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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 52 (1994), S. 61-67 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The article is concerned with a simple method for preparing cationic resins from polycondensation of Egyptian bagasse pith (as a source of cheap and renewable material) with phenol and paraformaldehyde as a cross-linking agent. Optimum principal reaction conditions of the preparation and properties are determined and compared with resin without bagasse pith content. The Synthesized resins are stable in water, organic solvents, thermal treatment, and mineral acids (1M). The sample having a cation exchange capacity up to 3.92 meq g-1 of dry resins are being introduced as new cationic exchangers. The synthesized resins are used in the study of the possible separation of univalent cations. The rational thermodynamic equilibrium constants (In K) are calculated for Li+ -Na+ exchanges on the resins having a various amount of bagasse pith. The thermodynamic parameters are computed and suitable explanations are described. © 1994 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 218 (1994), S. 1-10 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Eine Reihe sulfonierter kationischer m-Kresol-Paraformaldehyd-Harze wurden aus dem Mark ägyptischer Bagasse hergestellt. Reaktionsbedingungen werden angegeben, und die Eigenschaften der hergestellten Bagassemark/m-Kresol/Formaldehyd-Harze werden mit denen von Harzen ohne Bagassemark verglichen. Die synthetisierten Polymere sind stabil in Wasser, verdünnten Mineralsäuren (1 M) und organischen Lösungsmitteln sowie gegenüber thermischer Behandlung. Die Harze besitzen Kationenaustauscherkapazitäten von bis zu 2,91 meq/g (bezogen auf trockenes Harz) und werden als Austauschermaterialien für eine mögliche Trennung zweiwertiger Kationen getestet.
    Notes: A series of sulfonated cationic resins have been prepared and characterized from Egyptian bagasse pith wastes (as a source of cheaper and renewable material) with m-cresol and paraformaldehyde as a crosslinking agent. Reaction conditions for the preparation are presented and properties of the synthesized sulfonated bagasse pith-m-cresol-formaldehyde resins are described and compared with resin not containing bagasse pith. The synthesized resins are stable in water, dilute mineral acids (1 M), organic solvents, and to thermal treatment. The resins having a cation exchange capacity up to 2.91 meq g-1 of dry resin, are being introduced as new exchangers. The synthesized resins are used in the study of the possible separation of some bivalent cations.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Phenolharze, die durch Polykondensation von Phenol mit Furfural, Xylose, Glucose, Holocellulose, reinem Sodalignin und Bagassemark in saurem Medium hergestellt worden waren, wurden infrarotspektroskopisch untersucht. Im Infrarotspektrum des Sodalignin-Phenolharzes wird die Anwesenheit von aliphatischen Methyl-, Methylen-, Methin- und stark gebundenen OH-Gruppen nachgewisen. Deutliche Änderungen der Lage und Intensität der Banden werden in den Infrarotspektren von reinem Sodalignin bzw. Bagassemark und den entsprechenden Phenolharzen gefunden, was darauf hinweist, daß bei den Kondensationsreaktionen Abbauprozesse stattfinden. Die Infrarotspektren von Fraktionen des Bagassemark-Phenolharzes geben einen Einblick in die komplizierte Struktur dieser Verbindung. NMR- und UV- spektroskopische Untersuchungen bestätigen die IR-Ergebnisse.
    Notes: Infrared spectroscopic studies on some phenolic resins prepared by condensation of phenol with furfural, xylose, glucose, holocellulose, resistant cellulose, pure soda lignin, and bagasse pith, were carried out. The IR spectrum of soda ligninphenol resin proves the presence of aliphatic methyl, methylene, methine and strong bonded OH groups. Drastic changes in band position and intensity are observed in the IR spectra of pure soda lignin or bagasse pith and the respective phenolic resins, indicating that degradation processes could take place during the condensation reactions. The IR spectra of fractions of the bagasse pith-phenol resin give an insight in the complicated structure of this resin. NMR and UV spectroscopic studies confirm the IR data.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Um die chemische Konstitution von Polykondensationsharzen aus Bagassemark und Phenol zu untersuchen, wurden verschiedene Kondensationsprodukte auf Basis von Phenol und Verbindungen, die bei der Säurehydrolyse von Bagassemark entstehen oder Bestandteile des Bagassemarks sind, hergestellt. Die optimalen Bedingungen für die Trennung dieser Polykondensationsharze durch Dünnschichtchromatographie wurden ermittelt. Die angenommene chemische Struktur und das chemische Reaktionsschema werden an Hand der Ergebnisse der Elementaranalyse, der Dünnschichtchromatographie und der UV-Spektren diskutiert.
    Notes: In order to investigate the chemical constitution of bagasse pith-phenol polycondensate resin, different resins were prepared by condensation of phenol with compounds that may be produced during the acid hydrolysis of bagasse pith and with different constituents of bagasse pith. The optimum conditions for thin layer chromatographic separation of these polycondensate resins were determined. The proposed chemical structure and the pattern of chemical reactions were discussed on the bases of elemental analysis, TLC and UV spectroscopic studies.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Aus mit Aluminiumpulver gefüllten Polykondensaten von ägyptischem Maiskolbenpulver und Bisphenol wurden verschiedene Formkörper hergestellt. Die Harze wurden mit Phenolformaldehyd, Naphthalenformaldehyd und Anthrazenformaldehyd modifiziert. Die Gleichstromleitfähigkeit der Proben steigt mit zunehmender Temperatur und höherem Aluminiumgehalt an. Alle Proben weisen Halbleitereigenschaften auf.
    Notes: Different types of moulded shapes were prepared from Egyptian corncobs-bisphenol polycondensate resins and aluminium powder. Modifications of the produced resin with phenol-formaldehyde, naphthalene-formaldehyde, and anthracene-formaldehyde, were performed. The electrical conductivity of the samples increases with the increase of temperature and aluminium concent. All samples reveal semiconducting behaviour.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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