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Dispersion Stability of Pigments in Aqueous Solution of Anionic Oligo-Type Surfactants(Parts 2) - Dispersion of Red Iron Oxide or Titanium Dioxide - (올리고머형 음이온성 계면활성제 수용액에서 안료의 분산안정성(제2보) - 산화철이나 산화티티늄의 분산 -)

  • Lee, Hyang Woo;Lee, Jin Hee;Park, Heung Joe;Nam, Ki Dae
    • Applied Chemistry for Engineering
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    • v.10 no.1
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    • pp.1-5
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    • 1999
  • The dispersing performance of oligomer-type anionic surfactants (CmDNa), cooligomers of diethylester maleate and alkylvinylether of different alkyl chain lengths or polymerization degree were studied on the aqueous suspension of iron dxide or titanium dioxide particles which are hydrophilic pigments. The dispersion behavior of oligomer-type surfactants for these dispersoids, although anion charges on the surface of pigments particles showed different dispersing properties, was dependent upon the side alkyl chain length. Oligomer-type surfactants having more than C8 side alkyl chain exhibited large dispersing action for relatively hydrophobic αFe2O3 and Anatase TiO2 in the concentration range of more than 0.1% oligomer-type surfactant solutions.

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The Variation of Surface Area in Porous Poly(Styrene-co-Divinylbenzene) Resin Beads (다공성 스티렌-디비닐벤젠 공중합 수지입자의 표면적 변화)

  • Kim, Yong-Man;Ihm, Son-Ki;Kim, Jong-Chan;Lee, Dong-Keun;Ahn, Jou-Hyeon
    • Applied Chemistry for Engineering
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    • v.7 no.5
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    • pp.843-848
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    • 1996
  • Porous resin beads of Poly(styrene-co-divinylbenzene) have been prepared by suspension polymerization. The bead could be made porous in the region above 30wt% of the crosslinking agent(divinylbenzene ) and the porogenic agent(toluene), respectively. The specific surface area of porous beads increased with increasing the concentrations of divinylbenzene and toluene. The specific surface area of the porous resin bead decreased, when sulfonated with concentrated sulfuric acid. The catalytic activity of sulfonated resin catalyses increased with increasing the degree of crosslinking in the liquid-phase reesterification of ethyl acetate with 1-propanol. The adsorbed quantity of sodium dodecylbenzene sulfonate in an aqueous solution also increased with increasing surface area of porous resins.

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Preparation and Characterization of Rice Starch Maltodextrin (쌀전분 Maltodextrin의 제조와 특성 연구)

  • Kim, Jong-Wook;Shin, Hae-Hun;Kim, Jung-Min;Kim, Young-Sook;Pyun, Yu-Ryang
    • Korean Journal of Food Science and Technology
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    • v.26 no.6
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    • pp.819-823
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    • 1994
  • For the development of rice-derived fat replacing ingredient, low dextrose equivalent (D.E.) malto dextrin was prepared by enzyme hydrolysis, and its physical and rheological properties were studied. The molecular sizes of rice maltodextrin were measured by gel permeation chromatography on Sephadex G-50. Gel permeation column chromatograms showed a large single peak, suggesting a limited hydrolysis, and the average degree of polymerization decreased from 72.8 for 3 D.E. maltodextrin to 48.7 for 6 D.E. maltodextrin. Cold water solubility of maltodextrin was increased with increasing D.E. value and its values ranged from 47.3% to 71.3%. 8% solution of rice maltodextrin showed pseudoplastic behavior. Flow behavior index was decreased as D.E. value was increased.

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Multi-functional Finish of Polypropylene Nonwoven by Photo-induced Graft Polymerization (II) - Grafting of Styrene and Its Ammonia Adsorption Behavior - (광그라프팅에 의한 폴리프로필렌 부직포의 복합기능화 가공(II) -스티렌의 그라프트 반응 및 암모니아 흡착거동 -)

  • 김상률;최창남
    • Polymer(Korea)
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    • v.25 no.5
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    • pp.642-648
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    • 2001
  • An attempt was made to synthesize an ammonia adsorbent by the photo-induced grafting of styrene (St) onto polypropylene (PP) nonwoven using benzoin ethyl ether (BEE) as a photosensitizer with urea and trimethylol propane triacrylate in methanol medium. As styrene concentration was increased, the graft yield was increased. It was also found that the graft yield increased with reaction time. The polypropylene grafted with styrene (PP-g-St) was sulfonated by chlorosulfonic acid in dichloroethane and complexed with several metal ion, such as cO+2, nI+2, cU+2, Zn+2. The amount of ammonia gas adsorbed by these sample was dependent on the degree of sulfonation, adsorption time, and ammonia gas pressure. The adsorption capacity of ammonia gas by the sulfonated PP-g-St(SPP-g-St) nonwoven with 4. 25 mmol H+/g was 6.61 mmol/g. Metal ion complexed SPP-g-St nonwovens had higher adsorption capacity than SPP-g-St nonwoven and the Co+2 complexed SPP-g-St showed 9.90 mmol NH3/g, which was much higher than that of active carbon or silica gel.

