• Title/Summary/Keyword: Organosoluble

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Characterization of by-products from organosolv pretreatments of yellow poplar wood (Liriodendron tulipifera) in the presence of acid and alkali catalysts

  • Koo, Bon-Wook;Gwak, Ki-Seob;Park, Na-Hyun;Jeong, Han-Seob;Choi, Joon-Weon;Yeo, Hwan-Myeong;Choi, In-Gyu
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.11a
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    • pp.520-520
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    • 2009
  • Organic by-products derived from cellulose and lignin during organosolv pretreatments of yellow poplar wood (Liriodendron tulipifera) in the presence of $H_2SO_4$ and NaOH as catalysts, respectively, were subjected to various analyses to elucidate their effects on further performance of biological ethanol fermentation and provide preliminary data for the structure and utilization of organosolv lignin. Monomeric sugars amounted to ca. 2.2-7.7% in the organosoluble fraction of the organosolv pretreatment with $H_2SO_4$, while significantly low amount of sugars (0.2-0.3%) were determined in that of the organosolv pretreatment with NaOH. In case of addition of $H_2SO_4$ during organosolv pretreatment of biomass, a fermentation of the organosoluble fraction could be considered as an essential process to increase an efficiency of biomass utilization as well as yield of bioethanol. Precipitates, insoluble by-products in the solvent mixture, were also cficiency oed by diverse analytical methods and revealed that these were typically composed of a lignin moiety regardless of catalyst. According to the results of nuclear magnetic resonance (NMR), Fourier Tcinsform Infrared Spectroscopy (FT-IR) and Gel permeation chromatograp r (GPC), the main components of precipitates seem to be lignin polymers. However, their structures could be slightly modified during pretreatment and mixed with some carbohydrates by chemical bonds and/or physical associations.

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Rapid Formation of Optically Active and Organosoluble Polyamides Containing L-Alaninephthalimide Side Chain via Microwave Irradiation

  • Mallakpour, Shadpour;Rafiee, Zahra
    • Macromolecular Research
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    • v.17 no.11
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    • pp.901-906
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    • 2009
  • Several aromatic optically active polyamides (PA)s were synthesized from 5-(2-phthalimidiylpropanoylamino)isophthalic acid with various aromatic diamines via direct polycondensation with triphenyl phosphite and pyridine in the presence of calcium chloride and N-methyl-2-pyrrolidone under microwave irradiation and conventional heating conditions. Under the optimized conditions, the reaction mixture was irradiated for 2 min. with a 100% irradiation power (900 W). The resulting polymers were obtained in high yield and moderate inherent viscosity ranging from 0.35 to 0.60 dL/g. All synthesized polymers showed excellent solubility in amide-type solvents. Thermogravimetric analysis revealed a 10% weight loss temperature and char yield at $600^{\circ}C$ in a nitrogen atmosphere of > $350^{\circ}C$ and > 58%, respectively, which suggests that the resulting PAs have good thermal stability.

New Hyperbranched Polyimides and Polyamides: Synthesis, Chain-End Functionalizations, Curing Studies, and Some Physical Properties (새로운 Hyperbranchedpolyimidesandpolyamides: 합성, 말단기 변형, 경화 연구, 그리고 물리적 성질)

  • Baek, Jong-Beom;Chris B. Lyon;Tan, Loon-Seng
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2003.10a
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    • pp.1-2
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    • 2003
  • While aromatic polyimides and polyamides have found widespread use as high performance polymers, the present work addressed the need for organosoluble materials through the use of a hyperbranching scheme. The $AB_2$ monomers were prepared. The $AB_2$ monomers were then polymerized via aromatic fluoride-displacement and Yamazaki reactions to afford the corresponding hydroxyl-terminated hyperbranched polyimides (HT-PAEKI) and amine-terminated hyperbranched polyamides, respectively. HT-FAEKI was then functionalized with allyl and propargyl bromides as well as epichlorohydrin to afford allyl-terminated AT-PAEKI, propargyl-terminated PT-PAEKI, and epoxy (glycidyl)-terminated ET-PAEKI, in that order. All hyperbranched poly(ether-ketone-imide)s were soluble in common organic solvents. AT-PAEKI was blended with a bisphenol-A-based bismaleimide (BFA-BMI) in various weight ratios. Thermal, rheological, and mechanical properties of these blend systems were evaluated. Two characteristic hyperbranched polyamides, which the one has para-electron donating groups to the surface amine groups and the other has para-electron withdrawing groups to the surface amine groups, were selected to compare BMI curing behaviors. The electron rich polymer displayed ordinary Michael addition type exothermic reaction, while electron deficient polymer did display unusual curing behaviors. Based on analytical data, the later system provided the strong evidences to support room temperature curing of BMI by reactive intermediates instead of reactive primary amine groups on the macromolecule surface.

