, Vincent G.

    2015-01-01

    Highlights: • High-coercivity cobalt carbides were synthesized by polyol method. • No rare earth elements were used during synthesis process. • Process parameters (reaction temperature, precursors’ concentrations, surfactants and reaction duration) were studied/optimized. • Process was scaled-up to synthesis more than 5 g powders per batch. - Abstract: Cobalt carbide magnetic nanoparticles were successfully synthesized via a modified polyol process without using a rare-earth catalyst during the synthesis process. The present results show admixtures of Co 2 C and Co 3 C phases possessing magnetization values exceeding 47 emu/g and coercivity values exceeding 2.3 kOe at room temperature. Moreover, these experiments have illuminated the important role of the reaction temperature, hydroxyl ion concentrations and the reaction duration on the crystallographic structure and magnetic properties of the nanoparticles. The crystallographic structure and particle size of the Co x C nanoparticles were characterized by X-ray diffractometry and scanning electron microscopy. Vibrating sample magnetometry was used to determine magnetic properties. Scale-up of synthesis to more than 5 g per batch was demonstrated with no significant degradation of magnetic properties

  13. Enhanced removal of lead from contaminated soil by polyol-based deep eutectic solvents and saponin

    Science.gov (United States)

    Mukhopadhyay, Soumyadeep; Mukherjee, Sumona; Hayyan, Adeeb; Hayyan, Maan; Hashim, Mohd Ali; Sen Gupta, Bhaskar

    2016-11-01

    Deep eutectic solvents (DESs) are a class of green solvents analogous to ionic liquids, but less costly and easier to prepare. The objective of this study is to remove lead (Pb) from a contaminated soil by using polyol based DESs mixed with a natural surfactant saponin for the first time. The DESs used in this study were prepared by mixing a quaternary ammonium salt choline chloride with polyols e.g. glycerol and ethylene glycol. A natural surfactant saponin obtained from soapnut fruit pericarp, was mixed with DESs to boost their efficiency. The DESs on their own did not perform satisfactory due to higher pH; however, they improved the performance of soapnut by up to 100%. Pb removal from contaminated soil using mixture of 40% DES-Gly and 1% saponin and mixture of 10% DES-Gly and 2% saponin were above 72% XRD and SEM studies did not detect any major corrosion in the soil texture. The environmental friendliness of both DESs and saponin and their affordable costs merit thorough investigation of their potential as soil washing agents.

  14. Polyol Synthesis of Silver Nanowires by Heterogeneous Nucleation and Mechanistic Aspects Influencing its Length and Diameter

    Science.gov (United States)

    Schuette, Waynie Mark

    Various additives are employed in the polyol synthesis of silver nanowires (Ag NWs), which are typically halide salts such as NaCl. A variety of mechanistic roles have been suggested for these additives. My research showed that the early addition of NaCl in the polyol synthesis of Ag NWs from AgNO3 in ethylene glycol results in the rapid formation of AgCl nanocubes, which induce the heterogeneous nucleation of metallic Ag upon their surfaces. Ag NWs subsequently grow from these nucleation sites. The conclusions are supported by studies using ex-situ generated AgCl nanocubes. Additionally, the final mean silver nanowire diameter is found to be independent of the size of the heterogeneous nucleant, showing that the diameter is not significantly influenced by the nucleation event. Kinetics studies determine that nanowire diameter, length, and aspect ratio grow in parallel to one another and with the extent of the Ag+ reduction reaction, demonstrating that growth is reduction-rate limited. The results are interpreted to support nanowire growth by a surface-catalyzed reduction process occurring on all nanowire surfaces, and to exclude nanoparticle aggregation or Ostwald ripening as primary components of the growth mechanism.

  15. Microwave-polyol synthesis and electrocatalytic performance of Pt/graphene nanocomposites

    International Nuclear Information System (INIS)

    Liao, Chien-Shiun; Liao, Chien-Tsao; Tso, Ching-Yu; Shy, Hsiou-Jeng

    2011-01-01

    Highlights: · One-pot microwave-polyol synthesis of Pt/graphene electrocatalyst. · Simultaneous formation of Pt nanoparticles and reduction of graphene oxide. · Electrocatalytic activities depend on the morphology of the deposited Pt particles. · Dense dispersion of isolated Pt particles with high electrochemical active surface. · Few particle clusters of Pt have large number of active sites for methanol oxidation. - Abstract: Graphene oxide (GO) prepared by the modified Hummers method is used as a support in the formation of a Pt/GO nanocomposite electrocatalyst by microwave-polyol synthesis. The effects of microwave reaction times on particle size, dispersion, and electrocatalytic performance of Pt nanoparticles are studied using wide-angle X-ray diffractometery, Raman spectroscopy, transmission electron microscopy and three-electrode electrochemical measurements. The results indicate that Pt nanoparticles nucleation and growth occur, and the particles are uniformly deposited on the GO nanosheets within a short time. The maximum electrochemical active surface area 85.71 m 2 g -1 for a Pt/GO reaction time of 5 min, is a result of the deposition of a dense dispersion of small Pt particles. The highest methanol oxidation peak current density, I f , of 0.59 A mg -1 occurs for a Pt/GO reaction time of 10 min and is due to the formation of interconnecting Pt particles clusters. This novel Pt/GO nanocomposite electrocatalyst with high electrocatalytic activities has the potential for use as an anode material in fuel cells.

  16. High Performance Shape Memory Polyurethane Synthesized with High Molecular Weight Polyol as the Soft Segment

    Directory of Open Access Journals (Sweden)

    Manzoor Ahmad

    2012-05-01

    Full Text Available Shape memory polyurethanes (SMPUs are typically synthesized using polyols of low molecular weight (MW~2,000 g/mol as it is believed that the high density of cross-links in these low molecular weight polyols are essential for high mechanical strength and good shape memory effect. In this study, polyethylene glycol (PEG-6000 with MW ~6000 g/mol as the soft segment and diisocyanate as the hard segment were used to synthesize SMPUs, and the results were compared with the SMPUs with polycaprolactone PCL-2000. The study revealed that although the PEG-6000-based SMPUs have lower maximum elongations at break (425% and recovery stresses than those of PCL-based SMPUs, they have much better recovery ratios (up to 98% and shape fixity (up to 95%, hence better shape memory effect. Furthermore, PEG-based SMPUs showed a much shorter actuation time of < 10 s for up to 90% shape recovery compared to typical actuation times of tens of seconds to a few minutes for common SMPUs, demonstrated their great potential for applications in microsystems and other engineering components.

  17. Effect of sodium tetraborate (borax) on the thermal properties of frozen aqueous sugar and polyol solutions.

    Science.gov (United States)

    Izutsu, Ken-ichi; Rimando, Annie; Aoyagi, Nobuo; Kojima, Shigeo

    2003-06-01

    The effect of sodium tetraborate (Na(2)B(4)O(7), borax) on the thermal property of frozen aqueous sugar and polyol solutions was studied through thermal analysis. Addition of borax raised the thermal transition temperature (glass transition temperature of maximally freeze-concentrated solutes; T(g)') of frozen sucrose solutions depending on the borax/sucrose concentration ratios. Changes in the T(g)' of frozen mono- and disaccharide solutions suggested various forms of complexes, including those of a borate ion and two saccharide molecules. Borax exerted the maximum effect to raise the oligosaccharide and dextran T(g)'s at borax/saccharide molar ratios of approximately 1-2 (maltose and maltooligosaccharides), 2 (dextran 1060), 5 (dextran 4900), and 10 (dextran 10200). Further addition of borax lowered T(g)'s of the saccharide solutions. Borax also raised T(g) and T(g)' temperatures of frozen aqueous glycerol solutions. The decreased solute mobility in frozen solutions by the borate-polyol complexes suggested higher collapse temperature in the freeze-drying process and improved stability of biological systems in frozen solutions.

  18. Process optimization and properties of magnetically hard cobalt carbide nanoparticles via modified polyol method

    Energy Technology Data Exchange (ETDEWEB)

    Zamanpour, Mehdi; Bennett, Steven P. [Center for Microwave Magnetic Materials and Integrated Circuits (CM3IC), Northeastern University, Boston, MA 02115 (United States); Majidi, Leily [Department of Mechanical and Industrial Engineering, Northeastern University, Boston, MA 02115 (United States); Chen, Yajie [Center for Microwave Magnetic Materials and Integrated Circuits (CM3IC), Northeastern University, Boston, MA 02115 (United States); Harris, Vincent G. [Center for Microwave Magnetic Materials and Integrated Circuits (CM3IC), Northeastern University, Boston, MA 02115 (United States); Department of Electrical and Computer Engineering, Northeastern University, Boston, MA 02115 (United States)

    2015-03-15

    Highlights: • High-coercivity cobalt carbides were synthesized by polyol method. • No rare earth elements were used during synthesis process. • Process parameters (reaction temperature, precursors’ concentrations, surfactants and reaction duration) were studied/optimized. • Process was scaled-up to synthesis more than 5 g powders per batch. - Abstract: Cobalt carbide magnetic nanoparticles were successfully synthesized via a modified polyol process without using a rare-earth catalyst during the synthesis process. The present results show admixtures of Co{sub 2}C and Co{sub 3}C phases possessing magnetization values exceeding 47 emu/g and coercivity values exceeding 2.3 kOe at room temperature. Moreover, these experiments have illuminated the important role of the reaction temperature, hydroxyl ion concentrations and the reaction duration on the crystallographic structure and magnetic properties of the nanoparticles. The crystallographic structure and particle size of the Co{sub x}C nanoparticles were characterized by X-ray diffractometry and scanning electron microscopy. Vibrating sample magnetometry was used to determine magnetic properties. Scale-up of synthesis to more than 5 g per batch was demonstrated with no significant degradation of magnetic properties.

  19. A novel polyol method to synthesize colloidal silver nanoparticles by ultrasonic irradiation.

    Science.gov (United States)

    Byeon, Jeong Hoon; Kim, Young-Woo

    2012-01-01

    A polyol synthesis of silver nanoparticles in the presence of ultrasonic irradiation was compared with other configurations (at ambient temperature, 120° C, and 120 °C with injected solutions) in the absence of ultrasonic irradiation in order to obtain systematic results for morphology and size distribution. For applying ultrasonic irradiation, rather fine and uniform spherical silver particles (21±3.7 nm) were obtained in a simple (at ambient temperature without mechanical stirring) and fast (within 4 min, 3.61×10(-3) mol min(-1)) manner than other cases (at ambient temperature (for 8 h, 0.03×10(-3) mol min(-1)): 86±16.8 nm, 120 °C (for 12 min, 1.16×10(-3) mol min(-1)): 64±14.9 nm, and 120 °C with injected solutions (during 12 min): 35±6.8 nm; all other cases contained anisotropic shaped particles). Even though the temperature of polyol reaction reached only at 80 °C (silver particle and surrounding components) by ultrasonic irradiation might induce a better formation kinetics and morphological uniformity. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Polyol synthesis of silver nanoplates: The crystal growth mechanism based on a rivalrous adsorption

    International Nuclear Information System (INIS)

    Luo Xiaolin; Li Zongxiao; Yuan Chunlan; Chen Yashao

    2011-01-01

    Highlights: → Silver nanoplates have been successfully synthesized by polyol reduction in the presence of poly (vinylpyrrolidone) (PVP) and HNO 3 . → Due to the discovery of CN - ions in the solution, a mechanism for the anisotropic growth of silver nanoplates is systematically discussed. → TG, FT-IR and SERS were used to provide some direct evidences of rivalrous adsorption between PVP and CN - ions on the surface of the silver crystals. - Abstract: A polyol reducing approach has been applied to synthesize silver nanoplates with an average thickness of 50 nm and edge length of 3 μm in the presence of poly (vinylpyrrolidone) (PVP) and HNO 3 . X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscropy (TEM), and electron diffraction are used to characterize these silver nanoplates. Findings indicate that the nanoplates are single crystals and with their basal plane as (1 1 1) lattice plane. On the basis of the results from thermogravimetric analysis (TG), Fourier transform infrared spectroscopy (FT-IR) and Raman spectroscopy, a crystal growth mechanism based on the rivalrous adsorption between PVP and CN - ions on the surface of silver nanoplates is supposed to explain the crystal anisotropic growth.

  1. Microbial degradation of aliphatic and aliphatic-aromatic co-polyesters.

    Science.gov (United States)

    Shah, Aamer Ali; Kato, Satoshi; Shintani, Noboru; Kamini, Numbi Ramudu; Nakajima-Kambe, Toshiaki

    2014-04-01

    Biodegradable plastics (BPs) have attracted much attention since more than a decade because they can easily be degraded by microorganisms in the environment. The development of aliphatic-aromatic co-polyesters has combined excellent mechanical properties with biodegradability and an ideal replacement for the conventional nondegradable thermoplastics. The microorganisms degrading these polyesters are widely distributed in various environments. Although various aliphatic, aromatic, and aliphatic-aromatic co-polyester-degrading microorganisms and their enzymes have been studied and characterized, there are still many groups of microorganisms and enzymes with varying properties awaiting various applications. In this review, we have reported some new microorganisms and their enzymes which could degrade various aliphatic, aromatic, as well as aliphatic-aromatic co-polyesters like poly(butylene succinate) (PBS), poly(butylene succinate)-co-(butylene adipate) (PBSA), poly(ε-caprolactone) (PCL), poly(ethylene succinate) (PES), poly(L-lactic acid) (PLA), poly(3-hydroxybutyrate) and poly(3-hydoxybutyrate-co-3-hydroxyvalterate) (PHB/PHBV), poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT), poly(butylene adipate-co-terephthalate (PBAT), poly(butylene succinate-co-terephthalate) (PBST), and poly(butylene succinate/terephthalate/isophthalate)-co-(lactate) (PBSTIL). The mechanism of degradation of aliphatic as well as aliphatic-aromatic co-polyesters has also been discussed. The degradation ability of microorganisms against various polyesters might be useful for the treatment and recycling of biodegradable wastes or bioremediation of the polyester-contaminated environments.

  2. Biodegradation of Halloysite Nanotubes-Polyester Nanocomposites Exposed to Short Term Seawater Immersion

    Directory of Open Access Journals (Sweden)

    Mohd Shahneel Saharudin

    2017-07-01

    Full Text Available Halloysite nanotubes (HNTs-polyester nanocomposites with four different concentrations were produced using solution casting technique and the biodegradation effect of short-term seawater exposure (120 h was studied. Monolithic polyester was observed to have the highest seawater absorption with 1.37%. At 0.3 wt % HNTs reinforcement, the seawater absorption dropped significantly to the lowest value of 0.77% due to increase of liquid diffusion path. For samples tested in dry conditions, the Tg, storage modulus, tensile properties and flexural properties were improved. The highest improvement of Tg was from 79.3 to 82.4 °C (increase 3.1 °C in the case of 0.3 wt % HNTs. This can be associated with the exfoliated HNTs particles, which restrict the mobility of polymer chains and thus raised the Tg. After seawater exposure, the Tg, storage modulus, tensile properties and flexural properties of polyester and its nanocomposites were decreased. The Young’s modulus of 0.3 wt % HNTs-polyester dropped 20% while monolithic polyester dropped up to 24% compared to their values in dry condition. Apart from that, 29% flexural modulus reduction was observed, which was 18% higher than monolithic polyester. In contrast, fracture toughness and surface roughness increased due to plasticization effect. The presence of various microbial communities caused gradual biodegradation on the microstructure of the polyester matrix as also evidently shown by SEM images.

  3. Synthesis and Properties of Some polyurethane/ Partially Aromatic Polyester Casting Samples

    International Nuclear Information System (INIS)

    Sadek, E.M.; Mazroua, A.M.; Emam, A.S.; Motawie, A.M.

    2005-01-01

    A series of partially aromatic terephthalate polyesters were synthesized by melt transesterification of dimethyl terephthalate with various types of aliphatic diol compounds in 1:1.1 molar ratio. Ethylene-, di-, tri-, tetra ethylene glycol and polyethylene glycol with different molecular weights 1000, 4000, 6000 as well as the prepared dihydroxy natural rubber were used. Another series of partially aromatic adipate and sebacate polyesters based on the prepared bisphenol A and its tetrabromo derivative were also synthesized by direct polycondensation esterification with adipic and sebacic acid. Polyurethane with NCO/OH ratio equal 4 was prepared from the reaction of 2,4 toluene diisocyanate with polyethylene glycol 1000. The prepared polyurethane was mixed with different weight percentages (2, 4, 6, 8, 10 or 12 % w/w) of the prepared partially aromatic polyesters to give polyurethane/polyester compositions. Mechanical and electrical properties as well as water and chemical resistance of the prepared film samples with thickness 3-4 mm were determined and compared with those of polyurethane film sample without polyester. The data indicate that 10 % w/w of the added partially aromatic polyester increases polyurethane tensile strength, improves its insulation properties and hydrolytic stability as well as its chemical resistance. Film samples based on bisphenol A impart excellent properties as compared with those based on aliphatic glycol species and dihydroxy natural rubber. Keywords: Partially aromatic polyesters, Dimethyl terephthalate, Glycols, Bisphenol A, Tetrabromo bisphenol A, Natural rubber, Adipic acid, Sebacic acid, Polyurethane, Casting

  4. The biomechanical evaluation of polyester as a tension band for the internal fixation of patellar fractures.

    LENUS (Irish Health Repository)

    McGreal, G

    2012-02-03

    We use a braided polyester suture in place of cerclage wire in tension band fixations. The objective of this study was to test the biomechanical properties of this technique. Sixteen cadaveric patellae were fractured and repaired by modified tension band fixation. Eight were fixed using eighteen gauge stainless steel wire as a tension band and eight using braided polyester. All specimens were subjected to tensile testing. Polyester was 75.0% as strong as wire. For dynamic testing, the patellae of seven cadaveric knees were fractured and then fixed with polyester tension bands. These were mounted in a device capable of extending the knees from 90 degrees to neutral against an applied force. None of the fixations failed. Three of the specimens fixed using 18 gauge stainless steel wire were compared with three fixed using polyester over 2000 cycles of knee flexion and extension. Polyester performed as well as wire. We conclude that polyester is an acceptable alternative to wire in tension band fixation.

  5. Recent Advances in the Design of Water Based-Flame Retardant Coatings for Polyester and Polyester-Cotton Blends

    Directory of Open Access Journals (Sweden)

    Jenny Alongi

    2016-10-01

    Full Text Available Over the last ten years a new trend of research activities regarding the flame retardancy of polymeric materials has arisen. Indeed, the continuous search for new flame retardant systems able to replace the traditional approaches has encouraged alternative solutions, mainly centred on nanotechnology. In this context, the deposition of nanostructured coatings on fabrics appears to be the most appealing and performance suitable approach. To this aim, different strategies can be exploited: from the deposition of a single monolayer consisting of inorganic nanoparticles (single-step adsorption to the building-up of more complex architectures derived from layer by layer assembly (multi-step adsorption. The present paper aims to review the application of such systems in the field of polyester and polyester-cotton blend fabrics. The results collated by the authors are discussed and compared with those published in the literature on the basis of the different deposition methods adopted. A critical analysis of the advantages and disadvantages exhibited by these approaches is also presented.

  6. Study on the improvement of hydrophilic character on polyvinylalcohol treated polyester fabric

    Directory of Open Access Journals (Sweden)

    S. Pitchai

    2014-12-01

    Full Text Available Polyester fabric was treated with polyvinyl alcohol in alkaline medium. The moisture regain, water retention and wettability of the PVA treated polyester fabric were tested. The PVA treated PET fabric was dyed with disperse dye. The presence of PVA in the treated PET fabric was assessed by spot test. The treated fabric was also characterized by scanning electron microscope, FTIR and differential scanning calorimetry. The PVA treated polyester fabric showed improved hydrophilic character over intact and sodium hydroxide treated PET fabrics.

  7. Study of the properties and biodegradability of polyester/starch blends submitted to microbial attack

    International Nuclear Information System (INIS)

    Vinhas, Gloria M.; Almeida, Yeda M.B. de; Lima, Maria Alice Gomes de Andrade; Santos, Livia Almeida

    2007-01-01

    This work deals with the biodegradation of blends of poly(beta-hydroxybutyrate)/starch and poly(beta-hydroxybutyrate-cohydroxyvalerate)/ starch. The blends were obtained by evaporation of the solvent in the mixture of the polymers in chloroform. Tests were carried out in presence of micro-organisms which acted as biodegradation agents. The blends were consumed as carbon substrate and the production of CO 2 was evaluated in the process. In addition, the polyesters' mechanical properties were reduced by the incorporation of starch in its structure. ( 1 H) NMR and infrared spectroscopy detected some characteristic polyester degradation groups in the polyesters' chemical structure, thus confirming the alteration suffered by it. (author)

  8. Microwave-irradiation polyol synthesis of PVP-protected Pt–Ni electrocatalysts for methanol oxidation reaction

    CSIR Research Space (South Africa)

    Mathe, Ntombizodwa R

    2017-01-01

    Full Text Available ://doi.org/10.1007/s12678-017-0441-3 Microwave-Irradiation Polyol Synthesis of PVP-Protected Pt–Ni Electrocatalysts for Methanol Oxidation Reaction Ntombizodwa R. Mathe Manfred R. Scriba Rirhandzu S. Rikhotso Neil J. Coville ABSTRACT: Bimetallic Pt...

  9. Radiation-induced changes affecting polyester based polyurethane binder

    Science.gov (United States)

    Pierpoint, Sujita Basi

    The application of thermoplastic polyurethane elastomers as binders in the high energy explosives particularly when used in weapons presents a significantly complex and challenging problem due to the impact of the aging of this polymer on the useful service life of the explosive. In this work, the effects of radiation on the aging of the polyester based polyurethane were investigated using both electron beam and gamma irradiation at various dose rates in the presence and absence of oxygen. It was found by means of GPC that, in the presence and absence of oxygen, the poly (ester urethane) primarily undergoes cross-linking, by means of a carbon-centered secondary alkyl radical. It was also concluded that the polymer partially undergoes scission of the backbone of the main chain at C-O, N-C, and C-C bonds. Substantial changes in the conditions of irradiation and in dose levels did not affect the cross-linking and scission yields. Experiments were also performed with EPR spectroscopy for the purpose of identifying the initial carbon-centered free radicals and for studying the decay mechanisms of these radicals. It was found that the carbon-centered radical which is produced via C-C scission (primary alkyl radical) is rapidly converted to a long-lived allylic species at higher temperatures; more than 80% radicals are converted to allyl species in 2.5 hours. In the presence of oxygen, the allyl radical undergoes a fast reaction to produce a peroxyl radical; this radical decays with a 1.7 hour half-life by pseudo first-order kinetics to negligible levels in 13 hours. FTIR measurements were conducted to identify the radiation-induced changes to the functional groups in the polyester polyurethane. These measurements show an increase in carbonyl, amine and carboxylic groups as a result of reaction of H atoms with R-C-O·, ·NH-R and R-COO·. The FTIR results also demonstrate the production of the unsaturation resulting from hydrogen atom transfer during intrachain conversion

  10. Influence of the polyol pathway on norepinephrine transporter reduction in diabetic cardiac sympathetic nerves: implications for heterogeneous accumulation of MIBG

    International Nuclear Information System (INIS)

    Kiyono, Yasushi; Kajiyama, Satomi; Fujiwara, Hiromi; Kanegawa, Naoki; Saji, Hideo

    2005-01-01

    Cardiac scintigraphic studies using 123 I-labeled metaiodobenzylguanidine ([ 123 I]MIBG) have demonstrated heterogeneous myocardial accumulation of MIBG in diabetes. The accumulation has been found to correlate with a heterogeneous decrease in the expression of norepinephrine transporter (NET). In diabetic peripheral nerve tissue, polyol pathways are activated and cause nerve dysfunction and degeneration. However, there has been little research on the polyol pathway and cardiac sympathetic nerves. Therefore, to assess the influence of the polyol pathway on cardiac sympathetic nervous function, we investigated the regional accumulation of MIBG and NET protein expression in diabetic model rats treated with aldose reductase inhibitor (ARI) for the blockade of polyol pathways. Rats were given a single intravenous injection of streptozotocin (n=76, STZ-D rats). Starting the day after STZ injection, ARI was administered daily to 42 of the rats for 4 weeks (ARI-D rats). To assess the cardiac sympathetic nervous function, [ 125 I]MIBG autoradiographic experiments were carried out. Finally, NET protein expression was assessed with a saturation binding assay. The myocardial sorbitol concentration was significantly higher in STZ-D rats than in ARI-D rats. There was no heterogeneous accumulation of MIBG in ARI-D rats. There was a heterogeneous decrease of NET expression in STZ-D rats, but not in ARI-D or control rats. The gathered data indicate that the enhanced polyol pathway correlates with the decrease in regional cardiac sympathetic nervous function, and this impairment may lead to the reduction of NET protein in cardiac sympathetic nerves of the diabetic inferior wall. (orig.)

  11. Polyester Sulphonic Acid Interstitial Nanocomposite Platform for Peroxide Biosensor

    Directory of Open Access Journals (Sweden)

    Emmanuel I. Iwuoha

    2009-12-01

    Full Text Available A novel enzyme immobilization platform was prepared on a platinum disk working electrode by polymerizing aniline inside the interstitial pores of polyester sulphonic acid sodium salt (PESA. Scanning electron microscopy study showed the formation of homogeneous sulphonated polyaniline (PANI nanotubes (~90 nm and thermogravimetric analysis (TGA confirmed that the nanotubes were stable up to 230 °C. The PANI:PESA nanocomposite showed a quasi-reversible redox behaviour in phosphate buffer saline. Horseradish peroxidase (HRP was immobilized on to this modified electrode for hydrogen peroxide detection. The biosensor gave a sensitivity of 1.33 μA (μM-1 and a detection limit of 0.185 μM for H2O2. Stability experiments showed that the biosensor retained more than 64% of its initial sensitivity over four days of storage at 4 °C.

  12. Preparation of polyester /Calcium sulfate/ composites using radiation

    International Nuclear Information System (INIS)

    Ajji, Z.

    2004-01-01

    Different composites have been prepared using various doses of gamma radiation. Two polyesters, Super Mastics and General, and calcium sulfate or natural gypsum have been used for preparing the composites. Some physical properties of the composites and the influence of Gamma rays on it has been studied as: compression, hardness, thermal decomposition temperature in nitrogen or oxygen, and change in weight in aqua solutions with different pH. Our results show that the glass transition temperature increases by increasing the absorbed dose up to a plateau. Further, the composites show a good thermal stability, and the absorbed dose does not affect the thermal decomposition temperature or the oxidation induction time for the prepared composites. Compression strength of the prepared composites decreases by increasing the filler ratios, and the absorbed does not seem to influence this property significantly. (author)

  13. Preparation of polyester /Calcium sulfate/ composites using radiation

    International Nuclear Information System (INIS)

    Ajji, Z.

    2003-04-01

    Different composites have been prepared using various doses of gamma radiation. Two polyesters, Super Mastics and General, and calcium sulfate or natural gypsum have been used for preparing the composites. Some physical properties of the composites and the influence of Gamma rays on it has been studied as: compression, hardness, thermal decomposition temperature in nitrogen or oxygen, and change in weight in aqua solutions with different pH. Our results show that the glass transition temperature increases by increasing the absorbed dose up to a plateau. Further, the composites show a good thermal stability, and the absorbed dose does not affect the thermal decomposition temperature or the oxidation induction time for the prepared composites. Compression strength of the prepared composites decreases by increasing the filler ratios, and the absorbed does not seem to influence this property significantly. (author)

  14. Radiation curable coatings from palm oil acrylated polyester prepolymer

    International Nuclear Information System (INIS)

    Azam Ali, M.; Ooi, T.L.; Salmiah, A.; Ishiaku, U.S.; Mohd Ishak, Z.A.

    2002-01-01

    Radiation (ultra-violet, UV) curable coatings were prepared by using palm oil acrylated polyester prepolymer (PEPP-1) in combination with different reactive diluents in the presence of photoinitiator Irgacure 184 (Irg184). The effects of viscosity of coating materials, radiation dose and curing behavior were investigated. The UV cured polymeric films properties such as pendulum hardness, wettability (contact angle), gel ,content, swelling character, tensile strength, elongation at break, and deformation stability were then determined. The optimum formulations were also coated on wood substrates after which the gloss and hardness of the cured film on the wood substrate were measured. Some formulations showed promising coatings properties and has a good potential application for the wood coating industry. (Author)

  15. Degradation Mechanisms of Poly(ester urethane) Elastomer

    Energy Technology Data Exchange (ETDEWEB)

    Edgar, Alexander S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-30

    This report describes literature regarding the degradation mechanisms associated with a poly(ester urethane) block copolymer, Estane® 5703 (Estane), used in conjunction with Nitroplasticizer (NP), and 1,3,5,7-tetranitro-1,3,5,7-tetrazocane, also known as high molecular weight explosive (HMX) to produce polymer bonded explosive PBX 9501. Two principal degradation mechanisms are reported: NO2 oxidative reaction with the urethane linkage resulting in crosslinking and chain scission events, and acid catalyzed hydrolysis of the ester linkage. This report details future work regarding this PBX support system, to be conducted in late 2017 and 2018 at Engineered Materials Group (MST-7), Materials Science and Technology Division, Los Alamos National Laboratory. This is the first of a series of three reports on the degradation processes and trends of the support materials of PBX 9501.

  16. Kekuatan Lentur Komposit Polyester Berpenguat Serat Tapis Kelapa

    Directory of Open Access Journals (Sweden)

    I Made Astika

    2015-07-01

    Full Text Available Penelitian ini bertujuan untuk menyelidiki sifat mekanis yaitu kekuatan lentur dari kompositpolyester yang diperkuat dengan serat tapis kelapa. Di masa depan komposit ini dapatdigunakan untuk menggantikan kayu, bambu dan gipsun yang harganya mahal dan tidaktahan air. Komposit dibuat dengan memanfaatkan serat sabut kelapa dan matriks resinUnsaturated-Polyester (UPRs jenis Yucalac 157 BQTN, campuran 1% hardener jenis MEKPO(Methyl Ethyl Ketone Peroxide dan perendaman serat dalam larutan alkali KMnO4 0,5%.Metode produksi yang digunakan adalah press hand lay up dengan orientasi serat acak.Desain komposit dengan variasi fraksi volume serat 20, 25 dan 30% dan variasi panjang serat5, 10 dan 15 mm. Hasil penelitian menunjukkan bahwa semakin besar fraksi volume danpanjang serat dalam komposit maka kekuatan lentur semakin tinggi. Mode patahan yangteramati adalah patah getas, debonding, pullout dan crack deflection.Kata kunci: komposit, serat tapis kelapa, kekuatan lentur, mode patahan The purpose of this study is to investigate the mechanical properties i.e. flexural strength ofcomposites coconut filter fiber. In the future this material can be used to replace the wood,bamboo and gipsun which are high price and lower water resistance.The research material made with coconut filter fiber as reinforcement and matrix resinunsaturated polyester (UPRs type Yukalac BQTN 157, with 1% hardener types MEKPO(Methyl Ethyl Ketone Peroxide and fiber treatment by 0.5% KMnO4. Production methods arepress hand lay-up and the variations of fiber volume fraction are 20, 25 and 30% and fiberlength are 5, 10 and 15 mm. Testing of mechanical properties is flexural test (ASTM - D790The results of research show that the longer of fiber and the bigger of fiber volume fraction,the higher of flexural strength are obtained. The fracture mode are overload, debonding ,pullout and crack deflectionKeywords : composites, coconut filter fiber, flexural strength, fracture mode

  17. Influence of the molecular structure on hydrolysability of unsaturated polyesters

    International Nuclear Information System (INIS)

    Pays, M.F.; Denis, V.

    1993-09-01

    EDF has decided to replace conventional materials by glass reinforced plastics for certain PWR water distribution systems (raw water system, essential service water system, firefighting water distribution system, etc...). Since steel corrodes rapidly in these pipings, introducing composite materials will be economically beneficial if the long-term resistance of these materials can be guaranteed. However, due to hydrolysis of the resin or of the fiber-matrix interface, composite materials deteriorations may occur during service life. This paper reports on the hydrolysis resistance of polyester and vinylester resins. - Model monomers were studied to relate the molecular structure to the hydrolysis resistance. Two ester categories were determined, the diacids and the diols. For the diacids, we obtained the following classification in increasing order of resistance: < maleates < ethoxysuccinates < succinates < fumerates < terephtalates < orthophtalates < isophtalates and for the diols: trioxyethylene glycol << butane diol ∼ ethylene glycol < neopentyl glycol < bisphenol A. The positions obtained for neopentyl glycol and isophtalic acid on this scale justify their inclusion in the formulation of hydrolysis-resistant resins. Since aliphatic unsaturated esters are highly sensitive to hydrolysis, the cross linking procedures for these materials, notably the post-cure stages, must be the subject of particular care. - The hydrolytic degradation of cross linked materials was studied. It was shown that hydrolysis could be monitored by a simple gravimetric method. Used in association with accelerated aging tests, it predicts the time lapse to initiation of the phenomenon. The better hydrolysis resistance of vinylester resins as compared with unsaturated polyesters has been demonstrated. However, forecasting over a 30-year life span is difficult to guarantee in that this involves indicating in the resin specifications the in-service stress which it will be required to

  18. Effective Interfacially Polymerized Polyester Solvent Resistant Nanofiltration Membrane from Bioderived Materials

    KAUST Repository

    Abdellah, Mohamed H.; Perez Manriquez, Liliana; Puspasari, Tiara; Scholes, Colin A.; Kentish, Sandra E.; Peinemann, Klaus-Viktor

    2018-01-01

    Utilization of sustainable and environmentally friendly solvents for the preparation of membranes has attracted growing interest in recent years. In this work, a polyester thin film composite solvent resistant nanofiltration (SRNF) membrane

  19. Filler Fraction Effect on Creep Response of Crosslinked Polyester Matrix with Mineral Filler

    Czech Academy of Sciences Publication Activity Database

    Hristova, J.; Minster, Jiří

    Vol. 89, - (2003), s. 3329-3335 ISSN 0021-8995 Institutional research plan: CEZ:AV0Z2071913 Keywords : polyester composites * creep * ageing Subject RIV: JI - Composite Materials Impact factor: 1.017, year: 2003

  20. 78 FR 17637 - Polyester Staple Fiber From Taiwan: Preliminary Results of Antidumping Duty Administrative Review...

    Science.gov (United States)

    2013-03-22

    ... DEPARTMENT OF COMMERCE International Trade Administration [A-583-833] Polyester Staple Fiber From... Administration, International Trade Administration, Department of Commerce. SUMMARY: The Department of Commerce.../CVD Operations, Office 1, Import Administration, International Trade Administration, U.S. Department...

  1. Effect of structural parameters on burning behavior of polyester fabrics having flame retardancy property

    Science.gov (United States)

    Çeven, E. K.; Günaydın, G. K.

    2017-10-01

    The aim of this study is filling the gap in the literature about investigating the effect of yarn and fabric structural parameters on burning behavior of polyester fabrics. According to the experimental design three different fabric types, three different weft densities and two different weave types were selected and a total of eighteen different polyester drapery fabrics were produced. All statistical procedures were conducted using the SPSS Statistical software package. The results of the Analysis of Variance (ANOVA) tests indicated that; there were statistically significant (5% significance level) differences between the mass loss ratios (%) in weft and mass loss ratios (%) in warp direction of different fabrics calculated after the flammability test. The Student-Newman-Keuls (SNK) results for mass loss ratios (%) both in weft and warp directions revealed that the mass loss ratios (%) of fabrics containing Trevira CS type polyester were lower than the mass loss ratios of polyester fabrics subjected to washing treatment and flame retardancy treatment.

  2. [Analysis of anatomical pieces preservation with polyester resin for human anatomy study].

    Science.gov (United States)

    de Oliveira, Ítalo Martins; Mindêllo, Marcela Maria Aguiar; Martins, Yasmin de Oliveira; da Silva Filho, Antônio Ribeiro

    2013-01-01

    To evaluate the use of polyester resin in preserving anatomical specimens for the study of human anatomy. We used 150 anatomical specimens, comprised of unfixed (fresh), fixed in 10% formalin and vascular casts of organs injected with vinyl acetate and polyester resin. The solution used consisted of polyester resin with the diluent styrene monomer and catalyst (peroxol). After embedding in this solution, models in transparent resin were obtained, allowing full observation of structures and conservation of the specimens used. upon evaluation of the specimens, we observed a high degree of transparency, which promoted a complete visualization of structures with perfect preservation of the anatomy. The average time for the completion of the embedding was 48 hours. Only 14 specimens (9.3%) were lost during the preparation. Polyester resin can be used for preserving anatomical specimens for teaching human anatomy in a practical, aesthetic and durable way.

  3. Dynamic mechanical and dielectric behavior of banana–glass hybrid fiber reinforced polyester composites.

    CSIR Research Space (South Africa)

    Pothan, LA

    2009-01-01

    Full Text Available Hybrid composites of glass and banana fiber (obtained from the pseudo stem of Musa sapientum) in polyester matrix, are subjected to dynamic mechanical analysis over a range of temperature and three different frequencies. The effect of temperature...

  4. Investigation of Mechanical Properties of Unidirectional Steel Fiber/Polyester Composites: Experiments and Micromechanical Predictions

    DEFF Research Database (Denmark)

    Raghavalu Thirumalai, Durai Prabhakaran; Løgstrup Andersen, Tom; Bech, Jakob Ilsted

    2016-01-01

    the role of material and process parameters on material properties. Two types of SFRP were studied: polyester resin reinforced by both steel fabric containing unidirectional fibers and steel fibers wound on a metal frame with 0° orientations. The effects of the fiber volume fraction and the role of polymer......The article introduces steel fiber reinforced polymer composites, which is considered new for composite product developments. These composites consist of steel fibers or filaments of 0.21 mm diameter embedded in a polyester resin. The goal of this investigation is to characterize the mechanical...... performance of steel fiber reinforced polyester composites at room temperature. The mechanical properties of unidirectional steel fiber reinforced polyester composites (SFRP) are evaluated experimentally and compared with the predicted values by micro-mechanical models. These predictions help to understand...

  5. High Efficiency Particulate Air (HEPA) filters from polyester and polypropylene fibre nonwovens

    CSIR Research Space (South Africa)

    Boguslavsky, L

    2010-10-01

    Full Text Available filtration efficiency. Glass fibres are more harmful to human, compared to polypropylene and polyester fibre which are chemically inert. Hydroentanglement and chemical bonding techniques were utilised in manufacturing nonwovens for dry filtration. Acrylic...

  6. Effect of Argon Plasma Treatment Variables on Wettability and Antibacterial Properties of Polyester Fabrics

    Science.gov (United States)

    Senthilkumar, Pandurangan; Karthik, Thangavelu

    2016-04-01

    In this research work, the effect of argon plasma treatment variables on the comfort and antibacterial properties of polyester fabric has been investigated. The SEM micrographs and FTIR analysis confirms the modification of fabric surface. The Box-Behnken design was used for the optimization of plasma process variables and to evaluate the effects and interactions of the process variables, i.e. operating power, treatment time and distance between the electrodes on the characteristics of polyester fabrics. The optimum conditions of operating power 600 W, treatment time 30 s, and the distance between the electrodes of 2.8 mm was arrived using numerical prediction tool in Design-Expert software. The plasma treated polyester fabrics showed better fabric characteristics particularly in terms of water vapour permeability, wickability and antibacterial activity compared to untreated fabrics, which confirms that the modified structure of polyester fabric.

  7. Fully Biobased Unsaturated Aliphatic Polyesters from Renewable Resources : Enzymatic Synthesis, Characterization, and Properties

    NARCIS (Netherlands)

    Jiang, Yi; Alberda van Ekenstein, Gerhard; Woortman, Albert J. J.; Loos, Katja

    2014-01-01

    Fully biobased saturated and unsaturated aliphatic polyesters and oligoesters are successfully prepared by Candida antarctica lipase B (CALB)-catalyzed polycondensations of succinate, itaconate, and 1,4-butanediol. The effects of monomer substrates and polymerization methods on enzymatic

  8. Effect of polyester fiber reinforcement on the mechanical properties of interim fixed partial dentures

    Directory of Open Access Journals (Sweden)

    N. Gopichander

    2015-10-01

    Conclusion: Within the limitations of this study, polyester fiber reinforcements improved the mechanical properties of heat-polymerized PMMA, cold-polymerized PMMA, and bis-acrylic provisional FPD materials.