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Synthesis and Characterization of Electro-Active Poly(2-acrylamido-2-methylpropanesulfonic acid) Polymer Gel Actuator (전기활성 Poly(2-acrylamido-2-methylpropanesulfonic acid) 고분자 겔 구동기의 합성 및 특성분석)

  • 송영진;심우선;김홍경;김학길;최혁렬;김훈모;전재욱;이영관;남재도
    • Polymer(Korea)
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    • v.25 no.5
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    • pp.736-743
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    • 2001
  • An electro- active polymer (EAP) (poly(2-acrylamido-2- methyl propane sulfonic acid), PAMPS) gel crosslinked with N,N-methylenebisacrylamide (MBAA) has been prepared by free radical polymerization in aqueous solution with potassium persulfate as initiator PAMPS gel was swollen in surfactant solution to substitute surfactant for using as actuator. PAMPS gel showed a large movement in the surfactant solution by electric field. PAMPS gel showed the reversible binding and fast response rate. Bending mechanism of gel is related to the cooperative process of hydrophobic interaction, swelling-deswelling of gel and the electrostatic attraction between anode (+) and the anions of PAMPS gel. The response rate of PAMPS gel was increased as the applied potential and the degree of cross-linkage were increased. The response rate was increased as the bending cycle was repeated, but it was decreased with increasing the gel thickness.

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DETECTION OF PHYSIOLOGICAL PROCESSES IN WHEAT BY NIR

  • Salgo, A.;Gergely, Sz.;Scholz, E.
    • Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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    • 2001.06a
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    • pp.1158-1158
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    • 2001
  • Fast and dynamic biochemical, enzymatic and morphological changes occur during the so-called generative development and during the vegetative processes in seeds. The most characteristic biochemical and compositional changes of this period are the formation and decline of storage components or their precursors, the change of their degree in polymerization and an extensive change in water content. The aim of the present study was to detect the maturation processes in seed nondestructively and to verify the applicability of near infrared spectroscopic methods in the measurement of physiological, chemical and biochemical changes in wheat seed. The amount and variation of different water “species” has been changed intensively during maturation. Characteristic changes of three water absorption bands (1920, 1420 and 1150 nm) during maturation were analysed. It was concluded that the free/bound transition of water molecules could be followed sensitively in different region of NIR spectra. Kinetic changes of carbohydrate reserves were characteristic during maturation. An intensive formation and decline of carbohydrate reserves were observed during early stage of maturation (0 -13 days, high energy demand). An accelerated formation of storage carbohydrates (starch) was detected in the second phase of maturation. Five characteristic absorption bands were analysed which were sensitive indicators the changes of carbohydrates occurred during maturation. Precursors of protein synthesis and the synthesis of reserve proteins and their kinetic changes during maturation were followed from NIR spectra qualitative and qualitatively. Dynamic formation of amino acids and the changes of N forms were detected by spectroscopic, chromatographic and by capillary electrophoresis methods. Calibration equations were developed and validated in order to measure the optimal maturation time protein and moisture content of developing wheat seeds. The spectroscopic methods are offering chance and measurement potential in order to detect fine details of physiological processes. The spectra have many hidden details, which can help to understand the biochemical background of processes.

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Purification and Properties of Wheat Fructan Exohydrolase (밀 Frucdtan Exohydrolase의 분리 및 특성)

  • Byeong Ryong, Jeong;Thomas L, Housley
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.41 no.4
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    • pp.456-464
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    • 1996
  • Fructans are the major vegetative storage carbohydrate in wheat(Triticum aestivum L.). The depolymerization of fructans occurs by the sequential removal of terminal fructosyl residues by a specific fructan exohydrolase(FEH). The objective of this study was to isolate and characterize this enzyme in wheat. From stems and sheaths of field-grown wheat(cv. Clark), FEH was purified 356-fold using salt precipitation and a series of chromatographic procedures including size exclusion, anion exchange, and affinity chromatography. FEH had a molecular weight of 63.7 kD and an optima at pH 5.5 and 30C. The Kms for β(2 longrightarrow1) linked oligofructans varied, from 10 to 37mM, with the lowest Km for tetrasaccharide. The Vmax increased as degree of polymerization (DP) increased. Wheat FEH hydrolyzed only, β(2 longrightarrow1) linked fructans but not, β(2 longrightarrow6) linked timothy fructan or sucrose. The role of this FEH in fructan metabolism in wheat is discussed.sed.

