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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Cellulose 2 (1995), S. 41-49 
    ISSN: 1572-882X
    Keywords: Cellulose ; Oxidized cellulose ; Thermal analysis ; Stability ; Degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Three series of oxidized celluloses – 2,3-dialdehyde celluloses (DACs), 2,3-dicarboxycelluloses (DCCs) and sodium 2,3-dicarboxycelluloses (NaDCCs) — were prepared, having incremental changes in their degrees of oxidation. Their thermogravimetric analysis (TG) and differential thermal analysis (DTA) were studied. It was found that oxidation generally destabilized cellulose at lower temperatures (below ∼ 250 °C), but at higher temperatures the oxidized products were found to be more stable. Cellulose, DACs, and DCCs all showed final weight losses in the region of 80–85%. However, 80% NaDCC and 98% NaDCC showed weight losses of only 30 and 37%, respectively.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Cellulose 1 (1994), S. 215-219 
    ISSN: 1572-882X
    Keywords: cellulose fillers ; epoxy resins ; lignocellulosic materials
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Cellulosic fillers have been chemically modified by attaching pendant primary amine groups (diamino propane). The modified cellulose fillers were used for curing an epoxy resin (diglycidyl ether of bisphenol A). Gel times thus obtained are much less than systems containing unmodified cellulose. The advantages from the use of such modified organic fillers are discussed. Our investigations could encourage greater utilization of renewable lignocellulosic materials as reactionincorporated fillers for polymer composites.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 132 (1985), S. 203-209 
    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: Mit Ton, Wollastonit, Silica, Talk und Calciumcarbonat gefüllte Elastomere aus Rizinusöl und polymerem 4,4′-Diphenylmethandiisocyanat (PMDI; Funktionalität 2.7) wurden hergestellt und ihre Eigenschaften mit denen der ungefüllten Polymeren verglichen. Es wurde gefunden, daß Ton und Wollastonit ohne abträgliche Effekte auf die mechanischen Eigenschaften als Füllmaterialien zur Kostenreduzierung benutzt werden können. Rasterelektronenmikroskopische Aufnahmen von frisch geschnittenen Oberflächen der silikatgefüllten Elastomeren zeigten, daß Ton und Wollastonit weitaus besser mit dem Elastomeren verträglich sind als Silica, Talk und Calciumcarbonat. Auch Resultate von Gelzeitmessungen bei der Reaktion zwischen Rizinusöl und PMDI wurden als Hilfe beim Festlegen von Verarbeitungsparametern bei der Herstellung der gefüllten und ungefüllten Elastomeren angegeben.
    Notes: Elastomers of castor oil and polymeric 4,4′-diphenylmethane diisocyanate (PMDI; functionality 2.7) filled with clay, wollastonite, silica, talc, and calcium carbonate were prepared and their properties compared with the unfilled elastomer. It was found that clay and wollastonite fillers can be used for cost reduction without any detrimental effects on the mechanical properties. Scanning electron micrograph studies of freshly cut surfaces of the silicate filled elastomers showed that clay and wollastonite are much more compatible with the elastomer than silica, talc, and calcium carbonate. Results of gel time measurements in the castor oil  -  PMDI reaction are also presented as a help for the selection of processing parameters in the manufacture of the filled and unfilled elastomer.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 15 (1977), S. 1189-1197 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Insoluble polysalt complexes are formed on mixing aqueous solutions of poly(vinylbenzo-18-crown-6) (P18C6) and sodium carboxymethylcellulose (CMC) in the presence of certain salts. Potassium salts are especially effective, converting the neutral P18C6 into a polycation which then interacts with sodium CMC. Nearly quantitative precipitation can be achieved at low KCl concentration (ca. 0.005M) for a crown/carboxylate ratio of approximately 5, while for 0.1-0.2M KCl the precipitation is close to completion at a crown/CMC ratio of about 2. The precipitates solubilize again on addition of water or concentrated KCl. Precipitation also occurs with CsCl but not with NaCl. Potentiometric measurements were carried out to determine the complex formation constant of the three alkali ions to P18C6. Their values can be used to rationalize the observed phenomena. Charge equivalence appears to play an important role in the formation of the polysalt complexes.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 17 (1979), S. 1573-1581 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Macrocyclic polyether or crown ether ester derivatives of acrylic and methacrylic acid were synthesized and polymerized. The cation binding properties of the polymers determined by extraction of picrate salts were similar to those obtained for poly(crown ether)s derived from styrene. In the presence of a crown-complexable cation both polymers form insoluble polysalt complexes with sodium carboxymethylcellulose, potassium poly(styrene sulfonate), and potassium polyacrylate. The extent of precipitation depends on the type and concentration of cation as well as on the ratio polyanion to poly(crown ether). The precipitate appears to have an equal number of positive and negative charges. An insoluble hydrogen-bonded complex is formed in the absence of salt when poly(vinylbenzo-18-crown-6) and poly(acrylic acid) are mixed in 0.01M HCl. Organic solutes bound to the poly(crown ether)s, which occur in an aqueous mixture of poly(vinylbenzo-18-crown-6) and picrate anions, are precipitated with the poly(crown ether) when the polysalt complex is formed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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