  9. Growth mechanism of silver nanowires synthesized by polyvinylpyrrolidone-assisted polyol reduction

    International Nuclear Information System (INIS)

    Gao Yan; Jiang Peng; Song Li; Liu Lifeng; Yan Xiaoqin; Zhou Zhenping; Liu Dongfang; Wang Jianxiong; Yuan Huajun; Zhang Zengxing; Zhao Xiaowei; Dou Xinyuan; Zhou Weiya; Wang Gang; Xie Sishen

    2005-01-01

    Silver (Ag) nanowires with a pentagonal cross section have been synthesized by polyvinylpyrrolidone (PVP)-assisted polyol reduction in the presence of Pt nanoparticle seeds. The UV-visible absorption spectra and scanning electron microscopy have been used to trace the growth process of the Ag nanowires. X-ray photoelectron spectroscopy investigation further shows that the PVP molecules are adsorbed on the surface of the Ag nanowires through Ag : O coordination. Comparing with the growth process of Ag nanoparticles, a possible growth mechanism of the Ag nanowires has been proposed. It is implied that the PVP molecules are used as both a protecting agent and a structure-directing agent for the growth of Ag nanowires. It is concluded that the five-fold twinning Ag nanoparticles are formed through heterogenous nucleation after the introduction of Pt nanoparticle seeds and then grow anisotropically along the (110) direction, while the growth along (100) is relatively depressed

  10. Study the Polyol Process of Preparing the ru Doped FePt Nanoparticles

    Science.gov (United States)

    Lee, Chih-Hao; Hsu, Jen-Ho; Su, Hui-Chia; Huang, Tzu Wen

    The structure of Ru doped FePt nanoparticles using polyol process was studied. The particle size grown is around 5 nm, and a shell structure might be formed. By selecting the time and temperature of adding the Ru precursors into solution, three different processes to synthesize the FePtRu particles were studied resulting in different growing mechanics. The possible models during the reaction process are also discussed. The phase transition temperature for the as-grown FCC FePt nanoparticle to transform into L10 FePt nanoparticle is about 823 K which is about the same as the one without doping Ru atoms. From the XAS study of each element, the possible scenario is that: although Ru atoms with the size close to the Pt, they do not totally replace the Pt sites in the FePt alloy. Instead, most of Ru formed a shell outside the FePt nanoparticles and Fe atoms are replaced.

  11. Influence of surfactant on the preparation of silver nanoparticles by polyol method

    International Nuclear Information System (INIS)

    Dung Dang, Thi My; Tuyet Le, Thi Thu; Dang, Mau Chien; Fribourg-Blanc, Eric

    2012-01-01

    In this study, silver nanoparticles were synthesized from silver nitrate via a polyol method in ambient atmosphere. In our synthesis route, polyvinylpyrrolidone (PVP) is used as both size controller and capping agent, ethylene glycol acts both as solvent and reducing agent. The obtained silver nanoparticles were characterized by ultraviolet-visible spectrophotometry which indicated the formation of nanoparticles. Investigation of Fourier transform infrared spectroscopy clearly demonstrated the coordination between silver nanoparticles and PVP. Transmission electron microscopy (TEM) contributed to the particle size analysis. The surface plasmon resonance peak in absorption spectra of silver colloidal solution showed absorption from 406 to 409 nm. The average size of the resulting silver nanoparticles was below 10 nm with a dependency on the PVP concentration. (paper)

  12. Stelliosphaerols A and B, Sesquiterpene-Polyol Conjugates from an Ecuadorian Fungal Endophyte.

    Science.gov (United States)

    Forcina, Giovanni C; Castro, Amaya; Bokesch, Heidi R; Spakowicz, Daniel J; Legaspi, Michelle E; Kucera, Kaury; Villota, Stephany; Narváez-Trujillo, Alexandra; McMahon, James B; Gustafson, Kirk R; Strobel, Scott A

    2015-12-24

    Endophytic fungi are plant tissue-associated fungi that represent a rich resource of unexplored biological and chemical diversity. As part of an ongoing effort to characterize Amazon rainforest-derived endophytes, numerous fungi were isolated and cultured from plants collected in the Yasuní National Park in Ecuador. Of these samples, phylogenetic and morphological data revealed a previously undescribed fungus in the order Pleosporales that was cultured from the tropical tree Duroia hirsuta. Extracts from this fungal isolate displayed activity against Staphylococcus aureus and were thus subjected to detailed chemical studies. Two compounds with modest antibacterial activity were isolated, and their structures were elucidated using a combination of NMR spectroscopic analysis, LC-MS studies, and chemical degradation. These efforts led to the identification of stelliosphaerols A (1) and B (2), new sesquiterpene-polyol conjugates that are responsible, at least in part, for the S. aureus inhibitory activity of the fungal extract.

  13. Palladium-Catalyzed Telomerization of Butadiene with Polyols: From Mono to Polysaccharides

    Science.gov (United States)

    Bouquillon, Sandrine; Muzart, Jacques; Pinel, Catherine; Rataboul, Franck

    The telomerization of butadiene with alcohols is an elegant way to synthesize ethers with minimal environmental impact since this reaction is 100% atom efficient. Besides telomerization of butadiene with methanol and water that is industrially developed, the modification of polyols is still under development. Recently, a series of new substrates has been involved in this reaction, including diols, pure or crude glycerol, protected or unprotected monosaccharides, as well as polysaccharides. This opens up the formation of new products having specific physicochemical properties. We will describe recent advances in this field, focusing on the reaction of renewable products and more specifically on saccharides. The efficient catalytic systems as well as the optimized reaction conditions will be described and some physicochemical properties of the products will be reported.

  14. Polyol pathway and modulation of ischemia-reperfusion injury in Type 2 diabetic BBZ rat hearts

    Directory of Open Access Journals (Sweden)

    Guberski Dennis

    2008-10-01

    Full Text Available Abstract We investigated the role of polyol pathway enzymes aldose reductase (AR and sorbitol dehydrogenase (SDH in mediating injury due to ischemia-reperfusion (IR in Type 2 diabetic BBZ rat hearts. Specifically, we investigated, (a changes in glucose flux via cardiac AR and SDH as a function of diabetes duration, (b ischemic injury and function after IR, (c the effect of inhibition of AR or SDH on ischemic injury and function. Hearts isolated from BBZ rats, after 12 weeks or 48 weeks diabetes duration, and their non-diabetic littermates, were subjected to IR protocol. Myocardial function, substrate flux via AR and SDH, and tissue lactate:pyruvate (L/P ratio (a measure of cytosolic NADH/NAD+, and lactate dehydrogenase (LDH release (a marker of IR injury were measured. Zopolrestat, and CP-470,711 were used to inhibit AR and SDH, respectively. Myocardial sorbitol and fructose content, and associated changes in L/P ratios were significantly higher in BBZ rats compared to non-diabetics, and increased with disease duration. Induction of IR resulted in increased ischemic injury, reduced ATP levels, increases in L/P ratio, and poor cardiac function in BBZ rat hearts, while inhibition of AR or SDH attenuated these changes and protected hearts from IR injury. These data indicate that AR and SDH are key modulators of myocardial IR injury in BBZ rat hearts and that inhibition of polyol pathway could in principle be used as a therapeutic adjunct for protection of ischemic myocardium in Type 2 diabetic patients.

  15. Vascular filtration function in galactose-fed versus diabetic rats: The role of polyol pathway activity

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, G.; Tilton, R.G.; Speedy, A.; Chang, K.; Province, M.A.; Kilo, C.; Williamson, J.R. (Washington Univ. School of Medicine, St Louis, MO (USA))

    1990-07-01

    These studies were undertaken to assess the effects of increased galactose (v increased glucose) metabolism via the polyol pathway on vascular filtration function in the kidneys, eyes, nerves, and aorta. Quantitative radiolabeled tracer techniques were used to assess glomerular filtration rate (GFR) and regional tissue vascular clearance of plasma 131I-bovine serum albumin (BSA) in five groups of male Sprague-Dawley rats: nondiabetic controls, streptozotocin-diabetic rats, nondiabetic rats fed a 50% galactose diet, diabetic rats treated with sorbinil (an aldose reductase inhibitor), and galactose-fed rats treated with sorbinil. Sorbinil was added to the diet to provide a daily dose of approximately .2 mmol/kg body weight. After 2 months of diabetes or galactose ingestion, albumin clearance was increased twofold to fourfold in the eye (anterior uvea, choroid, and retina), sciatic nerve, aorta, and kidney; GFR was increased approximately twofold and urinary excretion of endogenous albumin and IgG were increased approximately 10-fold. Sorbinil treatment markedly reduced or completely prevented all of these changes in galactose-fed, as well as in diabetic rats. These observations support the hypothesis that increased metabolism of glucose via the sorbitol pathway is of central importance in mediating virtually all of the early changes in vascular filtration function associated with diabetes in the kidney, as well as in the eyes, nerves, and aorta. On the other hand, renal hypertrophy in diabetic rats and polyuria, hyperphagia, and impaired weight gain in galactose-fed and in diabetic rats were unaffected by sorbinil and therefore are unlikely to be mediated by increased polyol metabolism.

  16. Vascular filtration function in galactose-fed versus diabetic rats: The role of polyol pathway activity

    International Nuclear Information System (INIS)

    Pugliese, G.; Tilton, R.G.; Speedy, A.; Chang, K.; Province, M.A.; Kilo, C.; Williamson, J.R.

    1990-01-01

    These studies were undertaken to assess the effects of increased galactose (v increased glucose) metabolism via the polyol pathway on vascular filtration function in the kidneys, eyes, nerves, and aorta. Quantitative radiolabeled tracer techniques were used to assess glomerular filtration rate (GFR) and regional tissue vascular clearance of plasma 131I-bovine serum albumin (BSA) in five groups of male Sprague-Dawley rats: nondiabetic controls, streptozotocin-diabetic rats, nondiabetic rats fed a 50% galactose diet, diabetic rats treated with sorbinil (an aldose reductase inhibitor), and galactose-fed rats treated with sorbinil. Sorbinil was added to the diet to provide a daily dose of approximately .2 mmol/kg body weight. After 2 months of diabetes or galactose ingestion, albumin clearance was increased twofold to fourfold in the eye (anterior uvea, choroid, and retina), sciatic nerve, aorta, and kidney; GFR was increased approximately twofold and urinary excretion of endogenous albumin and IgG were increased approximately 10-fold. Sorbinil treatment markedly reduced or completely prevented all of these changes in galactose-fed, as well as in diabetic rats. These observations support the hypothesis that increased metabolism of glucose via the sorbitol pathway is of central importance in mediating virtually all of the early changes in vascular filtration function associated with diabetes in the kidney, as well as in the eyes, nerves, and aorta. On the other hand, renal hypertrophy in diabetic rats and polyuria, hyperphagia, and impaired weight gain in galactose-fed and in diabetic rats were unaffected by sorbinil and therefore are unlikely to be mediated by increased polyol metabolism

  17. Polyester-Based (Bio)degradable Polymers as Environmentally Friendly Materials for Sustainable Development

    Science.gov (United States)

    Rydz, Joanna; Sikorska, Wanda; Kyulavska, Mariya; Christova, Darinka

    2014-01-01

    This review focuses on the polyesters such as polylactide and polyhydroxyalkonoates, as well as polyamides produced from renewable resources, which are currently among the most promising (bio)degradable polymers. Synthetic pathways, favourable properties and utilisation (most important applications) of these attractive polymer families are outlined. Environmental impact and in particular (bio)degradation of aliphatic polyesters, polyamides and related copolymer structures are described in view of the potential applications in various fields. PMID:25551604

  18. Influence of the substituent on azobenzene side-chain polyester optical storage materials

    DEFF Research Database (Denmark)

    Pedersen, M; Hvilsted, Søren; Holme, NCR

    1999-01-01

    , chloro, and bromo. C-13 NMR spectroscopic and molecular mass investigations substantiate good film forming characteristics. The optical storage performance of thin polyester films are investigated through polarization holography. The resulting diffraction efficiency is mapped and discussed as a function...... of irradiation power and exposure time. Polytetradecanedioates with cyano-, nitro-, methyl-, fluoro-, or trinuoromethyl-azobenzene reach more than 50% diffraction efficiency. Investigations of anisotropy induced at different temperatures reveal that the polyesters are only photosensitive in a narrow temperature...

  19. Clinical outcomes after parastomal hernia repair with a polyester monofilament composite mesh

    DEFF Research Database (Denmark)

    Oma, E; Pilsgaard, B; Jorgensen, L N

    2018-01-01

    with intraperitoneal placement of a polyester monofilament macroporous composite mesh. METHODS: Data on all patients undergoing parastomal hernia repair with Parietex™ Composite Parastomal Mesh at our institution during a 4-year period were examined. Patients with urostomy were excluded. A team of three experienced...... chronic pain. CONCLUSION: In this study, we found low rates of recurrence and chronic pain following parastomal hernia repair using intraperitoneal reinforcement with a polyester monofilament composite mesh....

  20. New UV-curable acrylated polyester prepolymers from palm oil based products

    International Nuclear Information System (INIS)

    Mohd Azam Ali; Ooi, T.L.; Salmiah Ahmad; Umaru, S.I.; Mohd Ishak, Z.A.

    1999-01-01

    Acrylated polyester prepolymers (PEPP-1 and PEPP-2) were synthesized from palm oil and its products. UV-curing and characteristic properties of UV-cured films of synthesized polyester resins were studied. The characteristic properties studied include pendulum hardness, gel content, FT-IR analysis, tensile strength and elongation at break. The materials have good potential for the production of radiation curable coating applications

  1. 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.

  2. A study on effect of ATH on Euphorbia coagulum modified polyester banana fiber composite

    Science.gov (United States)

    Kumari, Sanju; Rai, Bhuvneshwar; Kumar, Gulshan

    2018-02-01

    Fiber reinforced polymer composites are used for building and structural applications due to their high strength. In conventional composites both the binder and the reinforcing fibers are synthetic or either one of the material is natural. In the present study coagulum of Euphorbia royleana has been used for replacing polyester resinas binder in polyester banana composite. Euphorbia coagulum (driedlatex) is rich in resinous mass (60-80%), which are terpenes and polyisoprene (10-20%). Effect of varying percentage of coagulum content on various physico-mechanical properties of polyester-banana composites has been studied. Since banana fiber is sensitive to water due to presence of polar group, banana composite undergoes delamination and deterioration under humid condition. Alkali treated banana fiber along with coagulum content has improved overall mechanical properties and reduction in water absorption. The best physico-mechanical properties have been achieved on replacing 40% of polyester resin by coagulum. An increase of 50% in bending strength, 30% bending modulus and 45% impact strength as well as 68% decrease in water absorption was observed. Incorporation of 20% ATH as flame retardant in coagulum modified banana polyester composite enhanced limiting oxygen index from 20.6 to 26.8% and smoke density reduced up to 40%. This study presents the possibility of utilization of renewable materials for environmental friendly composite development as well as to find out alternative feedstock for petroleum products. Developed Euphorbia latex modified banana polyester composites can have potential utility in hardboard, partition panel, plywood and automotive etc.

  3. Synthesis, characterization and ESR study of polyesters containing isomeric naphthylene units by gamma irradiation

    International Nuclear Information System (INIS)

    Choi, B.K.; Hill, D.J.T.; Choi, E.J.; Ahn, H.K.

    1998-01-01

    Full text: Aromatic polyesters containing naphthalene groups have interesting properties because the geometry of the naphthalene group can provide many of the structural features for the polymer chain. In this study we synthesized six polyesters from 4,4 ' - (hexafluoroisopropyl-idene)bis(benzoic acid) and isomeric naphthylene-diols. An ESR study of the radicals formed on gamma radiolysis of the polyesters has been undertaken to investigate their relative radiation sensitivities. The structures of the polyesters were characterized by means of IR spectroscopy. Inherent viscosities were measured in the range of 0.11 - 0.46 dL/g. Thermal properties of polyesters were determined by DSC and TGA thermograms, respectively. All polyesters were irradiated in an AECL Gamma cell with a dose rate of approximately 6.7kGy h -1 to doses in the range of 0 - 15kGy at 77K and 300K, respectively. In order to identify other radicals present at 77K, annealing studies were utilized by taking advantage of the different reactivities of these radicals

  4. Electrochemical and Electronic Charge Transport Properties of Ni-Doped LiMn2O4 Spinel Obtained from Polyol-Mediated Synthesis

    Directory of Open Access Journals (Sweden)

    Shuo Yang

    2018-05-01

    Full Text Available LiNi0.5Mn1.5O4 (LNMO spinel has been extensively investigated as one of the most promising high-voltage cathode candidates for lithium-ion batteries. The electrochemical performance of LNMO, especially its rate performance, seems to be governed by its crystallographic structure, which is strongly influenced by the preparation methods. Conventionally, LNMO materials are prepared via solid-state reactions, which typically lead to microscaled particles with only limited control over the particle size and morphology. In this work, we prepared Ni-doped LiMn2O4 (LMO spinel via the polyol method. The cycling stability and rate capability of the synthesized material are found to be comparable to the ones reported in literature. Furthermore, its electronic charge transport properties were investigated by local electrical transport measurements on individual particles by means of a nanorobotics setup in a scanning electron microscope, as well as by performing DFT calculations. We found that the scarcity of Mn3+ in the LNMO leads to a significant decrease in electronic conductivity as compared to undoped LMO, which had no obvious effect on the rate capability of the two materials. Our results suggest that the rate capability of LNMO and LMO materials is not limited by the electronic conductivity of the fully lithiated materials.

  5. Development of a readily recyclable sound insulation material made of polyester fibers. Application of the PET fibers from plastic bottles; Recycle kanona jidoshayo polyester sei kyuon zairyo no kaihatsu. Shiyozumi pet bottle zai no insulator zai eno tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Nemoto, K; Watanabe, K; Sugawara, H; Minemura, Y [Nissan Motor Co. Ltd., Tokyo (Japan)

    1997-10-01

    We have developed new polyester sound-absorbing materials made of fine and modified-cross-section polyester fabric. They provide noticeably higher sound-absorbing performance than traditional materials. Another feature of the new materials is their excellent recyclability since they are made of polyester. Application of the new materials to the dash silencer and the floor carpeting produced a great improvement in sound-insulation performance with less weight. 2 refs., 7 figs.

  6. The influences of microwave irradiation and polyol precursor pH on Cu/AC catalyst and its CO oxidation performance

    Science.gov (United States)

    Chuang, Kui-Hao; Shih, Kaimin; Wey, Ming-Yen

    2012-10-01

    This study evaluated the effects of microwave irradiation parameters and the pH of the polyol precursor on the morphological features and catalytic performances of Cu/activated carbon (AC) catalysts. Experimental results of carbon monoxide (CO) oxidation indicated that the highest catalytic activity is achieved when the Cu/AC catalyst is prepared with microwave irradiation at 700 W for 60 s. Scanning electron microscopy revealed the presence of beneficial small copper aciculae on the Cu/AC catalyst under such a microwave irradiation scheme. Further investigation of operational parameters found that the performance of Cu/AC catalysts is enhanced by adopting a pH = 12 polyol precursor solution. With the observation that small cube copper ( 16 nm) aggregates form when a pH = 12 polyol precursor solution is used, this study also demonstrated the importance of controlling the morphology of metal nanoparticles on Cu/AC catalysts when using the microwave-assisted polyol method.

  7. The influences of microwave irradiation and polyol precursor pH on Cu/AC catalyst and its CO oxidation performance

    International Nuclear Information System (INIS)

    Chuang, Kui-Hao; Shih, Kaimin; Wey, Ming-Yen

    2012-01-01

    This study evaluated the effects of microwave irradiation parameters and the pH of the polyol precursor on the morphological features and catalytic performances of Cu/activated carbon (AC) catalysts. Experimental results of carbon monoxide (CO) oxidation indicated that the highest catalytic activity is achieved when the Cu/AC catalyst is prepared with microwave irradiation at 700 W for 60 s. Scanning electron microscopy revealed the presence of beneficial small copper aciculae on the Cu/AC catalyst under such a microwave irradiation scheme. Further investigation of operational parameters found that the performance of Cu/AC catalysts is enhanced by adopting a pH = 12 polyol precursor solution. With the observation that small cube copper (∼16 nm) aggregates form when a pH = 12 polyol precursor solution is used, this study also demonstrated the importance of controlling the morphology of metal nanoparticles on Cu/AC catalysts when using the microwave-assisted polyol method.

  8. A low fermentable oligo-di-mono-saccharides and polyols (FODMAP) diet is a balanced therapy for fibromyalgia with nutritional and symptomatic benefits

    OpenAIRE

    Marum, Ana Paula; Moreira, Cátia; Tomas-Carus, Pablo; Saraiva, Fernando; Guerreiro, Catarina Sousa

    2017-01-01

    Introduction: Fibromyalgia is a chronic rheumatic disease producing widespread pain, associated to a major comorbidity -irritable bowel syndrome. Low FODMAPS diet (low fermentable oligo-di-mono-saccharides and polyols diet) has been effective in controlling irritable bowel syndrome symptoms. Overweight is an aggravating factor for fibromyalgia. We studied effects of low fermentable oligo-di-mono-saccharides and polyols diets on fibromyalgia symptoms and weight status. Methods: A longitudinal ...

  9. The influence of seeding conditions and shielding gas atmosphere on the synthesis of silver nanowires through the polyol process

    Science.gov (United States)

    Chen, Chang; Wang, Li; Jiang, Guohua; Yang, Qiang; Wang, Jianjun; Yu, Haojie; Chen, Tao; Wang, Chiliang; Chen, Xu

    2006-01-01

    The polyol process including the introduction of preformed seeds and the inducement of poly(vinyl pyrrolidone) (PVP) has been developed as a powerful approach for synthesizing silver nanowires. Here, silver nanowires without other metal elements as impurities were synthesized through a silver seeding polyol process in a shielding gas atmosphere. It is demonstrated that the first seeding step is critical in obtaining silver nanowires as the principal product, and we also observe that the shielding gas atmosphere not only improves the repeatability of experiments but also affects the morphology of the final product. We obtained nanocubes with hydrogen gas shielding in a short reaction time; these would scarcely appear with argon or air shielding. Our work supplies new evidence to explain the actual growth mechanism of silver nanowires.

  10. Synthesis and characterization of silver-copper core-shell nanoparticles using polyol method for antimicrobial agent

    Science.gov (United States)

    Hikmah, N.; Idrus, N. F.; Jai, J.; Hadi, A.

    2016-06-01

    Silver and copper nanoparticles are well-known as the good antimicrobial agent. The nano-size of particles influences in enhancing the antimicrobial activity. This paper discusses the effect of molarity on the microstructure and morphology of silver-copper core-shell nanoparticles prepared by a polyol method. In this study, silver-copper nanoparticles are synthesized through the green approach of polyol method using ethylene glycol (EG) as green solvent and reductant, and polyoxyethylene-(80)-sorbitan monooleate (Tween 80) as a nontoxic stabilizer. The phase and morphology of silver-copper nanoparticles are characterized by X-ray diffraction (XRD) and Field emission scanning electron microscope (FESEM) and Transmission electron microscope (TEM). The results XRD confirm the pure crystalline of silver and copper nanoparticles with face-centered cubic (FCC) structure. FESEM and TEM analysis confirm the existence of Ag and Cu nanoparticles in core-shell shape.

  11. Synthesis and degradation kinetics of a novel polyester containing bithiazole rings

    Energy Technology Data Exchange (ETDEWEB)

    He, W., E-mail: hwdut2003@yahoo.com [Research Center of Plastic Engineering, Shenyang University of Chemical Technology, Shenyang 110142 (China); State Key Laboratory of Robotics (China); Department of Chemistry, University of the Free State (Qwaqwa Campus), Private Bag X13, Phuthaditjhaba 9866 (South Africa); Jiang, Y.Y. [Research Center of Plastic Engineering, Shenyang University of Chemical Technology, Shenyang 110142 (China); State Key Laboratory of Robotics (China); Luyt, A.S. [Department of Chemistry, University of the Free State (Qwaqwa Campus), Private Bag X13, Phuthaditjhaba 9866 (South Africa); Ocaya, R.O. [Department of Physics, University of the Free State (Qwaqwa Campus), Private Bag X13, Phuthaditjhaba 9866 (South Africa); Ge, T.J. [Research Center of Plastic Engineering, Shenyang University of Chemical Technology, Shenyang 110142 (China); State Key Laboratory of Robotics (China)

    2011-10-20

    Highlights: {yields} A novel Schiff base type polyester was synthesized and characterized by FTIR spectroscopy, elemental analysis, and X-ray diffraction spectroscopy. {yields} Thermal degradation of the polyester in nitrogen has been studied at several heating rates by thermogravimetric analysis. {yields} The activation energies were calculated by different methods. And the possible conversation function was estimated. {yields} The life time estimates for the polyester can be determined and the results demonstrate that the polymer possesses good thermal resistance. - Abstract: A novel Schiff base type polyester containing 2,2'-diamino-4,4'-bithiazole (DABT) was prepared by low-temperature interface polycondensation of 1,4-benzenedicarbonyl dichloride with 4,4'-(4,4'-bithiazole-2,2'-diylbis(imine-2,1-diyl) diphenol (BDDP), which is derived from a 2,2'-diamino-4,4'-bithiazole (DABT) Schiff base reacted with a 4-hydroxybenzaldehyde monomer. The newly generated polyester was characterized by FTIR spectroscopy, elemental analysis, and X-ray diffraction spectroscopy. The thermal decomposition was investigated in nitrogen atmosphere using thermogravimetric analysis. The activation energies of the decomposition step of the polyester were calculated through the isoconversional methods of Kissinger-Akahira-Sunose (K-A-S) and the iterative equation. In order to estimate the reaction model that best describes the experimental data, the use of an empirical kinetic equation based on that proposed by Sestak-Berggren was investigated here. On the basis of the kinetic data, the life time estimates for the polyester generated from the weight loss of 5%, 10%, and 15% were also constructed.

  12. Effect of the Reduction Temperature of PdAg Nanoparticles during the Polyol Process in the Ethanol Electrooxidation Reaction

    OpenAIRE

    Carrera-Cerritos, R.; Salazar-Hernandez, C.; Galindo-Esquivel, I. R.; Fuentes-Ramirez, R.

    2018-01-01

    This work reports the effect of reduction temperature during the synthesis of PdAg catalysts through the polyol process and their evaluation in the ethanol electrooxidation reaction (EOR). The characterization was performed using Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD). The electrochemical evaluation for the ethanol electrooxidation reaction was implemented in alkaline medium using chronoamperometry (CA) and cyclic voltammetry (CV). An important effect of the reduct...

  13. Regulation of intracellular glucose and polyol pathway by thiamine and benfotiamine in vascular cells cultured in high glucose.

    Science.gov (United States)

    Berrone, Elena; Beltramo, Elena; Solimine, Carmela; Ape, Alessandro Ubertalli; Porta, Massimo

    2006-04-07

    Hyperglycemia is a causal factor in the development of the vascular complications of diabetes. One of the biochemical mechanisms activated by excess glucose is the polyol pathway, the key enzyme of which, aldose reductase, transforms d-glucose into d-sorbitol, leading to imbalances of intracellular homeostasis. We aimed at verifying the effects of thiamine and benfotiamine on the polyol pathway, transketolase activity, and intracellular glucose in endothelial cells and pericytes under high ambient glucose. Human umbilical vein endothelial cells and bovine retinal pericytes were cultured in normal (5.6 mmol/liter) or high (28 mmol/liter) glucose, with or without thiamine or benfotiamine 50 or 100 mumol/liter. Transketolase and aldose reductase mRNA expression was determined by reverse transcription-PCR, and their activity was measured spectrophotometrically; sorbitol concentrations were quantified by gas chromatography-mass spectrometry and intracellular glucose concentrations by fluorescent enzyme-linked immunosorbent assay method. Thiamine and benfotiamine reduce aldose reductase mRNA expression, activity, sorbitol concentrations, and intracellular glucose while increasing the expression and activity of transketolase, for which it is a coenzyme, in human endothelial cells and bovine retinal pericytes cultured in high glucose. Thiamine and benfotiamine correct polyol pathway activation induced by high glucose in vascular cells. Activation of transketolase may shift excess glycolytic metabolites into the pentose phosphate cycle, accelerate the glycolytic flux, and reduce intracellular free glucose, thereby preventing its conversion to sorbitol. This effect on the polyol pathway, together with other beneficial effects reported for thiamine in high glucose, could justify testing thiamine as a potential approach to the prevention and/or treatment of diabetic complications.

  14. 77 FR 1267 - National Emission Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins...

    Science.gov (United States)

    2012-01-09

    ... Cooling Tower PEPO--Polyether Polyols PET--Poly (Ethylene Terephthalate) Resin PM--Particulate Matter POM...., fixed roofs on storage vessels and oil water separators; covers on surface impoundments, containers and... category: Solid-state resins (PET bottle grade resins), polyester film and engineering resins. They are all...

  15. The Modification of Polyurethane Foams Using New Boroorganic Polyols (II) Polyurethane Foams from Boron-Modified Hydroxypropyl Urea Derivatives

    Science.gov (United States)

    2014-01-01

    The work focuses on research related to determination of application possibility of new, ecofriendly boroorganic polyols in rigid polyurethane foams production. Polyols were obtained from hydroxypropyl urea derivatives esterified with boric acid and propylene carbonate. The influence of esterification type on properties of polyols and next on polyurethane foams properties was determined. Nitrogen and boron impacts on the foams' properties were discussed, for instance, on their physical, mechanical, and electric properties. Boron presence causes improvement of dimensional stability and thermal stability of polyurethane foams. They can be applied even at temperature 150°C. Unfortunately, introducing boron in polyurethanes foams affects deterioration of their water absorption, which increases as compared to the foams that do not contain boron. However, presence of both boron and nitrogen determines the decrease of the foams combustibility. Main impact on the decrease combustibility of the obtained foams has nitrogen presence, but in case of proper boron and nitrogen ratio their synergic activity on the combustibility decrease can be easily seen. PMID:24587721

  16. Optimum Drafting Conditions Of Polyester And Viscose Blend Yarns

    Directory of Open Access Journals (Sweden)

    Hatamvand Mohammad

    2017-09-01

    Full Text Available In this study, we used an experimental design to investigate the influence of the total draft, break draft, distance between the aprons (Clips and production roller pressure on yarn quality in order to obtain optimum drafting conditions for polyester and viscose (PES/CV blend yarns in ring spinning frame. We used PES fibers (1.4 dtex × 38 mm long and CV fibers (1.6 dtex × 38 mm long to spin a 20 Tex blend yarn of PES (70%/CV (30% blend ratio. When the break draft, adjustment of distance between of aprons and roller pressure is not reasonable, controlling and leading of the fibers is not sufficient for proper orientation of the fibers in the yarn structure to produce a high quality yarn. Experimental results and statistical analysis show that the best yarn quality will be obtained under drafting conditions total draft of 38, 1.2 break draft, 2.8 mm distance between of aprons and maximum pressure of the production top roller (18daN.

  17. In situ polymerization of vinyl monomers in polyester yarns

    International Nuclear Information System (INIS)

    Avny, Y.; Rebenfeld, L.; Weigmann, H.D.

    1978-01-01

    The effects of a pretreatment of polyester (PET) yarns with a strongly interacting solvent such as dimethylformamide (DMF) on vinyl monomer incorporation were investigated. When the DMF pretreatment is carried out at high temperatures (above 120 0 C), the swollen PET structure is stabilized by solvent-induced secondary crystallization. This substrate is highly suitable for the incorporation of vinyl monomers. In situ polymerization of vinyl monomers in DMF-treated PET was investigated using chemical and γ-irradiation polymerization techniques, both in the presence and in the absence of excess monomer outside the PET fibers. When polymerization was carried out in a system in which a constant supply of free radicals was available from the outside of the PET fibers, lower initiator concentrations and smaller γ-irradiation doses were necessary. These results are attributed to a low efficiency of the initiator inside the PET fiber due to mobility restrictions. Water uptake and moisture regain of PET yarns containing poly(hydroxyethyl methacrylate) and poly(acrylic acid) were also investigated. When most of the vinyl polymer was inside the PET fiber, water absorption was limited. The changes in mechanical properties of the PET yarns resulting from the DMF pretreatment were partially reversed by in situ polymerization of vinyl monomers

  18. Polyester composite versus PTFE in laparoscopic ventral hernia repair.

    Science.gov (United States)

    Colon, Modesto J; Telem, Dana A; Chin, Edward; Weber, Kaare; Divino, Celia M; Nguyen, Scott Q

    2011-01-01

    Both polyester composite (POC) and polytetrafluoroethylene (PTFE) mesh are commonly used for laparoscopic ventral hernia repair. However, sparse information exists comparing perioperative and long-term outcome by mesh repair. A prospective database was utilized to identify 116 consecutive patients who underwent laparoscopic ventral hernia repair at The Mount Sinai Hospital from 2004-2009. Patients were grouped by type of mesh used, PTFE versus POC, and retrospectively compared. Follow-up at a mean of 12 months was achieved by telephone interview and office visit. Of the 116 patients, 66 underwent ventral hernia repair with PTFE and 50 with POC mesh. Patients were well matched by patient demographics. No difference in mean body mass index (BMI) was demonstrated between the PTFE and POC group (31.8 vs. 32.5, respectively; P=NS). Operative time was significantly longer in the PTFE group (136 vs.106 minutes, PPTFE group and none in the POC group (P NS). No other major complications occurred in the immediate postoperative period (30 days). At a mean follow-up of 12 months, no significant difference was demonstrated between the PTFE and POC groups in hernia recurrence (3% vs. 2%), wound complications (1% vs. 0%), mesh infection, requiring removal (3% vs. 0%), bowel obstruction (3% vs. 2%), or persistent pain or discomfort (28% vs. 32%), respectively (P=NS). Our study demonstrated no significant association between types of mesh used and postoperative complications. In the 12-month follow-up, no differences were noted in hernia recurrence.

  19. Tearing resistance of some co-polyester sheets

    International Nuclear Information System (INIS)

    Kim, Ho Sung; Karger-Kocsis, Jozsef

    2004-01-01

    A three-zone model consisting of initial, evolutionary and stabilised plastic zones for tearing resistance was proposed for polymer sheets. An analysis with the model, based on the essential work of fracture (EWF) approach, was demonstrated to be capable for predicting specific total work of fracture along the tear path across all the plastic zones although accuracy of specific essential work of fracture is subject to improvement. Photo-elastic images were used for identification of plastic deformation sizes and profiles. Fracture mode change during loading was described in relation with the three zones. Tearing fracture behaviour of extruded mono- and bi-layer sheets of different types of amorphous co-polyesters and different thicknesses was investigated. Thick material exhibited higher specific total work of tear fracture than thin mono-layer sheet in the case of amorphous polyethylene terephthalate (PET). This finding was explained in terms of plastic zone size formed along the tear path, i.e., thick material underwent larger plastic deformation than thin material. When PET and polyethylene terephthalate glycol (PETG) were laminated with each other, specific total work of fracture of the bi-layer sheets was not noticeably improved over that of the constituent materials

  20. Uranium biosorption by Trichoderma harzianum entrapped in polyester foam beads

    International Nuclear Information System (INIS)

    Khalid, A.M.; Shemsi, A.M.; Akhtar, K.; Anwar, M.A.

    1993-01-01

    Mechanism of uranium biosorption by resting cells of Trichoderma harzianum was studied at pH 4.5. Time-dependent uptake of uranium by Trichoderma harzianum was also determined. Various cations (Na, K, Ca and Fe, etc.) were found to affect the adsorption capability of these cells. Different theoretical thermodynamic models governing the adsorption behavior of uranium were also tested and it was found to follow the Langmuir and Freundlich adsorption isotherms. The constants of Freundlich adsorption isotherm A and 1/n were found to be 1.5 x 10 -6 mole/g and 0.31 respectively. Dubinin Radushkevich equation was tested and the maximum adsorption capacity (X m ) of Trichoderma harzianum and sorption energy (E s ) for the ion exchange process computed. Data of uranium sorption were also examined using Weber Morris's equation. The upscaling of uranium biosorption by Trichoderma harzianum entrapped in commercial foam (polyesters) was carried out in glass columns. It was found to recover more than 85% of the total uranium present in bacterial leachate

  1. Recent Advances in 3D Printing of Aliphatic Polyesters.

    Science.gov (United States)

    Chiulan, Ioana; Frone, Adriana Nicoleta; Brandabur, Călin; Panaitescu, Denis Mihaela

    2017-12-24

    3D printing represents a valuable alternative to traditional processing methods, clearly demonstrated by the promising results obtained in the manufacture of various products, such as scaffolds for regenerative medicine, artificial tissues and organs, electronics, components for the automotive industry, art objects and so on. This revolutionary technique showed unique capabilities for fabricating complex structures, with precisely controlled physical characteristics, facile tunable mechanical properties, biological functionality and easily customizable architecture. In this paper, we provide an overview of the main 3D-printing technologies currently employed in the case of poly (lactic acid) (PLA) and polyhydroxyalkanoates (PHA), two of the most important classes of thermoplastic aliphatic polyesters. Moreover, a short presentation of the main 3D-printing methods is briefly discussed. Both PLA and PHA, in the form of filaments or powder, proved to be suitable for the fabrication of artificial tissue or scaffolds for bone regeneration. The processability of PLA and PHB blends and composites fabricated through different 3D-printing techniques, their final characteristics and targeted applications in bioengineering are thoroughly reviewed.

  2. Fatigue life prediction in woven carbon fabric polyester composites

    International Nuclear Information System (INIS)

    Khan, Z.; Al-Sulaiman, F.S.; Farooqi, J.K.

    1999-01-01

    An analytical model, based on stiffness degradation during fatigue loading, which has been used for fatigue life predictions in the Fiber Reinforced Plastics (FRP), is employed to examine its validity to the fatigue life predictions in the Woven Fabric Reinforced Plastics. The rate of stiffness degradation (dE/dN) has been obtained from the constant amplitude fatigue testing of 8-ply coupons made from prepreg plain-weave woven carbon-carbon fabric having a polyester resin as the matrix material. The test coupons had three different ply stacking sequences, namely, the unidirectional (0)8,and two off axis plied (0,0,+45,-45)s, and (+45,-45,0,0)s orientations. The estimated fatigue lives obtained from the damage rate function dD/dN, which in turn was a function of the stiffness degradation rate dE/dN, were compared with the experimentally observed fatigue life data. It is shown that the stiffness degradation model provides reasonably good correlation between the analytically determined fatigue lives and the experimentally observed fatigue for the plain-weave woven Carbon-Carbon Fabric Reinforced Plastic Composites. (author)

  3. Recent Advances in 3D Printing of Aliphatic Polyesters

    Science.gov (United States)

    Frone, Adriana Nicoleta; Brandabur, Călin

    2017-01-01

    3D printing represents a valuable alternative to traditional processing methods, clearly demonstrated by the promising results obtained in the manufacture of various products, such as scaffolds for regenerative medicine, artificial tissues and organs, electronics, components for the automotive industry, art objects and so on. This revolutionary technique showed unique capabilities for fabricating complex structures, with precisely controlled physical characteristics, facile tunable mechanical properties, biological functionality and easily customizable architecture. In this paper, we provide an overview of the main 3D-printing technologies currently employed in the case of poly (lactic acid) (PLA) and polyhydroxyalkanoates (PHA), two of the most important classes of thermoplastic aliphatic polyesters. Moreover, a short presentation of the main 3D-printing methods is briefly discussed. Both PLA and PHA, in the form of filaments or powder, proved to be suitable for the fabrication of artificial tissue or scaffolds for bone regeneration. The processability of PLA and PHB blends and composites fabricated through different 3D-printing techniques, their final characteristics and targeted applications in bioengineering are thoroughly reviewed. PMID:29295559

  4. Recent Advances in 3D Printing of Aliphatic Polyesters

    Directory of Open Access Journals (Sweden)

    Ioana Chiulan

    2017-12-01

    Full Text Available 3D printing represents a valuable alternative to traditional processing methods, clearly demonstrated by the promising results obtained in the manufacture of various products, such as scaffolds for regenerative medicine, artificial tissues and organs, electronics, components for the automotive industry, art objects and so on. This revolutionary technique showed unique capabilities for fabricating complex structures, with precisely controlled physical characteristics, facile tunable mechanical properties, biological functionality and easily customizable architecture. In this paper, we provide an overview of the main 3D-printing technologies currently employed in the case of poly (lactic acid (PLA and polyhydroxyalkanoates (PHA, two of the most important classes of thermoplastic aliphatic polyesters. Moreover, a short presentation of the main 3D-printing methods is briefly discussed. Both PLA and PHA, in the form of filaments or powder, proved to be suitable for the fabrication of artificial tissue or scaffolds for bone regeneration. The processability of PLA and PHB blends and composites fabricated through different 3D-printing techniques, their final characteristics and targeted applications in bioengineering are thoroughly reviewed.