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Secretory Production of Rahnella aquatilis ATCC 33071 Levansucrase Expressed in Escherichia coli

  • KANG , SOON-AH;LEE, JAE-CHEOL;PARK, YOUNG-MIN;LEE, CHAN;KIM, SEUNG-HWAN;CHANG, BYUNG-IL;KIM, CHUL-HO;SEO, JEONG-WOO;RHEE, SANG-KI;JUNG, SUNG-JE;KIM, SANG-MOO;PARK, SEONG-KYU;JANG, KI-HYO
    • Journal of Microbiology and Biotechnology
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    • v.14 no.6
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    • pp.1232-1238
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    • 2004
  • To investigate the production and characteristics of thermostable levan sucrase from Rahnella aquatilis ATCC 33071, the levan sucrase gene from R. aquatilis was cloned and expressed in Escherichia coli without induction system. Expression of levansucrase gene in E. coli had no notable or detrimental effect on the growth of host strain, and the recombinant levan sucrase exhibited levan synthesis activity. Levansucrase was secreted to the periplasm in E. coli, and addition of 0.5% glycine yielded further secretion of levansucrase to the growth medium and resulted in an increase of total levansucrase activity. Furthermore, the cellular levansucrase was evaluated for the production of levan by using toluene­permeabilized whole-cells. The levansucrase was thermostable at 37C. The molecular size oflevan was 1×106 Da, as determined by HPLC, and the degree of polymerization of levan varied with incubation temperatures: Low incubation temperature was preferable for the production of high-molecular size levan. The present study demonstrated that the mass production of levan and levan oligosaccharides can be achieved by glycine supplementation to the growth medium or by toluene­permeabilized whole-cells.

Effect of Amylose Content on Corn Starch Modification by Thermus aquaticus 4-α-Glucanotransferase

  • Cho, Kyoung-Hee;Auh, Joong-Hyuck;Kim, Jung-Hwan;Ryu, Je-Hoon;Park, Kwan-Hwa;Park, Cheon-Seok;Yoo, Sang-Ho
    • Journal of Microbiology and Biotechnology
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    • v.19 no.10
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    • pp.1201-1205
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    • 2009
  • Corn starches with different amylose contents were enzymatically modified using Thermus aquaticus 4-α-glucanotransferase (TAαGTase). Upon the enzyme treatment, the chain-length distributions of isoamylolytically debranched products became broader [degree of polymerization (DP): 3-40] than those of untreated corn starches. In addition, a variety of cycloamyloses (CAs) with different sizes were formed by the glucanotransfer activity of TAαGTase. CAs with DP 5-40 were detectable in all of the TAαGTase-treated corn starches. From the results of high-performance anion-exchange chromatography and high-performance size-exclusion chromatography analyses, it was suggested that the amount of CAs produced by the enzyme treatment increased as the amylose content of the starches increased. Thus, we concluded that the extent of modification of starch molecules was enhanced in proportion to amylose content by the transfer activity of TAαGTase. This finding could be useful for developing an efficient process of CA production using this enzyme.

Effect of Deodorizing Temperature on Physicochemical Characteristics in Corn Oil IV. Effect of Deodorizing Temperature on Volatile Flavor Component Composition in Corn Oil (탈취온도가 옥수수기름의 이화학적 특성에 미치는 영향 제4보, 탈취온도가 옥수수기름의 휘발성 냄새성분 변화에 미치는 영향)

  • 이근보;한명규;이미숙
    • The Korean Journal of Food And Nutrition
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    • v.11 no.3
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    • pp.272-277
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    • 1998
  • We carried out separation and guantitation of flavor components by GC about essential oils extracted from deodorized corn oil at the different deodorizing temperature. Flavor components were detected total 16 kinds included aldehydes of 8 kinds, major components were propane, pentane, hexanal etc. These major components content was about 70~75% of the total flavor components. According to rise of deodorizing temperature, both ethane and aldehydes of 8 kinds content were in proportion to increase, but propane, pentane, hexane, octan, pentyl furan content were decreased by contraries, respectively. On the other hand, total flavor component content was appeared the lowest level at 245C treating group, aldehydes content was in proportion to increase according to rise of deodorizing temperature. These phenomenons consider that the undesirable reactions such as partial auto-oxidation, degradation, polymerization and hydrolysis etc. by effecting factors of stripping steam and vacuum degree. Conclusively, deodorizing temperature under high temperature was undesirable for the minimization of off-flavor materials.

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