淡江大學機構典藏:Item 987654321/60150
English  |  正體中文  |  简体中文  |  Items with full text/Total items : 64178/96951 (66%)
Visitors : 10046250      Online Users : 21496
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library & TKU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
    •  Adv. Search
    Home ‧ Login ‧ Upload ‧ Help ‧ About ‧ Administer Goto mobile version


    Please use this identifier to cite or link to this item: https://tkuir.lib.tku.edu.tw/dspace/handle/987654321/60150


    Title: Free rradical degradation of chitosan with potassium persulfate
    Authors: 董崇民;Don, Trong-ming;Hsu, Shih-chang;Chiu, Wen-yen
    Contributors: 淡江大學化學工程與材料工程學系
    Keywords: Chitosan;Potassium persulfate;Free radical;Degradation
    Date: 2002-01
    Issue Date: 2011-10-13 13:05:53 (UTC+8)
    Abstract: A thermal dissociation initiator, potassium persulfate (KPS), is added to the chitosan solution at 70 °C; immediately, the solution viscosity and the molecular weight of chitosan decrease in a very short time. Size exclusion chromatography, nuclear magnetic resonance and electron spin resonance were used to study the degradation mechanism. A free radical degradation mechanism of chitosan by KPS is then proposed. When KPS is thermally dissociated into anionic radicals, they are attracted to the cationic amino group in the chitosan ring. Subsequently, the anionic radical attacks the C-4 carbon and transfers the radical to the C-4 carbon by subtracting the hydrogen from it. The presence of free radical at C-4 carbon eventually results in the breakage of the glycosidic C–O–C bond in the chitosan main chain. According to this mechanism, the concentrations of KPS, total free radicals and the degraded chitosan chain at different degradation times are all calculated by solving the rate equations. Finally, the calculated average molecular weights of the degraded chitosan chains at different reaction times agree with the experimental values.
    Relation: Polymer degradation and stability 75(1), pp.73-83
    DOI: 10.1016/S0141-3910(01)00205-1
    Appears in Collections:[Graduate Institute & Department of Chemical and Materials Engineering] Journal Article

    Files in This Item:

    File SizeFormat
    index.html0KbHTML169View/Open

    All items in 機構典藏 are protected by copyright, with all rights reserved.

    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library & TKU Library IR teams. Copyright ©   - Feedback