  5. Polyol synthesis, functionalisation, and biocompatibility studies of superparamagnetic iron oxide nanoparticles as potential MRI contrast agents

    Science.gov (United States)

    Hachani, Roxanne; Lowdell, Mark; Birchall, Martin; Hervault, Aziliz; Mertz, Damien; Begin-Colin, Sylvie; Thanh, Nguy&Ecirtil; N. Thi&Cmb. B. Dot; Kim

    2016-02-01

    Iron oxide nanoparticles (IONPs) of low polydispersity were obtained through a simple polyol synthesis in high pressure and high temperature conditions. The control of the size and morphology of the nanoparticles was studied by varying the solvent used, the amount of iron precursor and the reaction time. Compared with conventional synthesis methods such as thermal decomposition or co-precipitation, this process yields nanoparticles with a narrow particle size distribution in a simple, reproducible and cost effective manner without the need for an inert atmosphere. For example, IONPs with a diameter of ca. 8 nm could be made in a reproducible manner and with good crystallinity as evidenced by X-ray diffraction analysis and high saturation magnetization value (84.5 emu g-1). The surface of the IONPs could be tailored post synthesis with two different ligands which provided functionality and stability in water and phosphate buffer saline (PBS). Their potential as a magnetic resonance imaging (MRI) contrast agent was confirmed as they exhibited high r1 and r2 relaxivities of 7.95 mM-1 s-1 and 185.58 mM-1 s-1 respectively at 1.4 T. Biocompatibility and viability of IONPs in primary human mesenchymal stem cells (hMSCs) was studied and confirmed.Iron oxide nanoparticles (IONPs) of low polydispersity were obtained through a simple polyol synthesis in high pressure and high temperature conditions. The control of the size and morphology of the nanoparticles was studied by varying the solvent used, the amount of iron precursor and the reaction time. Compared with conventional synthesis methods such as thermal decomposition or co-precipitation, this process yields nanoparticles with a narrow particle size distribution in a simple, reproducible and cost effective manner without the need for an inert atmosphere. For example, IONPs with a diameter of ca. 8 nm could be made in a reproducible manner and with good crystallinity as evidenced by X-ray diffraction analysis and high

  6. The Degradation of Mechanical Properties in Halloysite Nanoclay-Polyester Nanocomposites Exposed in Seawater Environment

    Directory of Open Access Journals (Sweden)

    Mohd Shahneel Saharudin

    2016-01-01

    Full Text Available Polyester based polymers are extensively used in aggressive marine environments; however, inadequate data is available on the effects of the seawater on the polyester based nanocomposites mechanical properties. This paper reports the effect of seawater absorption on the mechanical properties degradation of halloysite nanoclay-polyester nanocomposites. Results confirmed that the addition of halloysite nanoclay into polyester matrix was found to increase seawater uptake and reduce mechanical properties compared to monolithic polyester. The maximum decreases in microhardness, tensile and flexural properties, and impact toughness were observed in case of 1 wt% nanoclay. The microhardness decreased from 107 HV to 41.7 HV (61% decrease. Young’s modulus decreased from 0.6 GPa to 0.4 GPa (33% decrease. The flexural modulus decreased from 0.6 GPa to 0.34 GPa (43% decrease. The impact toughness dropped from 0.71 kJ/m2 to 0.48 kJ/m2 (32% decrease. Interestingly, the fracture toughness KIC increased with the addition of halloysite nanoclay due to the plasticization effect of the resin matrix. SEM images revealed the significant reduction in mechanical properties in case of 1 wt% reinforcement which is attributed to the degradation of the nanoclay-matrix interface influenced by seawater absorption and agglomeration of halloysite nanoclay.

  7. Recent developments and future prospects on bio-based polyesters derived from renewable resources: A review.

    Science.gov (United States)

    Zia, Khalid Mahmood; Noreen, Aqdas; Zuber, Mohammad; Tabasum, Shazia; Mujahid, Mohammad

    2016-01-01

    A significantly growing interest is to design a new strategy for development of bio-polyesters from renewable resources due to limited fossil fuel reserves, rise of petrochemicals price and emission of green house gasses. Therefore, this review aims to present an overview on synthesis of biocompatible, biodegradable and cost effective polyesters from biomass and their prospective in different fields including packaging, coating, tissue engineering, drug delivery system and many more. Isosorbide, 2,4:3,5-di-O-methylene-d-mannitol, bicyclic diacetalyzed galactaric acid, 2,5-furandicarboxylic acid, citric, 2,3-O-methylene l-threitol, dimethyl 2,3-O-methylene l-threarate, betulin, dihydrocarvone, decalactone, pimaric acid, ricinoleic acid and sebacic acid, are some important monomers derived from biomass which are used for bio-based polyester manufacturing, consequently, replacing the petrochemical based polyesters. The last part of this review highlights some recent advances in polyester blends and composites in order to improve their properties for exceptional biomedical applications i.e. skin tissue engineering, guided bone regeneration, bone healing process, wound healing and wound acceleration. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Polyester fabric coated with Ag/ZnO composite film by magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Xiaohong, E-mail: yxhong1981_2004@126.com [Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi 214122, Jiangsu (China); Faculty of Clothing and Design, Minjiang University, Fuzhou 350121, Fujian (China); Xu, Wenzheng, E-mail: xwz8199@126.com [Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi 214122, Jiangsu (China); Huang, Fenglin, E-mail: windhuang325@163.com [Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi 214122, Jiangsu (China); Chen, Dongsheng, E-mail: mjuchen@126.com [Faculty of Clothing and Design, Minjiang University, Fuzhou 350121, Fujian (China); Wei, Qufu, E-mail: qfwei@jiangnan.edu.cn [Key Laboratory of Eco-Textiles, Ministry of Education, Jiangnan University, Wuxi 214122, Jiangsu (China)

    2016-12-30

    Highlights: • Ag/ZnO composite film was successfully deposited on polyester fabric by magnetron sputtering technique. • Ag film was easily oxidized into Ag{sub 2}O film in high vacuum oxygen environment. • The zinc film coated on the surface of Ag film before RF reactive sputtering could protect the silver film from oxidation. • Polyester fabric coated with Ag/ZnO composite film can obtained structural color. • The anti-ultraviolet and antistatic properties of polyester fabric coated with Ag/ZnO composite film all were good. - Abstract: Ag/ZnO composite film was successfully deposited on polyester fabric by using direct current (DC) magnetron sputtering and radio frequency (RF) magnetron reaction sputtering techniques with pure silver (Ag) and zinc (Zn) targets. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were used to examine the deposited film on the fabric. It was found that the zinc film coated on Ag film before RF reactive sputtering could protect the silver film from oxidation. Anti-ultraviolet property and antistatic property of the coated samples using different magnetron sputtering methods were also investigated. The experimental results showed that Ag film was oxidized into in Ag{sub 2}O film in high vacuum oxygen environment. The deposition of Zn film on the surface of the fabric coated with Ag film before RF reactive sputtering, could successfully obtained Ag/ZnO composite film, and also generated structural color on the polyester fabric.

  9. Physico-chemical studies of gamma-irradiated polyester. Impregnated cement mortar composite

    International Nuclear Information System (INIS)

    Ismail, M.R.; Afifi, M.S.

    1998-01-01

    The effect of impregnation time on the physico-chemical and mechanical properties of polyester-cement mortar composite has been investigated. The samples were soaked in unsaturated polyester resin containing 40% styrene monomer at impregnation times ranging from 1-15 hours and then exposed to 50 kGy of γ-irradiation. The effects on polymer loading, compressive strength, apparent porosity, and water absorption in addition to IR spectra and TGA of the samples were studied. It was found that, the polymer loading and compressive strength increase with the increased of soaking time up to 4 hours and there is no significant improvement of the polymer loading and strength. Whereas, the apparent porosity and water absorption behave in an opposite direction. These are attributed to the presence of polymer in the pores of the samples. IR spectra showed that, new bands appeared as result of the reaction between polyester and set cement. TGA showed that, the polyester cement composite has higher thermal stability as a compared to irradiated polyester. (author)

  10. Influence of fibre treatments on mechanical properties of short Sansevieria cylindrica/polyester composites

    International Nuclear Information System (INIS)

    Sreenivasan, V.S.; Ravindran, D.; Manikandan, V.; Narayanasamy, R.

    2012-01-01

    Highlights: ► Fibre treatments were performed to improve interfacial bond between SCF and matrix. ► Mechanical properties of treated SCFP composites are greater than USCFP composites. ► PSCFP composites show maximum mechanical properties among treated SCFP composites. ► SEM analysis revealed that the wetting of PSCFs by the polyester resin was good. ► KMnO 4 treatment is ideal treatment for SCFs to get optimum mechanical properties. -- Abstract: In the present study, to improve the interfacial bond between Sansevieria cylindrica fibres (SCFs) and polyester matrix, chemical surface treatments have been performed on the fibres. Treatments including alkali, benzoyl peroxide, potassium permanganate and stearic acid were carried out to modify the fibre surface. Raw and each type of treated SCF samples were utilised separately for fabricating the composites. The mechanical properties of composites prepared from the chemically treated SCFs are found to be much better than those of the untreated ones. Potassium-permanganate-treated S. cylindrica fibre/polyester (PSCFP) composites showed optimum mechanical properties among the treated S. cylindrica fibre/polyester (SCFP) composites. The surface morphologies of fracture surfaces of composites were recorded using scanning electron microscopy (SEM). The SEM micrographs reveal that interfacial bonding between potassium-permanganate-treated SCF (PSCF) and polyester matrix has significantly improved, suggesting that better dispersion of PSCF into the matrix has occurred upon potassium permanganate treatment of SCF.

  11. Composite Preparation of Wood Dust-Polyester-Coconut Choir Fiber Mixture for Particle Board

    International Nuclear Information System (INIS)

    Danu, Sugiarto; Darsono; Padmono; Betty, Angesti

    2002-01-01

    Experiment on the use of γ-ray of Co 60 radiation has been used for curing of composite which made of wood dust, unsaturated polyester resin and coconut coir mixture. Composite was prepared by mixing of wood dust, polyester and coconut coir at a various mixture composition. Concentration of polyesters were 50, 55 and 60 % by weight based on saw dust and polyester mixture. Irradiation was conducted using 27,6 kCi acti vity Co 60 at a dose rate of 5 kGy/hrs and dose of 8, 10 and 12 kGy. Composite was also prepared conventionally by using peroxide catalyst. Parameters observed were density, pencil hardness and compression strength Experimental results showed that optimum condition wus achieved at irradiation dose of 12 kGy, polyester concentration of 60 % and coconut coir fiber of 4 %. In this condition, the density, hardness and compression strength were 1,115 g/cm 3, 5 Hand 6,815 kN/cm2 respectively. Density, hardness of composite prepared by radiation were almost the same whereas the compression strength was higher than that of composite prepared by conventional method

  12. Catalyst Influence on Undesired Side Reactions in the Polycondensation of Fully Bio-Based Polyester Itaconates

    Directory of Open Access Journals (Sweden)

    Ina Schoon

    2017-12-01

    Full Text Available Bio-based unsaturated polyester resins derived from itaconic acid can be an alternative to established resins of this type in the field of radical-curing resins. However, one of the challenges of these polyester itaconates is the somewhat more elaborate synthetic process, especially under polycondensation conditions used on an industrial scale. The α,β-unsaturated double bond of the itaconic acid is prone to side reactions that can lead to the gelation of the polyester resin under standard conditions. This is especially true when bio-based diols such as 1,3-propanediol or 1,4-butanediol are used to obtain resins that are 100% derived from renewable resources. It was observed in earlier studies that high amounts of these aliphatic diols in the polyester lead to low conversion and gelation of the resins. In this work, a catalytic study using different diols was performed in order to elucidate the reasons for this behavior. It was shown that the choice of catalyst has a crucial influence on the side reactions occurring during the polycondensation reactions. In addition, the side reactions taking place were identified and suppressed. These results will allow for the synthesis of polyester itaconates on a larger scale, setting the stage for their industrial application.

  13. Effect of γ-radiation sterilization on the stability of polyurethane potting compounds based on castor oil/SMDI and caprolactone polyol/SMDI, used for hollow fibre haemodialyzer

    International Nuclear Information System (INIS)

    Jayabalan, M.; Lizymol, P.P.

    1997-01-01

    Stability of polyurethane potting compounds based on castor oil/SMDI and caprolactone polyol/SMDI in repeated gamma radiation sterilization was studied. Radiation-induced degradation and leaching of low molecular weight fragments are higher in castor oil based polyurethane than in caprolactone polyol based polyurethane. For castor oil and caprolactone polyol based polyurethanes degradation increases up to 5 Mrad dose of sterilization. Further increase of dose of sterilization decreases leaching in caprolactone polyol based polyurethane which has resulted from secondary reactions leading to crosslinking. In the case of castor oil based polyurethane such crosslinks undergo cleavage at 10 Mrad dose of sterilization. (author)

  14. Magnetic properties of zinc ferrite nanoparticles synthesized by hydrolysis in a polyol medium

    International Nuclear Information System (INIS)

    Ammar, Souad; Jouini, Noureddine; Fievet, Fernand; Beji, Zyed; Smiri, Leila; Moline, Philippe; Danot, Michel; Greneche, Jean-Marc

    2006-01-01

    Highly crystalline, nanometre sized ZnFe 2 O 4 particles with different diameters, 6.6 and 14.8 nm, were prepared by forced hydrolysis in a polyol medium. The DC magnetic properties exhibit a strong dependence on the particle size as a result of the unusual cation distribution. They clearly establish their superparamagnetic character at room temperature and the occurrence of ferrimagnetic or ferromagnetic ordering at low temperature. The magnetization is found to increase with grain size reduction. The 57 Fe Moessbauer spectra were recorded at 300 and 4.5 K. There is no evidence for the presence of the Fe 2+ charge state, confirming the perfect stoichiometry of the two samples. At 300 K, the Moessbauer spectra consist of doublets due to the superparamagnetic behaviour whereas at 4.5 K they reveal a magnetically blocked state. Moessbauer spectra at 10 K in an external 6 T magnetic field applied parallel to the direction of the gamma rays clearly show a close to collinear Neel-like ferrimagnetic ordering for the 6.6 nm particles and a canted Yafet-Kittel-like ferrimagnetic ordering for the 14.8 nm ones

  15. Magnetic properties of zinc ferrite nanoparticles synthesized by hydrolysis in a polyol medium

    Energy Technology Data Exchange (ETDEWEB)

    Ammar, Souad [ITODYS, UMR-CNRS 7086, Universite Paris 7, 75251 Paris (France); Jouini, Noureddine [ITODYS, UMR-CNRS 7086, Universite Paris 7, 75251 Paris (France); Fievet, Fernand [ITODYS, UMR-CNRS 7086, Universite Paris 7, 75251 Paris (France); Beji, Zyed [ITODYS, UMR-CNRS 7086, Universite Paris 7, 75251 Paris (France); Smiri, Leila [LSSMI, UR-99/1230, Faculte des Sciences de Bizerte, 7021 Zarzouna (Tunisia); Moline, Philippe [Institut Jean Rouxel des Materiaux, 44072 Nantes (France); Danot, Michel [Institut Jean Rouxel des Materiaux, 44072 Nantes (France); Greneche, Jean-Marc [LPEC, UMR-CNRS 6087, Universite du Maine, 72085 Le Mans (France)

    2006-10-04

    Highly crystalline, nanometre sized ZnFe{sub 2}O{sub 4} particles with different diameters, 6.6 and 14.8 nm, were prepared by forced hydrolysis in a polyol medium. The DC magnetic properties exhibit a strong dependence on the particle size as a result of the unusual cation distribution. They clearly establish their superparamagnetic character at room temperature and the occurrence of ferrimagnetic or ferromagnetic ordering at low temperature. The magnetization is found to increase with grain size reduction. The {sup 57}Fe Moessbauer spectra were recorded at 300 and 4.5 K. There is no evidence for the presence of the Fe{sup 2+} charge state, confirming the perfect stoichiometry of the two samples. At 300 K, the Moessbauer spectra consist of doublets due to the superparamagnetic behaviour whereas at 4.5 K they reveal a magnetically blocked state. Moessbauer spectra at 10 K in an external 6 T magnetic field applied parallel to the direction of the gamma rays clearly show a close to collinear Neel-like ferrimagnetic ordering for the 6.6 nm particles and a canted Yafet-Kittel-like ferrimagnetic ordering for the 14.8 nm ones.

  16. Preparation of polyurethane microcapsule using 1,3 propanediol as the polyol component

    International Nuclear Information System (INIS)

    Ahmad Randy; Dewi Sondari; Evi Triwulandari; Murni Handayani

    2010-01-01

    Self-healing property is the ability of a material to heal damages automatically and autonomously. Its application would be ranged from paint coating, anti corrosion coating, space shuttle material, construction (concrete) and automotive. Extrinsic self healing requires self healing agent pre embedded or incorporated into polymer matrix that would be released and close the damage in the polymer system, where the polymer itself is not healable. Healing agents are encapsulated or embedded into the material prior application. Example of monomer encapsulated to give self healing property is isophorone diisocyanate (IPDI) encapsulated in polyurethane shell. In this study, we studied the possibility of 1,3 propanediol, that can be derived from palm oil as polyol monomer for polyurethane microcapsule shell containing IPDI or stannous octoate as a self healing agent. Microcapsule in this study was prepared by interfacial polymerization technique to form IPDI monomer in polyurethane shell. FT-IR analysis show that polyurethane prepolymer produced still have unreacted isocyanate group necessary for interfacial polymerization of polyurethane. Morphological analyses of the microcapsule products show that the products have spherical shapes with smooth surface and some with wrinkled surface. The particle sizes were ranged from 40.29 to 526.80 μm. (author)

  17. Synthesis and properties of ionic polyurethane dispersions: influence of polyol molecular weight

    International Nuclear Information System (INIS)

    Valipour Ebrahimi, M.; Barikani, M.; Mohammad Seyed Mohaghegh, S.

    2006-01-01

    A series of water dispersible polyurethanes containing carboxylate anion as the hydrophilic pendant group were prepared from toluene diisocyanate (TDI), 1,4- butanediol (1,4-BDO), dimethylol propionic acid and different molecular weight of polytetramethylene glycol . IR Spectroscopy was used to check the end of polymerization reaction and characterization of polymer. The effect of polytetramethylene glycol molecular weight was studied on the particle size distribution, contact angle, and mechanical and thermal properties of the emulsion-cast films. Average particle size of prepared polyurethane emulsions decreases with increasing the polytetramethylene glycol molecular weight. Tensile strength and hardness decrease and elongation-at-break and contact angle increase with increase of the polytetramethylene glycol molecular weight. Thermal property and thermal stability are also effected by variation of polytetramethylene glycol molecular weight. The thermal stability increases with increasing polytetramethylene glycol molecular weight. Glass transition temperature (T g ) moved toward the lower temperatures by increasing molecular weight of the polyol. Decrease in T g and tensile properties are interpreted in terms of the decrease in hard segments and the increase in chain flexibility and phase separation in high molecular weight polytetramethylene glycol based polyurethane

  18. Synthesis and Raman analysis of SnS nanoparticles synthesized by PVP assisted polyol method

    Energy Technology Data Exchange (ETDEWEB)

    Baby, Benjamin Hudson; Mohan, D. Bharathi, E-mail: d.bharathimohan@gmail.com [Department of Physics, School of Physical, Chemical and Applied Sciences, Pondicherry University, R.V. Nagar, Kalapet, Puducherry-605014 (India)

    2015-06-24

    SnS film was prepared by a simple drop casting method after synthesizing SnS nanoparticles by using PVP assisted polyol method. Confocal Raman study was carried out for the as deposited and annealed (150, 300 and 400 °C) films at two different excitation wavelengths 514 and 785 nm. At the excitation wavelength of 514 nm, the Raman modes showed for a mixed phase of SnS and SnS{sub 2} up to 150 °C and then only a pure SnS phase was observed up to 400 °C due to the dissociation of SnS{sub 2} in to SnS by releasing S. The increase in intensity of Raman (A{sub g} and B{sub 3g}) as well as IR (B{sub 3u}) active modes of SnS are observed with increasing annealing temperature at excitation wavelength 785 nm due to the increased crystallinity and inactiveness of SnS{sub 2} modes. X-ray diffraction confirming the formation of a single phase of SnS while the greater homogeneity in both size and shape of SnS nanoparticles were confirmed through surface morphology from SEM.

  19. Efficacy of turmeric on blood sugar and polyol pathway in diabetic albino rats.

    Science.gov (United States)

    Arun, N; Nalini, N

    2002-01-01

    In the traditional system of medicine, Ayurveda, several spices and herbs are thought to possess medicinal properties. Among the spices, turmeric rhizomes (Curcuma longa. Linn.) are used as flavoring and coloring agents in the Indian diet everyday. In this research, we studied the effect of turmeric and its active principle, curcumin, on diabetes mellitus in a rat model. Alloxan was used to induce diabetes. Administration of turmeric or curcumin to diabetic rats reduced the blood sugar, Hb and glycosylated hemoglobin levels significantly. Turmeric and curcumin supplementation also reduced the oxidative stress encountered by the diabetic rats. This was demonstrated by the lower levels of TBARS (thiobarbituric acid reactive substances), which may have been due to the decreased influx of glucose into the polyol pathway leading to an increased NADPH/NADP ratio and elevated activity of the potent antioxdiant enzyme GPx. Moreover, the activity of SDH (sorbitol dehydrogenase), which catalyzes the conversion of sorbitol to fructose, was lowered significantly on treatment with turmeric or curcumin. These results also appeared to reveal that curcumin was more effective in attenuating diabetes mellitus related changes than turmeric.

  20. Convenient, rapid synthesis of silver nanocubes and nanowires via a microwave-assisted polyol method

    Science.gov (United States)

    Chen, Dapeng; Qiao, Xueliang; Qiu, Xiaolin; Chen, Jianguo; Jiang, Renzhi

    2010-01-01

    Silver nanostructures have been synthesized via a microwave-assisted polyol method by adding sodium sulfide (Na2S) into the solution. An interesting morphology evolution can be observed by adjusting the concentration of Na2S and the heating power. It is found that the ideal concentration of Na2S is 31.25-500 µM for the fast reduction of Ag+ at 300 W under optimal conditions for producing monodispersed silver nanocubes. When the heating power is increased to 400 W, 62.5-250 µM is the ideal concentration of Na2S for the synthesis of silver nanocubes. On increasing the concentration of Na2S (>500 µM), a mixture of silver nanowires, nanocubes, bipyramids, and irregular/quasispherical particles is synthesized at 300 and 400 W. In particular, an increase in the concentration of Na2S to 750 µM at 400 W leads to the production of a quantity of silver nanowires. In addition, silver nanocubes with controllable sizes can be obtained by changing the concentration of Na2S and the heating power. Compared to traditional wet-chemical methods, this method has the advantage of a marked decrease in reaction time to 3.5 min. Finally, our work provides a simple strategy for fabricating silver nanostructures with controllable morphologies and sizes.

  1. Convenient, rapid synthesis of silver nanocubes and nanowires via a microwave-assisted polyol method

    Energy Technology Data Exchange (ETDEWEB)

    Chen Dapeng; Qiao Xueliang; Chen Jianguo; Jiang Renzhi [State Key Laboratory of Plastic Forming Simulation and Die and Mold Technology, Huazhong University of Science and Technology, Wuhan, 430074, Hubei (China); Qiu Xiaolin, E-mail: dpchenhust@yahoo.com.cn [Nanomaterials Research Center, Nanchang Institute of Technology, Nanchang, 330013, Jiangxi (China)

    2010-01-15

    Silver nanostructures have been synthesized via a microwave-assisted polyol method by adding sodium sulfide (Na{sub 2}S) into the solution. An interesting morphology evolution can be observed by adjusting the concentration of Na{sub 2}S and the heating power. It is found that the ideal concentration of Na{sub 2}S is 31.25-500 {mu}M for the fast reduction of Ag{sup +} at 300 W under optimal conditions for producing monodispersed silver nanocubes. When the heating power is increased to 400 W, 62.5-250 {mu}M is the ideal concentration of Na{sub 2}S for the synthesis of silver nanocubes. On increasing the concentration of Na{sub 2}S (>500 {mu}M), a mixture of silver nanowires, nanocubes, bipyramids, and irregular/quasispherical particles is synthesized at 300 and 400 W. In particular, an increase in the concentration of Na{sub 2}S to 750 {mu}M at 400 W leads to the production of a quantity of silver nanowires. In addition, silver nanocubes with controllable sizes can be obtained by changing the concentration of Na{sub 2}S and the heating power. Compared to traditional wet-chemical methods, this method has the advantage of a marked decrease in reaction time to 3.5 min. Finally, our work provides a simple strategy for fabricating silver nanostructures with controllable morphologies and sizes.

  2. Convenient, rapid synthesis of silver nanocubes and nanowires via a microwave-assisted polyol method

    International Nuclear Information System (INIS)

    Chen Dapeng; Qiao Xueliang; Chen Jianguo; Jiang Renzhi; Qiu Xiaolin

    2010-01-01

    Silver nanostructures have been synthesized via a microwave-assisted polyol method by adding sodium sulfide (Na 2 S) into the solution. An interesting morphology evolution can be observed by adjusting the concentration of Na 2 S and the heating power. It is found that the ideal concentration of Na 2 S is 31.25-500 μM for the fast reduction of Ag + at 300 W under optimal conditions for producing monodispersed silver nanocubes. When the heating power is increased to 400 W, 62.5-250 μM is the ideal concentration of Na 2 S for the synthesis of silver nanocubes. On increasing the concentration of Na 2 S (>500 μM), a mixture of silver nanowires, nanocubes, bipyramids, and irregular/quasispherical particles is synthesized at 300 and 400 W. In particular, an increase in the concentration of Na 2 S to 750 μM at 400 W leads to the production of a quantity of silver nanowires. In addition, silver nanocubes with controllable sizes can be obtained by changing the concentration of Na 2 S and the heating power. Compared to traditional wet-chemical methods, this method has the advantage of a marked decrease in reaction time to 3.5 min. Finally, our work provides a simple strategy for fabricating silver nanostructures with controllable morphologies and sizes.

  3. Rigid Polyurethane Foam from Glyco lysed Polyethylene Terephthalate Dissolved in Palm-based Polyol

    International Nuclear Information System (INIS)

    Khairiah Badri; Lily Iliyana Mohd Dawi; Nur Ashikin Abdul Aziz

    2013-01-01

    An investigation on the thermal and mechanical properties of rigid polyurethane (PU) foam from polyethylene terephthalate (PET) waste (of plastic drinking bottles) was conducted. The PET waste was glyco lysed with ethylene glycol prior to blending with palm based-polyol (PKO-p). This blend was then reacted with 2, 4-methylene diphenyl diisocyanate (MDI) at a ratio of 1:1 to form the PU foam. The incorporation of the glyco lysed PET (g-PET) into the PKO-p was studied at 50, 70 and 100 % w/ w loading. PU foam prepared from 100 % w/ w g-PET (without PKO-p) resulted in PU with high glass transition temperature and mechanical strength. This water-blown foam has molded and core densities of 182 kg m -3 and 179 kg m -3 , respectively, with maximum compressive stress and modulus at 396 kPa and 1920 kPa, respectively. An initial enthalpy value of 3164.8 cal g -1 and a glass transition temperature of 65 degree Celsius were observed. (author)

  4. Synthesis of hybrid Au–ZnO nanoparticles using a one pot polyol process

    Energy Technology Data Exchange (ETDEWEB)

    Mezni, Amine [Unité de recherche “Synthèse et Structure de Nanomatériaux” UR11ES30, Faculté des Sciences de Bizerte, Université de Carthage, 7021 Jarzouna (Tunisia); Centre d' Elaboration de Matériaux et d' Etudes Structurales, CNRS, UPR 8011, Université de Toulouse, 29 Rue Jeanne Marvig, 31055 Toulouse (France); Mlayah, Adnen; Serin, Virginie [Centre d' Elaboration de Matériaux et d' Etudes Structurales, CNRS, UPR 8011, Université de Toulouse, 29 Rue Jeanne Marvig, 31055 Toulouse (France); Smiri, Leila Samia, E-mail: lsmiri@gmail.com [Unité de recherche “Synthèse et Structure de Nanomatériaux” UR11ES30, Faculté des Sciences de Bizerte, Université de Carthage, 7021 Jarzouna (Tunisia)

    2014-10-15

    In this work, we report on the synthesis of hybrid Au–ZnO nanoparticles using a one-pot chemical method that makes use of 1,3-propanediol as a solvent, a reducing agent and a stabilizing layer. The produced nanoparticles consisted of Au cores decorated with ZnO nanoparticles. The structure and morphology of the nanoparticles were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDX) and Raman spectroscopy. Optical extinction measurements, combined with numerical simulations, showed that the Au–ZnO nanoparticles exhibit a localized surface plasmon resonance (SPR) clearly red-shifted with respect to that of bare Au nanoparticles (AuNPs). This work contributes to the emergence of multi-functional nanomaterials with possible applications in surface plasmon resonance based biosensors, energy-conversion devices, and in water-splitting hydrogen production. - Highlights: • Hybrid Au–ZnO nanoparticles were synthesized by a novel one-pot synthesis method that makes use of 1,3-propanediol. • The polyol solvent 1,3-propanediol plays the roles of the reducing agent and the stabilizer layer. • The Au–ZnO nanoparticles exhibit a strong localized surface plasmon resonance.

  5. Synthesis and Characterization of Nanocomposites Tin Oxide-Graphene Doping Pd Using Polyol Method

    Directory of Open Access Journals (Sweden)

    Aminuddin Debataraja

    2018-05-01

    Full Text Available This paper report on polyol method for Pd doped tin oxide-graphene nanocomposite thin film. XRD result shows sharp peaks at certain 2θ value and match with tin oxide, graphene, and Pd database. FTIR result shows peak from alcohol chain for –OH strong bonded absorption (3444 cm-1, also there are aldehyde and ketone which are indicated by C=O strong absorption (1751 cm-1. Moreover, alkene is also formed for decreasing symmetry intensity C=C (1616 cm-1, while alkyne is formed at strong deformation absorption at 646 and 613 cm-1. SEM and TEM result show SnO2 particles are attached uniformly on graphene surface layer. The composition for C, O, Sn, and Pd are 33.13, 25.58, 35.35 and 5.94%, respectively. This result indicated that the good composition is formed for Pd doped SnO2-graphene nanocomposite. The nanocomposite is promising materials for toxic gas sensor application at low temperature.

  6. Continuous Polyol Synthesis of Metal and Metal Oxide Nanoparticles Using a Segmented Flow Tubular Reactor (SFTR

    Directory of Open Access Journals (Sweden)

    Andrea Testino

    2015-06-01

    Full Text Available Over the last years a new type of tubular plug flow reactor, the segmented flow tubular reactor (SFTR, has proven its versatility and robustness through the water-based synthesis of precipitates as varied as CaCO3, BaTiO3, Mn(1−xNixC2O4·2H2O, YBa oxalates, copper oxalate, ZnS, ZnO, iron oxides, and TiO2 produced with a high powder quality (phase composition, particle size, and shape and high reproducibility. The SFTR has been developed to overcome the classical problems of powder production scale-up from batch processes, which are mainly linked with mass and heat transfer. Recently, the SFTR concept has been further developed and applied for the synthesis of metals, metal oxides, and salts in form of nano- or micro-particles in organic solvents. This has been done by increasing the working temperature and modifying the particle carrying solvent. In this paper we summarize the experimental results for four materials prepared according to the polyol synthesis route combined with the SFTR. CeO2, Ni, Ag, and Ca3(PO42 nanoparticles (NPs can be obtained with a production rate of about 1–10 g per h. The production was carried out for several hours with constant product quality. These findings further corroborate the reliability and versatility of the SFTR for high throughput powder production.

  7. Modeling and measurements of solid-liquid and vapor-liquid equilibria of polyols and carbohydrates in aqueous solution

    DEFF Research Database (Denmark)

    Jonsdottir, Svava Osk; Cooke, S.A.; Macedo, E.A.

    2002-01-01

    The solubilities of five saccharides in water have been measured at various temperatures. This includes the monosaccharides xylose and galactose, and the disaccharides maltose monohydrate, cellobiose and trehalose dihydrate. A method that uses interaction energies and interaction parameters...

  8. Mechanical properties of water hyacinth fibers – polyester composites before and after immersion in water

    International Nuclear Information System (INIS)

    Abral, H.; Kadriadi, D.; Rodianus, A.; Mastariyanto, P.; Ilhamdi; Arief, S.; Sapuan, S.M.; Ishak, M.R.

    2014-01-01

    Highlights: • Moisture absorption of water hyacinth (WH) fibers was measured. • WH fibers polyester composites immersed in water decreased mechanical properties. • Improvement fibers fraction in polyester increases mechanical properties. - Abstract: This study reported moisture absorption of untreated and treated individual water hyacinth (WH) fibers as well as comparison the mechanical properties of WH fibers – unsaturated polyester (UPR) matrix composites after and before immersion in water. The result shows that the individual WH fibers treated with various alkali concentration did not exhibit significantly decreases of their moisture absorption. SEM photograph in cross section of the treated WH fibers shows swollen cell wall containing more nano and micro hollows. Tensile and flexure strength of the wet composite samples are lower than that of dried ones. However, increases volume fraction of the WH fibers in UPR matrix affected slightly on enhancement mechanical properties of the composite samples

  9. Azobenzene side-chain liquid crystalline polyesters with outstanding optical storage properties

    DEFF Research Database (Denmark)

    Hvilsted, Søren; Pedersen, M; Holme, NCR

    1998-01-01

    A flexible azobenzene side-chain liquid crystalline (SCLC) polyester architecture employed for reversible optical storage is described. The modular design allows four structural parameters to be individually modified. These parameters: i- the methylene side-chain spacer length, ii- the substituent......,000 are routinely obtained by melt transesterification of the novel diols and selected diacid precursors (parameter iii). Prominent storage features include no prealignment of thin SCLC polyester films prior to the writing process, and sensitivity in a broad laser wavelength window (415-532 nm). Additionally...... sign of fatigue. The non-destructive read out is performed with red light (600-750 nm). Finally, erasing the information can be achieved by heating the polyester film to 80 degrees C or irradiating it briefly with UV-light. In the latter case at least 10,000 write, read and erase cycles are possible...

  10. Photoinduced anisotropy in a family of amorphous azobenzene polyesters for optical storage

    DEFF Research Database (Denmark)

    Nedelchev, Lian; Matharu, Avtar S.; Hvilsted, Søren

    2003-01-01

    of E1aX polymers characterized by two-ring aromatic substituent in the main chain is a good candidate for optical data storage media. A recording energy of approximately 2 J/cm(2) is sufficient to induce high refractive-index modulations of Deltan = 0.13 in these materials, which is retained even......We investigate parameters associated with optical data storage in a variety of amorphous side-chain azobenzene-containing polyesters denoted as E1aX. The polyesters possess a common cyano-substituted azobenzene chromophore as a side chain, but differ in their main-chain polyester composition....... Seventeen different polymers from the E1aX family divided into four classes, depending on the type of the main-chain substituent (one-, two-, and three-ring aromatic or alicyclic) have been thoroughly investigated. Various parameters characterizing the photoinduced birefringence in these materials...

  11. Chemical structures and thermal properties of polyesters obtained from different samples of bio diesel epoxidized

    International Nuclear Information System (INIS)

    Samios, Dimitrios; Reiznautt, Quelen B.; Nicolau, Aline; Martini, Denise D.; Chagas, Arthur L. das

    2009-01-01

    In this work new structures from oligo esters and polyesters from different oils (olive oil, sunflower oil and linseed oil) were synthesized and characterized. Oligo esters and polyesters were synthesized from the reaction of fatty acid methyl epoxy-esters, obtained from different oils, with cis-1,2-cyclohexanedicarboxylic anhydride in the presence of triethylamine (TEA). Different amounts of the resin 1,4-butanediol diglycidyl ether (BDGE) were added in order to increase the capacity of crosslinking. The molar ratio of BDGE used in system was between 0 and 0.066. The intermediate structures, as well as the oligo esters and polyesters produced, were analyzed by using Fourier Transform Infrared Spectroscopy and Nuclear Magnetic Resonance ( 1 H - NMR). The thermal behavior of the products was realized through differential scanning calorimetry and Thermogravimetric analyses. The presence of BDGE in the materials chains increases the bonding capacity resulting in a higher molecular weight material which presents good thermal stability. (author)

  12. Polyesters production from the mixture of phthalic acid, terephthalic and glycerol

    International Nuclear Information System (INIS)

    Carvalho, A.L.S.; Oliveira, J.C.; Miranda, C.S.; Boaventura, J.S.; Jose, N.M.; Carvalho, R.F.

    2010-01-01

    Glycerin, a byproduct of biodiesel is currently an environmental and economic problem for producers of this renewable fuel in Brazil and in others parts of the world. In order to offer new proposals for recovery, it is used for the manufacture of polyesters used in applications in diverse areas such as construction and automobile industry. This work reports the production of polymer from the mixture of terephthalic and phthalic acid in three different proportions. The polyesters showed good thermal stability, analyzed by TGA and DSC, with an increase proportional to the terephthalic acid content. The X-ray diffraction patterns show that the samples are semi crystalline polymers. The micrographs indicated the presence of a smoother surface in the polyester that has a larger amount of phthalic acid, as reported in the literature. Therefore, the materials showed good thermal properties and morphological characteristics, so it consists in a new alternative to use glycerin. (author)

  13. Biodegradative Activities of Selected Environmental Fungi on a Polyester Polyurethane Varnish and Polyether Polyurethane Foams.

    Science.gov (United States)

    Álvarez-Barragán, Joyce; Domínguez-Malfavón, Lilianha; Vargas-Suárez, Martín; González-Hernández, Ricardo; Aguilar-Osorio, Guillermo; Loza-Tavera, Herminia

    2016-09-01

    Polyurethane (PU) is widely used in many aspects of modern life because of its versatility and resistance. However, PU waste disposal generates large problems, since it is slowly degraded, there are limited recycling processes, and its destruction may generate toxic compounds. In this work, we isolated fungal strains able to grow in mineral medium with a polyester PU (PS-PU; Impranil DLN) or a polyether PU (PE-PU; Poly Lack) varnish as the only carbon source. Of the eight best Impranil-degrading strains, the six best degraders belonged to the Cladosporium cladosporioides complex, including the species C. pseudocladosporioides, C. tenuissimum, C. asperulatum, and C. montecillanum, and the two others were identified as Aspergillus fumigatus and Penicillium chrysogenum The best Impranil degrader, C. pseudocladosporioides strain T1.PL.1, degraded up to 87% after 14 days of incubation. Fourier transform infrared (FTIR) spectroscopy analysis of Impranil degradation by this strain showed a loss of carbonyl groups (1,729 cm(-1)) and N-H bonds (1,540 and 1,261 cm(-1)), and gas chromatography-mass spectrometry (GC-MS) analysis showed a decrease in ester compounds and increase in alcohols and hexane diisocyanate, indicating the hydrolysis of ester and urethane bonds. Extracellular esterase and low urease, but not protease activities were detected at 7 and 14 days of culture in Impranil. The best eight Impranil-degrading fungi were also able to degrade solid foams of the highly recalcitrant PE-PU type to different extents, with the highest levels generating up to 65% of dry-weight losses not previously reported. Scanning electron microscopy (SEM) analysis of fungus-treated foams showed melted and thinner cell wall structures than the non-fungus-treated ones, demonstrating fungal biodegradative action on PE-PU. Polyurethane waste disposal has become a serious problem. In this work, fungal strains able to efficiently degrade different types of polyurethanes are reported, and

  14. A critical review of algal biomass: A versatile platform of bio-based polyesters from renewable resources.

    Science.gov (United States)

    Noreen, Aqdas; Zia, Khalid Mahmood; Zuber, Mohammad; Ali, Muhammad; Mujahid, Mohammad

    2016-05-01

    Algal biomass is an excellent renewable resource for the production of polymers and other products due to their higher growth rate, high photosynthetic efficiency, great potential for carbon dioxide fixation, low percentage of lignin and high amount of carbohydrates. Algae contain unique metabolites which are transformed into monomers suitable for development of novel polyesters. This review article mainly focuses on algal bio-refinery concept for polyester synthesis and on exploitation of algae-based biodegradable polyester blends and composites in tissue engineering and controlled drug delivery system. Algae-derived hybrid polyester scaffolds are extensively used for bone, cartilage, cardiac and nerve tissue regeneration due to their biocompatibility and tunable biodegradability. Microcapsules and microspheres of algae-derived polyesters have been used for controlled and continuous release of several pharmaceutical agents and macromolecules to produce humoral and cellular immunity with efficient intracellular delivery. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. In Situ Studies and Magnetic Properties of the Cmcm Polymorph of LiCoPO4 with a Hierarchical Dumbbell-Like Morphology Synthesized by Easy Single-Step Polyol Synthesis

    Directory of Open Access Journals (Sweden)

    Carlos Alarcón-Suesca

    2016-11-01

    Full Text Available LiCoPO4 (LCP exists in three different structural modifications: LCP-Pnma (olivine structure, LCP-Pn21a (KNiPO4 structure type, and LCP-Cmcm (Na2CrO4 structure type. The synthesis of the LCP-Cmcm polymorph has been reported via high pressure/temperature solid-state methods and by microwave-assisted solvothermal synthesis. Phase transitions from both LCP-Pn21a and LCP-Cmcm to LCP-Pnma upon heating indicates a metastable behavior. However, a precise study of the structural changes during the heating process and the magnetic properties of LCP-Cmcm are hitherto unknown. Herein, we present the synthesis and characterization of LCP-Cmcm via a rapid and facile soft-chemistry approach using two different kinetically controlled pathways, solvothermal and polyol syntheses, both of which only require relatively low temperatures (~200 °C. Additionally, by polyol, method a dumbbell-like morphology is obtained without the use of any additional surfactant or template. A temperature-dependent in situ powder XRD shows a transition from LCP-Cmcm at room temperature to LCP-Pnma and finally to LCP-Pn21a at 575 and 725 °C, respectively. In addition to that, the determination of the magnetic susceptibility as a function of temperature indicates a long-range antiferromagnetic order below TN = 11 K at 10 kOe and 9.1 K at 25 kOe. The magnetization curves suggests the presence of a metamagnetic transition.