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Optically Active and Organosoluble Poly(amide-imide)s Derived from N,N'-(Pyromellitoyl)bis-L-histidine and Various Diamines: Synthesis and Characterization

  • Faghihi, Khalil;Shabanian, Meisam;Hajibeygi, Mohsen
    • Macromolecular Research
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    • v.17 no.11
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    • pp.912-918
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    • 2009
  • An optically active diacid containing the L-histidine moiety was prepared by reacting pyromellitic dianhydride (1,2,4,5-benzenetetracarboxylic acid 1,2,4,5-dianhydride) 1 with L-histidine 2 in acetic acid, and was polymerized with several aromatic diamines 5a-g to obtain a new series of optically active poly(amide-imide)s (PAIs) using two different methods, such as direct polycondensation in a medium consisting of N-methyl-2-pyrrolidone (NMP)/triphenyl phosphite (TPP)/calcium chloride ($CaCl_2$)/pyridine (Py) and direct polycondensation in a tosyl chloride (TsCl)/pyridine (Py)/N,N-dimethylformamide (DMF) system as a condensation agent. The resulting new polymers 6a-g with inherent viscosity was obtained in good yield. The polymers were readily soluble in polar organic solvents, such as N,N-dimethyacetamide (DMAc), N,N-dimethyformamide (DMF), and dimethyl sulfoxide (DMSO). The obtained polymers were characterized by FTIR, specific rotation, elemental analysis as well as $^1$H-NMR spectroscopy and gel permeation chromatography (GPC). The thermal stability of the resulting PAIs was evaluated with thermogravimetric analysis techniques under a nitrogen atmosphere.

Studies on the Antimicrobial Activities of the Extractives from Magnolia (Magnolia kobus DC. var. borealis Sarg.) (목련(Magnolia kobus DC. var. borealis Sarg.) 추출성분의 항균성에 관한 연구)

  • Kim, Yun-Geun
    • Journal of the Korean Wood Science and Technology
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    • v.27 no.1
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    • pp.105-114
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    • 1999
  • Antimicrobial activities of the organosoluble extracts, seperated fractions and isolated lignans from the leaves tissue of Magnolia kobus DC. var. borealis Sarg. were investigated. The results are summarized as follows : 1. The inhibitory components against the spore growing test were concentrated on light petroleum ether and diethyl ether soluble fractions. The light petroleum ether solubles of the leaves tissue had terpenes compound, so, that they caused growing inhibition. These appearance showed high values of Rf on TLC bioautography and GC analyses with monoterpenes. 2. In the lignans, syringaresinol(X III), medioresinol(VI), phillygenin(VIII), kobusinol A(X) showed relatively high inhibitory effects in the spore growing test, and these are all showed structural characteristic of the phenolic hydroxyl group of guaiacyl and syringyl skelecton. 3. The light petroleum ether soluble fraction showed the strongest inhibitory effect against the antimicrobial activity in the seperated fractions. 4. The inhibitory effects of the lignans against the bacteria showed not so pronounced independantly, but the extracts and separated fractions contained with these lignans showed something synergism.

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The Alignment of Liquid Crystals on the Film Surfaces of Soluble Aromatic Polyimides Bearing t-Butylphenyl and Trimethylsilylphenyl Side Groups