  16. The axial crushes behaviour on foam-filled round Jute/Polyester composite tubes

    Science.gov (United States)

    Othman, A.; Ismail, A. E.

    2018-04-01

    The present paper investigates the effect of axial loading compression on jute fibre reinforced polyester composite round tubes. The specimen of composite tube was fabricated by hand lay-up method of 120 mm length with fix 50.8 mm inner diameter to determine the behaviour of energy absorption on number of layers of 450 angle fibre and internally reinforced with and without foam filler material. The foam filler material used in this studies were polyurethane (PU) and polystyrene (PE) with average of 40 and 45 kg/m3 densities on the axial crushing load against displacement relations and on the failure modes. The number of layers of on this study were two; three and four were selected to calculate the crush force efficiency (CFE) and the specific energy absorption (SEA) of the composite tubes. Result indicated that the four layers’ jute/polyester show significant value in term of crushing load compared to 2 and 3 layers higher 60% for 2 layer and 3% compared to 3 layers. It has been found that the specific energy absorption of the jute/polyester tubes with polystyrene foam-filled is found higher respectively 10% to 12% than empty and polyurethane (PU) foam tubes. The increase in the number of layers from two to four increases the mean axial load from 1.01 KN to 3.60 KN for empty jute/polyester and from 2.11 KN to 4.26 KN for the polyurethane (PU) foam-filled jute/polyester tubes as well as for 3.60 KN to 5.58 KN for the polystyrene (PE) foam-filled jute/polyester. The author’s found that the failure of mechanism influence the characteristic of curve load against displacement obtained and conclude that an increasing number of layers and introduce filler material enhance the capability of specific absorbed energy.

  17. Adsorption of uranium ions by crosslinked polyester resin functionalized with acrylic acid from aqueous solutions

    International Nuclear Information System (INIS)

    Cemal Oezeroglu; Niluefer Metin

    2012-01-01

    In this paper, the crosslinked polyester resin containing acrylic acid functional groups was used for the adsorption of uranium ions from aqueous solutions. For this purpose, the crosslinked polyester resin of unsaturated polyester in styrene monomer (Polipol 353, Poliya) and acrylic acid as weight percentage at 80 and 20%, respectively was synthesized by using methyl ethyl ketone peroxide (MEKp, Butanox M60, Azo Nobel)-cobalt octoate initiator system. The adsorption of uranium ions on the sample (0.05 g copolymer and 5 mL of U(VI) solution were mixed) of the crosslinked polyester resin functionalized with acrylic acid was carried out in a batch reactor. The effects of adsorption parameters of the contact time, temperature, pH of solution and initial uranium(VI) concentration for U(VI) adsorption on the crosslinked polyester resin functionalized with acrylic acid were investigated. The adsorption data obtained from experimental results depending on the initial U(VI) concentration were analyzed by the Freundlich, Langmuir and Dubinin-Radushkevich (D-R) adsorption isotherms. The adsorption capacity and free energy change were determined by using D-R isotherm. The obtained experimental adsorption data depending on temperature were evaluated to calculate the thermodynamic parameters of enthalpy (ΔH o ), entropy (ΔS o ) and free energy change (ΔG o ) for the U(VI) adsorption on the crosslinked polyester resin functionalized with acrylic acid from aqueous solutions. The obtained adsorption data depending on contact time were analyzed by using adsorption models such as the modified Freundlich, Elovich, pseudo-first order and pseudo-second-order kinetic models. (author)

  18. Antifungal activity of fabrics knitted by metalized Silver/Polyester composite yarn

    Science.gov (United States)

    Özkan, İ.; Duru Baykal, P.

    2017-10-01

    In this study, antifungal properties of fabric knitted from metalized silver/polyester composite yarn were investigated. Intermingling is an alternative technique for yarn blending process. Yarns having different features can be combined by feeding the same intermingling jet. This process is defined as commingling. In the study, intermingling process was used to produce metalized silver/polyester composite yarn. Commingled yarns were knitted to single jersey fabrics by IPM brand sample type circular knitting machine. Antifungal activity test was applied to samples against Aspergillus Niger according to AATCC 30 test procedure. It has been identified that the application provides antifungal activity to fabric.

  19. Measurement of salivary cortisol--effects of replacing polyester with cotton and switching antibody

    DEFF Research Database (Denmark)

    Hansen, Ase Marie; Garde, Anne Helene; Persson, Roger

    2008-01-01

    measurements in our laboratory were affected by: 1) changes in the tampon material and 2) changes in the antibody of the analytical kit. In study 1, saliva from healthy subjects (n = 19) was split and spiked to Salivette polyester and cotton tampons, respectively, and treated as ordinary samples before being...... analysed for cortisol using a Spectria RIA kit for cortisol. In study 2, 68 anonymous saliva samples were analysed with the Spectria Cortisol RIA kit both before and after the manufacturer changed the antibody. The change from polyester to cotton tampons reduced the measured concentration of salivary...

  20. Radioluminescence of polyester resin modified with acrylic acid and its salts

    Science.gov (United States)

    Szalińska, H.; Wypych, M.; Pietrzak, M.; Szadkowska-Nicze, M.

    Polimal-109 polyester resin and its compounds containing acrylic acid and its salts such as: sodium, potassium, magnesium, calcium, barium, iron, cobalt, copper and manganese acrylates were studied by the radioluminescence method, including isothermal luminescence (ITL) at a radiation temperature of 77 K, thermoluminescence (RTL) and spectral distributions of isothermal luminescence. Measurements of optical absorption at 77 K before and after irradiation of the investigated samples were also carried out. The results obtained have shown that metal ions play a significant part in the processes taking place in the polyester matrix under the influence of γ 60Co radiation.

  1. Radioluminescence of polyester resin modified with acrylic acid and its salts

    International Nuclear Information System (INIS)

    Szalinska, H.; Wypych, M.; Pietrzak, M.; Szadkowska-Nicze, M.

    1987-01-01

    Polimal-109 polyester resin and its compounds containing acrylic acid and its salts such as: sodium, potassium, magnesium, calcium, barium, iron, cobalt, copper and manganese acrylates were studied by the radioluminescence method, including isothermal luminescence (ITL) at a radiation temperature of 77 K, thermoluminescence (RTL) and spectral distributions of isothermal luminescence. Measurements of optical absorption at 77K before and after irradiation of the investigated samples were also carried out. The results obtained have shown that metal ions play a significant part in the processes taking place in the polyester matrix under the influence of γ 60 Co radiation. (author)

  2. Purification and Properties of a Polyester Polyurethane-Degrading Enzyme from Comamonas acidovorans TB-35

    OpenAIRE

    Akutsu, Yukie; Nakajima-Kambe, Toshiaki; Nomura, Nobuhiko; Nakahara, Tadaatsu

    1998-01-01

    A polyester polyurethane (PUR)-degrading enzyme, PUR esterase, derived from Comamonas acidovorans TB-35, a bacterium that utilizes polyester PUR as the sole carbon source, was purified until it showed a single band in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This enzyme was bound to the cell surface and was extracted by addition of 0.2% N,N-bis(3-d-gluconamidopropyl)deoxycholamide (deoxy-BIGCHAP). The results of gel filtration and SDS-PAGE showed that the PUR este...

  3. Influence of Immersion Conditions on The Tensile Strength of Recycled Kevlar®/Polyester/Low-Melting-Point Polyester Nonwoven Geotextiles through Applying Statistical Analyses

    Directory of Open Access Journals (Sweden)

    Jing-Chzi Hsieh

    2016-05-01

    Full Text Available The recycled Kevlar®/polyester/low-melting-point polyester (recycled Kevlar®/PET/LPET nonwoven geotextiles are immersed in neutral, strong acid, and strong alkali solutions, respectively, at different temperatures for four months. Their tensile strength is then tested according to various immersion periods at various temperatures, in order to determine their durability to chemicals. For the purpose of analyzing the possible factors that influence mechanical properties of geotextiles under diverse environmental conditions, the experimental results and statistical analyses are incorporated in this study. Therefore, influences of the content of recycled Kevlar® fibers, implementation of thermal treatment, and immersion periods on the tensile strength of recycled Kevlar®/PET/LPET nonwoven geotextiles are examined, after which their influential levels are statistically determined by performing multiple regression analyses. According to the results, the tensile strength of nonwoven geotextiles can be enhanced by adding recycled Kevlar® fibers and thermal treatment.

  4. High yield polyol synthesis of round- and sharp-end silver nanowires with high aspect ratio

    Energy Technology Data Exchange (ETDEWEB)

    Nekahi, A.; Marashi, S.P.H., E-mail: pmarashi@aut.ac.ir; Fatmesari, D. Haghshenas

    2016-12-01

    Long silver nanowires (average length of 28 μm, average aspect ratio of 130) with uniform diameter along their length were produced by polyol synthesis of AgNO{sub 3} in ethylene glycol in the presence of PVP as preferential growth agent. Nanowires were produced with no addition of chloride salts such as NaCl or CuCl{sub 2} (or other additives such as Na{sub 2}S) which are usually used for lowering reduction rate of Ag ions by additional etchant of O{sub 2}/Cl{sup −}. Lower reduction rate was obtained by increasing the injection time of PVP and AgNO{sub 3} solutions, which was the significant factor in the formation of nanowires. Therefore, there was enough time for reduced Ag atoms to be deposited preferentially in the direction of PVP chains, resulting in high yield (the fraction of nanowires in the products) of nanowires (more than 95%) with high aspect ratio. The produced nanowires had both round- and sharp-ends with pentagonal cross section. Higher energy level of Ag atoms in borders of MTPs, which increases the dissolution rate of precipitated atoms, in addition to partial melting of MTPs at high synthesis temperatures, leads to the curving of the surfaces of exposed (111) crystalline planes in some MTPs and the formation of round-end silver nanowires. - Highlights: • Long silver nanowires with high aspect ratio of 130 were produced. • More than 95% nanowires were produced in products. • The produced nanowires had round- and sharp-ends with pentagonal cross section. • Additives were needed neither for high yield synthesis nor for round-end nanowires. • Melting and etching of MTPs in high energy borders resulted to round-end nanowires.

  5. Tethering of hyperbranched polyols using PEI as a building block to synthesize antifouling PVDF membranes

    Science.gov (United States)

    Wang, Xushan; Wang, Zihong; Wang, Zhe; Cao, Yu; Meng, Jianqiang

    2017-10-01

    Antifouling PVDF membranes were prepared by grafting hyperbranched polyols on the membrane surface via a three-step modification method. The membrane was first prepared by alkaline treatment to introduce alkenyl groups, then chemically immobilizing hyperbranched poly(ethyleneimine) (HPEI) on membrane surface through Michael reaction followed by ring opening reaction of the glycidol with amine groups. Chemical compositions, surface morphology and physicochemical properties of the original and modified membranes were characterized via attenuated total refection-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), water contact angle (WCA) and zeta potential measurements. The antifouling property of the modified membrane was assessed by the static bovine serum albumin (BSA) and lysozyme (LZM) adsorption as well as cross-flow filtration of BSA aqueous solution. The results explicate that surface modification using hyperbranched polymers can alter membrane chemistry and morphology significantly. In contrast to the original PVDF membrane, the modified membrane shows superhydrophilic property and relatively high capability to resist nonspecific protein adsorption. Three HPEIs were used for modification and the obtained PVDFA-g-PG60,000 membrane has a static BSA protein adsorption of 45 μg/cm2 and shows the highest protein resistance. However, the PVDF-g-PG membrane is positively charged due to the unreacted amine groups. As a result, the PVDF-g-PG membranes also show high flux decline during the filtration of BSA aqueous solution due to the electrostatic interaction. In spite of that, the PVDF-g-PG membranes still maintain high flux recovery ratio and good washing properties.

  6. Mining the Sinorhizobium meliloti transportome to develop FRET biosensors for sugars, dicarboxylates and cyclic polyols.

    Directory of Open Access Journals (Sweden)

    Alexandre Bourdès

    Full Text Available Förster resonance energy transfer (FRET biosensors are powerful tools to detect biologically important ligands in real time. Currently FRET bisosensors are available for twenty-two compounds distributed in eight classes of chemicals (two pentoses, two hexoses, two disaccharides, four amino acids, one nucleobase, two nucleotides, six ions and three phytoestrogens. To expand the number of available FRET biosensors we used the induction profile of the Sinorhizobium meliloti transportome to systematically screen for new FRET biosensors.Two new vectors were developed for cloning genes for solute-binding proteins (SBPs between those encoding FRET partner fluorescent proteins. In addition to a vector with the widely used cyan and yellow fluorescent protein FRET partners, we developed a vector using orange (mOrange2 and red fluorescent protein (mKate2 FRET partners. From the sixty-nine SBPs tested, seven gave a detectable FRET signal change on binding substrate, resulting in biosensors for D-quinic acid, myo-inositol, L-rhamnose, L-fucose, β-diglucosides (cellobiose and gentiobiose, D-galactose and C4-dicarboxylates (malate, succinate, oxaloacetate and fumarate. To our knowledge, we describe the first two FRET biosensor constructs based on SBPs from Tripartite ATP-independent periplasmic (TRAP transport systems.FRET based on orange (mOrange2 and red fluorescent protein (mKate2 partners allows the use of longer wavelength light, enabling deeper penetration of samples at lower energy and increased resolution with reduced back-ground auto-fluorescence. The FRET biosensors described in this paper for four new classes of compounds; (i cyclic polyols, (ii L-deoxy sugars, (iii β-linked disaccharides and (iv C4-dicarboxylates could be developed to study metabolism in vivo.

  7. Fabrication and Characterization of ZnO Nano-Clips by the Polyol-Mediated Process.

    Science.gov (United States)

    Wang, Mei; Li, Ai-Dong; Kong, Ji-Zhou; Gong, You-Pin; Zhao, Chao; Tang, Yue-Feng; Wu, Di

    2018-02-09

    ZnO nano-clips with better monodispersion were prepared successfully using zinc acetate hydrate (Zn(OAc) 2 ·nH 2 O) as Zn source and ethylene glycol (EG) as solvent by a simple solution-based route-polyol process. The effect of solution concentration on the formation of ZnO nano-clips has been investigated deeply. We first prove that the 0.01 M Zn(OAc) 2 ·nH 2 O can react with EG without added water or alkaline, producing ZnO nano-clips with polycrystalline wurtzite structure at 170 °C. As-synthesized ZnO nano-clips contain a lot of aggregated nanocrystals (~ 5 to 15 nm) with high specific surface area of 88 m 2 /g. The shapes of ZnO nano-clips basically keep constant with improved crystallinity after annealing at 400-600 °C. The lower solution concentration and slight amount of H 2 O play a decisive role in ZnO nano-clip formation. When the solution concentration is ≤ 0.0125 M, the complexing and polymerization reactions between Zn(OAc) 2 ·nH 2 O and EG predominate, mainly elaborating ZnO nano-clips. When the solution concentration is ≥ 0.015 M, the alcoholysis and polycondensation reactions of Zn(OAc) 2 ·nH 2 O and EG become dominant, leading to ZnO particle formation with spherical and elliptical shapes. The possible growth mechanism based on a competition between complexing and alcoholysis of Zn(OAc) 2 ·nH 2 O and EG has been proposed.

  8. Stability of endoglucanases from mesophilic fungus and thermophilic bacterium in acidified polyols.

    Science.gov (United States)

    Chong, Barrie Fong; Harrison, Mark D; O'Hara, Ian M

    2014-01-01

    Recent developments in chemical pretreatments of lignocellulosic biomass using polyols as co-solvents (e.g., glycerol and ethylene glycol) at temperatures less than 100°C may allow the effective use of thermostable and non-thermostable cellulases in situ during the saccharification process. The potential of biomass saccharifying enzymes, endoglucanases (EG) from a thermophilic bacterium (Thermotoga maritima) and a mesophilic fungus (Trichoderma longibrachiatum), to retain their activity in aqueous buffer, acidified glycerol, and acidified ethylene glycol used as co-solvents at pretreatment temperatures at or below 100°C were examined. The results show that despite its origin, T. longibrachiatum EG (Tl-EG) retained 75% of its activity after exposure to 100°C for 5 min in aqueous buffer while T. maritima EG (Tm-EG) retained only 5% activity. However, at 90°C both enzymes retained over 87% of their activity. In acidified (0.1% (w/w) H2SO4) glycerol, Tl-EG retained similar activity (80%) to that obtained in glycerol alone, while Tm-EG retained only 35%. With acidified ethylene glycol under these conditions, both Tl-EG and Tm-EG retained 36% of their activity. The results therefore show that Tl-EG is more stable in both acidified glycerol and ethylene glycol than Tm-EG. A preliminary kinetic study showed that pure glycerol improved the thermal stability of Tl-EG but destabilized Tm-EG, relative to the buffer solution. The half-lives of both Tl-EG and Tm-EG are 4.5 min in acidified glycerol, indicating that the effectiveness of these enzymes under typical pretreatment times of greater than 15 min will be considerably diminished. Attempts have been made to explain the differences in the results obtained between the two enzymes. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Fabrication and Characterization of ZnO Nano-Clips by the Polyol-Mediated Process

    Science.gov (United States)

    Wang, Mei; Li, Ai-Dong; Kong, Ji-Zhou; Gong, You-Pin; Zhao, Chao; Tang, Yue-Feng; Wu, Di

    2018-02-01

    ZnO nano-clips with better monodispersion were prepared successfully using zinc acetate hydrate (Zn(OAc)2·nH2O) as Zn source and ethylene glycol (EG) as solvent by a simple solution-based route-polyol process. The effect of solution concentration on the formation of ZnO nano-clips has been investigated deeply. We first prove that the 0.01 M Zn(OAc)2·nH2O can react with EG without added water or alkaline, producing ZnO nano-clips with polycrystalline wurtzite structure at 170 °C. As-synthesized ZnO nano-clips contain a lot of aggregated nanocrystals ( 5 to 15 nm) with high specific surface area of 88 m2/g. The shapes of ZnO nano-clips basically keep constant with improved crystallinity after annealing at 400-600 °C. The lower solution concentration and slight amount of H2O play a decisive role in ZnO nano-clip formation. When the solution concentration is ≤ 0.0125 M, the complexing and polymerization reactions between Zn(OAc)2·nH2O and EG predominate, mainly elaborating ZnO nano-clips. When the solution concentration is ≥ 0.015 M, the alcoholysis and polycondensation reactions of Zn(OAc)2·nH2O and EG become dominant, leading to ZnO particle formation with spherical and elliptical shapes. The possible growth mechanism based on a competition between complexing and alcoholysis of Zn(OAc)2·nH2O and EG has been proposed.

  10. Inhibition of d-xylose isomerase by polyols: atomic details by joint X-ray/neutron crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Kovalevsky, Andrey, E-mail: ayk@lanl.gov [Los Alamos National Laboratory, PO Box 1663, MS M888, Los Alamos, NM 87545 (United States); Hanson, B. Leif [University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606 (United States); Mason, Sax A. [Institut Laue–Langevin, 6 Rue Jules Horowitz, 38042 Grenoble (France); Forsyth, V. Trevor [Institut Laue–Langevin, 6 Rue Jules Horowitz, 38042 Grenoble (France); Keele University, Staffordshire (United Kingdom); Fisher, Zoe [Los Alamos National Laboratory, PO Box 1663, MS M888, Los Alamos, NM 87545 (United States); Mustyakimov, Marat [Los Alamos National Laboratory, PO Box 1663, MS M888, Los Alamos, NM 87545 (United States); Oak Ridge National Laboratory, PO Box 2008, MS 6475, Oak Ridge, TN 37831 (United States); Blakeley, Matthew P. [Institut Laue–Langevin, 6 Rue Jules Horowitz, 38042 Grenoble (France); Keen, David A. [Harwell Science and Innovation Campus, Didcot, Oxon OX11 0QX (United Kingdom); Langan, Paul [Oak Ridge National Laboratory, PO Box 2008, MS 6475, Oak Ridge, TN 37831 (United States); Los Alamos National Laboratory, PO Box 1663, MS M888, Los Alamos, NM 87545 (United States)

    2012-09-01

    A joint X-ray/neutron structure of d-xylose isomerase in complex with the inhibitor sorbitol was determined at room temperature at an acidic pH of 5.9. Protonation of the O5 O atom of the sugar was directly observed in the nuclear density maps. Under acidic conditions sorbitol gains a water-mediated interaction with the enzyme active site, which may explain the increased potency of the inhibitor at low pH. d-Xylose isomerase (XI) converts the aldo-sugars xylose and glucose to their keto analogs xylulose and fructose, but is strongly inhibited by the polyols xylitol and sorbitol, especially at acidic pH. In order to understand the atomic details of polyol binding to the XI active site, a 2.0 Å resolution room-temperature joint X-ray/neutron structure of XI in complex with Ni{sup 2+} cofactors and sorbitol inhibitor at pH 5.9 and a room-temperature X-ray structure of XI containing Mg{sup 2+} ions and xylitol at the physiological pH of 7.7 were obtained. The protonation of oxygen O5 of the inhibitor, which was found to be deprotonated and negatively charged in previous structures of XI complexed with linear glucose and xylulose, was directly observed. The Ni{sup 2+} ions occupying the catalytic metal site (M2) were found at two locations, while Mg{sup 2+} in M2 is very mobile and has a high B factor. Under acidic conditions sorbitol gains a water-mediated interaction that connects its O1 hydroxyl to Asp257. This contact is not found in structures at basic pH. The new interaction that is formed may improve the binding of the inhibitor, providing an explanation for the increased affinity of the polyols for XI at low pH.

  11. The identification of cutin synthase: formation of the plant polyester cutin

    DEFF Research Database (Denmark)

    Yeats, Trevor H.; Martin, Laetitia B. B.; Viart, Helene Marie-France

    2012-01-01

    A hydrophobic cuticle consisting of waxes and the polyester cutin covers the aerial epidermis of all land plants, providing essential protection from desiccation and other stresses. We have determined the enzymatic basis of cutin polymerization through characterization of a tomato extracellular...

  12. 76 FR 52935 - Certain Polyester Staple Fiber From Korea: Rescission of Antidumping Duty Administrative Review

    Science.gov (United States)

    2011-08-24

    ... conform to the Department's revised 19 CFR 351.303(g) certification language as announced in Certification... the correct certification language in a timely manner. On June 28, 2011, in accordance with 19 CFR 351... polyesters measuring 3.3 decitex (3 denier, inclusive) or more in diameter. This merchandise is cut to...

  13. Dipeptide-based polyphosphazene and polyester blends for bone tissue engineering.

    Science.gov (United States)

    Deng, Meng; Nair, Lakshmi S; Nukavarapu, Syam P; Jiang, Tao; Kanner, William A; Li, Xudong; Kumbar, Sangamesh G; Weikel, Arlin L; Krogman, Nicholas R; Allcock, Harry R; Laurencin, Cato T

    2010-06-01

    Polyphosphazene-polyester blends are attractive materials for bone tissue engineering applications due to their controllable degradation pattern with non-toxic and neutral pH degradation products. In our ongoing quest for an ideal completely miscible polyphosphazene-polyester blend system, we report synthesis and characterization of a mixed-substituent biodegradable polyphosphazene poly[(glycine ethyl glycinato)(1)(phenyl phenoxy)(1)phosphazene] (PNGEG/PhPh) and its blends with a polyester. Two dipeptide-based blends namely 25:75 (Matrix1) and 50:50 (Matrix2) were produced at two different weight ratios of PNGEG/PhPh to poly(lactic acid-glycolic acid) (PLAGA). Blend miscibility was confirmed by differential scanning calorimetry, Fourier transform infrared spectroscopy, and scanning electron microscopy. Both blends resulted in higher tensile modulus and strength than the polyester. The blends showed a degradation rate in the order of Matrix2PLAGA in phosphate buffered saline at 37 degrees C over 12 weeks. Significantly higher pH values of degradation media were observed for blends compared to PLAGA confirming the neutralization of PLAGA acidic degradation by polyphosphazene hydrolysis products. The blend components PLAGA and polyphosphazene exhibited a similar degradation pattern as characterized by the molecular weight loss. Furthermore, blends demonstrated significantly higher osteoblast growth rates compared to PLAGA while maintaining osteoblast phenotype over a 21-day culture. Both blends demonstrated improved biocompatibility in a rat subcutaneous implantation model compared to PLAGA over 12 weeks. (c) 2010 Elsevier Ltd. All rights reserved.

  14. A facile fabrication of multifunctional knit polyester fabric based on chitosan and polyaniline polymer nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Xiaoning [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Tian, Mingwei [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao University, Qingdao, Shandong 266071 (China); Qu, Lijun, E-mail: lijunqu@126.com [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao University, Qingdao, Shandong 266071 (China); Zhu, Shifeng [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Guo, Xiaoqing [College of Textiles, Qingdao University, Qingdao, Shandong 266071 (China); Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao University, Qingdao, Shandong 266071 (China); Han, Guangting [Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao, Shandong 266071 (China); Collaborative Innovation Center for Marine Biomass Fibers, Materials and Textiles of Shandong Province, Qingdao University, Qingdao, Shandong 266071 (China); and others

    2014-10-30

    Highlights: • Multifunctional knit polyester fabric was facile fabricated by the combination of pad-dry-cure process and in situ chemical polymerization route. • High electrical conductivity and efficient water-repellent properties were endowed to the polymer nanocomposite coated fabric. • The polymer nanocomposite coated fabric also performed efficient and durable photocatalytic activities under the illumination of ultraviolet light. - Abstract: Knit polyester fabric was successively modified and decorated with chitosan layer and polyaniline polymer nanocomposite layer in this paper. The fabric was firstly treated with chitosan to form a stable layer through the pad-dry-cure process, and then the polyaniline polymer nanocomposite layer was established on the outer layer by in situ chemical polymerization method using ammonium persulfate as oxidant and chlorhydric acid as dopant. The surface morphology of coated fabric was characterized by scanning electron microscopy (SEM), and the co-existence of chitosan layer and granular polyaniline polymer nanocomposite was confirmed and well dispersed on the fabric surface. The resultant fabric was endowed with remarkable electrical conductivity properties and efficient water-repellent capability, which also have been found stable after water laundering. In addition, the photocatalytic decomposition activity for reactive red dye was observed when the multifunctional knit polyester fabric was exposed to the illumination of ultraviolet lamp. These results indicated that chitosan and polyaniline polymer nanocomposite could form ideal multifunctional coatings on the surface of knit polyester fabric.

  15. Synthesis of a novel polyester building block from pentoses by tin-containing silicates

    DEFF Research Database (Denmark)

    Elliot, Samuel Gilbert; Andersen, Christian; Tolborg, Søren

    2017-01-01

    a product containing functional groups originating from trans-2,5-dihydroxy-3-pentenoic acid methyl ester in the polyester backbone. The reactivity of the incorporated olefin and hydroxyl moieties was investigated using trifluoroacetic anhydride and thiol-ene chemisitry, thus illustrating the potential...

  16. Ultrasound enhanced 50 Hz plasma treatment of glass-fiber-reinforced polyester at atmospheric pressure

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Norrman, Kion; Singh, Shailendra Vikram

    2013-01-01

    Glass-fiber-reinforced polyester (GFRP) plates are treated using a 50Hz dielectric barrier discharge at a peak-to-peak voltage of 30 kV in helium at atmospheric pressure with and without ultrasonic irradiation to study adhesion improvement. The ultrasonic waves at the fundamental frequency...

  17. Gliding arc surface treatment of glass-fiber-reinforced polyester enhanced by ultrasonic irradiation

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Norrman, Kion; Drews, Joanna Maria

    2011-01-01

    . The efficiency of such a plasma treatment at atmospheric pressure can be further improved by ultrasonic irradiation onto the surface during the treatment. In the present work glass fiber reinforced polyester (GFRP) plates are treated using an atmospheric pressure gliding arc with and without ultrasonic...

  18. 50-Hz plasma treatment of glass fibre reinforced polyester at atmospheric pressure enhanced by ultrasonic irradiation

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Norrman, Kion; Singh, Shailendra Vikram

    2011-01-01

    Glass fibre reinforced polyester (GFRP) plates are treated using a 50-Hz dielectric barrier discharge at peak-to-peak voltage of 30 kV in helium at atmospheric pressure with and without ultrasonic irradiation to study adhesion improvement. The ultrasonic waves at the fundamental frequency of around...

  19. Development of a model for the synthesis of unsaturated polyester by reactive distillation

    NARCIS (Netherlands)

    Shah, M.R.; Zondervan, E.; Oudshoorn, M.L.; Haan, de A.B.; Haan, de A.B.; Kooijman, H.; Górak, A.

    2010-01-01

    Traditionally polyester production is done in a batch reactor equipped with a separation column for batch distillation. A promising alternative for the intensification of this process is reactive distillation. In this paper, a reactive distillation model is developed for the synthesis of an

  20. Plasma Surface Modification of Glass-Fibre-Reinforced Polyester Enhanced by Ultrasonic Irradiation

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Singh, Shailendra Vikram; Bardenshtein, Alexander

    2010-01-01

    treatment can be highly enhanced by simultaneous high-power ultrasonic irradiation of the treating surface, because the delivered acoustic energy can reduce the thickness of the boundary gas layer. Here surfaces of glass-fibre-reinforced polyester (GFRP) plates were treated using an atmospheric pressure...

  1. Material characterization of a polyester resin system for the pultrusion process

    DEFF Research Database (Denmark)

    Baran, Ismet; Akkerman, Remko; Hattel, Jesper Henri

    2014-01-01

    In the present work, the chemo-rheology of an industrial ‘‘orthophthalic’’ polyester system specifically prepared for a pultrusion process is characterized. The curing behaviour is first characterized using the differential scanning calorimetry (DSC). Isothermal and dynamic scans are performed...

  2. High diffraction efficiency polarization gratings recorded by biphotonic holography in an azobenzene liquid crystalline polyester

    DEFF Research Database (Denmark)

    Sánchez, C; Alcalá, R; Hvilsted, Søren

    2001-01-01

    High diffraction efficiencies have been achieved with polarization gratings recorded in thin films of an azobenzene side-chain liquid crystalline polyester by means of biphotonic processes. Efficiency values up to 30% have been reached after an induction period of 300 s and subsequent evolution...

  3. Gliding arc discharge — Application for adhesion improvement of fibre reinforced polyester composites

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Teodoru, Steluta; Leipold, Frank

    2008-01-01

    production, and surface treatment. However, the application for adhesion improvement of structural materials has been rarely reported. In the present work, glass fibre reinforced polyester plates were treated using atmospheric pressure gliding arcs with high speed air flow for adhesion improvement...

  4. Novel biphotonic holographic storage in a side-chain liquid crystalline polyester

    DEFF Research Database (Denmark)

    Ramanujam, P.S.; Hvilsted, S.; Andruzzi, F.

    1993-01-01

    We report novel biphotonic holographic storage of text and gratings on unoriented films of a side-chain liquid crystalline polyester capable of high density storage and complete erasure. The holograms have a typical size of 1 mm. The recording utilizes unusual photochemistry involving azo dye...

  5. Thermoplastic poly(urethane urea)s from novel, bio-based amorphous polyester diols

    NARCIS (Netherlands)

    Tang, D.; Noordover, B.A.J.; Sablong, R.J.; Koning, C.E.

    2012-01-01

    In this study, two novel, bio-based, amorphous polyester diols, namely poly(1,2-dimethylethylene adipate) (PDMEA) and poly(1,2-dimethylethylene succinate) (PDMES) are used to prepare thermoplastic poly(urethane urea)s (TPUUs). Interestingly, the TPUUs based on PDMEA show similar thermal and

  6. Adhesion improvement of glass-fibre-reinforced polyester composites by gliding arc discharge treatment

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Sørensen, Bent F.; Løgstrup Andersen, Tom

    2013-01-01

    A gliding arc is a plasma that can be operated at atmospheric pressure and applied for plasma surface treatment for adhesion improvement. In the present work, glass-fibre-reinforced polyester plates were treated using an atmospheric pressure gliding arc discharge with an air flow to improve...

  7. Comparison of storage stability of odorous VOCs in polyester aluminum and polyvinyl fluoride tedlar bags

    Science.gov (United States)

    Whole air sampling using containers such as flexible bags or rigid canisters is commonly used to collect samples of volatile organic compounds (VOC) in air. The objective of this study was to compare the stability of polyester aluminum (PEA) and polyvinyl fluoride (PVF, brand name Tedlar®) bags for ...

  8. Polyester composites reinforced with corona-treated fibers from pine, eucalyptus and sugarcane bagasse

    Science.gov (United States)

    This study aims to evaluate plant fibers that were surface activated with NaOH and corona discharge before incorporating in ortho unsaturated polyester-based fiber composites. It demonstrates the potential use of lignocellulosic particles, especially eucalyptus that presented the higher values for a...

  9. Design and Applications of Biodegradable Polyester Tissue Scaffolds Based on Endogenous Monomers Found in Human Metabolism

    Directory of Open Access Journals (Sweden)

    Devin G. Barrett

    2009-10-01

    Full Text Available Synthetic polyesters have deeply impacted various biomedical and engineering fields, such as tissue scaffolding and therapeutic delivery. Currently, many applications involving polyesters are being explored with polymers derived from monomers that are endogenous to the human metabolism. Examples of these monomers include glycerol, xylitol, sorbitol, and lactic, sebacic, citric, succinic, α-ketoglutaric, and fumaric acids. In terms of mechanical versatility, crystallinity, hydrophobicity, and biocompatibility, polyesters synthesized partially or completely from these monomers can display a wide range of properties. The flexibility in these macromolecular properties allows for materials to be tailored according to the needs of a particular application. Along with the presence of natural monomers that allows for a high probability of biocompatibility, there is also an added benefit that this class of polyesters is more environmentally friendly than many other materials used in biomedical engineering. While the selection of monomers may be limited by nature, these polymers have produced or have the potential to produce an enormous number of successes in vitro and in vivo.

  10. The application of FT-IR spectrum method in photocuring process for polyester acrylate

    International Nuclear Information System (INIS)

    Cao Jin; Lu Xianliang; Zhang Zhenli

    1995-01-01

    This paper describes that the UV curing process of polyester acrylate can be monitored by measuring the degree of double bonds conversion with FT-IR spectroscopy. The various factors effect the UV curing rate. The relation between the curing rate and the concentration of photoinitiator, crosslinking agent, UV light intensity was discussed. (author)

  11. Thermal studies of poly(esters) containing silicon or germanium in the main chain

    International Nuclear Information System (INIS)

    Tagle, L.H.; Terraza, C.; Valenzuela, P.; Leiva, A.; Urzua, M.

    2005-01-01

    The thermal properties of poly(esters) containing Si and/or Ge in the main chain derived from the acid dichlorides bis(4-chloroformyl-phenyl)-dimethyl-silane, bis(4-chloroformyl-phenyl)-dimethyl-germane, bis(4-chloroformyl-phenyl)-diphenyl-silane and bis(4-chloroformyl-phenyl)-diphenyl-silane, and the diphenols bis(4-hydroxyphenyl)-dimethyl-silane, bis(4-hydroxyphenyl)-dimethyl-germane, bis(4-hydroxyphenyl)-diphenyl-silane and bis(4-hydroxyphenyl)-diphenyl-germane were studied by differential scanning calorimetry and dynamic thermogravimetry. Poly(esters) with two Si atoms in the main chain showed higher values of T g than those with two Ge atoms, and the same was observed for poly(esters) with phenyl groups bonded to the heteroatoms, instead of those with methyl groups. Thermal decomposition temperatures were also higher for those poly(esters) with two Si atoms in the main chain and those in which the heteroatom is bonded to phenyl groups, due to the higher polarity of the Si-C bond in front of the Ge-C

  12. Eco-friendly surface modification on polyester fabrics by esterase treatment

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jindan; Cai, Guoqiang; Liu, Jinqiang; Ge, Huayun; Wang, Jiping, E-mail: jipingwanghz@gmail.com

    2014-03-01

    Graphical abstract: - Highlights: • We used a simple and easy way to measure the enzyme activity. • We studied the mechanism by characterizing the chemical changes in the surface of fabric. • We studied the advantages in surface wettability, fiber integrity and mechanical performance of cutinase treated fabrics. • Cutinase pretreated fibers exhibited much improved fabric wicking and better fiber integrity comparing to alkali treated ones. • Cutinase pretreatment technology promotes energy conservation and emission reduction. - Abstract: Currently, traditional alkali deweighting technology is widely used to improve the hydrophilicity of polyester fabrics. However, the wastewater and heavy chemicals in the effluent cause enormous damage to the environment. Esterase treatment, which is feasible in mild conditions with high selectivity, can provide a clean and efficient way for polyester modification. Under the optimum conditions, the polyester fabric hydrolysis process of esterase had a linear kinetics. X-ray photoelectron spectrometry (XPS) results showed that hydroxyl and carboxyl groups were produced only on the surface of modified fiber without changing the chemical composition of the bulk. These fibers exhibited much improved fabric wicking, as well as greatly improved oily stain removal performance. Compared to the harsh alkali hydrolysis, the enzyme treatment led to smaller weight loss and better fiber integrity. The esterase treatment technology is promising to produce higher-quality polyester textiles with an environmental friendly approach.

  13. A facile fabrication of multifunctional knit polyester fabric based on chitosan and polyaniline polymer nanocomposite

    International Nuclear Information System (INIS)

    Tang, Xiaoning; Tian, Mingwei; Qu, Lijun; Zhu, Shifeng; Guo, Xiaoqing; Han, Guangting

    2014-01-01

    Highlights: • Multifunctional knit polyester fabric was facile fabricated by the combination of pad-dry-cure process and in situ chemical polymerization route. • High electrical conductivity and efficient water-repellent properties were endowed to the polymer nanocomposite coated fabric. • The polymer nanocomposite coated fabric also performed efficient and durable photocatalytic activities under the illumination of ultraviolet light. - Abstract: Knit polyester fabric was successively modified and decorated with chitosan layer and polyaniline polymer nanocomposite layer in this paper. The fabric was firstly treated with chitosan to form a stable layer through the pad-dry-cure process, and then the polyaniline polymer nanocomposite layer was established on the outer layer by in situ chemical polymerization method using ammonium persulfate as oxidant and chlorhydric acid as dopant. The surface morphology of coated fabric was characterized by scanning electron microscopy (SEM), and the co-existence of chitosan layer and granular polyaniline polymer nanocomposite was confirmed and well dispersed on the fabric surface. The resultant fabric was endowed with remarkable electrical conductivity properties and efficient water-repellent capability, which also have been found stable after water laundering. In addition, the photocatalytic decomposition activity for reactive red dye was observed when the multifunctional knit polyester fabric was exposed to the illumination of ultraviolet lamp. These results indicated that chitosan and polyaniline polymer nanocomposite could form ideal multifunctional coatings on the surface of knit polyester fabric

  14. Synthetic scaffolds based on biodegradable, functionalized polyesters for tissue engineering applications

    NARCIS (Netherlands)

    Seyednejad, S.H.

    2012-01-01

    The aim of this thesis was to investigate the possibility of using a novel hydroxyl-functionalized polyester [poly(hydroxymethylglycolide-co-ε-caprolactone), pHMGCL] (Fig.9) to fabricate scaffolds for tissue engineering applications. Degradable polymers that are frequently used for tissue

  15. The use of sterilised polyester mosquito net mesh for inguinal hernia repair in Ghana

    NARCIS (Netherlands)

    Clarke, M. G.; Oppong, C.; Simmermacher, R.; Park, K.; Kurzer, M.; Vanotoo, L.; Kingsnorth, A. N.

    The use of alloplastic mesh is now commonplace in hernia repair. However, in developing countries, cheaper alternatives to commercial mesh are required due to the high associated cost. Whilst nylon mosquito net mesh has been trialled previously, this study aimed to assess the use of polyester

  16. Corona Glow Discharge Plasma Treatment for Hidrophylicity Improvement of Polyester and Cotton Fabrics

    Science.gov (United States)

    Susan, A. I.; Widodo, M.; Nur, M.

    2017-07-01

    The effects of irradiation by a corona glow discharge plasma on hidrophylicity properties of polyester and cotton fabrics were investigated. We used a corona glow discharge plasma reactor with multiple points to plane electrodes, which was generated by a high voltage DC. Factors that affect the hidrophylicity properties were identified and evaluated as functions of irradiation parameters, which include duration of treatment, distance between electrodes, and bias voltage. It was readily observed from SEM examinations that plasma changed the surface morphology of both polyester and cotton fibers, giving result to an increased roughness to both of them. Results also showed that the hidrophylicityof polyester and cotton fabrics improved by the treatment, which is proportional to the time of treatment and voltage, but inversely proportional to the distance between electrodes. Time of treatment that provided the optimum enhancement of hidrophylicity for cotton is 15 minutes which improved the wetting time from 8.16 seconds to 1.26 seconds. For polyester, it took 15 minutes of irradiation time to improve the wetting time from 7340 seconds to 2905 seconds. The optimum distance between electrodes for both fabrics in this study was found to be 2 cm. Further analysis showed that the improved hidrophylicity properties is due to the creation of surface radicals by free radicals in the plasma leading to the formation of new water-attracting functional groups on the fiber surface.

  17. Exploring the Substrate Scope of Baeyer–Villiger Monooxygenases with Branched Lactones as Entry towards Polyesters

    NARCIS (Netherlands)

    Delgove, Marie; Fürst, Maximilian; Fraaije, Marco; Bernaerts, Katrien; de Wildeman, Stefaan

    2018-01-01

    Baeyer–Villiger monooxygenases (BVMOs) are biocatalysts that are able to convert cyclic ketones into lactones by the insertion of oxygen. The aim of this study was to explore the substrate scope of several BVMOs with (biobased) cyclic ketones as precursors for the synthesis of branched polyesters.

  18. Exploring the substrate scope of Baeyer-Villiger monooxygenases with branched lactones as entry towards polyesters

    NARCIS (Netherlands)

    Delgove, Marie; Fürst, Maximilian; Fraaije, Marco; Bernaerts, Katrien; De Wildeman, Stefaan M A

    2018-01-01

    Baeyer-Villiger monooxygenases (BVMOs) are biocatalysts able to convert cyclic ketones to lactones by the insertion of oxygen. The aim of this study was to explore the substrate scope of several BVMOs with (biobased) cyclic ketones as precursors for the synthesis of branched polyesters.The product

  19. Fabrication of narrow surface relief features in a side-chain azobenzene polyester with a scanning near-field microscope

    DEFF Research Database (Denmark)

    Ramanujam, P.S.; Holme, N. C. R.; Pedersen, M.

    2001-01-01

    We show that it is possible to fabricate topographic submicron features in a side-chain azobenzene polyester with a scanning near-field optical microscope, Through irradiation at a wavelength of 488 run at intensity levels of 12 W/cm(2), topographic features as narrow as 240 nm and as high as 6 nm...... have been reproducibly recorded in a thin film of the polyester. These observations are consistent with the fact that at low intensities peaks are produced evolving into formation of trenches at high intensities in the case of amorphous side-chain azobenzene polyesters. This may find applications...

  20. A Novel Methodology for the Synthesis of Acyloxy Castor Polyol Esters: Low Pour Point Lubricant Base Stocks.

    Science.gov (United States)

    Kamalakar, Kotte; Mahesh, Goli; Prasad, Rachapudi B N; Karuna, Mallampalli S L

    2015-01-01

    Castor oil, a non-edible oil containing hydroxyl fatty acid, ricinoleic acid (89.3 %) was chemically modified employing a two step procedure. The first step involved acylation (C(2)-C(6) alkanoic anhydrides) of -OH functionality employing a green catalyst, Kieselguhr-G and solvent free medium. The catalyst after reaction was filtered and reused several times without loss in activity. The second step is esterification of acylated castor fatty acids with branched mono alcohol, 2-ethylhexanol and polyols namely neopentyl glycol (NPG), trimethylolpropane (TMP) and pentaerythritol (PE) to obtain 16 novel base stocks. The base stocks when evaluated for different lubricant properties have shown very low pour points (-30 to -45°C) and broad viscosity ranges 20.27 cSt to 370.73 cSt, higher viscosity indices (144-171), good thermal and oxidative stabilities, and high weld load capacities suitable for multi-range industrial applications such as hydraulic fluids, metal working fluids, gear oil, forging and aviation applications. The study revealed that acylated branched mono- and polyol esters rich in monounsaturation is desirable for developing low pour point base stocks.

  1. Structure-property studies of thermoplastic and thermosetting polyurethanes using palm and soya oils-based polyols.

    Science.gov (United States)

    Mohammed, Issam Ahmed; Al-Mulla, Emad Abbas Jaffar; Kadar, Nurul Khizien Abdul; Ibrahim, Mazlan

    2013-01-01

    Palm and soya oils were converted to monoglycerides via transesterification of triglycerides with glycerol by one step process to produce renewable polyols. Thermoplastic polyurethanes (TPPUs) were prepared from the reaction of the monoglycerides which act as polyol with 4,4'-methylenediphenyldiisocyanate (MDI) whereas, thermosetting polyurethanes (TSPUs) were prepared from the reaction of glycerol, MDI and monoglycerides in one pot. Characterization of the polyurethanes was carried out by FT-IR, (1)H NMR, and iodine value and sol-gel fraction. The TSPUs showed good thermal properties compared to TPPUs as well as TSPUs exhibits good properties in pencil hardness and adhesion, however poorer in flexural and impact strength compared to TPPUs. The higher percentage of cross linked fraction, the higher degree of cross linking occurred, which is due to the higher number of double bond presents in the TSPUs. These were reflected in iodine value test as the highest iodine value of the soya-based thermosetting polyurethanes confirmed the highest degree of cross linking. Polyurethanes based on soya oil showed better properties compared to palm oil. This study is a breakthrough development of polyurethane resins using palm and soya oils as one of the raw materials.

  2. Microwave-assisted polyol synthesis and characterization of pvp-capped cds nanoparticles for the photocatalytic degradation of tartrazine

    International Nuclear Information System (INIS)

    Darwish, Maher; Mohammadi, Ali; Assi, Navid

    2016-01-01

    Highlights: • PVP-stabilized CdS nanoparticles have been fabricated by a polyol-microwave method. • CdS nanoparticles were characterized and the size was approximately 48 ± 10 nm. • Catalytic activity of our nanoparticles was examined for tartrazine degradation. • Remarkable results were obtained under both UV and visible light irradiations. - Abstract: Polyvinylpyrrolidone capped cadmium sulfide nanoparticles have been successfully synthesized by a facile polyol method with ethylene glycol. Microwave irradiation and calcination were used to control the size and shape of nanoparticles. Characterization with scanning electron microscopy revealed a restricted nanoparticles growth comparing with the uncapped product, hexagonal phase and 48 nm average particle size were confirmed by X-ray diffraction, and finally mechanism of passivation was suggested depending on Fourier transform infrared spectra. The efficiency of nanoparticles was evaluated by the photocatalytic degradation of tartrazine in aqueous solution under UVC and visible light irradiation. Complete degradation of the dye was observed after 90 min of UVC irradiation under optimized conditions. Kinetic of reaction fitted well to the pseudo-first-order kinetic and Langmuir–Hinshelwood models. Furthermore, 85% degradation of the dye in 9 h under visible light suggests that cadmium sulfide is a promising tool to work under visible light for environmental remediation.

  3. Controlled synthesis of multi-arm star polyether-polycarbonate polyols based on propylene oxide and CO2.

    Science.gov (United States)

    Hilf, Jeannette; Schulze, Patricia; Seiwert, Jan; Frey, Holger

    2014-01-01

    Multi-arm star copolymers based on a hyperbranched poly(propylene oxide) polyether-polyol (hbPPO) as a core and poly(propylene carbonate) (PPC) arms are synthesized in two steps from propylene oxide (PO), a small amount of glycidol and CO2 . The PPC arms are prepared via carbon dioxide (CO2 )/PO copolymerization, using hbPPO as a multifunctional macroinitiator and the (R,R)-(salcy)CoOBzF5 catalyst. Star copolymers with 14 and 28 PPC arms, respectively, and controlled molecular weights in the range of 2700-8800 g mol(-1) are prepared (Mw /Mn = 1.23-1.61). Thermal analysis reveals lowered glass transition temperatures in the range of -8 to 10 °C for the PPC star polymers compared with linear PPC, which is due to the influence of the flexible polyether core. Successful conversion of the terminal hydroxyl groups with phenylisocyanate demonstrates the potential of the polycarbonate polyols for polyurethane synthesis. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Mechanism and microstructural evolution of polyol mediated synthesis of nanostructured M-type SrFe12O19

    International Nuclear Information System (INIS)

    Tenorio Gonzalez, F.N.; Bolarín Miró, A.M.; Sánchez De Jesús, F.; Cortés Escobedo, C.A.; Ammar, S.

    2016-01-01

    The synthesis mechanism of nanostructured M-type strontium hexaferrite SrFe 12 O 19 with high coercivity (5.7 kOe) obtained by a polyol process and annealing is proposed. The results show that the hexaferrite is synthesized through the formation of a complex with diethylene glycol during the hydrolysis and solvation stage, followed by the condensation of magnetite and strontium oxide. The results of the monitoring of the process by X-ray diffraction (XRD) of synthesized powders, magnetization hysteresis loops and micromorphology are presented and discussed. The proposed mechanism suggests the intermediate formation of the magnetite phase, which shows coercivity near zero at room temperature and confirms the nanoscale of the particles. Results of thermogravimetric and differential thermal analysis indicate that this phase is followed by the formation of the hematite phase after a heat treatment up to 543 °C in an oxidizing atmosphere. Finally, the hexagonal phase is obtained after application of annealing at 836 °C through the reaction between hematite and strontium oxide. - Highlights: • SrFe 12 O 19 was successfully obtained by a polyol-assisted synthesis. • Magnetite nanoparticles have been obtained as intermediate phase. • A synthesis mechanism for the growing stage of magnetite is proposed. • A reaction sequence and the synthesis mechanism to obtain hexaferrite is presented.

  5. Microwave-assisted polyol synthesis and characterization of pvp-capped cds nanoparticles for the photocatalytic degradation of tartrazine

    Energy Technology Data Exchange (ETDEWEB)

    Darwish, Maher, E-mail: m-darwish@razi.tums.ac.ir [Department of Drug and Food Control, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Mohammadi, Ali, E-mail: alimohammadi@tums.ac.ir [Department of Drug and Food Control, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Nanotechnology Research Centre, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Assi, Navid, E-mail: navid_a30@yahoo.com [Department of Drug and Food Control, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2016-02-15

    Highlights: • PVP-stabilized CdS nanoparticles have been fabricated by a polyol-microwave method. • CdS nanoparticles were characterized and the size was approximately 48 ± 10 nm. • Catalytic activity of our nanoparticles was examined for tartrazine degradation. • Remarkable results were obtained under both UV and visible light irradiations. - Abstract: Polyvinylpyrrolidone capped cadmium sulfide nanoparticles have been successfully synthesized by a facile polyol method with ethylene glycol. Microwave irradiation and calcination were used to control the size and shape of nanoparticles. Characterization with scanning electron microscopy revealed a restricted nanoparticles growth comparing with the uncapped product, hexagonal phase and 48 nm average particle size were confirmed by X-ray diffraction, and finally mechanism of passivation was suggested depending on Fourier transform infrared spectra. The efficiency of nanoparticles was evaluated by the photocatalytic degradation of tartrazine in aqueous solution under UVC and visible light irradiation. Complete degradation of the dye was observed after 90 min of UVC irradiation under optimized conditions. Kinetic of reaction fitted well to the pseudo-first-order kinetic and Langmuir–Hinshelwood models. Furthermore, 85% degradation of the dye in 9 h under visible light suggests that cadmium sulfide is a promising tool to work under visible light for environmental remediation.

  6. Recent advances in solid polymer electrolytes for lithium batteries

    Institute of Scientific and Technical Information of China (English)

    Qingqing Zhang; Kai Liu; Fei Ding; Xingjiang Liu

    2017-01-01

    Solid polymer electrolytes are light-weight,flexible,and non-flammable and provide a feasible solution to the safety issues facing lithium-ion batteries through the replacement of organic liquid electrolytes.Substantial research efforts have been devoted to achieving the next generation of solid-state polymer lithium batteries.Herein,we provide a review of the development of solid polymer electrolytes and provide comprehensive insights into emerging developments.In particular,we discuss the different molecular structures of the solid polymer matrices,including polyether,polyester,polyacrylonitrile,and polysiloxane,and their interfacial compatibility with lithium,as well as the factors that govern the properties of the polymer electrolytes.The discussion aims to give perspective to allow the strategic design of state-of-the-art solid polymer electrolytes,and we hope it will provide clear guidance for the exploration of high-performance lithium batteries.

  7. A route to quantitative 13C NMR analysis of multicomponent polyesters

    DEFF Research Database (Denmark)

    Hvilsted, S.

    1991-01-01

    A protocol for quantitative sequential 13C NMR analysis is developed for polyesters composed of trimethylol propane (TMP), neopentyl glycol (NPG), and adipic and isophthalic acids. TMP centred, structural models with methyl adipate and isophthalate branches in all possible combinations...

  8. Safety of intradiscal injection and biocompatibility of polyester amide microspheres in a canine model predisposed to intervertebral disc degeneration

    NARCIS (Netherlands)

    Willems, Nicole; Mihov, George; Grinwis, Guy C M; van Dijk, Maarten; Schumann, Detlef; Bos, Clemens; Strijkers, Gustav J; Dhert, Wouter J A; Meij, Björn P; Creemers, Laura B.; Tryfonidou, Marianna A

    Repair of degenerated intervertebral discs (IVD) might be established via intradiscal delivery of biologic therapies. Polyester amide polymers (PEA) were evaluated for in vitro cytotoxicity and in vivo biocompatibility, and thereafter intradiscal application of PEA microspheres (PEAMs) in a canine

  9. Safety of intradiscal injection and biocompatibility of polyester amide microspheres in a canine model predisposed to intervertebral disc degeneration

    NARCIS (Netherlands)

    Willems, Nicole; Mihov, George; Grinwis, Guy C. M.; van Dijk, Maarten; Schumann, Detlef; Bos, Clemens; Strijkers, Gustav J.; Dhert, Wouter J. A.; Meij, Björn P.; Creemers, Laura B.; Tryfonidou, Marianna A.

    2017-01-01

    Repair of degenerated intervertebral discs (IVD) might be established via intradiscal delivery of biologic therapies. Polyester amide polymers (PEA) were evaluated for in vitro cytotoxicity and in vivo biocompatibility, and thereafter intradiscal application of PEA microspheres (PEAMs) in a canine

  10. California State Implementation Plan; San Diego County Air Pollution Control District; VOC Emissions from Polyester Resin Operations

    Science.gov (United States)

    EPA is taking final action to approve revisions to the San Diego County Air Pollution Control District (SDCAPCD) portion of the California SIP concerning volatile organic compound (VOC) emissions from polyester resin operations.

  11. Quasi-static axial crushes on woven jute/polyester AA6063T52 composite tubes

    Science.gov (United States)

    Othman, A.; Ismail, AE

    2018-04-01

    Quasi-static axial loading have been studied in this paper to determine the behaviour of jute/polyester wrapped on aluminium alloy 6063T52. The filler material also was include into crush box specimen, which is polyurethane (PU) and polystyrene (PE) rigid foam at ranging 40 and 45 kg/m3 densities. All specimen profile was fabricated using hand layup techniques and the length of each specimen were fixed at 100 mm as well as diameter and width of the tube at 50.8 mm. The two types of tubular cross-section were studied of round and square thin-walled profiles and the angle of fibre at 450 were analysed for four layers. Thin walled of aluminium was 1.9 mm and end frontal of each specimen of composite were chamfered at 450 to prevent catastrophic failure mode. The specific absorbed energy (SEA) and crush force efficiency (CFE) were analyses for each specimen to see the behaviour on jute/polyester wrapped on metallic structure can give influence the energy management for automotive application. Result show that the four layers’ jute/polyester with filler material show significant value in term of specific absorbed energy compared empty and polyurethane profiles higher 26.66% for empty and 15.19% compared to polyurethane profiles. It has been found that the thin walled square profile of the jute/polyester tubes with polystyrene foam-filled is found higher respectively 27.42% to 13.13% than empty and polyurethane (PU) foam tubes. An introduce filler material onto thin walled composite profiles gave major advantage increases the mean axial load of 31.87% from 32.94 kN to 48.35 kN from empty to polystyrene thin walled round jute/polyester profiles and 31.7% from 23.11 KN to 33.84 kN from empty to polystyrene thin walled square jute/polyester profiles. Failure mechanisms of the axially loaded composite tubes were also observed and discussed.

  12. Structural and Functional Studies of A. oryzae Cutinase: Enhanced Thermostability and Hydrolytic Activity of Synthetic Ester and Polyester Degradation

    OpenAIRE

    Liu, Zhiqiang; Gosser, Yuying; Baker, Peter James; Ravee, Yaniv; Lu, Ziying; Alemu, Girum; Li, Huiguang; Butterfoss, Glenn L.; Kong, Xiang-Peng; Gross, Richard; Montclare, Jin Kim

    2009-01-01

    Cutinases are responsible for hydrolysis of the protective cutin lipid polyester matrix in plants and thus have been exploited for hydrolysis of small molecule esters and polyesters. Here we explore the reactivity, stability, and structure of Aspergillus oryzae cutinase and compare it to the well-studied enzyme from Fusarium solani. Two critical differences are highlighted in the crystallographic analysis of the A. oryzae structure: (i) an additional disulfide bond and (ii) a topologically fa...

  13. Development auxiliaries for dyeing polyester with disperse dyes at low temperatures

    Science.gov (United States)

    Carrion-Fite, F. J.; Radei, S.

    2017-10-01

    High-molecular weight organic compounds known as carriers are widely used to expedite polyester dyeing at atmospheric pressure at 100 °C. However, carriers are usually poorly biodegradable and can partially plasticize fibres. Also, dyeing at temperatures above 100 °C in the absence of a carrier entails using expensive equipment. In this work, we developed an alternative method for dyeing polyester at temperatures below 100 °C that reduces energy expenses, dispenses with the need to invest in new equipment and avoids the undesirable effects of non-biodegradable carriers. The method uses disperse dyes in a microemulsion containing a low proportion of a non-toxic organic solvent and either of two alternative development auxiliaries (coumarin and o-vanillin) that is prepared with the aid of ultrasound.

  14. Performance of Plain Woven Jute Fabric-Reinforced Polyester Matrix Composite in Multilayered Ballistic System

    Directory of Open Access Journals (Sweden)

    Sergio Neves Monteiro

    2018-02-01

    Full Text Available The ballistic performance of plain woven jute fabric-reinforced polyester matrix composites was investigated as the second layer in a multilayered armor system (MAS. Volume fractions of jute fabric, up to 30 vol %, were mixed with orthophthalic polyester to fabricate laminate composites. Ballistic tests were conducted using high velocity 7.62 mm ammunition. The depth of penetration caused by the bullet in a block of clay witness, simulating a human body, was used to evaluate the MAS ballistic performance according to the international standard. The fractured materials after tests were analyzed by scanning electron microscopy (SEM. The results indicated that jute fabric composites present a performance similar to that of the much stronger Kevlar™, which is an aramid fabric laminate, as MAS second layer with the same thickness. The mechanism of this similar ballistic behavior as well as the comparative advantages of the jute fabric composites over the Kevlar™ are discussed.

  15. Synthesis and characterization of poly(ester amide from remewable resources through melt polycondensation

    Directory of Open Access Journals (Sweden)

    B. B. Wang

    2014-01-01

    Full Text Available Biodegradable poly(ester amides (PEAs were synthesized from lactic acid and 11-aminoundecanoic acid via melt polycondensation. Molecular weights, chemical structures and thermal properties of the poly(ester amides were characterized in terms of gel permeation chromatography (GPC, Fourier transform infrared spectroscopy (FTIR, 1H nuclear magnetic resonance (1H NMR, differential scanning calorimetry (DSC and thermogravimetric analysis (TGA, respectively. The PEAs have low molecular weights and display a lower cold crystallization temperature as well as smaller crystallinity by comparison with the pure poly(lactic acid (PLA. The incorporation of the 11-aminoundecanoic acid into the PLA chain not only improved the thermal stability but changed the decomposition process.

  16. Technology change priorities influencing competition quality promotion: Case study of Iran Keaton Polyester Manufacturing Company

    Directory of Open Access Journals (Sweden)

    Pouria Nour

    2012-10-01

    Full Text Available In the changing world with various customers’ demands the businesses tend to improve their advantages to beat their rivals by means of better quality, lower prices and so. For Iranian polyester market quality is of crucial importance and is achieved through changing and updating technologies. According to highly regarded model of CAPTECH, which is recommended by UNIDO, technology parameters are defined in each phase and not generally as a whole. In the end the biggest gaps are defined. The main goal is to prioritize the main parameters affecting Iranian polyester company's quality. In order to fulfill our goal, 20 high and medium managers were questioned for this paper. The questions were gathered according to UNIDO samples. After a qualitative and quantitative test we concluded that the biggest gap is for supply chain(56.91 and the lowest gap is for combination phase(43.97.

  17. Impact behaviour of Napier/polyester composites under different energy levels

    Energy Technology Data Exchange (ETDEWEB)

    Fahmi, I., E-mail: fahmi-unimap@yahoo.com; Majid, M. S. Abdul, E-mail: shukry@unimap.edu.my; Afendi, M., E-mail: afendirojan@unimap.edu.my; Haameem, J. M.A., E-mail: mhaameem@gmail.com [School of Mechatronic Engineering, Universiti Malaysia Perlis, Arau (Malaysia); Haslan, M., E-mail: haslan@sirim.my; Helmi, E. A., E-mail: hilmi@sirim.my [Advanced Material Research Centre (AMREC), SIRIM Berhad, Kulim (Malaysia)

    2016-07-19

    The effects of different energy levels on the impact behaviour of Napier fibre/polyester reinforced composites were investigated. Napier fibre was extracted using traditional water retting process to be utilized as reinforcing materials in polyester composite laminates. 25% fibre loading composite laminates were prepared and impacted at three different energy levels; 2.5,5 and 7.5 J using an instrumented drop weight impact testing machine (IMATEK IM10). The outcomes show that peak force and contact time increase with increased impact load. The energy absorption was then calculated from the force displacement curve. The results indicated that the energy absorption decreases with increasing energy levels of the impact. Impacted specimens were observed visually for fragmentation fracture using an optical camera to identify the failure mechanisms. Fracture fragmentation pattern from permanent dent to perforation with radial and circumferential was observed.

  18. Preparation of Acetylated Guar Gum – Unsaturated Polyester Composites & Effect of Water on Their Properties

    Directory of Open Access Journals (Sweden)

    David D’Melo

    2012-07-01

    Full Text Available Guar gum has seen extensive use in blends, however, its application as a filler in thermoset composites has as yet not been investigated. The effect of the addition of guar gum and its acetyl derivatives on the kinetics of water diffusion in unsaturated polyester composites was studied. The effect of water on the mechanical properties of the composites was studied with respect to the nature of filler, filler concentration and time of immersion. All the mechanical properties were observed to decrease on exposure to water. Further, it was observed that acetylated guar gum, with a degree of substitution of 0.21, showed the best mechanical properties, surpassing the other filled composites and that of the pure unsaturated polyester. Thus, acetylated guar gum showed promise as eco-friendly filler in composite formulation.

  19. Going greener: Synthesis of fully biobased unsaturated polyesters for styrene crosslinked resins with enhanced thermomechanical properties

    Directory of Open Access Journals (Sweden)

    C. S. M. F. Costa

    2017-11-01

    Full Text Available The main goal of this work was the development of fully biobased unsaturated polyesters (UPs that upon crosslinking with unsaturated monomers (UM could lead to greener unsaturated polyester resins (UPRs with similar thermomechanical properties to commercial fossil based UPR. After the successful synthesis of the biobased UPs, those were crosslinked with styrene (Sty, the most commonly used monomer, and the influence of the chemical structure of the UPs on the thermomechanical characteristics of UPRs were evaluated. The properties were compared with those of a commercial resin (Resipur 9837©. The BioUPRs presented high gel contents and contact angles that are similar to the commercial resin. The thermomechanical properties were evaluated by dynamic mechanical thermal analysis (DMTA and it was found that the UPR synthesized using propylene glycol (PG, succinic acid (SuAc and itaconic acid (ItAc presented very close thermomechanical properties compared to the commercial resin.

  20. Structural, optical and electrical characteristics of ITO thin films deposited by sputtering on different polyester substrates

    International Nuclear Information System (INIS)

    Guillen, C.; Herrero, J.

    2008-01-01

    Indium tin oxide (ITO) thin films were deposited by sputtering at room temperature on glass and different polyester substrates; namely polyarylate (PA), polycarbonate (PC) and polyethylene terephtalate (PET). The influence of the substrate on the structural, optical and electrical characteristics of the ITO layers was investigated. The sputtered films exhibited crystallization in the (2 2 2) orientation, with higher mean crystallite size and lower structural distortion onto PET than onto PA, PC or glass substrates. ITO films deposited onto PET showed also higher band gap energy, higher carrier concentration and lower resistivity than the ITO layers onto the other tested substrates. These optical and electrical characteristics have been related to the structural distortion that was found dependent on the specific polyester substrate

  1. Enzymatic Synthesis and Characterization of Hydrophilic Sugar Based Polyesters and Their Modification with Stearic Acid

    Directory of Open Access Journals (Sweden)

    Muhammad Humayun Bilal

    2016-03-01

    Full Text Available Biodegradable and hydrophilic functional polyesters were synthesized enzymatically using xylitol or d-sorbitol together with divinyl adipate and lipase B from Candida antartica (CAL-B. The resulting polyesters had pendant OH-groups from their sugar units which were esterified to different degrees with stearic acid chloride. The structure and the degrees of polymerization of the resulting graft copolymers based on poly(xylitol adipate and poly(d-sorbitol adipate were characterized by 1H NMR spectroscopy and SEC. DSC, WAXS and SAXS measurements indicated that a phase separation between polymer backbone and stearoyl side chains occurred in the graft copolymers, and, additionally, the side chains were able to crystallize which resulted in the formation of a lamellar morphology. Additionally, nanoparticles of the graft copolymers in an aqueous environment were studied by DLS and negative stain TEM.

  2. Preparation and characterization of polymer blends based on recycled PET and polyester derived by terephthalic acid

    International Nuclear Information System (INIS)

    Ohara, L.; Miranda, C.S.; Fiuza, R.P.; Luporini, S.; Carvalho, R.F.; Jose, N.M.

    2010-01-01

    Environmentally friendly materials, made from industrial waste, are being increasingly used as a solution to the growing amount of waste generated by society, but also as a cheaper alternative to replace conventional materials for use in construction. In this work were investigated the properties of polymer blends based on recycled PET and a polyester derived from terephthalic acid and glycerin, a co-product of biodiesel. The samples were characterized by XRD, TGA, DSC, FTIR and SEM. The polyester synthesized showed a degradation event near 300 deg C. The blends with higher ratio of PET showed thermal behavior similar to pure PET. The X-ray diffraction showed that the polymer blends are semicrystalline materials. The micrographs presents the presence of a smooth surface, indicating the possibility of miscibility between the arrays. Therefore, the blending makes possible the fabrication of low-cost materials with applications in several areas. (author)

  3. Experimental Investigation on Mechanical Properties of Hemp/E-Glass Fabric Reinforced Polyester Hybrid Composites

    Directory of Open Access Journals (Sweden)

    M R SANJAY

    2016-09-01

    Full Text Available This research work has been focusing on Hemp fibers has an alternative reinforcement for fiber reinforced polymer composites due to its eco-friendly and biodegradable characteristics. This work has been carried out to evaluate the mechanical properties of hemp/E-glass fabrics reinforced polyester hybrid composites. Vacuum bagging method was used for the preparation of six different kinds of hemp/glass fabrics reinforced polyester composite laminates as per layering sequences. The tensile, flexural, impact and water absorption tests of these hybrid composites were carried out experimentally according to ASTM standards. It reveals that an addition of E-glass fabrics with hemp fabrics can increase the mechanical properties of composites and decrease the water absorption of the hybrid composites.

  4. Polymeric blends from post-consumer PET and polyester becoming of glycerol and phthalic acid

    International Nuclear Information System (INIS)

    Miranda, C.S.; Brioude, M.; Fiuza, R.P.; Luporini, S.; Carvalho, R.F.; Jose, N.M.

    2010-01-01

    Preparation of physical mixture or polymer blends is a very important method to obtain a final product with excellent balance of properties, where one component can compensate for the poor property of another, and is often a modified low cost compared to development and synthesis of a new polymer. PET has become a major waste of post-consumer plastics and aiming to remedy this problem, this work aims to obtain blends from recycled PET and polyesters derived from glycerol and phthalic acid. The material with higher proportion of PET showed better thermal properties, observed by TGA and DSC, with a similar profile of pure PET. In XRD analysis showed a semicrystalline, while the SEM is a smooth surface on all materials, characteristic of pure polyester. The ratio of 50% its surface showed a probable immiscibility of polymers. (author)

  5. Manufacturing of kevlar/polyester composite by resin transfer moulding using conventional and microwave heating

    International Nuclear Information System (INIS)

    Abdullah, I.

    2015-01-01

    Microwave heating was incorporated into the resin transfer moulding technique. Polytetrafluoroethylene (PTFE) mould was used to cure the composite panel. Through the use of microwave heating, the mechanical and physical properties of produced Kevlar fibre/polyester composites were compared to those manufactured by conventional resin transfer moulding. The flexural modulus and flexural strength of 6-ply conventionally cured composites was 45% and 9% higher than the flexural modulus and flexural strength of 6-ply microwaved cured composites, respectively. However, 19% increase in interlaminar shear strength (ILSS) and 2% increase in compressive strength was observed in 6-ply microwave cured composites. This enhancement in ILSS and compressive strength is attributed to the better interfacial bonding of polyester resin with Kevlar fibres in microwaved cured composite, which was also confirmed via electron microscopy scanning. Furthermore, the microwave cured composite yielded maximum void contents (3%). (author)

  6. Diffraction from polarization holographic gratings with surface relief in side-chain azobenzene polyesters

    DEFF Research Database (Denmark)

    Naydenova, I; Nikolova, L; Todorov, T

    1998-01-01

    We investigate the polarization properties of holographic gratings in side-chain azobenzene polyesters in which an anisotropic grating that is due to photoinduced linear and circular birefringence is recorded in the volume of the material and a relief grating appears on the surface. A theoretical...... model is proposed to explain the experimental results, making it possible to understand the influence of the different photoinduced effects. It is shown that at low intensity the polarization properties of the diffraction at these gratings are determined by the interaction of the linear and circular...... photobirefringences, and at larger intensity the influence of the surface relief dominates the effect of the circular anisotropy. Owing to the high recording efficiency of the polyesters, the +/-1-order diffracted waves change the polarization interference pattern during the holographic recording, resulting...

  7. Thermal and mechanical behaviour of sub micron sized fly ash reinforced polyester resin composite

    Science.gov (United States)

    Nantha Kumar, P.; Rajadurai, A.; Muthuramalingam, T.

    2018-04-01

    The utilization of particles reinforced resin matrix composites is being increased owing to its lower density and high strength to weight ratio. In the present study, an attempt has been made to synthesize fly ash particles reinforced polyester resin composite for engine cowling application. The thermal stability and mechanical behaviours such as hardness and flexural strength of the composite with 2, 3 and 4 weight % of reinforcement is studied and analyzed. The thermo gravimetric analysis indicates that the higher addition of reinforcement increases the decomposition temperature due to its refractory nature. It is also observed that the hardness increases with higher filler addition owing to the resistance of FA particles towards penetration. The flexural strength is found to increase up to the addition of 3% of FA particles, whereas the polyester resin composite prepared with 4% FA particles addition is observed to have low flexural strength owing to agglomeration of particles.

  8. Hydrodynamic parameters of linear aromatic polyester of 3-phenylglutaric acid and bisphenol A

    Czech Academy of Sciences Publication Activity Database

    Netopilík, Miloš; Kratochvíl, Jaroslav; Schallausky, F.; Reichelt, S.; Lederer, A.

    2007-01-01

    Roč. 12, č. 4 (2007), s. 285-300 ISSN 1023-666X R&D Projects: GA ČR GA203/07/0659; GA AV ČR IAA400500703 Institutional research plan: CEZ:AV0Z40500505 Keywords : chain parameters * linear polyester * size exclusion chromatography Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.386, year: 2007

  9. Characterization of polyester composites from recycled polyethylene terephthalate reinforced with empty fruit bunch fibers

    International Nuclear Information System (INIS)

    Tan, Chiachun; Ahmad, Ishak; Heng, Muichin

    2011-01-01

    Highlights: → Unsaturated polyester resin (UPR) was synthesized from recycled PET. → Effect of surface treatment on EFB/UPR was studied. → Treatment on EFB improved the mechanical and thermal properties. → Treatment on EFB also improved fiber-matrix interaction. -- Abstract: Unsaturated polyester resin (UPR) was synthesized from recycled polyethylene terephthalate (PET) which acted as a matrix for the preparation of UPR/empty fruit bunch fibers (EFB) composite. Chemical recycling on fine pieces of PET bottles were conducted through glycolysis process using ethylene glycol. The unsaturated polyester resin (UPR) was then prepared by reacting the glycolysed product with maleic anhydride. FTIR analysis of glycolyzed product and prepared UPR showed that cross-links between unsaturated polyester chain and styrene monomer occurred at the unsaturated sites which resulted in the forming of cross-linking network. The preparation of UPR/EFB composite was carried out by adding EFB into prepared UPR matrix. The effects of surface treatment on EFB with sodium hydroxide solution (NaOH), silane coupling agent and maleic anhydride (MA) were then studied. The experimental results showed that treated EFB have higher values of tensile and impact strength compared with untreated EFB. The best results were obtained for silane treatment followed by MA and NaOH treatments where the tensile strength was increased by about 21%, 18% and 13% respectively. SEM micrographs of the tensile fracture surfaces of UPR/EFB composite also proved that treatment on EFB has increased the interfacial adhesion between the fiber and UPR matrix compared to the untreated UPR/EFB composite.

  10. Preparation and characterization of metal complex hydrogels crosslinked with hyperbranched polyester

    Czech Academy of Sciences Publication Activity Database

    Haroun, A. A.; Hakeim, O. A.; Trhlíková, Olga; Šlouf, Miroslav; Netopilík, Miloš

    2017-01-01

    Roč. 60, č. 5 (2017), s. 849-856 ISSN 0449-2285 R&D Projects: GA ČR(CZ) GC17-04258J Grant - others:AV ČR(CZ) ASRT-16-02 Program:Bilaterální spolupráce Institutional support: RVO:61389013 Keywords : hyperbranched polyester * chitosan * miniemulsion Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science

  11. Observation of hairpin defects in a nematic main-chain polyester

    Science.gov (United States)

    Li, M. H.; Brûlet, A.; Davidson, P.; Keller, P.; Cotton, J. P.

    1993-04-01

    The conformation of a main-chain liquid crystalline polyester in its oriented nematic phase has been determined by small-angle neutron scattering. The data are fitted by a model of rigid cylinder with orientational fluctuations. For a low degree of polymerization (~9) the chain is almost completely elongated in the direction of the nematic field. For a polymer 3 times longer, the existence of two hairpins is shown at high temperature; this number decreases with decreasing temperature.

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

    OpenAIRE

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

    2013-01-01

    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 des...

  13. Side-chain liquid-crystalline polyesters for optical information storage

    DEFF Research Database (Denmark)

    Hvilsted, Søren; Andruzzi, F.; Ramanujam, P.S.

    1992-01-01

    We report erasable holographic recording with a resolution of at least 2500 lines/mm on unoriented films of side-chain liquid-crystalline polyesters. Recording energies of approximately 1 J/cm2 have been used. We have obtained a diffraction efficiency of approximately 30% with polarization record...... recording of holograms. The holograms can be erased by heating them to approximately 80-degrees-C for approximately 2 min and are available for rerecording....

  14. Fungal Communities Associated with the Biodegradation of Polyester Polyurethane Buried under Compost at Different Temperatures

    OpenAIRE

    Zafar, Urooj; Houlden, Ashley; Robson, Geoffrey D.

    2013-01-01

    Plastics play an essential role in the modern world due to their low cost and durability. However, accumulation of plastic waste in the environment causes wide-scale pollution with long-lasting effects, making plastic waste management expensive and problematic. Polyurethanes (PUs) are heteropolymers that made up ca. 7% of the total plastic production in Europe in 2011. Polyester PUs in particular have been extensively reported as susceptible to microbial biodegradation in the environment, par...

  15. Rammed earth walls strengthened with polyester fabric strips: Experimental analysis under in-plane cyclic loading

    Czech Academy of Sciences Publication Activity Database

    Miccoli, L.; Müller, U.; Pospíšil, Stanislav

    2017-01-01

    Roč. 149, September (2017), s. 29-36 ISSN 0950-0618 R&D Projects: GA MŠk(CZ) LO1219 Keywords : rammed earth * pseudo-dynamic loads * shear-compression tests * strengthening * polyester fabric strips Subject RIV: JM - Building Engineering OBOR OECD: Construction engineering, Municipal and structural engineering Impact factor: 3.169, year: 2016 http://www.sciencedirect.com/science/article/pii/S0950061817310000

  16. Polyester-Based, Biodegradable Core-Multishell Nanocarriers for the Transport of Hydrophobic Drugs

    Directory of Open Access Journals (Sweden)

    Karolina A. Walker

    2016-05-01

    Full Text Available A water-soluble, core-multishell (CMS nanocarrier based on a new hyperbranched polyester core building block was synthesized and characterized towards drug transport and degradation of the nanocarrier. The hydrophobic drug dexamethasone was encapsulated and the enzyme-mediated biodegradability was investigated by NMR spectroscopy. The new CMS nanocarrier can transport one molecule of dexamethasone and degrades within five days at a skin temperature of 32 °C to biocompatible fragments.

  17. Reduced toxicity polyester resins and microvascular pre-preg tapes for advanced composites manufacturing

    Science.gov (United States)

    Poillucci, Richard

    Advanced composites manufacturing broadly encapsulates topics ranging from matrix chemistries to automated machines that lay-up fiber-reinforced materials. Environmental regulations are stimulating research to reduce matrix resin formulation toxicity. At present, composites fabricated with polyester resins expose workers to the risk of contact with and inhalation of styrene monomer, which is a potential carcinogen, neurotoxin, and respiratory irritant. The first primary goal of this thesis is to reduce the toxicity associated with polyester resins by: (1) identification of potential monomers to replace styrene, (2) determination of monomer solubility within the polyester, and (3) investigation of approaches to rapidly screen a large resin composition parameter space. Monomers are identified based on their ability to react with polyester and their toxicity as determined by the Globally Harmonized System (GHS) and a green screen method. Solubilities were determined by the Hoftyzer -- Van Krevelen method, Hansen solubility parameter database, and experimental mixing of monomers. A combinatorial microfluidic mixing device is designed and tested to obtain distinct resin compositions from two input chemistries. The push for safer materials is complemented by a thrust for multifunctional composites. The second primary goal of this thesis is to design and implement the manufacture of sacrificial fiber materials suitable for use in automated fiber placement of microvascaular multifunctional composites. Two key advancements are required to achieve this goal: (1) development of a roll-to-roll method to place sacrificial fibers onto carbon fiber pre-preg tape; and (2) demonstration of feasible manufacture of microvascular carbon fiber plates with automated fiber placement. An automated method for placing sacrificial fibers onto carbon fiber tapes is designed and a prototype implemented. Carbon fiber tows with manual placement of sacrificial fibers is implemented within an

  18. Test procedures for polyester immobilized salt-containing surrogate mixed wastes

    International Nuclear Information System (INIS)

    Biyani, R.K.; Hendrickson, D.W.