  • Hahm, Suk-Gyu;Jin, Kyeong-Sik;Park, Sam-Dae;Ree, Moon-Hor;Kim, Hyung-Sun;Kwon, Soon-Ki;Kim, Yun-Hi
    • Macromolecular Research
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    • v.17 no.12
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    • pp.976-986
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    • 2009
  • With the study goal of firstly elucidating the anisotropic interactions between oriented polymer chain segments and liquid crystal (LC) molecules, and secondly of determining the contributions of the chemical components of the polymer segments to the film surface topography, LC alignment, pretilt, and anchoring energy, we synthesized three dianhydrides, 1,4-bis(4'-t-butylphenyl)pyromellitic dianhydride (BBPD), 1,4-bis(4'-trimethylsilylphenyl)pyromellitic dianhydride(BTPD), and 2,2'-bis(4"-tert-butylphenyl)-4,4',5,5'-biphenyltetracarboxylic dianhydride (BBBPAn), and a series of their organosoluble polyirnides, BBPD-ODA, BBPD-MDA, BBPD-FDA, BTPD-FDA, and BBBPAn-FDA, which contain the diamines 4,4'-oxydianiline (ODA), 4,4'-methylenediamine (MDA), and 4,4'-(hexafluoroisopropylidene)dianiline (FDA). All the polyimides were determined to be positive birefringent polymers, regardless of the chemical components. Although all the rubbed polyimide films exhibited microgrooves which were created by rubbing process, the film surface topography varied depending on the polyimides. In all the rubbed films, the polymer chains were unidirectionally oriented along the rubbing direction. However, the degree of in-plane birefringence in the rubbed film varied depending on the polyimides. The rubbing-aligned polymer chains in the polyimide films effectively induced the alignment of nematic LCs along their orientation directors by anisotropic interactions between the preferentially oriented polymer chain segments and the LCs. The azimuthal and polar anchoring energies of the LCs ranged from $0.45{\times}10^{-4}\;-\;1.37{\times}10^{-4}\;J/m^2$ and from $0.86{\times}10^{-5}\;-\;4.26{\times}10^{-5}\;J/m^2$, respectively, depending on the polyimides. The pretilt angles of the LCs were in the range $0.10-0.62^{\circ}$. In summary, the soluble aromatic polyimides reported here are promising LC alignment layer candidates for the production of advanced LC display devices.

Antimicrobial Activity and Antioxidative Activity in the Extractives of Quercus dentata Thunberg (떡갈나무 추출물의 항균활성 및 항산화활성)

  • Kim, Min-Young;Kim, Yun-Geun;Kim, Tae-Hong;Jo, Jong-Soo;Yang, Jae-Kyung
    • Journal of the Korean Wood Science and Technology
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    • v.28 no.3
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    • pp.42-51
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    • 2000
  • Antimicrobial activity and antioxidative activity of the organosoluble extractives from the leaves, bark and xylem of Quercus dentata were investigated. Antimicrobial activity was tested by paper disk method and bioautography methods, The most pronounced antimicrobial activities of leaves parts were ethyl acetate solubles fraction against the Klebsiella pneumoniae by the paper disk method. The strongest activities of bark parts were ethyl acetate solubles fraction against Bacillus subtilis, Klebsiella pneumoniae. Ethanol extractives from xylem parts showed high activities against Bacillus subtilis, Staphylococcus aureus, Klebsiella pneumoniae and Vibrio parahaemolyticus. These antimicrobial activities of ethanol extractives from Quercus dentata were in order to xylem > bark > leaves. The strong inhibition zones of the ethanol extractives and its fractions of xylem showed Rf values in 0.41~0.63. In leaves extractives, the petroleum ether solubles showed lower antioxidative activity and ethyl acetate insolubles showed higher antioxidative activity of 70% compared with the $EC_{50}$ values of the control. Antioxidative activity of bark and xylem extractives showed higher approximately 2 times than the control except the petroleum ether solubles.

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In vivo Metabolism of Endosulfan in Carp (Cyprinus carpio) (In vivo 시험에 의한 잉어체내 $^{14}C-endosulfan$의 대사)

  • Lee, K.B.;Shim, J.H.;Suh, Y.T.
    • Applied Biological Chemistry
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    • v.37 no.3
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    • pp.203-209
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    • 1994
  • When $^{14}C-{\alpha}-endosulfan$ was incubated with carp liver, kidney and gut preparations, it was metabolized to water soluble and organosoluble metabolites. In an in vitro test, endosulfan was converted to endosulfan ${\alpha}-hydroxyether$ (EHE), endosulfan alcohol (EA) and endosulfan ether (EE). The addition of NADPH resulted in rapid conversion of endosulfan to the metabolites in 105,000 g soluble fraction and microsomes. However, the rate of metabolism of endosulfan in liver, kidney and gut supplemented with NADPH as a cofactor was higher in the 105,000 g soluble fraction than that in the microsomes of carp under incubation conditions. The enzymes probably involved in the metabolism of endosulfan include the glutathione S-transferase (GST) and the mixed function oxidases (MFO), based on the evidence that addition of either GSH or NADPH increased the degradation of endosulfan.

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