    1997-01-01

    These test procedures are written to meet the procedural needs of the Test Plan for immobilization of salt containing surrogate mixed waste using polymer resins, HNF-SD-RE-TP-026 and to ensure adequacy of conduct and collection of samples and data. This testing will demonstrate the use of four different polyester vinyl ester resins in the solidification of surrogate liquid and dry wastes, similar to some mixed wastes generated by DOE operations

  19. Tandem mass spectrometry characteristics of polyester anions and cations formed by electrospray ionization.

    Science.gov (United States)

    Arnould, Mark A; Buehner, Rita W; Wesdemiotis, Chrys; Vargas, Rafael

    2005-01-01

    Electrospray ionization of polyesters composed of isophthalic acid and neopentyl glycol produces carboxylate anions in negative mode and mainly sodium ion adducts in positive mode. A tandem mass spectrometry (MS/MS) study of these ions in a quadrupole ion trap shows that the collisionally activated dissociation pathways of the anions are simpler than those of the corresponding cations. Charge-remote fragmentations predominate in both cases, but the spectra obtained in negative mode are devoid of the complicating cation exchange observed in positive mode. MS/MS of the Na(+) adducts gives rise to a greater number of fragments but not necessarily more structural information. In either positive or negative mode, polyester oligomers with different end groups fragment by similar mechanisms. The observed fragments are consistent with rearrangements initiated by the end groups. Single-stage ESI mass spectra also are more complex in positive mode because of extensive H/Na substitutions; this is also true for matrix-assisted laser desorption ionization (MALDI) mass spectra. Hence, formation and analysis of anions might be the method of choice for determining block length, end group structure and copolymer sequence, provided the polyester contains at least one carboxylic acid end group that is ionizable to anions.

  20. Preparation and properties of aromatic polyester/TiO{sub 2} nanocomposites from polyethylene terephthalate

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Leonardo Moreira dos; Carone, Carlos Leonardo Pandolfo; Einloft, Sandra Mara Oliveira; Ligabue, Rosane Angelica, E-mail: rligabue@pucrs.br [Pontificia Universidade Catolica do Rio Grande do Sul (PUCRS), Porto Alegre, RS (Brazil). Programa de Graduacao em Engenharia e Tecnologia de Materiais

    2016-01-15

    The development of polyester based materials with enhanced properties as well as the use of post- consumer plastics as raw material has been an increasing market demand. This work aims the synthesis and characterization of aromatic polyesters/titanium dioxide nanocomposites from PET and using TiO{sub 2} (0, 1, 3 and 5% w/w) as filler by in situ polymerization. The results obtained by DSC, XRD and FTIR analyzes evidenced an interaction between the OH groups on the TiO{sub 2} surface with the ester groups of the polymer leading to decrease of the polymer crystallinity and of hydrophilicity. By SEM images was possible to note a homogeneous distribution of the filler into polymer matrix with 1%w/w TiO{sub 2} (average particle size of 199 nm), however for larger amounts of filler (3 and 5% TiO{sub 2}) revealed the aggregates formation. The results showed an improvement of thermal properties and hardness of the nanocomposites containing TiO{sub 2} nanoparticles compared to pristine polyester. (author)

  1. Development of sugar palm yarn/glass fibre reinforced unsaturated polyester hybrid composites

    Science.gov (United States)

    Nurazzi, N. Mohd; Khalina, A.; Sapuan, S. Mohd; Rahmah, M.

    2018-04-01

    This study investigates the effect of fibre hybridization for sugar palm yarn fibre with glass fibre reinforced with unsaturated polyester composites. In this work, unsaturated polyester resin are reinforced with fibre at a ratio of 70:30 wt% and 60:40 wt%. The hybrid composites were characterized in terms of physical (density and water absorption), mechanical (tensile, flexural and compression) and thermal properties through thermal gravimetry analysis (TGA). Density determination showed that density increased with higher wt% of glass fibre. The inherently higher density of glass fibre increased the density of hybrid composite. Resistance to water absorption is improved upon the incorporation of glass fibre and the hybrid composites were found to reach equilibrium absorption at days 4 and 5. As for mechanical performance, the highest tensile strength, tensile modulus, flexural strength, flexural modulus and compression strength were obtained from 40 wt% of fibres reinforcement with ratio of 50:50 wt% of sugar palm yarn fibre and glass fibre reinforced unsaturated polyester composites. The increase of glass fibre loading had a synergistic effect on the mechanical properties to the composites structure due to its superior strength and modulus. The thermal stability of hybrid composites was improved by the increase of onset temperature and the reduction of residues upon increase in temperature.

  2. Sulfonation of polyester fabrics by gaseous sulfur oxide activated by UV irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kordoghli, Bessem [Laboratory of Applied Chemical and Environment (UR-CAE) - University of Monastir (Tunisia); Textile Research Laboratory (LRT) - ISET Kasr Hellal, University of Monastir (Tunisia); Khiari, Ramzi, E-mail: khiari_ramzi2000@yahoo.fr [Laboratory of Applied Chemical and Environment (UR-CAE) - University of Monastir (Tunisia); LGP2 - Laboratory of Pulp and Paper Science, 461, Rue de la Papeterie - BP 65, 38402 Saint Martin d' Heres Cedex (France); Mhenni, Mohamed Farouk [Laboratory of Applied Chemical and Environment (UR-CAE) - University of Monastir (Tunisia); Sakli, Faouzi [Textile Research Laboratory (LRT) - ISET Kasr Hellal, University of Monastir (Tunisia); Belgacem, Mohamed Naceur [LGP2 - Laboratory of Pulp and Paper Science, 461, Rue de la Papeterie - BP 65, 38402 Saint Martin d' Heres Cedex (France)

    2012-10-01

    Highlights: Black-Right-Pointing-Pointer In this paper, an original technique was present to improve the hydrophilic properties of polyester fibres. Black-Right-Pointing-Pointer The modification of PET fabric was carried out using gaseous sulfur trioxide activated by UV irradiations. Black-Right-Pointing-Pointer We fully characterized the modified and untreated fabrics. - Abstract: This paper describes an original technique aiming to improve the hydrophilic properties of polyester fibres. In this method, the sulfonation of the aromatic rings is carried out using gaseous sulfur trioxide activated by UV irradiations. Thus, exposing the polyester textile fabric to the UVC light (wavelength around 254 nm) under a stream of sulfur trioxide leads to the fixation of -SO{sub 3}H groups. The amounts of the fixed sulfonate groups depended on the reaction conditions. Evidence of grafting deduced from the measurements of hygroscopic properties was carried out by contact angle measurement, moisture regain as well as by measuring the rate of retention. SEM and FT-IR analysis, DSC and DTA/TGA thermograms showed that no significant modifications have occurred in the bulk of the treated PET fabrics.

  3. The effect of mechanical loads on the degradation of aliphatic biodegradable polyesters.

    Science.gov (United States)

    Li, Ying; Chu, Zhaowei; Li, Xiaoming; Ding, Xili; Guo, Meng; Zhao, Haoran; Yao, Jie; Wang, Lizhen; Cai, Qiang; Fan, Yubo

    2017-06-01

    Aliphatic biodegradable polyesters have been the most widely used synthetic polymers for developing biodegradable devices as alternatives for the currently used permanent medical devices. The performances during biodegradation process play crucial roles for final realization of their functions. Because physiological and biochemical environment in vivo significantly affects biodegradation process, large numbers of studies on effects of mechanical loads on the degradation of aliphatic biodegradable polyesters have been launched during last decades. In this review article, we discussed the mechanism of biodegradation and several different mechanical loads that have been reported to affect the biodegradation process. Other physiological and biochemical factors related to mechanical loads were also discussed. The mechanical load could change the conformational strain energy and morphology to weaken the stability of the polymer. Besides, the load and pattern could accelerate the loss of intrinsic mechanical properties of polymers. This indicated that investigations into effects of mechanical loads on the degradation should be indispensable. More combination condition of mechanical loads and multiple factors should be considered in order to keep the degradation rate controllable and evaluate the degradation process in vivo accurately. Only then can the degradable devise achieve the desired effects and further expand the special applications of aliphatic biodegradable polyesters.

  4. Thread angle dependency on flame spread shape over kenaf/polyester combined fabric

    Science.gov (United States)

    Azahari Razali, Mohd; Sapit, Azwan; Nizam Mohammed, Akmal; Nor Anuar Mohamad, Md; Nordin, Normayati; Sadikin, Azmahani; Faisal Hushim, Mohd; Jaat, Norrizam; Khalid, Amir

    2017-09-01

    Understanding flame spread behavior is crucial to Fire Safety Engineering. It is noted that the natural fiber exhibits different flame spread behavior than the one of the synthetic fiber. This different may influences the flame spread behavior over combined fabric. There is a research has been done to examined the flame spread behavior over kenaf/polyester fabric. It is seen that the flame spread shape is dependent on the thread angle dependency. However, the explanation of this phenomenon is not described in detail in that research. In this study, explanation about this phenomenon is given in detail. Results show that the flame spread shape is dependent on the position of synthetic thread. For thread angle, θ = 0°, the polyester thread is breaking when the flame approach to the thread and the kenaf thread tends to move to the breaking direction. This behavior produces flame to be ‘V’ shape. However, for thread angle, θ = 90°, the polyester thread melts while the kenaf thread decomposed and burned. At this angle, the distance between kenaf threads remains constant as flame approaches.

  5. Biodegradable polyesters reinforced with triclosan loaded polylactide micro/nanofibers: Properties, release and biocompatibility

    Directory of Open Access Journals (Sweden)

    L. J. del Valle

    2012-04-01

    Full Text Available Mechanical properties and drug release behavior were studied for three biodegradable polyester matrices (polycaprolactone, poly(nonamethylene azelate and the copolymer derived from 1,9-nonanediol and an equimolar mixture of azelaic and pimelic acids reinforced with polylactide (PLA fibers. Electrospinning was used to produce suitable mats constituted by fibers of different diameters (i.e. from micro- to nanoscale and a homogeneous dispersion of a representative hydrophobic drug (i.e. triclosan. Fabrics were prepared by a molding process, which allowed cold crystallization of PLA micro/nanofibers and hot crystallization of the polyester matrices. The orientation of PLA molecules during electrospinning favored the crystallization process, which was slightly enhanced when the diameter decreased. Incorporation of PLA micro/nanofibers led to a significant increase in the elastic modulus and tensile strength, and in general to a decrease in the strain at break. The brittle fracture was clearer when high molecular weight samples with high plastic deformation were employed. Large differences in the release behavior were detected depending on the loading process, fiber diameter size and hydrophobicity of the polyester matrix. The release of samples with the drug only loaded into the reinforcing fibers was initially fast and then became slow and sustained, resulting in longer lasting antimicrobial activity. Biocompatibility of all samples studied was demonstrated by adhesion and proliferation assays using HEp-2 cell cultures.

  6. 3D printing of new biobased unsaturated polyesters by microstereo-thermal-lithography

    International Nuclear Information System (INIS)

    Gonçalves, Filipa A M M; Costa, Cátia S M F; Fabela, Inês G P; Simões, Pedro N; Serra, Arménio C; Coelho, Jorge F J; Farinha, Dina; Faneca, Henrique; Bártolo, Paulo J

    2014-01-01

    New micro three-dimensional (3D) scaffolds using biobased unsaturated polyesters (UPs) were prepared by microstereo-thermal-lithography (μSTLG). This advanced processing technique offers indubitable advantages over traditional printing methods. The accuracy and roughness of the 3D structures were evaluated by scanning electron microscopy and infinite focus microscopy, revealing a suitable roughness for cell attachment. UPs were synthesized by bulk polycondensation between biobased aliphatic diacids (succinic, adipic and sebacic acid) and two different glycols (propylene glycol and diethylene glycol) using fumaric acid as the source of double bonds. The chemical structures of the new oligomers were confirmed by proton nuclear magnetic resonance spectra, attenuated total reflectance Fourier transform infrared spectroscopy and matrix assisted laser desorption/ionization-time of flight mass spectrometry. The thermal and mechanical properties of the UPs were evaluated to determine the influence of the diacid/glycol ratio and the type of diacid in the polyester’s properties. In addition an extensive thermal characterization of the polyesters is reported. The data presented in this work opens the possibility for the use of biobased polyesters in additive manufacturing technologies as a route to prepare biodegradable tailor made scaffolds that have potential applications in a tissue engineering area. (paper)

  7. Cationization and gamma irradiation effects on the dyeability of polyester fabric towards disperse dyes

    Energy Technology Data Exchange (ETDEWEB)

    Zohdy, Maged H. [Department of Radiation Chemistry, National Center for Radiation Research and Technology, P.O. Box 29, Nasr City, Cairo (Egypt)]. E-mail: mhzohdy@yahoo.com

    2005-06-01

    The effect of hydrazine hydrate (HZH) treatment and/or gamma irradiation on the dyeing, mechanical and thermal properties of polyester fabrics (PET) was studied. The different factors that may affect the dyeing performance, such as concentrations of HZH, benzyl alcohol and pH values, were investigated. In this regard, the colour strength of untreated polyester fabrics dyed with the dyestuffs Dispersol blue BR, Dispersol orange B2R and Dispersol red B2B was found to be 10.34, 10.76 and 10.12 compared to 24.61, 24.90 and 23.00 in the case of irradiated and HZH-treated polyester fabrics, respectively. These colour strength values were achieved by preirradiation at a dose of 75kGy followed by treatment with 15mll-1 of HZH. Thermogravimetric analysis (TGA) showed that the thermal decomposition stability was improved by using gamma irradiation and the treatment with HZH as indicated by the calculated activation energies. FT-IR spectroscopy showed that the treatment with HZH acts as cationizer prior to dyeing with disperse dyes.

  8. Cationization and gamma irradiation effects on the dyeability of polyester fabric towards disperse dyes

    International Nuclear Information System (INIS)

    Zohdy, Maged H.

    2005-01-01

    The effect of hydrazine hydrate (HZH) treatment and/or gamma irradiation on the dyeing, mechanical and thermal properties of polyester fabrics (PET) was studied. The different factors that may affect the dyeing performance, such as concentrations of HZH, benzyl alcohol and pH values, were investigated. In this regard, the colour strength of untreated polyester fabrics dyed with the dyestuffs Dispersol blue BR, Dispersol orange B2R and Dispersol red B2B was found to be 10.34, 10.76 and 10.12 compared to 24.61, 24.90 and 23.00 in the case of irradiated and HZH-treated polyester fabrics, respectively. These colour strength values were achieved by preirradiation at a dose of 75kGy followed by treatment with 15mll-1 of HZH. Thermogravimetric analysis (TGA) showed that the thermal decomposition stability was improved by using gamma irradiation and the treatment with HZH as indicated by the calculated activation energies. FT-IR spectroscopy showed that the treatment with HZH acts as cationizer prior to dyeing with disperse dyes

  9. Sulfonation of polyester fabrics by gaseous sulfur oxide activated by UV irradiation

    International Nuclear Information System (INIS)

    Kordoghli, Bessem; Khiari, Ramzi; Mhenni, Mohamed Farouk; Sakli, Faouzi; Belgacem, Mohamed Naceur

    2012-01-01

    Highlights: ► In this paper, an original technique was present to improve the hydrophilic properties of polyester fibres. ► The modification of PET fabric was carried out using gaseous sulfur trioxide activated by UV irradiations. ► We fully characterized the modified and untreated fabrics. - Abstract: This paper describes an original technique aiming to improve the hydrophilic properties of polyester fibres. In this method, the sulfonation of the aromatic rings is carried out using gaseous sulfur trioxide activated by UV irradiations. Thus, exposing the polyester textile fabric to the UVC light (wavelength around 254 nm) under a stream of sulfur trioxide leads to the fixation of -SO 3 H groups. The amounts of the fixed sulfonate groups depended on the reaction conditions. Evidence of grafting deduced from the measurements of hygroscopic properties was carried out by contact angle measurement, moisture regain as well as by measuring the rate of retention. SEM and FT-IR analysis, DSC and DTA/TGA thermograms showed that no significant modifications have occurred in the bulk of the treated PET fabrics.

  10. Soil-release behaviour of polyester fabrics after chemical modification with polyethylene glycol

    Science.gov (United States)

    Miranda, T. M. R.; Santos, J.; Soares, G. M. B.

    2017-10-01

    The fibres cleanability depends, among other characteristics, on their hydrophilicity. Hydrophilic fibres are easy-wash materials but hydrophobic fibres are difficult to clean due to their higher water-repellent surfaces. This type of surfaces, like polyester (PET), produce an accumulation of electrostatic charges, which favors adsorption and retention of dirt. Thus, the polyester soil-release properties can be increased by finishing processes that improve fiber hydrophilicity. In present study, PET fabric modification was described by using poly(ethylene glycol) (PEG) and N,N´-dimethylol-4,5-dihydroxyethylene urea (DMDHEU) chemically modified resin. Briefly, the modification process was carried out in two steps, one to hydrolyse the polyester and create hydroxyl and carboxylic acid groups on the surface and other to crosslink the PEG chains. The resulting materials were characterized by contact angle, DSC and FTIR-ATR methods. Additionally, the soil release behavior and the mechanical properties of modified PET were evaluated. For the best process conditions, the treated PET presented 0° contact angle, grade 5 stain release and acceptable mechanical performance.

  11. Construction of 2D transparent micromodels in polyester resin with porosity similar to carrots

    Directory of Open Access Journals (Sweden)

    Rodrigo Emilio Díaz

    2011-12-01

    Full Text Available Microscopic visualization, especially in transparent micromodels, can provide valuable information to understand the transport phenomena at pore scale in different process occurring in porous materials (food, timber, soils, etc.. Micromodels studies focus mainly on the observation of multi-phase flow, which presents a greater proximity to reality. The aim of this study was to study the process of flexography and its application in the manufacture of polyester resin transparent micromodels and its application to carrots. Materials used to implement a flexo station for micromodels construction were thermoregulated water bath, exposure chamber to UV light, photosensitive substance (photopolymer, RTV silicone polyester resin, and glass plates. In this paper, data on size distribution of a particular kind of carrot we used, and a transparent micromodel with square cross-section as well as a Log-normal pore size distribution with pore radii ranging from 10 to 110 µm (average of 22 µm and micromodel size of 10 × 10 cm were built. Finally, it stresses that it has successfully implemented the protocol processing 2D polyester resin transparent micromodels.

  12. Polyurethane coating from prepolymers and Crambe oil polyesters in oxygenates and green solvents

    International Nuclear Information System (INIS)

    Pinto, Elaine R.P.; Messaddeq, Younes; Polito, Wagner Luiz; Matinelli, Marcia

    2015-01-01

    The PU coatings are extremely used in areas that require high-performance. For several applications PU resin, the solvent base is commonly used, the problem is the solvents with high content of volatile organic compounds (VCO) like: toluene, xylene, benzene, etc.. In this work, we were synthesized and characterized four kinds of prepolymers with low-VCO from renewable sources such as castor oil and crambe oil with oxygenate and green solvents. The PU prepolymers had been synthesized in the proportions NCO/OH 2:1 and 3:1. The curing process was carried out with atmospheric moisture in the films. Characterization was made from prepolymers, oligomers and polyesters and PU films by FTIR, TGA / DTA, NMR, GPC and GC-FID, besides this the coatings were applied on aluminum and glass plates and, subjected to analysis chamber saline, hardness and adhesion. The results indicated that the reaction occurred between the prepolymers with oligomers or polyesters, because disappearance of the NCO band at 2270 cm"-"1. The PU films showed good thermal stability (> 270 °C), high tensile strength and deformation. Surround the formulations, the PU films with HDI prepolymers showed the best results with polyesters from crambe oil (PEC 02 and PEC 03). (author)

  13. Thermal Aging of Unsaturated Polyester Composite Reinforced with E-Glass Nonwoven Mat

    Directory of Open Access Journals (Sweden)

    Hossain Milon

    2017-12-01

    Full Text Available An experiment was carried out using glass fiber (GF as reinforcing materials with unsaturated polyester matrix to fabricate composite by hand layup technique. Four layers of GF were impregnated by polyester resin and pressed under a load of 5 kg for 20 hours. The prepared composite samples were treated by prolonged exposure to heat for 1 hour at 60-150°C and compared with untreated GF-polyester composite. Different mechanical test of the fabricated composite were investigated. The experiment depicted significant improvement in the mechanical properties of the fabricated composite resulted from the heat treatment. The maximum tensile strength of 200.6 MPa is found for 90°C heat-treated sample. The mechanical properties of the composite do seem to be very affected negatively above 100°C. Water uptake of the composite was carried out and thermal stability of the composite was investigated by thermogravimetric analysis, and it was found that the composite is stable up to 600°C. Fourier transform infrared spectroscopy shows the characteristic bond in the composite. Finally, the excellent elevated heat resistant capacity of glass-fiber-reinforced polymeric composite shows the suitability of its application to heat exposure areas such as kitchen furniture materials, marine, and electric board.

  14. A facile fabrication of multifunctional knit polyester fabric based on chitosan and polyaniline polymer nanocomposite

    Science.gov (United States)

    Tang, Xiaoning; Tian, Mingwei; Qu, Lijun; Zhu, Shifeng; Guo, Xiaoqing; Han, Guangting; Sun, Kaikai; Hu, Xili; Wang, Yujiao; Xu, Xiaoqi

    2014-10-01

    Knit polyester fabric was successively modified and decorated with chitosan layer and polyaniline polymer nanocomposite layer in this paper. The fabric was firstly treated with chitosan to form a stable layer through the pad-dry-cure process, and then the polyaniline polymer nanocomposite layer was established on the outer layer by in situ chemical polymerization method using ammonium persulfate as oxidant and chlorhydric acid as dopant. The surface morphology of coated fabric was characterized by scanning electron microscopy (SEM), and the co-existence of chitosan layer and granular polyaniline polymer nanocomposite was confirmed and well dispersed on the fabric surface. The resultant fabric was endowed with remarkable electrical conductivity properties and efficient water-repellent capability, which also have been found stable after water laundering. In addition, the photocatalytic decomposition activity for reactive red dye was observed when the multifunctional knit polyester fabric was exposed to the illumination of ultraviolet lamp. These results indicated that chitosan and polyaniline polymer nanocomposite could form ideal multifunctional coatings on the surface of knit polyester fabric.

  15. High Throughput Screening of Valganciclovir in Acidic Microenvironments of Polyester Thin Films

    Directory of Open Access Journals (Sweden)

    Teilo Schaller

    2015-04-01

    Full Text Available Ganciclovir and valganciclor are antiviral agents used for the treatment of cytomegalovirus retinitis. The conventional method for administering ganciclovir in cytomegalovirus retinitis patients is repeated intravitreal injections. In order to obviate the possible detrimental effects of repeated intraocular injections, to improve compliance and to eliminate systemic side-effects, we investigated the tuning of the ganciclovir pro-drug valganciclovir and the release from thin films of poly(lactic-co-glycolic acid (PLGA, polycaprolactone (PCL, or mixtures of both, as a step towards prototyping periocular valganciclovir implants. To investigate the drug release, we established and evaluated a high throughput fluorescence-based quantification screening assay for the detection of valganciclovir. Our protocol allows quantifying as little as 20 ng of valganciclovir in 96-well polypropylene plates and a 50× faster analysis compared to traditional HPLC measurements. This improvement can hence be extrapolated to other polyester matrix thin film formulations using a high-throughput approach. The acidic microenvironment within the polyester matrix was found to protect valganciclovir from degradation with resultant increases in the half-life of the drug in the periocular implant to 100 days. Linear release profiles were obtained using the pure polyester polymers for 10 days and 60 days formulations; however, gross phase separations of PCL and acid-terminated PLGA prevented tuning within these timeframes due to the phase separation of the polymer, valganciclovir, or both.

  16. Dsc cure kinetics of an unsaturated polyester resin using empirical kinetic model

    International Nuclear Information System (INIS)

    Abdullah, I.

    2015-01-01

    In this paper, the kinetics of curing of unsaturated polyester resin initiated with benzoyl peroxide was studied. In case of unsaturated polyester (UP) resin, isothermal test alone could not predict correctly the curing time of UP resin. Therefore, isothermal kinetic analysis through isoconventional adjustment was used to correctly predict the curing time and temperature of UP resin. Isothermal kinetic analysis through isoconversional adjustment indicated that 97% of UP resin cures in 33 min at 120 degree C. Curing of UP resin through microwaves was also studied and found that 67% of UP resin cures in 1 min at 120 degree C. The crosslinking reaction of UP resin is so fast at 120 degree C that it becomes impossible to predict correctly the curing time of UP resin using isothermal test and the burial of C=C bonds in microgels makes it impossible to be fully cured by microwaves at 120 degree C. The rheological behaviour of unsaturated polyester resin was also studied to observe the change in viscosity with respect to time and temperature. (author)

  17. The size control of silver nanocrystals with different polyols and its application to low-reflection coating materials

    Energy Technology Data Exchange (ETDEWEB)

    Park, Keum Hwan; Park, O Ok [Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Im, Sang Hyuk, E-mail: imromy@krict.re.kr, E-mail: ookpark@kaist.ac.kr [Korea Research Institute of Chemical Technology (KRICT), 19 Singsungno, Yuseong-gu, Daejeon 305-600 (Korea, Republic of)

    2011-01-28

    The size of silver nanocrystals in polyol synthesis can be simply controlled by tuning the viscosity of the reaction medium such as ethylene glycol, 1,2-propanediol, 1,4-butanediol and 1,5-pentanediol. We found that a higher viscose medium (1,5-pentanediol) led to monodispersed smaller particles thanks to the slow addition of silver atoms into the nuclei. Size-controlled silver nanocrystals of 30 nm were obtained in a viscosity controlled medium of 1,5-pentanediol to synthesize a low refractive index filler by coating with silica and subsequent etching of the silver core. The coated low-reflection layer from the hollow silica nanoparticles on polyethylene terephthalate (PET) film can greatly reduce the reflection of the PET film from 10% to 2% over the entire visible region.

  18. Preparation, microstructure and magnetic properties of Sm(Co,Hf){sub 7}/Co nanocomposite particles by polyol method

    Energy Technology Data Exchange (ETDEWEB)

    Bu, Shao-Jing; Duan, Xiu-Li; Han, Xu-Hao; Sun, Ji-Bing, E-mail: hbgdsjb@126.com; Chi, Xiang; Cui, Chun-Xiang

    2017-02-01

    Hard/soft Sm-Co/Co nanocomposite particles were prepared by reducing CoCl{sub 2}·6H{sub 2}O in the solution containing ball-milled Sm(Co, Hf){sub 7} particles by a simple polyol method with ethylene glycol as the solvent. Phase composition, microstructure and magnetic properties of the particles were analyzed by XRD, TEM (HRTEM) and VSM, respectively. It has been found that Sm-Co/Co core/shell structure is formed in which the Co shell is 3–5 nm in thickness and mainly exists in hcp-Co phase. At the same time, fcc-Co tends to nucleate and grow independently between Sm-Co particles. The formation mechanism of Sm-Co/Co composite particles is discussed and corresponding model is established. Sm-Co/Co composite particles perform obvious remanence enhancement effects especially after being heated at 450 °C for 15 min.

  19. Effect of the Reduction Temperature of PdAg Nanoparticles during the Polyol Process in the Ethanol Electrooxidation Reaction

    Directory of Open Access Journals (Sweden)

    R. Carrera-Cerritos

    2018-01-01

    Full Text Available This work reports the effect of reduction temperature during the synthesis of PdAg catalysts through the polyol process and their evaluation in the ethanol electrooxidation reaction (EOR. The characterization was performed using Transmission Electron Microscopy (TEM and X-Ray Diffraction (XRD. The electrochemical evaluation for the ethanol electrooxidation reaction was implemented in alkaline medium using chronoamperometry (CA and cyclic voltammetry (CV. An important effect of the reduction temperature on electroactivity and catalytic stability was observed: both the maximum current density and the catalytic stability were higher in the catalyst synthesized at the highest temperature (135°C. This performance was associated with the extent of the interaction between Pd and Ag which was measured in terms of the structural expansion of Pd.

  20. Hyperbranched-polyol-tethered poly (amic acid) electrospun nanofiber membrane with ultrahigh adsorption capacity for boron removal

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhe; Wu, Zhongyu; Zhang, Yufeng; Meng, Jianqiang, E-mail: jianqiang.meng@hotmail.com

    2017-04-30

    Highlights: • Electrospun nanofiber membranes were grafted with hyperbranched polyols. • The membrane had a maximum boron uptake of 5.68 mmol/g. • The membrane could adsorb 0.82 mmol/g boron from a 5 mg/L solution in 15 min. • The membrane obeyed the Langmuir and the pseudo-first-order kinetic model. • The regeneration efficiency remained over 90% after 10 cycled uses. - Abstract: The development of efficient adsorbents with high sorption capacity remains as a challenge for the removal of micropollutants occurred globally in water resources. In this work, poly (amic acid) (PAA) electrospun nanofiber membranes grafted with hyperbranched polyols were synthesized and used for boron removal. The PAA nanofiber was reacted with hyperbranched polyethylenimine (HPEI) and further with glycidol to introduce the vicinal hydroxyl groups. The chemical composition and surface characteristics of the obtained PAA-g-PG membranes were evaluated by FESEM, FTIR, XPS and water contact angles (WCA) measurements. The boron adsorption thermodynamics and kinetics were investigated systematically. The results showed that the PAA nanofiber spun from concentration of 15% had uniform morphology and narrow diameter distribution. The PAA-g-PG nanofiber membrane had a maximum boron uptake of 5.68 mmol/g and could adsorb 0.82 mmol/g boron from a 5 mg/L solution in 15 min. Both the high surface area of nanofibers and the hyperbranched structure should contribute to the high boron uptake and high adsorption rate. The nanofiber membrane obeyed the Langmuir adsorption model and the pseudo-first-order kinetic model. The regeneration efficiency of the nanofiber membrane remained 93.9% after 10 cycled uses, indicating good regenerability of the membrane.

  1. Nanostructured cobalt powders synthesised by polyol process and consolidated by Spark Plasma Sintering: Microstructure and mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Fellah, F.; Schoenstein, F.; Dakhlaoui-Omrani, A.; Cherif, S.M.; Dirras, G.; Jouini, N., E-mail: jouini@univ-paris13.fr

    2012-07-15

    Bulk nanostructured cobalt was processed using a bottom-up strategy. Nanostructured particle agglomerates of about 50 and 240 nm in diameter were synthesised using a polyol route and subsequently consolidated by Spark Plasma Sintering (SPS). The microstructure of the starting powders and of the processed bulk samples was studied and characterised by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD patterns of the as-prepared powders showed predominantly a face centred cubic (fcc) crystalline phase, whereas both fcc and hexagonal close packed (hcp) phases were found within the consolidated samples. A sample with the highest relative mass density (94.5%) was obtained from the small powder particles. TEM observations revealed a lamellar substructure with a high density of nanotwins and stacking faults in every grain in the sample with the highest density. Brillouin light scattering (BLS) and quasistatic compression tests were used to investigate the mechanical properties of the consolidated samples. The two techniques yielded Young modulus values of 168 GPa and 130 GPa, respectively, in the sample with the highest density. This sample also exhibited a yield stress higher than 1 GPa after the compression test, which is mainly attributed to the lamellar-like structure occurring in almost every grain of the polycrystalline aggregate. - Highlights: Black-Right-Pointing-Pointer Cobalt nanoparticles produced by the polyol process present mainly the fcc metastable phase. Black-Right-Pointing-Pointer Bulk nanostructured cobalt is obtained from the nano-particles by Spark Plasma Sintering consolidation. Black-Right-Pointing-Pointer Nanotwins and stacking faults are present in every grain of the more dense sample. Black-Right-Pointing-Pointer Yield strength and plastic domain may be varied depending on the nanoparticle size and the porosity of the consolidated material.

  2. Soybean-oil-based waterborne polyurethane dispersions: effects of polyol functionality and hard segment content on properties.

    Science.gov (United States)

    Lu, Yongshang; Larock, Richard C

    2008-11-01

    The environmentally friendly vegetable-oil-based waterborne polyurethane dispersions with very promising properties have been successfully synthesized without difficulty from a series of methoxylated soybean oil polyols (MSOLs) with different hydroxyl functionalities ranging from 2.4 to as high as 4.0. The resulting soybean-oil-based waterborne polyurethane (SPU) dispersions exhibit a uniform particle size, which increases from about 12 to 130 nm diameter with an increase in the OH functionality of the MSOL from 2.4 to 4.0 and decreases with increasing content of the hard segments. The structure and thermophysical and mechanical properties of the resulting SPU films, which contain 50-60 wt % MSOL as renewable resources, have been studied by Fourier transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical analysis, thermogravimetric analysis, transmission electron microscopy, and mechanical testing. The experimental results reveal that the functionality of the MSOLs and the hard segment content play a key role in controlling the structure and the thermophysical and mechanical properties of the SPU films. These novel films exhibit tensile stress-strain behavior ranging from elastomeric polymers to rigid plastics and possess Young's moduli ranging from 8 to 720 MPa, ultimate tensile strengths ranging from 4.2 to 21.5 MPa, and percent elongation at break values ranging from 16 to 280%. This work has addressed concerns regarding gelation and higher cross-linking caused by the high functionality of vegetable-oil-based polyols. This article reports novel environmentally friendly biobased SPU materials with promising applications as decorative and protective coatings.

  3. Ex vivo assessment of polyol coated-iron oxide nanoparticles for MRI diagnosis applications: toxicological and MRI contrast enhancement effects

    Science.gov (United States)

    Bomati-Miguel, Oscar; Miguel-Sancho, Nuria; Abasolo, Ibane; Candiota, Ana Paula; Roca, Alejandro G.; Acosta, Milena; Schwartz, Simó; Arus, Carles; Marquina, Clara; Martinez, Gema; Santamaria, Jesus

    2014-03-01

    Polyol synthesis is a promising method to obtain directly pharmaceutical grade colloidal dispersion of superparamagnetic iron oxide nanoparticles (SPIONs). Here, we study the biocompatibility and performance as T2-MRI contrast agents (CAs) of high quality magnetic colloidal dispersions (average hydrodynamic aggregate diameter of 16-27 nm) consisting of polyol-synthesized SPIONs (5 nm in mean particle size) coated with triethylene glycol (TEG) chains (TEG-SPIONs), which were subsequently functionalized to carboxyl-terminated meso-2-3-dimercaptosuccinic acid (DMSA) coated-iron oxide nanoparticles (DMSA-SPIONs). Standard MTT assays on HeLa, U87MG, and HepG2 cells revealed that colloidal dispersions of TEG-coated iron oxide nanoparticles did not induce any loss of cell viability after 3 days incubation with dose concentrations below 50 μg Fe/ml. However, after these nanoparticles were functionalized with DMSA molecules, an increase on their cytotoxicity was observed, so that particles bearing free terminal carboxyl groups on their surface were not cytotoxic only at low concentrations (MRI studies in mice indicated that both types of coated-iron oxide nanoparticles produced higher negative T2-MRI contrast enhancement than that measured for a similar commercial T2-MRI CAs consisting in dextran-coated ultra-small iron oxide nanoparticles (Ferumoxtran-10). In conclusion, the above attributes make both types of as synthesized coated-iron oxide nanoparticles, but especially DMSA-SPIONs, promising candidates as T2-MRI CAs for nanoparticle-enhanced MRI diagnosis applications.

  4. Production of fungal antibiotics using polymeric solid supports in solid-state and liquid fermentation.

    Science.gov (United States)

    Bigelis, Ramunas; He, Haiyin; Yang, Hui Y; Chang, Li-Ping; Greenstein, Michael

    2006-10-01

    The use of inert absorbent polymeric supports for cellular attachment in solid-state fungal fermentation influenced growth, morphology, and production of bioactive secondary metabolites. Two filamentous fungi exemplified the utility of this approach to facilitate the discovery of new antimicrobial compounds. Cylindrocarpon sp. LL-Cyan426 produced pyrrocidines A and B and Acremonium sp. LL-Cyan416 produced acremonidins A-E when grown on agar bearing moist polyester-cellulose paper and generated distinctly different metabolite profiles than the conventional shaken or stationary liquid fermentations. Differences were also apparent when tenfold concentrated methanol extracts from these fermentations were tested against antibiotic-susceptible and antibiotic-resistant Gram-positive bacteria, and zones of inhibition were compared. Shaken broth cultures of Acremonium sp. or Cylindrocarpon sp. showed complex HPLC patterns, lower levels of target compounds, and high levels of unwanted compounds and medium components, while agar/solid support cultures showed significantly increased yields of pyrrocidines A and B and acremonidins A-E, respectively. This method, mixed-phase fermentation (fermentation with an inert solid support bearing liquid medium), exploited the increase in surface area available for fungal growth on the supports and the tendency of some microorganisms to adhere to solid surfaces, possibly mimicking their natural growth habits. The production of dimeric anthraquinones by Penicillium sp. LL-WF159 was investigated in liquid fermentation using various inert polymeric immobilization supports composed of polypropylene, polypropylene cellulose, polyester-cellulose, or polyurethane. This culture produced rugulosin, skyrin, flavomannin, and a new bisanthracene, WF159-A, after fermentation in the presence and absence of polymeric supports for mycelial attachment. The physical nature of the different support systems influenced culture morphology and relative

  5. Study on Energy Absorption Capacity of Steel-Polyester Hybrid Fiber Reinforced Concrete Under Uni-axial Compression

    Science.gov (United States)

    Chella Gifta, C.; Prabavathy, S.

    2018-05-01

    This work presents the energy absorption capacity of hybrid fiber reinforced concrete made with hooked end steel fibers (0.5 and 0.75%) and straight polyester fibers (0.5, 0.8, 1.0 and 2.0%). Compressive toughness (energy absorption capacity) under uni-axial compression was evaluated on 100 × 200 mm size cylindrical specimens with varying steel and polyester fiber content. Efficiency of the hybrid fiber reinforcement is studied with respect to fiber type, size and volume fractions in this investigation. The vertical displacement under uni-axial compression was measured under the applied loads and the load-deformation curves were plotted. From these curves the toughness values were calculated and the results were compared with steel and polyester as individual fibers. The hybridization of 0.5% steel + 0.5% polyester performed well in post peak region due to the addition of polyester fibers with steel fibers and the energy absorption value was 23% greater than 0.5% steel FRC. Peak stress values were also higher in hybrid series than single fiber and based on the results it is concluded that hybrid fiber reinforcement improves the toughness characteristics of concrete without affecting workability.

  6. The Degradation of Mechanical Properties in Halloysite Nano clay-Polyester Nano composites Exposed in Seawater Environment

    International Nuclear Information System (INIS)

    Saharudin, M.S.; Saharudin, M. Sh.; Wei, J.; Shyha, I.; Inam, F.

    2016-01-01

    Polyester based polymers are extensively used in aggressive marine environments; however, inadequate data is available on the effects of the seawater on the polyester based nano composites mechanical properties. This paper reports the effect of seawater absorption on the mechanical properties degradation of halloysite nano clay-polyester nano composites. Results confirmed that the addition of halloysite nano clay into polyester matrix was found to increase seawater uptake and reduce mechanical properties compared to monolithic polyester. The maximum decreases in microhardness, tensile and flexural properties, and impact toughness were observed in case of 1 wt% nano clay. The microhardness decreased from 107 HV to 41.7 HV (61% decrease). Young s modulus decreased from 0.6 GPa to 0.4 GPa (33% decrease). The flexural modulus decreased from 0.6 GPa to 0.34 GPa (43% decrease). The impact toughness dropped from 0.71 kJ/m"2 to 0.48 kJ/m"2 (32% decrease). Interestingly, the fracture toughnessκ_1C increased with the addition of halloysite nano clay due to the plasticization effect of the resin matrix. SEM images revealed the significant reduction in mechanical properties in case of 1 wt% reinforcement which is attributed to the degradation of the nano clay-matrix interface influenced by seawater absorption and agglomeration of halloysite nano clay.

  7. Mechanical Properties Analysis Of Composite Magnetic Base On hexa ferrite And Polyester Or Epoxy Matrix With Silane Additive Addition

    International Nuclear Information System (INIS)

    Sudirman; Ridwan; Mujamilah; K K, Aloma; Rembulan, Marisa; Fitriyanti

    2003-01-01

    Application of composite magnetic especially hexa ferrite magnet for industry and home industry in Indonesia has been used. Research purposes were making composite magnetic by mixing hexa ferrite powder with polyester or epoxy and studying the effect of coupling agent 3-aminopropyltriethoxysilane (3-APE) addition on mechanical properties of composite magnetic. The coupling agent may increase bonding properties between magnetic powder and matrix polymer, so that tensile strength of magnetic composite will increase without decreasing the magnetic properties. Magnetic powder (SrM or BaM) wich be coated by coupling agent were added to matrix polyester and mekpo or epoxy and versamid, mixed until homogen then pressing into to the dumbbell form molding. For epoxy matrix, pressing was done in hot press at 70 deg. C and 150 kg/cm 2 following by cooling in cold press, while for polyester matrix pressing was done in hydraulic press and following by curing at 70 deg. C in an oven for 1 hour. The composition of magnetic powder were varied to 30, 40 and 50% volume fraction and coupling agent were varied to 5, 10 and 15 ml for every volume fraction. The result showed that 10 ml added of coupling agent was give best mechanical properties both polyester and epoxy matrix. However generally, increasing of magnetic powder content decreased the tensile strength of magnetic composite. The properties of magnetic composite SrM was better than BaM either in polyester or epoxy matrix

  8. A novel polyester composite nanofiltration membrane formed by interfacial polymerization of pentaerythritol (PE) and trimesoyl chloride (TMC)

    Science.gov (United States)

    Cheng, Jun; Shi, Wenxin; Zhang, Lanhe; Zhang, Ruijun

    2017-09-01

    A novel polyester thin film composite nanofiltration (NF) membrane was prepared by interfacial polymerization of pentaerythritol (PE) and trimesoyl chloride (TMC) on polyethersulfone (PES) supporting membrane. The performance of the polyester composite NF membrane was optimized by regulating the preparation parameters, including reaction time, pH of the aqueous phase solution, pentaerythritol concentration and TMC concentration. A series of characterization, including permeation experiments, attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscope (SEM), atomic force microscopy (AFM), zeta potential analyzer and chlorine resistance experiments, were employed to study the properties of the optimized membrane. The results showed that the optimized polyester composite NF membrane exhibited very high rejection of Na2SO4 (98.1%), but the water flux is relatively low (6.1 L/m2 h, 0.5 MPa, 25 °C). The order of salt rejections is Na2SO4 > MgSO4 > MgCl2 > NaCl, which indicated the membrane was negatively charged, just consistent with the membrane zeta potential results. After treating by NaClO solutions with different concentrations (100 ppm, 500 ppm, 1000 ppm, 2000 ppm, 3000 ppm) for 48 h, the results demonstrated that the polyester NF membrane had good chlorine resistance. Additionally, the polyester TFC NF membrane exhibits good long-term stability.

  9. Synthesis, properties and applications of biodegradable polymers derived from diols and dicarboxylic acids: from polyesters to poly(ester amide)s.

    Science.gov (United States)

    Díaz, Angélica; Katsarava, Ramaz; Puiggalí, Jordi

    2014-04-25

    Poly(alkylene dicarboxylate)s constitute a family of biodegradable polymers with increasing interest for both commodity and speciality applications. Most of these polymers can be prepared from biobased diols and dicarboxylic acids such as 1,4-butanediol, succinic acid and carbohydrates. This review provides a current status report concerning synthesis, biodegradation and applications of a series of polymers that cover a wide range of properties, namely, materials from elastomeric to rigid characteristics that are suitable for applications such as hydrogels, soft tissue engineering, drug delivery systems and liquid crystals. Finally, the incorporation of aromatic units and α-amino acids is considered since stiffness of molecular chains and intermolecular interactions can be drastically changed. In fact, poly(ester amide)s derived from naturally occurring amino acids offer great possibilities as biodegradable materials for biomedical applications which are also extensively discussed.

  10. Production of Ag Nanocubes on a Scale of 0.1 g per Batch by Protecting the NaHS-Mediated Polyol Synthesis with Argon

    OpenAIRE

    Zhang, Qiang; Cobley, Claire; Au, Leslie; McKiernan, Maureen; Schwartz, Andrea; Wen, Long-Ping; Chen, Jingyi; Xia, Younan

    2009-01-01

    Gold nanocages synthesized from Ag nanocubes via the galvanic replacement reaction are finding widespread use in a range of applications due to their tunable optical properties. Most of these applications require the use of nanocages with a uniform size and in large quantities. This requirement translates into a demand for scaling up the production of Ag nanocubes with uniform, well-controlled sizes. Here we report such a method based on the modification of NaHS-mediated polyol synthesis with...

  11. A low fermentable oligo-di-mono-saccharides and polyols (FODMAP) diet is a balanced therapy for fibromyalgia with nutritional and symptomatic benefits

    Science.gov (United States)

    Marum, Ana Paula; Moreira, Cátia; Tomas-Carus, Pablo; Saraiva, Fernando; Guerreiro, Catarina Sousa

    2017-06-05

    Fibromyalgia is a chronic rheumatic disease producing widespread pain, associated to a major comorbidity -irritable bowel syndrome. Low FODMAPS diet (low fermentable oligo-di-mono-saccharides and polyols diet) has been effective in controlling irritable bowel syndrome symptoms. Overweight is an aggravating factor for fibromyalgia. We studied effects of low fermentable oligo-di-mono-saccharides and polyols diets on fibromyalgia symptoms and weight status. A longitudinal study was performed on 38 fibromyalgia patients using a four-week, repeated assessment as follow: M1 = first assessments/presentation of individual low fermentable oligo-di-mono-saccharides and polyols diet; M2 = second assessments/reintroduction of FODMAPs; M3 = final assessments/nutritional counselling. The assessment instruments applied were: Fibromyalgia Survey Questionnaire (FSQ); Severity Score System (IBS-SSS); visual analogic scale (VAS). Body mass-index/composition and waist circumference (WC) were also measured. Daily macro-micronutrients and FODMAP intake were quantified at each moment of the study. The studied cohort was 37% overweight, 34% obese (average body mass-index 27.4 ± 4.6; excess fat mass 39.4 ± 7%). Weight, body mass-index and waist circumference decreased significantly (p body composition was observed. All fibromyalgiasymptoms, including somatic pain, declined significantly post-LFD (p fibromyalgia [Fibromyalgia survey questionnaire: M1 = 21.8; M2 = 16.9; M3 = 17.0 (p < 0.01)]. The intake of essential nutrients (fiber, calcium, magnesium and vitamin D) showed no significant difference. The significant reduction in FODMAP intake (M1 = 24.4 g; M2 = 2.6g; p < 0.01) reflected the "Diet adherence" (85%). "Satisfaction with improvement of symptoms" (76%), showed correlating with "diet adherence" (r = 0.65; p < 0.01). Results are highly encouraging, showing low fermentable oligo-di-mono-saccharides and polyols diets as a nutritionally balanced approach, contributing to weight loss

  12. Full factorial design applied to the synthesis of Pd-?Ag nanobars by the polyol method and the perspective for ethanol oxidation

    OpenAIRE

    Carrera-Cerritos, Raul; Ponce de Leon, Carlos; Ledesma-Garcia, J.; Fuentes-Ramirez, R.; Arriaga, L.G.

    2014-01-01

    Full factorial design methodology was applied to the synthesis and optimization of Pd–Ag nanobars usingthe polyol process as the reducer. The concentration of Br? ions, the temperature and the reaction timewere selected as factors to study, whereas the yield (% nanobars) was the response to be analyzed. Thenanoparticles were characterized by X-ray diffraction, energy-dispersive X-ray spectroscopy,transmission electron microscopy, high-resolution transmission electron microscopy and X-rayphoto...

  13. Obtaining polyester from glycerin for synthesis of polyurethanes; Obtencao de poliester a partir da glicerina para sintese de poliuretanas

    Energy Technology Data Exchange (ETDEWEB)

    Breves, Rodolfo A.; Ghesti, Grace F.; Sales, Maria J.A., E-mail: eu_sou_o_rodolfo@hotmail.com [Universidade de Brasilia (LabPol/UnB), DF (Brazil). Laboratorio de Pesquisa em Polimeros; Silva, Jessica S.; Coelho, Paulo V.M.; Lopes, Roseany V.V. [Universidade de Brasilia (UnB), DF (Brazil). Faculdade do Gama; Brioude, Michel M. [Freiburg University (Germany)

    2014-07-01

    The use of renewable resources has been increasing, due to the development of materials that have viable applications that are environmentally friendly. In this paper, a polyester was synthesized from glycerin, with the addition of adipic acid in a molar ratio of 1: 1.5, with dilauryl tin catalyst, which was added in proportions of 1 to 3% obtained PUs from castor oil (Ricinus communis) and MDI (diphenyl methane diisocyanate). The materials were characterized by infrared spectroscopy (FTIR), nuclear magnetic resonance {sup 1}H NMR, thermogravimetry (TG) and derivative thermogravimetry (DTG). The reaction for obtaining the polyester was confirmed by FTIR, the absorption band between 1708-1730 cm{sup -1} and {sup 1}H NMR, in the region 1.4 to 1.8 ppm and 2.2 to 2.6 ppm. The thermal decomposition of polyester occurred with temperature above 300 ° C. PUs showed similar thermal stability. (author)

  14. Mechanical characterization of glass fiber (woven roving/chopped strand mat E-glass fiber) reinforced polyester composites

    Science.gov (United States)

    Bhaskar, V. Vijaya; Srinivas, Kolla

    2017-07-01

    Polymer reinforced composites have been replacing most of the engineering material and their applications become more and more day by day. Polymer composites have been analyzing from past thirty five years for their betterment for adapting more applications. This paper aims at the mechanical properties of polyester reinforced with glass fiber composites. The glass fiber is reinforced with polyester in two forms viz Woven Rovings (WRG) and Chopped Strand Mat (CSMG) E-glass fibers. The composites are fabricated by hand lay-up technique and the composites are cut as per ASTM Standard sizes for corresponding tests like flexural, compression and impact tests, so that flexural strength, compression strength, impact strength and inter laminar shear stress(ILSS) of polymer matrix composites are analyzed. From the tests and further calculations, the polyester composites reinforced with Chopped Strand Mat glass fiber have shown better performance against flexural load, compression load and impact load than that of Woven Roving glass fiber.

  15. Absorbable Polydioxanone (PDS) suture provides fewer wound complications than polyester (ethibond) suture in acute Tendo-Achilles rupture repair

    LENUS (Irish Health Repository)

    Baig, M N

    2017-05-01

    We prospectively studied acute Achilles tendon rupture in patients over a two 2-year period and reviewed the causes, outcome and complications. There were 53 patients included with acute Achilles rupture with minimum follow up period of 6 months. We compared the outcomes including infection rate and Boyden score between the two groups repaired by Polydioxanone and Polyester respectively. All infected cases had a suture repair using the polyester suture. The difference in the infection rate was highly significant between the 2 groups (p=0.001). All 34 patients (100%) in the PDS group had good \\/ excellent results based on the Boyden clinical assessment. Conversely, only 16 patients 9(68.4%) had good or excellent results IN Polyester repair group. Patients treated with a non- absorbable suture (ethibond) material for repair had a higher incidence infection and worse Boyden scores than the absorbable PDS group.

  16. Sup(1)H n.m.r. relaxation of radiation induced crosslinking in polyester-styrene systems

    International Nuclear Information System (INIS)

    Andreis, M.; Veksli, Z.; Ranogajec, F.; Hedvig, P.

    1989-01-01

    The structure and dynamics of a network formed by radiation induced crosslinking of polyesters based on 1,6-hexane diol and 1,2-propylene glycol and maleic anhydride (HDF and PGF, respectively) with styrene is studied by proton pulsed n.m.r. spectroscopy. The dependence of spin-lattice, T 1 , and spin-spin, T 2 , relaxation times on the structure of polyester chain, molar ratios of styrene to polyester unsaturations and the radiation doses are analysed in terms of network formation and structure, and their effect on molecular motion. Above the gel point, at temperatures above the glass transition, the presence of two T 2 components reflects the heterogeneity of the network structure in both resins. Parallel with the n.m.r. relaxation measurements the crosslink density was determined from the extracted gel phase or double bonds (fumaric and styrene) participating in the crosslinking process. (author)

  17. MECHANICAL AND THERMAL PROPERTIES OF COMPOSITES FROM UNSATURATED POLYESTER FILLED WITH OIL PALM ASH

    Directory of Open Access Journals (Sweden)

    M.S. Ibrahim

    2012-06-01

    Full Text Available Oil palm ash (OPA is available in abundance, is renewable, can be obtained at no cost and shows good performance at high thermal conditions. Combinations of the unsaturated polyester with natural fillers have been reported to improve the mechanical and thermal properties of composites. Utilisation of oil palm ash as a filler in the manufacture of polymer composites can significantly reduce the requirement for other binders or matrixes of composite materials. This research uses oil palm ash as a filler to form composites through the investigation of the effect of different contents of filler on the properties of OPA-filled unsaturated polyester (UP/OPA composites. The effect of different volume fractions, i.e., 0, 10, 20 and 30 vol.% of oil palm ash introduced into 100, 90, 80 and 70 vol.% of an unsaturated polyester matrix on the composite mechanical properties, i.e., tensile and flexural, has been studied, together with thermal gravimetric analysis (TGA and differential scanning calorimetric (DSC. Specimens were prepared using compression moulding techniques based on the ASTM D790 and D5083 standards for flexural and tensile tests, respectively. The tensile and flexural mechanical properties of UP/OPA composites were improved in modulus by increasing the filler content. Thermal stability of the composites increased as the OPA filler content was increased, which was a logical consequence because of the high thermal stability of the silica compound of the OPA filler compared with that of the UP matrix. The results from the surface electron microscope (SEM analysis were the extension of mechanical and thermal tests.

  18. Physical stability and moisture sorption of aqueous chitosan-amylose starch films plasticized with polyols

    DEFF Research Database (Denmark)

    Cervera, Mirna Fernández; Karjalainen, Milja; Airaksinen, Sari

    2004-01-01

    The short-term stability and the water sorption of films prepared from binary mixtures of chitosan and native amylose maize starch (Hylon VII) were evaluated using free films. The aqueous polymer solutions of the free films contained 2% (w/w) film formers, glycerol, or erythritol as a plasticizer...... in the crystallinity of the films are evident within a 3-month period of storage, and the changes in the solid state are dependent on the plasticizer and storage conditions. When stored at ambient conditions for 3 months, the aqueous chitosan-amylose starch films plasticized with erythritol exhibited a partly...

  19. Composition and hydrophilicity control of Mn-doped ferrite (MnxFe3-xO4) nanoparticles induced by polyol differentiation.

    Science.gov (United States)

    Vamvakidis, Kosmas; Katsikini, Maria; Vourlias, George; Angelakeris, Mavroeidis; Paloura, Eleni C; Dendrinou-Samara, Catherine

    2015-03-28

    Manganese doped ferrite (MnxFe3-xO4) nanoparticles with x = 0.29-0.77 were prepared under solvothermal conditions in the presence solely of a polyol using the trivalent manganese and iron acetylacetonates as precursors. In this facile approach, a variety of polyols such as polyethylene glycol (PEG 8000), tetraethylene glycol (TEG), propylene glycol (PG) and a mixture of TEG and PG (1 : 1) were utilized in a triple role as a solvent, a reducing agent and a surface-functionalizing agent. The composition of the fine cubic-spinel structures was found to be related to the reductive ability of each polyol, while determination of structural characteristics plus the inversion parameter (i = 0.18-0.38) were provided by X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy at both the Fe and Mn K-edges. The saturation magnetization increased up to 80 emu g(-1) when x = 0.35 and i = 0.22. In addition, the as-prepared nanocrystals coated with PEG, PG and PG&TEG showed excellent colloidal stability in water, while the TEG-coated particles were not water dispersible and converted to hydrophilic when were extra PEGylated. Measurements of the (1)H NMR relaxation in water were carried out and the nanoprobes were evaluated as potential contrast agents.

  20. Fluorescence ratiometric sensing of polyols by phenylboronic acid complexes with ligands exhibiting excited-state intramolecular proton transfer in aqueous micellar media

    Energy Technology Data Exchange (ETDEWEB)

    Trejo-Huizar, Karla Elisa; Jiménez-Sánchez, Arturo; Martínez-Aguirre, Mayte A.; Yatsimirsky, Anatoly K., E-mail: anatoli@unam.mx

    2016-11-15

    2-Phenyl-3-hydroxy-4(1H)-quinolone possessing dual fluorescence due to excited-state intramolecular proton transfer (ESIPT) forms stable complex with phenylboronic acid with blue shifted emission maximum in micellar medium of a cationic surfactant even though the compound lacks required for complexation with boronic acids cis-diol structure. No complexation is observed in the presence of neutral or anionic surfactants. Titrations of this complex with polyols including sugars and nucleotides at pH 8 displace free quinolone showing ratiometric response, which allows determination of polyols with detection limits 0.05–1 mM and unusually wide linear dynamic ranges. Another ESIPT dye 2-(2′-hydroxyphenyl)−1H-benzimidazole also lacking cis-diol structure forms equally stable complex with phenylboronic acid and allows ratiometric determination of polyols with similar characteristics. The results of this study demonstrate that blocking ESIPT of signaling molecule by complexation of the receptor with the proton donor group eliminates the low energy emission from tautomeric form but strongly enhances the high energy emission typical for “normal” form of signaling molecule creating a possibility of ratiometric sensing.

  1. The Cloud Condensation Nuclei (CCN properties of 2-methyltetrols and C3-C6 polyols from osmolality and surface tension measurements

    Directory of Open Access Journals (Sweden)

    S. Ekström

    2009-02-01

    Full Text Available A significant fraction of the organic material in aerosols is made of highly soluble compounds such as sugars (mono- and polysaccharides and polyols such as the 2-methyltetrols, methylerythritol and methyltreitol. Because of their high solubility these compounds are considered as potentially efficient CCN material. For the 2-methyltetrols, this would have important implications for cloud formation at global scale because they are thought to be produced by the atmospheric oxidation of isoprene. To investigate this question, the complete Köhler curves for C3-C6 polyols and the 2-methyltetrols have been determined experimentally from osmolality and surface tension measurements. Contrary to what was expected, none of these compounds displayed a higher CCN efficiency than organic acids. Their Raoult terms show that this limited CCN efficiency is due to their absence of dissociation in water, this in spite of slight surface-tension effects for the 2-methyltetrols. Thus, compounds such as saccharides and polyols would not contribute more to cloud formation than other organic compounds studied so far. In particular, the presence of 2-methyltetrols in aerosols would not particularly enhance cloud formation in the atmosphere, in contrary to recently suggested.

  2. Kinetics of an acid-base catalyzed reaction (aspartame degradation) as affected by polyol-induced changes in buffer pH and pK values.

    Science.gov (United States)

    Chuy, S; Bell, L N

    2009-01-01

    The kinetics of an acid-base catalyzed reaction, aspartame degradation, were examined as affected by the changes in pH and pK(a) values caused by adding polyols (sucrose, glycerol) to phosphate buffer. Sucrose-containing phosphate buffer solutions had a lower pH than that of phosphate buffer alone, which contributed, in part, to reduced aspartame reactivity. A kinetic model was introduced for aspartame degradation that encompassed pH and buffer salt concentrations, both of which change with a shift in the apparent pK(a) value. Aspartame degradation rate constants in sucrose-containing solutions were successfully predicted using this model when corrections (that is, lower pH, lower apparent pK(a) value, buffer dilution from the polyol) were applied. The change in buffer properties (pH, pK(a)) from adding sucrose to phosphate buffer does impact food chemical stability. These effects can be successfully incorporated into predictive kinetic models. Therefore, pH and pK(a) changes from adding polyols to buffer should be considered during food product development.

  3. Surface modification of polyester fabrics by atmospheric-pressure air/He plasma for color strength and adhesion enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chunming, E-mail: zcm1229@126.com [College of Textiles and Clothing, Qingdao University, Qingdao 266071 (China); Sunvim Grp Co Ltd, Gaomi 261500 (China); Zhao, Meihua; Wang, Libing; Qu, Lijun [College of Textiles and Clothing, Qingdao University, Qingdao 266071 (China); Men, Yajing [Sunvim Grp Co Ltd, Gaomi 261500 (China)

    2017-04-01

    Highlights: • Air/He plasma gave hydrophilicity on polyester surface and decreased contact angle to 18°. • The roughness of polyester increased and pit-like structures appeared on the surface after plasma treatment. • XPS confirmed the generation of new functional groups on polyester fabric. • The improved pigment color yield and anti-bleeding performance were contributed by the alteration of pigment adhesion. • The air/He plasma was more effective than air plasma at the same treatment time. - Abstract: Surface properties of water-based pigmented inks for ink-jet printed polyester fabrics were modified with atmospheric-pressure air/He plasma to improve the color strength and pigment adhesion of the treated surfaces. The influence of various parameters, including the surface morphology, chemical compositions, surface energy and dynamic contact angles of the control and plasma treated samples was studied. Color strength and edge definition were used to evaluate the ink-jet printing performance of fabrics. The change in pigment adhesion to polyester fibers was analyzed by SEM (scanning electron microscopy). AFM (Atomic force microscope) and XPS (X-ray photoelectron spectroscopy) analyses indicated the increase in surface roughness and the oxygen-containing polar groups(C=O, C−OH and COOH) reinforced the fixation of pigments on the fiber surface. The result from this study suggested that the improved pigment color yield was clearly affected by alteration of pigment adhesion enhanced by plasma surface modification. Polyester fabrics exhibited better surface property and ink-jet printing performance after the air/He mixture plasma treatment comparing with those after air plasma treatment.

  4. Surface modification of polyester fabrics by atmospheric-pressure air/He plasma for color strength and adhesion enhancement

    International Nuclear Information System (INIS)

    Zhang, Chunming; Zhao, Meihua; Wang, Libing; Qu, Lijun; Men, Yajing

    2017-01-01

    Highlights: • Air/He plasma gave hydrophilicity on polyester surface and decreased contact angle to 18°. • The roughness of polyester increased and pit-like structures appeared on the surface after plasma treatment. • XPS confirmed the generation of new functional groups on polyester fabric. • The improved pigment color yield and anti-bleeding performance were contributed by the alteration of pigment adhesion. • The air/He plasma was more effective than air plasma at the same treatment time. - Abstract: Surface properties of water-based pigmented inks for ink-jet printed polyester fabrics were modified with atmospheric-pressure air/He plasma to improve the color strength and pigment adhesion of the treated surfaces. The influence of various parameters, including the surface morphology, chemical compositions, surface energy and dynamic contact angles of the control and plasma treated samples was studied. Color strength and edge definition were used to evaluate the ink-jet printing performance of fabrics. The change in pigment adhesion to polyester fibers was analyzed by SEM (scanning electron microscopy). AFM (Atomic force microscope) and XPS (X-ray photoelectron spectroscopy) analyses indicated the increase in surface roughness and the oxygen-containing polar groups(C=O, C−OH and COOH) reinforced the fixation of pigments on the fiber surface. The result from this study suggested that the improved pigment color yield was clearly affected by alteration of pigment adhesion enhanced by plasma surface modification. Polyester fabrics exhibited better surface property and ink-jet printing performance after the air/He mixture plasma treatment comparing with those after air plasma treatment.

  5. Flexible Acyclic Polyol-Chloride Anion Complexes and Their Characterization by Photoelectron Spectroscopy and Variable Temperature Binding Constant Determinations

    Energy Technology Data Exchange (ETDEWEB)

    Shokri, Alireza; Wang, Xue B.; Wang, Yangping; O' Doherty, George A.; Kass, Steven R.

    2016-03-17

    Flexible acyclic alcohols with 1–5 hydroxyl groups were bound to chloride anion and these complexes were interrogated by negative ion photoelectron spectroscopy and companion density functional theory computations. The resulting vertical detachment energies are reproduced on average to 0.10 eV by M06-2X/aug-cc-pVTZ predictions and range from 4.45 – 5.96 eV. These values are 0.84 – 2.35 eV larger than the adiabatic detachment energy of Cl– as a result of the larger hydrogen bond networks in the bigger polyols. Adiabatic detachment energies of the alcohol–Cl– clusters are more difficult to determine both experimentally and computationally. This is due to the large geometry changes that occur upon photodetachment and the large bond dissociation energy of H–Cl which enables the resulting chlorine atom to abstract a hydrogen from any of the methylene (CH2) or methine (CH) positions. Both ionic and non-ionic hydrogen bonds (i.e., OH•••Cl– and OH•••OH•••Cl–) form in the larger polyols complexes, and are found to be energetically comparable. Subtle structural differences, consequently can lead to the formation of different types of hydrogen bonds and maximizing the ionic ones is not always preferred. Solution equilibrium binding constants between the alcohols and tetrrabuylammonium chloride (TBACl) in acetonitrile at -24.2, 22.0, and 53.6 °C were also determined. The free energies of association are nearly identical for all of the substrates (i.e., ΔG° = -2.8 ± 0.7 kcal mol–1). Compensating enthalpy and entropy values reveal, contrary to expectation and the intrinsic gas-phase preferences, that the bigger systems with more hydroxyl groups are entropically favored and enthalpically disfavored relative to the smaller species. This suggests that more solvent molecules are released upon binding TBACl to alcohols with more hydroxyl groups and is consistent with the measured negative heat capacities. These quantities increase with

  6. Biphotonic holographic gratings in azobenzene polyesters: Surface relief phenomena and polarization effects

    DEFF Research Database (Denmark)

    Sánchez, C.; Alcalá, R.; Hvilsted, Søren

    2000-01-01

    Biphotonic holographic gratings have been recorded in a side-chain azobenzene liquid crystalline polyester using a blue incoherent source and a He-Ne laser. Intensity gratings and the appearance of surface relief have been observed when two linearly polarized beams from a He-Ne laser are made...... to interfere on a film illuminated with blue light. Polarized holographic gratings are also created with two orthogonally circularly polarized He-Ne beams. All these gratings are stable in darkness but can be erased with blue light. (C) 2000 American Institute of Physics....

  7. Synthesis and Characterization of Ethylene DiamineTetera Acetic Acid Polyester-amides polymer with Aminoalcohol

    Directory of Open Access Journals (Sweden)

    Dakhil Nasser Taha

    2017-02-01

    Full Text Available linear aromatic and aliphatic polyester-amides (PEAs have been synthesized by polycondensation of aliphatic and aromatic aminoalcohol (Ethanol amine, 2-amino-2-methyl-propan-1-ol, m-amino phenol with Ethylenediaminetetraacetic acid (EDTA as a favorable and combined complexing compound was joined into the polymer backbone with poly addition reactions. These polymers were characterized by FTIR, 1H NMR, solubility studies , elemental analysis, , Thermal analyses such as TGA were measured, intrinsic viscosity. The poly(ester-amides obtained show good thermal stability.

  8. Karakteristik Sifat Tarik Dan Mode Patahan Komposit Polyester Berpenguat Serat Tapis Kelapa

    OpenAIRE

    Astika, I Made; Dwijana, I Gusti Komang

    2014-01-01

    The purpose of this study is to investigate the mechanical properties i.e. tensile strength of composites coconut filter fiber. In the future this material can be used to replace the wood, bamboo and gipsun which are high price and lower water resistance. The research material made with coconut filter fiber as reinforcement and matrix resin unsaturated polyester (UPRs) type Yukalac BQTN 157, with 1% hardener types MEKPO (Methyl Ethyl Ketone Peroxide) and fiber treatment by  0.5% KMnO4...

  9. Influence of UV irradiation on the blue and red light photoinduced processes in azobenzene polyesters

    DEFF Research Database (Denmark)

    Rodríguez, F.J.; Sánchez, C.; Villacampa, B.

    2004-01-01

    light that yields the films into the isotropic state at room temperature (RT) was compared with the quenching from temperatures above the isotropic transition temperature Ti. UV–visible spectra of the thermally quenched films show the presence of aggregates when measured at RT. We have found that UV......Birefringence induced in a series of liquid crystalline side-chain azobenzene polyesters with different substituent groups was investigated under irradiation with 488 and 633 nm linearly polarized lights. Two different initial conditions have been used: the effect of a previous irradiation with UV...

  10. Synthesis and characterization of polyesters derived from glycerol and phthalic acid

    Directory of Open Access Journals (Sweden)

    Danilo Hansen Guimarães

    2007-09-01

    Full Text Available The production of polyester via polycondensation between glycerol and phthalic acid using dibutyltin dilaurate is reported. Three glycerol:phthalic acid molar ratio used for the bulk polymerization were: 2:2; 2:3 and 2:4. FTIR confirmed the esterification of glycerol by the acid for all the polymers. DSC indicated no crystallinity, although the XRD plots indicate a very incipient crystallinity for the polymers containing higher amounts of phthalic anhydride. Scanning electron microscopy results indicates high homogeneity for all the polymers prepared.

  11. Aluminium trihydroxide in combination with ammonium polyphosphate as flame retardants for unsaturated polyester resin

    Directory of Open Access Journals (Sweden)

    2009-11-01

    Full Text Available The thermal and reaction to fire characteristics of a flame retardant unsaturated polyester (UP ternary system are presented here. Thermal gravimetric analysis showed an improved thermal stability between 200–600°C with the addition of ammonium polyphosphate (APP and aluminium trihydroxide (ATH formulation. Cone calorimetry tests indicated that ATH is more efficient than calcium carbonate at delaying the ignition time, lowering the carbon monoxide yield and lowering the peak heat release (PHRR. However the addition of APP and ATH to the formulation failed to demonstrate any significant synergistic effect at reducing the PHRR.

  12. UV-hardening of coating materials on the basis of unsaturated polyesters

    International Nuclear Information System (INIS)

    Patheiger, M.; Fuhr, K.

    1975-01-01

    The UV-hardening of coated materials based on unsaturated polyester resins is successful in practice. Resins, modified by acrylic acid, are gaining importance for thin coating from paper coatings up to printing colours. A report is given on the binding classes which come into question as photo initiators and whose ways of reaction with UV-irradiation are so far known. The photopolymerizeable coating systems can be used from undercoats to coating varnishes and from thick layers (polishing varnishes) to thinnest layers (printing colours). The economical significance of the UV-process today is illustrated by statistics on the use of binding agents and coating materials. (orig./AK) [de

  13. Chemical Resistance of Ornamental Compound Stone Produced with Marble Waste and Unsaturated Polyester

    Science.gov (United States)

    Ribeiro, Carlos E. Gomes; Rodriguez, Rubén J. Sánchez; Vieira, Carlos M. Fontes

    Ornamental compound stone are produced by industry for decades, however, few published studies describe these materials. Brazil has many deposits of stone wastes and a big potential to produce these materials. This work aims to evaluate the chemical resistance of ornamental compound stones produced with marble waste and unsaturated polyester. An adaptation of Annex H of ABNT NBR 13818:97 standard, with reagents commonly used in household products, was used. The results were compared with those obtained for natural stone used in composite production.

  14. Preparation and Properties of Polyester-Based Nanocomposite Gel Coat System

    Directory of Open Access Journals (Sweden)

    P. Jawahar

    2006-01-01

    Full Text Available Nanocomposite gel coat system is prepared using unsaturated polyester resin with aerosil powder, CaCO3, and organoclay. The influence of organoclay addition on mechanical and water barrier properties of gel coat system is studied for different amount (1, 2, and 3 wt % of organoclay. The nanolevel incorporation of organoclay improves the mechanical and water barrier properties of nanocomposite gel coat system. The nanocomposite gel coat system exhibits 55% improvement in tensile modulus and 25% improvement in flexural modulus. There is a 30% improvement in impact property of nanocomposite gel coat system. The dynamic mechanical analysis shows a slight increase in glass transition temperature for nanocomposite gel coat system.

  15. Optimization of Cutting Parameters on Delamination of Drilling Glass-Polyester Composites

    Directory of Open Access Journals (Sweden)

    Majid Habeeb Faidh-Allah

    2018-02-01

    Full Text Available This paper attempted to study the effect of cutting parameters (spindle speed and feed rate on delamination phenomena during the drilling glass-polyester composites. Drilling process was done by CNC machine with 10 mm diameter of high-speed steel (HSS drill bit. Taguchi technique with L16 orthogonal layout was used to analyze the effective parameters on delamination factor. The optimal experiment was no. 13 with spindle speed 1273 rpm and feed 0.05 mm/rev with minimum delamination factor 1.28.

  16. Radiation curable coatings containing hydroxy functional polyethers and polyesters of monoethylenic acids or hydroxy esters thereof

    International Nuclear Information System (INIS)

    Kaufman, M.L.

    1978-01-01

    Relatively water insoluble hydroxy functional monoethylenic polyethers or polyesters of monoethylenic carboxylic acids or hydroxy alkyl esters thereof are formed by adducting the monoethylenic acid or its hydroxy ester with an anhydride selected from monoepoxides, lactones, or mixtures thereof in the presence of a Lewis acid catalyst, such as BF 3 etherate, at a temperature below that at which the unsaturation is consumed, typically about 30 to 70 0 C. These adducts are of low volatility and of low toxicity and can be radiation cured in admixture with polyacrylates to form coatings having improved resistance to elevated temperature exposure

  17. Synthesis and characterization of sulfonated polyesters derived from glycerol; Sintese e caracterizacao de poliesteres sulfonados obtidos a partir do glicerol

    Energy Technology Data Exchange (ETDEWEB)

    Fiuza, R.A.; Jose, N.M.; Boaventura, J.S. [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica; Fiuza, R.P. [Universidade Federal da Bahia (EP/UFBA), Salvador, BA (Brazil). Escola Politecnica. Curso de Mestrado em Engenharia Quimica

    2010-07-01

    In this work were synthesized polyesters from glycerol and acid sulfonated phthalic previously. The materials were characterized by DSC, TGA, FTIR, SEM, XRD and XRF. The results showed effective sulfonation of phthalic acid. The presence of sulfonic groups promoted strong changes in the crystallinity of the new material makes the lens. The polyesters made from phthalic acid sulfonated combine characteristics such as heat resistance and groups that drivers potentiate the electrolyte for application in fuel cells proton exchange membrane and also for gas separation. (author)

  18. Ultrasound enhanced plasma treatment of glass-fibre-reinforced polyester in atmospheric pressure air for adhesion improvement

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Singh, Shailendra Vikram; Norrman, Kion

    2011-01-01

    A glass-fibre-reinforced polyester (GFRP) plate was treated with dielectric barrier discharge (DBD) at atmospheric pressure in air for adhesion improvement. The effects of ultrasonic irradiation using a high-power gas-jet generator during the treatment were investigated. The optical emission...... damage of the GFRP plates. The polar component of the surface energy of the polyester plate was 21 mJ/m2 before the treatment, increased markedly to 52 mJ/m2 after 2-s plasma treatment without ultrasonic irradiation, and further increased slightly after longer treatments. In addition, the polar component...

  19. Novel acyloxy derivatives of branched mono- and polyol esters of sal fat: multiviscosity grade lubricant base stocks.

    Science.gov (United States)

    Kamalakar, Kotte; Sai Manoj, Gorantla N V T; Prasad, Rachapudi B N; Karuna, Mallampalli S L

    2014-12-10

    Sal fat, a nontraditional seed oil, was chemically modified to obtain base stocks with a wide range of specifications that can replace mineral oil base stocks. Sal fatty acids were enriched to 72.6% unsaturation using urea adduct method and reacted with branched mono alcohol, 2-ethylhexanol (2-EtH), and polyols namely neopentyl glycol (NPG) and trimethylolpropane (TMP) to obtain corresponding esters. The esters were hydroxylated and then acylated using propionic, butyric, and hexanoic anhydrides to obtain corresponding acylated derivatives. The acylated TMP esters exhibited very high viscosities (427.35-471.93 cSt at 40 °C) similar to those of BS 150 mineral oil base stock range, ISO VG 460, while the acylated NPG esters (268.81-318.84 cSt at 40 °C) and 2-EtH esters viscosities (20.94-24.44 cSt at 40 °C) exhibited viscosities in the range of ISO VG 320 and 22 respectively with good viscosity indices. Acylated NPG esters were found suitable for high temperature and acylated 2-ethylhexyl esters for low viscosity grade industrial applications. It was observed that the thermo-oxidative stabilities of all acylated products were found better compared to other vegetable oil based base stocks. Overall, all the sal fat based lubricant base stocks are promising candidates with a wide range of properties, which can replace most of the mineral oil base stocks with appropriate formulations.

  20. Zeta potential study of Sb2S3 nanoparticles synthesized by a facile polyol method in various surfactants

    Science.gov (United States)

    Saxena, Monika; Okram, Gunadhor Singh

    2018-05-01

    In the present work, we report the successful synthesis of stibnite Sb2S3 nanoparticles (NPs) by a facile polyol method using various surfactant. The structural and optical properties were investigated by X-ray diffraction (XRD), Raman spectroscopy and Zeta potential. Rietveld refinement of XRD data confirms the single phase orthorhombic crystal structure of stibnite Sb2S3. Presence of six obvious Raman modes further confirmed their stoichiometric formation. Effect of different surfactants on the surface charge of Sb2S3 NPs was studied using Zeta potential measurement in deionized water at different pH values. They reveal that these NPs are more stable when it was synthesized in presence of EDTA than that of CTAB or without surfactant samples with high zeta potential. The isoelectronic point was found at pH = 6.4 for pure sample, 3.5 and 7.2 for CTAB and not found for EDTA Sb2S3 samples. This information can be useful for many industrial applications like pharmaceuticals, ceramics, waste water treatment and medicines.

  1. Zeta potential and Raman studies of PVP capped Bi2S3 nanoparticles synthesized by polyol method

    Science.gov (United States)

    Tarachand, Sathe, Vasant G.; Okram, Gunadhor S.

    2018-05-01

    Here we report the synthesis and characterisation of polyvinylpyrrolidone (PVP) capped Bi2S3 nanoparticles via one step catalyst-free polyol method. Raman spectroscopy, dynamic light scattering and zeta potential analysis were performed on it. Rietveld refinement of powder XRD of PVP capped samples confirmed the formation of single phase orthorhombic Bi2S3 for all PVP capped samples. The presence of eight obvious Raman modes further confirmed the formation of stoichiometric Bi2S3. Dynamic light scattering (DLS) studies show a clear increase in hydrodynamic diameter for samples made with increasing PVP concentration. Particle size obtained from DLS and XRD (using Scherrer's formula) combine with change in full width half maxima of Raman modes collectively suggest overall improvement in crystallinity and quality of product on introducing PVP. In zeta potential (ζ) measurement, steric hindrance of carbon chains plays very crucial role and a systematic reduction of ζ value is observed for samples made with decreasing PVP concentration. An isoelectric point is obtained for sample made with low PVP (1g). Present results are likely to open a window for its medical and catalytic applications.

  2. High stable suspension of magnetite nanoparticles in ethanol by using sono-synthesized nanomagnetite in polyol medium

    International Nuclear Information System (INIS)

    Bastami, Tahereh Rohani; Entezari, Mohammad H.

    2013-01-01

    Graphical abstract: - Highlights: • The sonochemical synthesis of magnetite nanoparticles was carried out in EG without any surfactant. • The nanoparticles with sizes ∼24 nm were composed of small building blocks with sizes ∼2 nm. • The hydrophilic magnetite nanoparticles were stable in ethanol even after 8 months. • Ultrasonic intensity showed a crucial role on the obtained high stable magnetite nanoparticles in ethanol. - Abstract: The sonochemical synthesis of magnetite nanoparticles was carried out at relatively low temperature (80 °C) in ethylene glycol (EG) as a polyol solvent. The particle size was determined by transmission electron microscopy (TEM). The magnetite nanoparticles with an average size of 24 nm were composed of small building blocks with an average size of 2–3 nm and the particles exhibited nearly spherical shape. The surface characterization was investigated by using Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). The stability of magnetite nanoparticles was studied in ethanol as a polar solvent. The nanoparticles showed an enhanced stability in ethanol which is due to the hydrophilic surface of the particles. The colloidal stability of magnetite nanoparticles in ethanol was monitored by UV–visible spectrophotometer. According to the results, the nanoparticles synthesized in 30 min of sonication with intensity of 35 W/cm 2 (50%) led to a maximum stability in ethanol as a polar solvent with respect to the other applied intensities. The obtained magnetite nanoparticles were stable for more than12 months

  3. Preparation and characterization of polyol assisted ultrafine Cu–Ni–Mg–Ca mixed ferrite via co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Boobalan, T. [Park College of Engineering and Technology, Coimbatore (India); Pavithradevi, S. [Department of Physics, Government College of Technology, Coimbatore (India); Suriyanarayanan, N., E-mail: nsuri22@gmail.com [Department of Physics, PSG Polytechnic College, Coimbatore (India); Manivel Raja, M. [Defence Metallurgical Research Laboratory, Ministry of Defence, Govt. of India, Hyderabad (India); Ranjith Kumar, E., E-mail: ranjueaswar@gmail.com [Dr. NGP Institute of Technology, Coimbatore (India)

    2017-04-15

    Nanocrystalline spinel ferrite of composition Cu{sub 0.2}Ni{sub 0.2}Mg{sub 0.2}Ca{sub 0.4}Fe{sub 2}O{sub 4} is synthesized by wet hydroxyl co-precipitation method in ethylene glycol as chelating agent and sodium hydroxide as precipitator at pH 8. Ethylene glycol is utilized as the medium which serves as the dissolvable and in addition a complexing specialist. The synthesized particles are annealed at various temperatures. Thermogravimetric investigation affirms that at 280 °C ethylene glycol is dissipated totally and stable phase arrangement happens over 680 °C. FTIR spectra of as synthesized and annealed at 1050 °C recorded between 400 cm{sup −1} and 4000 cm{sup −1}. Structural characterizations of all the samples are carried out by X-ray diffraction (XRD) technique. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) affirm that the particles are spherical and cubic shape with the crystallite size of 12 nm to 32 nm. Magnetic measurements are performed utilizing vibrating sample magnetometer at room temperature. - Highlights: • Polyol improves purity of the spinel ferrite. • TG curves confirm the single phase ferrite is obtained above 680 °C. • Super paramagnetic behavior is seen at lower annealing temperature. • Soft ferromagnetic behavior is obtained at 1050 °C.

  4. Thioether-Bearing Hyperbranched Polyether Polyols with Methionine-Like Side-Chains: A Versatile Platform for Orthogonal Functionalization.

    Science.gov (United States)

    Seiwert, Jan; Herzberger, Jana; Leibig, Daniel; Frey, Holger

    2017-01-01

    The synthesis of thioether-bearing hyperbranched polyether polyols based on an AB/AB 2 type copolymerization (cyclic latent monomers) is introduced. The polymers are prepared by anionic ring-opening multibranching copolymerization of glycidol and 2-(methylthio)ethyl glycidyl ether (MTEGE), which is conveniently accessible in a single etherification step. Slow monomer addition provides control over molecular weights. Moderate dispersities (Đ = 1.48-1.85) are obtained, given the hyperbranched structure. In situ 1 H NMR copolymerization kinetics reveal reactivity ratios of r G = 3.7 and r MTEGE = 0.27. Using slow monomer addition, copolymer composition can be systematically varied, allowing for the adjustment of the hydroxyl/thioether ratio, the degree of branching (DB = 0.36-0.48), thermal properties, and cloud point temperatures in aqueous solution in the range of 29-75 °C. Thioether oxidation to sulfoxides enables to tailor the copolymers' solubility profile. Use of these copolymers as a versatile, multifunctional platform for orthogonal modification is highlighted. The methyl sulfide groups can be selectively alkoxylated, using propylene oxide, allyl glycidyl ether, or furfuryl glycidyl ether, resulting in functional hyperbranched polyelectrolytes. Reaction of the alcohol groups with benzyl isocyanate demonstrates successful orthogonal functionalization. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. The Effect of Temperature on Kinetics and Diffusion Coefficients of Metallocene Derivatives in Polyol-Based Deep Eutectic Solvents.

    Directory of Open Access Journals (Sweden)

    Laleh Bahadori

    Full Text Available The temperature dependence of the density, dynamic viscosity and ionic conductivity of several deep eutectic solvents (DESs containing ammonium-based salts and hydrogen bond donvnors (polyol type are investigated. The temperature-dependent electrolyte viscosity as a function of molar conductivity is correlated by means of Walden's rule. The oxidation of ferrocene (Fc/Fc+ and reduction of cobaltocenium (Cc+/Cc at different temperatures are studied by cyclic voltammetry and potential-step chronoamperometry in DESs. For most DESs, chronoamperometric transients are demonstrated to fit an Arrhenius-type relation to give activation energies for the diffusion of redox couples at different temperatures. The temperature dependence of the measured conductivities of DES1 and DES2 are better correlated with the Vogel-Tamman-Fulcher equation. The kinetics of the Fc/Fc+ and Cc+/Cc electrochemical systems have been investigated over a temperature range from 298 to 338 K. The heterogeneous electron transfer rate constant is then calculated at different temperatures by means of a logarithmic analysis. The glycerol-based DES (DES5 appears suitable for further testing in electrochemical energy storage devices.

  6. Simultaneous production of intracellular triacylglycerols and extracellular polyol esters of fatty acids by Rhodotorula babjevae and Rhodotorula aff. paludigena.

    Science.gov (United States)

    Garay, Luis A; Sitepu, Irnayuli R; Cajka, Tomas; Cathcart, Erin; Fiehn, Oliver; German, J Bruce; Block, David E; Boundy-Mills, Kyria L

    2017-10-01

    Microbial oils have been analyzed as alternatives to petroleum. However, just a handful of microbes have been successfully adapted to produce chemicals that can compete with their petroleum counterparts. One of the reasons behind the low success rate is the overall economic inefficiency of valorizing a single product. This study presents a lab-scale analysis of two yeast species that simultaneously produce multiple high-value bioproducts: intracellular triacylglycerols (TG) and extracellular polyol esters of fatty acids (PEFA), two lipid classes with immediate applications in the biofuels and surfactant industries. At harvest, the yeast strain Rhodotorula aff. paludigena UCDFST 81-84 secreted 20.9 ± 0.2 g L -1 PEFA and produced 8.8 ± 1.0 g L -1 TG, while the yeast strain Rhodotorula babjevae UCDFST 04-877 secreted 11.2 ± 1.6 g L -1 PEFA and 18.5 ± 1.7 g L -1 TG. The overall glucose conversion was 0.24 and 0.22 g (total lipid) g (glucose) -1 , respectively. The results present a stable and scalable microbial growth platform yielding multiple co-products.

  7. Sustainable Synthesis of Oxalic and Succinic Acid through Aerobic Oxidation of C6 Polyols Under Mild Conditions.

    Science.gov (United States)

    Ventura, Maria; Williamson, David; Lobefaro, Francesco; Jones, Matthew D; Mattia, Davide; Nocito, Francesco; Aresta, Michele; Dibenedetto, Angela

    2018-03-22

    The sustainable chemical industry encompasses a shift from the use of fossil carbon to renewable carbon. The synthesis of chemicals from nonedible biomass (cellulosic or oil) represents one of the key steps for "greening" the chemical industry. In this paper, we report the aerobic oxidative cleavage of C6 polyols (5-HMF, glucose, fructose and sucrose) to oxalic acid (OA) and succinic acid (SA) in water under mild conditions using M@CNT and M@NCNT (M=Fe, V; CNT=carbon nanotubes; NCNT=N-doped CNT), which, under suitable conditions, were recoverable and reusable without any loss of efficiency. The influence of the temperature, O 2 pressure (PO2 ), reaction time and stirring rate are discussed and the best reaction conditions are determined for an almost complete conversion of the starting material and a good OA yield of 48 %. SA and formic acid were the only co-products. The former could be further converted into OA by oxidation in the presence of formic acid, resulting in an overall OA yield of >62 %. This process was clean and did not produce organic waste nor gas emissions. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Chloride ion addition for controlling shapes and properties of silver nanorods capped by polyvinyl alcohol synthesized using polyol method

    Energy Technology Data Exchange (ETDEWEB)

    Junaidi, E-mail: junaidi.1982@fmipa.unila.ac.id [Department of Physics, Universitas Gadjah Mada, Yogyakarta, 55281 (Indonesia); Department of Physics, Lampung University, Bandar Lampung (Indonesia); Yunus, Muhammad, E-mail: muhammad.yunus@mail.ugm.ac.id [Department of Physics, Universitas Gadjah Mada, Yogyakarta, 55281 (Indonesia); Triyana, Kuwat, E-mail: triyana@ugm.ac.id; Harsojo,, E-mail: harsojougm@ugm.ac.id; Suharyadi, Edi, E-mail: esuharyadi@ugm.ac.id [Department of Physics, Universitas Gadjah Mada, Yogyakarta, 55281 (Indonesia); Nanomaterials Research Group, Universitas Gadjah Mada, Yogyakarta, 55281 (Indonesia)

    2016-04-19

    We report our investigation on the effect of chloride ions on controlling the shapes and properties of silver nanorods (AgNRs) synthesized using a polyol method. In this study, we used polyvinyl alcohol (PVA) as a capping agent and sodium chloride (NaCl) as a salt precursor and performed at the oil bath temperature of 140°C. The chloride ions originating from the NaCl serve to control the growth of the silver nanorods. Furthermore, the synthesized silver nanorods were characterized using SEM and XRD. The results showed that besides being able to control the growth of AgCl atoms, the chloride ions were also able to control the growth of multi-twinned-particles into the single crystalline of silver nanorods by micrometer-length. At an appropriate concentration of NaCl, the diameter of silver nanorods decreased significantly compared to that of without chloride ion addition. This technique may be useful since a particular diameter of silver nanorods affects a particular application in the future.

  9. Fermentable oligosaccharide, disaccharide, monosaccharide and polyol content of foods commonly consumed by ethnic minority groups in the United Kingdom.

    Science.gov (United States)

    Prichard, Rebeca; Rossi, Megan; Muir, Jane; Yao, Ck; Whelan, Kevin; Lomer, Miranda

    2016-06-01

    Dietary restriction of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) is an effective management approach for functional bowel disorders; however, its application is limited by the paucity of food composition data available for ethnic minority groups. The aim was to identify and measure the FODMAP content of these commonly consumed foods. According to their perceived importance to clinical practise, the top 20 ranked foods underwent FODMAP analysis using validated analytical techniques (total fructans, Megazyme hexokinase (HK) assay; all others, high-performance liquid chromatography (HPLC) with evaporative light scattering detectors). Of the 20 foods analysed, five were identified as significant sources of at least one FODMAP. Fructans and galacto-oligosaccharides were the major FODMAPs in these foods, including channa dal (0.13 g/100 g; 0.36 g/100 g), fenugreek seeds (1.11 g/100 g; 1.27 g/100 g), guava (0.41 g/100 g; not detected), karela (not detected; 1.12 g/100 g) and tamarind (2.35 g/100 g; 0.02 g/100 g). Broadening the availability of FODMAP composition data will increase the cultural application of low FODMAP dietary advice.

  10. Shape-controlled synthesis of Pt-Pd core-shell nanoparticles exhibiting polyhedral morphologies by modified polyol method

    International Nuclear Information System (INIS)

    Long, Nguyen Viet; Asaka, Toru; Matsubara, Takashi; Nogami, Masayuki

    2011-01-01

    Pt-Pd core-shell nanoparticles were synthesized by a simple synthetic method. First, Pt nanoparticles were synthesized in a controlled manner via the reduction of chloroplantinic acid hexahydrate in ethylene glycol (EG) at 160 deg. C in the presence of silver nitrate and the stabilization of polyvinylpyrrolidon. AgNO 3 used acts as a structure-modifying agent to the morphology of the Pt nanoparticles. These Pt nanoparticles function as the seeds for the successive reduction of sodium tetrachloropalladate (II) hydrate in EG under stirring for 15 min at 160 deg. C in order to synthesize Pt-Pd core-shell nanoparticles. To characterize the as-prepared Pt-Pd nanoparticles, transmission electron microscopy (TEM) and high-resolution TEM are used. The high-resolution elemental mappings were carried out using the combination of scanning TEM and X-ray energy-dispersive spectroscopy. The results also demonstrate the homogeneous nucleation and growth of the Pd metal shell on the definite Pt core. The synthesized Pt-Pd core-shell nanoparticles exhibit a sharp and polyhedral morphology. The epitaxial growth of the controlled Pd shells on the Pt cores via a polyol method was observed. It is suggested that Frank-van der Merwe and Stranski-Krastanov growth modes coexisted in the nucleation and growth of Pt-Pd core-shell nanoparticles.

  11. Rapid Polyol-Assisted Microwave Synthesis of Nanocrystalline LiFePO4/C Cathode for Lithium-Ion Batteries.

    Science.gov (United States)

    Paul, Baboo Joseph; Gim, Jihyeon; Baek, Sora; Kang, Jungwon; Song, Jinju; Kim, Sungjin; Kim, Jaekook

    2015-08-01

    Nanocrystalline LiFePO4/C has been synthesized under a very short period of time (90 sec) using a polyol-assisted microwave heating synthesis technique. The X-ray diffraction (XRD) data indicates that the rapidly synthesized materials correspond to phase pure olivine. Post-annealing of the as-prepared sample at 600 °C in argon atmosphere yields highly crystalline LiFePO4/C. The morphology of the samples studied using scanning electron microscopy (SEM) reveals the presence of secondary particles formed from aggregation of primary particles in the range of 30-50 nm. Transmission electron microscopy (TEM) images reveal a thin carbon layer coating on the surface of the primary particle. The charge/discharge studies indicate that the as-prepared and annealed LiFePO4/C samples delivered initial discharge capacities of 126 and 160 mA h g-1, respectively, with good capacity retentions at 0.05 mA cm-2 current densities. The post-annealing process indeed improves the crystallinity of the LiFePO4 nanocrystals, which enhances the electrode performance of LiFePO4/C.

  12. Chloride ion addition for controlling shapes and properties of silver nanorods capped by polyvinyl alcohol synthesized by polyol method

    International Nuclear Information System (INIS)

    Junaidi; Triyana, Kuwat; Harsojo,; Suharyadi, Edi

    2016-01-01

    We report our investigation on the effect of chloride ions oncontrolling the shapes and properties of silver nanorods(AgNRs) synthesized using a polyol method. In this study, we used polyvinyl alcohol (PVA) as a capping agent and sodium chloride (NaCl) as asalt precursor and performed at the oilbath temperature of 140 °C. The chloride ions originating from the NaCl serve to control the growth of the silver nanorods. Furthermore, the synthesized silver nanorodswere characterized using UV-VIS, XRD, SEM and TEM. The results showed that besides being able to control the growth of AgCl atoms, the chloride ions were also able to control the growth of multi-twinned-particles into the single crystalline silver nanorods by micrometer-length. At an appropriate concentration of NaCl, the diameter of silver nanorodsdecreased significantly compared to that of without chloride ion addition. This technique may be useful since a particular diameter of silver nanorods affects a particular application in the future.

  13. Chloride ion addition for controlling shapes and properties of silver nanorods capped by polyvinyl alcohol synthesized using polyol method

    International Nuclear Information System (INIS)

    Junaidi; Yunus, Muhammad; Triyana, Kuwat; Harsojo,; Suharyadi, Edi

    2016-01-01

    We report our investigation on the effect of chloride ions on controlling the shapes and properties of silver nanorods (AgNRs) synthesized using a polyol method. In this study, we used polyvinyl alcohol (PVA) as a capping agent and sodium chloride (NaCl) as a salt precursor and performed at the oil bath temperature of 140°C. The chloride ions originating from the NaCl serve to control the growth of the silver nanorods. Furthermore, the synthesized silver nanorods were characterized using SEM and XRD. The results showed that besides being able to control the growth of AgCl atoms, the chloride ions were also able to control the growth of multi-twinned-particles into the single crystalline of silver nanorods by micrometer-length. At an appropriate concentration of NaCl, the diameter of silver nanorods decreased significantly compared to that of without chloride ion addition. This technique may be useful since a particular diameter of silver nanorods affects a particular application in the future.

  14. Characterization of polyesters by matrix-assisted laser desorption/ionization and Fourier transform mass spectrometry.

    Science.gov (United States)

    Mize, Todd H; Simonsick, William J; Amster, I Jonathan

    2003-01-01

    Two homopolyesters, poly(neopentyl glycol-alt-isophthalic acid) and poly(hexanediol-alt-azelaic acid), and two copolyesters, poly(dipropoxylated bisphenol-A-alt-(isophthalic acid-co-adipic acid)) and poly(neopentyl glycol-alt-(adipic acid-co-isophthalic acid)) were analyzed by internal source matrix assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS). The high resolution and high mass accuracy provided by FTMS greatly facilitate the characterization of the polyester and copolyester samples. Isobaric resolution allows the ion abundances of overlapping isotopic envelopes to be assessed. Repeat units were confirmed and end functionality assigned. Single shot mass spectra of the entire polymeric distribution demonstrate that the dynamic range of this internal MALDI source instrument and the analyzer cell exceeds performance of those previously reported for higher field instruments. Corrections of space charge mass shift effects are demonstrated for the analytes using an external calibrant and (subsequent to confirmation of structure) via internal calibration which removes ambiguity due to space charge differences in calibrant and analyte spectra. Capillary gel permeation chromatography was used to prepare low polydispersity samples from a high polydispersity polyester, improving the measurement of molecular weight distribution two-fold while retaining the benefits of high resolution mass spectrometry for elucidation of oligomer identity.

  15. Compressive fatigue tests on a unidirectional glass/polyester composite at cryogenic temperatures

    International Nuclear Information System (INIS)

    Stone, E.L.; El-Marazki, L.O.; Young, W.C.

    1979-01-01

    The fatigue testing of a unidirectional glass-reinforced polyester composite at cryogenic temperatures to simulate the cyclic compressive loads of the magnet support struts in a superconductive magnetic energy storage unit is reported. Right circular cylindrical specimens were tested at 77, 4.2 K and room temperature at different stress levels using a 1-Hz haversine waveform imposed upon a constant baseload in a load-controlled closed-loop electrohydraulic test machine. Two failure modes, uniform mushrooming near one end and a 45 deg fracture line through the middle of the specimen, are observed, with no systematic difference in fatigue life between the modes. Fatigue lives obtained at 77 and 4.2 K are found to be similar, with fatigue failure at 100,000 cycles occurring at stress levels of 70 and 75% of the ultimate compressive strengths of specimens at room temperature and 77 K, respectively. The room temperature fatigue lives of the glass/polyester specimens are found to be intermediate between those reported for glass/epoxy composites with different glass contents costing over twice as much

  16. Effect of Fiber Volume Fraction and Water Absorption toward Bending Strength of Coconut Filters/ Polyester Composite

    Directory of Open Access Journals (Sweden)

    I Putu Lokantara

    2012-11-01

    Full Text Available The variation of fibre volume and the duration of water soaking take influence on the mechanical properties of composite. This research aim is to know the influence of fraction volume fibre and soaking duration on the mineral watertoward the tensile strength and flexural of polyester-coconut-tapis composite. This research used coconut-tapis fibre which is cut 1 cm in length with 0%, 5%, 7,5%, and 10% fiber volume fraction, unsaturated-polyester (UPRs matrix resin type Yucalac 157 BQTN-EX, and MEKPO hardener. The flexure specimen are made by press hand lay-up method and cut according ASTM D790-03 for the flexure test. The result of flexure test shows that the duration of soaking and the fiber volume fraction give a significant effect on the flexural strength of composite. The highest strength are reached by composite with 10% fibre volume on 48 hour soaking time equal to 41.994 MPa. The flexure modulus happenend shows increasing until 24 hour soaking time. The highest modulus are reached by composite with 10% fibre volume equal to 7.114 GPa while the lowest are reached by composite with 0% fibre volume equal to 3,023 GPa.

  17. Surface modification of polyester synthetic leather with tetramethylsilane by atmospheric pressure plasma

    Energy Technology Data Exchange (ETDEWEB)

    Kan, C.W., E-mail: tccwk@polyu.edu.hk [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Kwong, C.H. [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong); Ng, S.P. [Hong Kong Community College, The Hong Kong Polytechnic University (Hong Kong)

    2015-08-15

    Highlights: • Atmospheric pressure plasma treatment improved surface performance of polyester synthetic leather with tetramethylsilane. • XPS and FTIR confirmed the deposition of organosilanes on the sample's surface. • Contact angle increases to 138° after plasma treatment. - Abstract: Much works have been done on synthetic materials but scarcely on synthetic leather owing to its surface structures in terms of porosity and roughness. This paper examines the use of atmospheric pressure plasma (APP) treatment for improving the surface performance of polyester synthetic leather by use of a precursor, tetramethylsilane (TMS). Plasma deposition is regarded as an effective, simple and single-step method with low pollution. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) confirm the deposition of organosilanes on the sample's surface. The results showed that under a particular combination of treatment parameters, a hydrophobic surface was achieved on the APP treated sample with sessile drop static contact angle of 138°. The hydrophobic surface is stable without hydrophilic recovery 30 days after plasma treatment.

  18. Study on transparency of adhesive joints of scintillation strips on the polyester basis

    International Nuclear Information System (INIS)

    Bondarenko, V.G.; Grigor'ev, V.A.; Kaplin, V.A.; Gushchin, V.V.; Prikhodchenko, N.N.; Silina, T.S.; Finashina, T.L.

    1979-01-01

    Optical transparency of adhesive joints of polyester-base scintillators is studied. To realize the optical contact between two scintillation strips of the 400x80x20 mm and 300x80x20 mm dimensions the following substances are used: KV-3 vaseline, 21-03V elastosyl adhesive and VK-14 adhesive. Using an installation for measuring adhesive joint transparency the dependence of the photomultiplier signal amplitude on the β-source coordinates is obtained. It is experimentally found that light losses on the adhesive joints were 8% for the VK-14 and elastosyl adhesives, and 10% for the VK-3 vase-line. The measurement error is +-1%. On the basis of the results obtained the conclusion is made that for adhesion of the scintillation detectors on the polyester basis the 21-03V elastosyl for detachable joints and the VK-14 adhesive - for permanent joints adhesive can be used. It is noted that while using the VK-14 adhesive it is necessary to pay attention to thorough preparation of the adhesive surfaces and provision of the necessary pressure during adhesion (not less than 2-3 kg/cm 2 ) [ru

  19. Physicomechanical evaluation of polypropylene, polyester, and polytetrafluoroethylene meshes for inguinal hernia repair.

    Science.gov (United States)

    Deeken, Corey R; Abdo, Michael S; Frisella, Margaret M; Matthews, Brent D

    2011-01-01

    For meshes to be used effectively for hernia repair, it is imperative that engineers and surgeons standardize the terminology and techniques related to physicomechanical evaluation of these materials. The objectives of this study were to propose standard techniques, perform physicomechanical testing, and classify materials commonly used for inguinal hernia repair. Nine meshes were evaluated: 4 polypropylene, 1 polyester, 1 polytetrafluoroethylene, and 3 partially absorbable. Physical properties were determined through image analysis, laser micrometry, and density measurements. Biomechanical properties were determined through suture retention, tear resistance, uniaxial, and ball burst testing with specimens tested in 2 different orientations. A 1-way ANOVA with Tukey's post-test or a t-test were performed, with p INFINIT (WL Gore & Associates) did not resist tearing as effectively as the others. All meshes exhibited supraphysiologic burst strengths except INFINIT and ULTRAPRO. Significant differences exist between the physicomechanical properties of polypropylene, polyester, polytetrafluoroethylene, and partially absorbable mesh prostheses commonly used for inguinal hernia repair. Orientation of the mesh was also shown to be critical for the success of meshes, particularly those demonstrating anisotropy. Copyright © 2011 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  20. Mechanical Properties of Mahogany (Swietenia Macrophylla and Araba (Ceiba Pentandra Dusts Reinforced Polyester Composites

    Directory of Open Access Journals (Sweden)

    Isiaka Oluwole OLADELE

    2013-11-01

    Full Text Available Comparative study of the reinforcement efficiency of hardwood and softwood dusts on the mechanical properties of polyester composites was investigated. Chemical treatment of the wood saw dusts were also carried out in order to further consider the possibility of surface modification of the saw dusts. Mahogany (Swietenia Macrophylla, a species of hard wood and Araba (Ceiba Pentandra, a species of soft wood saw dusts were selected and treated with a mixture of 1.0 M of NaOH and HCl at elevated temperature of 70°C for 3 hours followed by washing with distilled water and sieving before sun drying. The dried wood saw dusts was further oven dried at 60°C for 1 hour and pulverized with laboratory ball mill before being sieved with a mesh of grain size of 150 µm. The composites were produced by mixing the particulate fibres and the polyester matrix in predetermined proportions. Mechanical tests were carried out on the cured samples in order to determine properties such as: tensile, hardness and flexural. Scanning Electron Microscope (SEM was used to observe the miscibility or otherwise between the fibre and matrix at the fractured surfaces. From the analysis, treated hardwood saw dust samples gave possess better tensile properties while soft wood saw dusts in the treated and untreated reinforced composites produced the best results in flexural. The hardness result revealed a marginal improvement in the untreated hardwood dust sample.

  1. The Assessing of the Failure Behavior of Glass/Polyester Composites Subject to Quasi Static Stresses

    Science.gov (United States)

    Stanciu, M. D.; Savin, A.; Teodorescu-Drăghicescu, H.

    2017-06-01

    Using glass fabric reinforced composites for structure of wind turbine blades requires high mechanical strengths especially to cyclic stresses. Studies have shown that approximately 50% of composite material failure occurs because of fatigue. Composites behavior to cyclic stresses involves three stages regarding to stiffness variation: the first stage is characterized by the accelerated decline of stiffness with micro-cracks, the second stage - a slight decrease of stiffness characterized by the occurrence of delamination and third stage characterized by higher decreases of resistance and occurrence of fracture thereof. The aim of the paper is to analyzed the behavior of composites reinforced with glass fibers fabric type RT500 and polyester resin subjected to tensile cyclic loading with pulsating quasi-static regime with asymmetry coefficient R = 0. The samples were tested with the universal tensile machine LS100 Lloyd Instruments Plus, with a load capacity of 100 kN. The load was applied with different speeds of 1 mm/min, 10 mm/min and 20 mm/min. After tests, it was observed that the greatest permanent strains were recorded in the first load cycles when the total energy storage by material was lost due to internal friction. With increasing number of cycles, the glass/polyester composites ability to store energy of deformation decreases, the flow phenomenon characterized by large displacements to smaller loading forces appearing.

  2. Quasi-static puncture resistance behaviors of high-strength polyester fabric for soft body armor

    Directory of Open Access Journals (Sweden)

    Qiu-Shi Wang

    Full Text Available A series of economical and flexible fabrics were prepared using high-strength polyester yarns with different fabric structures, weft density and number of layers. The effect of these factors on quasi-static puncture resistance was comparatively studied. The failure mode of the fabrics was analyzed with SEM photographs. Findings indicate that the structure and the weft density affected the quasi-static puncture resistance property of the fabrics, the plain fabrics had better puncture resistance property than twill and satin fabrics. The max puncture force and puncture energy of the plain fabrics with 160 yarn/10 cm reached the max values which were 107.43 N and 0.44 J, respectively. The number of layers had a linear relationship to quasi-static puncture resistance. The contact pressure and friction of the probe against the fibers were the main hindrance during the quasi-static puncture process and the breakage of the fibers during the penetration was caused by the bend and tensile deformation. Keywords: High-strength polyester fabrics, Fabric structure, Multiple-layer fabrics, Quasi-static puncture resistance

  3. Effective Interfacially Polymerized Polyester Solvent Resistant Nanofiltration Membrane from Bioderived Materials

    KAUST Repository

    Abdellah, Mohamed H.

    2018-05-18

    Utilization of sustainable and environmentally friendly solvents for the preparation of membranes has attracted growing interest in recent years. In this work, a polyester thin film composite solvent resistant nanofiltration (SRNF) membrane is prepared by interfacial polymerization on a cellulose support. The cellulose support is prepared by nonsolvent‐induced phase separation from a dope solution containing an ionic liquid as an environmentally friendly solvent (negligible vapor pressure). The polyester film is formed via the interfacial reaction between quercetin, a plant‐derived polyphenol, and terephthaloyl chloride. Alpha‐pinene is used as a green alternative solvent to dissolve terephthaloyl chloride (TPC) while quercetin is dissolved in a 0.2 m NaOH solution. The interfacial polymerization reaction is successfully confirmed by Fourier transform infrared and X‐ray photoelectron spectroscopy while scanning electron and atomic force microscopy are used to characterize the membrane structure. The composite membrane shows an outstanding performance with a molecular weight cut‐off around 330 Da combined with a dimethylformamide (DMF) permeance up to 2.8 L m−2 bar−1 h−1. The membrane is stable in strong aprotic solvents such as DMF offering potential application in the pharmaceutical and petrochemical industries.

  4. Modelling of polyester fabric dyeing in the presence of ultrasonic waves

    Directory of Open Access Journals (Sweden)

    Kodrić Marija

    2017-01-01

    Full Text Available In this paper, modelling of dyeing, i.e. adsorptive behaviour of disperse dyes on polyester fibres (dyeing, under the influence of ultrasound has been considered with the aim of getting the data about mechanisms of binding the dyes and defining the conditions of dyeing process of this synthetic fibres along with additional energy source without the use of carriers, compounds that increase permeability of the fibres and help dyeing. Dyeing - adsorption is conducted under different conditions, and the concentration of dyes, mass of the substrate, recipes and time of dyeing were being varied. It has been established that ultrasound allows dyeing without carriers and the efficiency of dyeing depends on the time of contact, initial concentration of the dye and the amount of absorbent - material. There is the continuity of growth of the amount of bound dye to the mass of the absorbent. Characteristic graphs, obtained from Langmuir isotherm, have confirmed that this model ensures precise description of polyester dyeing by disperse dye. Kinetic of dyeing has been remarkably interpreted by pseudo second-order in regards to the high functionality.

  5. [A novel method based on Y-shaped cotton-polyester thread microfluidic channel].

    Science.gov (United States)

    Wang, Lu; Shi, Yan-ru; Yan, Hong-tao

    2014-08-01

    A novel method based on Y-shaped microfluidic channel was firstly proposed in this study. The microfluidic channel was made of two cotton-polyester threads based on the capillary effect of cotton-polyester threads for the determination solutions. A special device was developed to fix the Y-shaped microfluidic channel by ourselves, through which the length and the tilt angle of the channel can be adjusted as requested. The spectrophotometry was compared with Scan-Adobe Photoshop software processing method. The former had a lower detection limit while the latter showed advantages in both convenience and fast operations and lower amount of samples. The proposed method was applied to the determination of nitrite. The linear ranges and detection limits are 1.0-70 micromol x L(-1), 0.66 micromol x L(-1) (spectrophotometry) and 50-450 micromol x L(-1), 45.10 micromol x L(-1) (Scan-Adobe Photoshop software processing method) respectively. This method has been successfully used to the determination of nitrite in soil samples and moat water with recoveries between 96.7% and 104%. It was proved that the proposed method was a low-cost, rapid and convenient analytical method with extensive application prospect.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

    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. - Highlights: • Gamma irradiation of polyesters with different number of aromatic rings was studied. • Effect of gamma radiation on PBN, PDEN, PTDEN, PDET, and PTDET was investigated. • Irradiated polymers were studied by GPC, DSC and PALS. • Introduction of heteroatoms decreases polymers radiation resistance. • Presence of double aromatic ring confers a higher stability with increasing doses.

  7. Electromagnetic shielding mechanisms using soft magnetic stainless steel fiber enabled polyester textiles

    Science.gov (United States)

    Shyr, Tien-Wei; Shie, Jing-Wen

    2012-11-01

    This work studied the effects of conductivity, magnetic loss, and complex permittivity when using blended textiles (SSF/PET) of polyester fibers (PET) with stainless steel fibers (SSF) on electromagnetic wave shielding mechanisms at electromagnetic wave frequencies ranging from 30 MHz to 1500 MHz. The 316L stainless steel fiber used in this study had 38 vol% γ austenite and 62 vol% α' martensite crystalline phases, which was characterized by an x-ray diffractometer. Due to the magnetic and dielectric loss of soft metallic magnetic stainless steel fiber enabled polyester textiles, the relationship between the reflection/absorption/transmission behaviors of the electromagnetic wave and the electrical/magnetic/dielectric properties of the SSF and SSF/PET fabrics was analyzed. Our results showed that the electromagnetic interference shielding of the SSF/PET textiles show an absorption-dominant mechanism, which attributed to the dielectric loss and the magnetic loss at a lower frequency and attributed to the magnetic loss at a higher frequency, respectively.

  8. Novel polyester/SiO2 nanocomposite membranes: Synthesis, properties and morphological studies

    Science.gov (United States)

    Ahmadizadegan, Hashem; Esmaielzadeh, Sheida

    2018-06-01

    In this paper, a new type of soluble polyester/silica (PE/SiO2) hybrid was prepared by the ultrasonic irradiation process. The coupling agent γ-glycidyloxypropyltrimethoxysilane (GOTMS) was chosen to enhance the compatibility between the polyester (PE) and silica (SiO2). Furthermore, the effects of the coupling agent on the morphologies and properties of the PE/SiO2 hybrids were investigated using UV-vis and FT-IR spectroscopies and FE-SEM. The densities and solubilities of the PE/SiO2 hybrids were also measured. The results show that the size of the silica particle was markedly reduced by the introduction of the coupling agent, which made the PE/SiO2 hybrid films become transparent. Furthermore, thermal stability, residual solvent in the membrane film and structural ruination of membranes were analyzed by thermal gravimetric analysis (TGA). The effects of SiO2 nanoparticles on the glass transition temperature (Tg) of the prepared nanocomposites were studied by differential scanning calorimetry (DSC). Moreover, their mechanical properties were also characterized. It can be observed that the Young's moduli (E) of the hybrid films increase linearly with the silica content. The results obtained from gas permeation experiments with a constant pressure setup showed that adding SiO2 nanoparticles to the polymeric membrane structure increased the permeability of the membranes.

  9. The role of the substrate in micro-scale scratching of epoxy-polyester films

    Science.gov (United States)

    Barletta, M.; Gisario, A.

    2011-02-01

    The present investigation analyzes the deformation response of electrostatically sprayed epoxy-polyester powder coatings by 'in situ' micro-mechanical tests. The characterization of the performance of the coatings was carried out by micro-scale scratching, by varying the indenter type, the applied load and the sliding speed. The tests were carried out on polymeric coatings deposited on as-received, micro and macro-corrugated AISI 304 stainless steel substrates and 'rigidly adhered' to them. Further tests were performed on 'free-standing' coatings, that is, on the as-received metal substrates pre-coated with an intermediate layer of silicon-based heat curable release coating. Experimental data allow us to evaluate the influence of the contact conditions between substrate and indenter and the role of the loading conditions on the scratch and penetration resistance of the epoxy-polyester coatings. The different responses of the polymeric coatings when deposited on untreated or pre-treated substrates as well as on an intermediate layer of release coating, contribute to a better understanding of the intrinsic roles of the polymeric material and substrate as well as the influence of the interfacial adhesion between coating and substrate.

  10. Surface modification of polyester synthetic leather with tetramethylsilane by atmospheric pressure plasma

    International Nuclear Information System (INIS)

    Kan, C.W.; Kwong, C.H.; Ng, S.P.

    2015-01-01

    Highlights: • Atmospheric pressure plasma treatment improved surface performance of polyester synthetic leather with tetramethylsilane. • XPS and FTIR confirmed the deposition of organosilanes on the sample's surface. • Contact angle increases to 138° after plasma treatment. - Abstract: Much works have been done on synthetic materials but scarcely on synthetic leather owing to its surface structures in terms of porosity and roughness. This paper examines the use of atmospheric pressure plasma (APP) treatment for improving the surface performance of polyester synthetic leather by use of a precursor, tetramethylsilane (TMS). Plasma deposition is regarded as an effective, simple and single-step method with low pollution. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) confirm the deposition of organosilanes on the sample's surface. The results showed that under a particular combination of treatment parameters, a hydrophobic surface was achieved on the APP treated sample with sessile drop static contact angle of 138°. The hydrophobic surface is stable without hydrophilic recovery 30 days after plasma treatment

  11. Low-Cost and High-Impact Environmental Solutions for Military Composite Structures

    Science.gov (United States)

    2005-12-15

    moduli of UPE polymers are considerably increased when neopentyl glycol is used as the polyol instead of ethylene glycol in the formulations [56...general purpose unsaturated polyester based on phthalic anhydride, ethylene glycol , and maleic anhydride. The VIAPAL 570G was a colorless solid in the...modulus. In this case, the neopentyl center of the Bisphenol A backbone of the VE 828 polymer may be responsible for increased modulus values. The

  12. Miscibility and specific interactions in blends of poly(n-vinyl-2-pyrrolidone) and acid functional polyester resins.

    NARCIS (Netherlands)

    Senatore, D.; Berix, M.J.A.; Laven, J.; Benthem, van R.A.T.M.; With, de G.; Mezari, B.; Magusin, P.C.M.M.

    2008-01-01

    Miscibility and intermol. interactions of novel blends of poly(N-vinyl-2-pyrrolidone) (PVP) and acid functional polyester resins (APE) were studied by use of Differential Scanning Calorimetry (DSC), Attenuated Total Reflectance Fourier Transform IR (ATR-FTIR), Cross-Polarization Magic Angle Spinning

  13. One-pot preparation of unsaturated polyester nanocomposites containing functionalized graphene sheets via a novel solvent-exchange method

    Science.gov (United States)

    This paper reports a convenient one-pot method integrating a novel solvent-exchange method into in situ melt polycondensation to fabricate unsaturated polyester nanocomposites containing functionalized graphene sheets (FGS). A novel solvent-exchange method was first developed to prepare graphene oxi...

  14. 77 FR 54898 - Certain Polyester Staple Fiber From the People's Republic of China: Final Results of Expedited...

    Science.gov (United States)

    2012-09-06

    ... Fiber From the People's Republic of China: Final Results of Expedited Sunset Review of the Antidumping.... SUMMARY: On May 1, 2012, the Department of Commerce (``the Department'') initiated the first five-year (``sunset'') review of the antidumping duty order on certain polyester staple fiber from the People's...

  15. Liquid-crystalline polyesters with end nitroxyl radical and their use in living free-radical polymerization

    Czech Academy of Sciences Publication Activity Database

    Razina, A B.; Sedláková, Zdeňka; Bouchal, Karel; Tenkovtsev, A. V.; Ilavský, Michal

    2002-01-01

    Roč. 44, č. 9 (2002), s. 924-930 ISSN 0965-545X R&D Projects: GA AV ČR KSK4050111 Institutional research plan: CEZ:AV0Z4050913 Keywords : liquid crystal * polyesters * nitroxyl radical Subject RIV: CD - Macromolecular Chemistry Impact factor: 0.627, year: 2002

  16. A versatile family of degradable non-viral gene carriers based on hyperbranched poly(ester amine)s

    NARCIS (Netherlands)

    Zhong, Zhiyuan; Song, Y.; Engbersen, Johannes F.J.; Lok, Martin C.; Hennink, Wim E.; Feijen, Jan

    2005-01-01

    A variety of degradable hyperbranched poly(ester amine)s containing primary, secondary and tertiary amino groups, were synthesized and evaluated as non-viral gene carriers. The polymers were obtained in high yields through a Michael-type conjugate addition of diacrylate monomers with trifunctional

  17. Effect of particle size and concentration on the mechanical properties of polyester/date palm seed particulate composites

    Directory of Open Access Journals (Sweden)

    Alewo Opuada AMEH

    2015-05-01

    Full Text Available The use of cellulosic materials as reinforcement in composites can greatly enhance their properties. The thrust of this study was to investigate the effect of date palm seed particle on the properties of reinforced polyester. Unsaturated polyester resin was reinforced with date palm seed particles of 0.5, 2.0 and 2.8mm particle sizes using variable particle loadings of 5, 10, 15, 20 and 25wt%. The composites obtained were subjected to various types of mechanical and physical tests in order to assess their performance. The optimum tensile strength of 16.7619N/mm2 and elastic modulus of 343.8N/mm2 were attained at 15wt% and 10wt% loading (using 0.5mm particles respectively and percent water absorption was found to be least for 0.5mm particle size. The hardness was enhanced to the maximum of 74 HRF (Rockwell Hardness Factor by 2mm particle size at 25wt% loading. Pure unsaturated polyester resin recorded tensile strength of 17.5959N/mm2, elastic modulus of 316.7N/mm2 and hardness of 33.5 HRF. The results indicated that the use of date palm seed particles as reinforcement can enhance the properties of polyester composites.

  18. An analysis of the anisotropic and topographic gratings in a side-chain liquid crystalline azobenzene polyester

    DEFF Research Database (Denmark)

    Holme, N.C.R.; Nikolova, L.; Ramanujam, P.S.

    1997-01-01

    We have examined in detail the formation of surface relief structures in azobenzene polyesters formed by polarization holography with orthogonally circularly polarized laser beams, We show that it is possible to separate the contribution to the diffraction efficiency into an anisotropic part...

  19. 10,000 optical write, read, and erase cycles in an azobenzene sidechain liquid-crystalline polyester

    DEFF Research Database (Denmark)

    Holme, NCR; Ramanujam, P.S.; Hvilsted, Søren

    1996-01-01

    We show far what is believed to he the first time that it is possible tu generate 10,000 rapid write, read, and erase cycles optically in an azobenzene sidechain liquid-crystalline polyester. We do this by exposing the film alternately to visible light from an argon laser at 488 nm and ultraviolet...

  20. Synthesis and characterization of comb-shaped polyesters based on 2-octadecyl-1,3-propanediol and phthalic acids

    DEFF Research Database (Denmark)

    Andruzzi, F.; Hvilsted, S.; Paci, M.

    1994-01-01

    of 110 000 and higher. High-resolution, solution C-13 n.m.r. spectroscopy analysis of both the diphenyl ester precursors and polyesters identified the main-chain units, the isomeric aromatic acid residue and glycol carbons, the linking and the terminal ends of the octadecyl side chain, and finally...