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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of materials science 25 (1990), S. 2925-2928 
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Precipitated lignin from black liquor produced from rice straw pulping was thermally treated at different temperatures (25 to 260 ° C) for 1h. Lignin was also thermally treated at 230 ° C for various time intervals (0.5 to 2h). The infrared spectra from 200 to 4000 cm−1 were studied. It was found that the absorbance of OH as well as OCH3 bands decreased with increasing temperature and heating time. On the contrary, C=0 increased with increasing temperature and time. The OH and OCH3 vibrational bands began to disappear when the temperature rose above 230 ° C. A correlation between the absorbance of OH, OCH3 and C=O is made to give more information concerning the effect of thermal treatment on the molecular structure changes of lignin.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 127 (1984), S. 89-102 
    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: Polyacrylamid (PAM), das als homopolymeres Nebenprodukt bei der Pfropfung von Cellulose mit Acrylamid anfällt, wurde während 2 bzw. 4 h teilweise hydrolysiert. Die so hergestellten drei Polymeren wurden neben Accostrengthß 86, einem Harz zur Verbesserung der Trockenreißfestigkeit, das auch das Füllstoffrückhaltevermögen verbessert, als Hilfsmittel zur Füllstoffrückhaltung bei gebleichter Bagasse benutzt. Als Füllstoffe wurden Titandioxid, Kieselerde und Kaolin benutzt. Die erhaltenen Ergebnisse zeigten, daß Polyacrylamid, das 2 h hydrolysiert worden war, die besten Resultate sowohl für das Füllstoffrückhaltevermögen als auch für die Festigkeitseigenschaften lieferte. Die für dieses Polymere erhaltenen Werte waren vergleichbar mit solchen, die an handelsüblichen Polymeren gemessen wurden.
    Notes: The polyacrylamide (PAM) produced as a homopolymer byproduct during the grafting of cellulose by acrylamide was partially hydrolysed for 2 and 4 hours. The three prepared polymers besides Accostrength® 86, which is mainly a dry strength resin and also improves retention of fillers and fines, were used as filler retention aids for bleached bagasse. Three fillers were used, namely titanium dioxide, silica and kaolin. The results obtained showed that the PAM hydrolysed for 2 hours gave the best results for both filler retention and improvement of strength properties. The values obtained for this polymer were comparable with those obtained for the commercial polymer.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 38 (1987), S. 28-31 
    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: Baumwoll-Linters und Viskose-Zellstoff wurden nach dem Xanthatverfahren mit Acrylamid gepfropft. Die Einflüsse von Monomerkonzentration, Reaktionsdauer, Wassserstoffperoxidkonzentration, Reaktionstemperatur und Flottenverhältnis auf den Pfropfprozeß wurden untersucht. Die optimalen Bedingungen für die Durchführung der Pfropfung werden mitgeteilt.
    Notes: Cotton linters and viscose grade wood pulp were grafted with acrylamide using the xanthate method. The effects of monomer concentration, reaction time, hydrogen peroxide concentration, reaction temperature and liquor ratio on the grafting process were studied. Optimum conditions for the grafting reaction are established.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 40 (1989), S. 448-450 
    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: Die Pfropfcopolymerisation von Methylmethacrylat auf Papierzellstoff mit Cerammoniumnitrat als Initiator wurde untersucht. Die Pfropfung erfolgte in unterschiedlichen Medien, wie Wasser und Mischungen aus Wasser und organischen Lösungsmitteln. Der Einfluß der Zusammensetzung des Mediums und der Pfropftemperatur auf den Pfropfprozeß wurde ermittelt und diskutiert.
    Notes: Graft copolymerization of methyl methacrylate onto paper wood pulp using ceric ammonium nitrate as initiator is studied. Different experimental conditions have been used including both water and water/organic solvent systems. The effects of composition of the grafting medium and grafting temperature on the grafting process are examined.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 40 (1989), S. 68-71 
    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: Baumwoll-Linters wurden unter Verwendung eines KMnO4-Redoxsystems mit Methylmethacrylat gepfropft. Der Einfluß von Art und Konzentration der zur Aktivierung des KMnO4 eingesetzten Säure wurde untersucht. Weiterhin wurde die Abhängigkeit des Pfropfprozesses von verschiedenen Parametern, wie Reaktionstemperatur, Reaktionszeit und Monomerkonzentration, untersucht, um die optimalen Bedingungen für die Pfropfung zu ermitteln.
    Notes: Cotton linters were grafted with methyl methacrylate by using a KMnO4 redox system. The effect of type and concentration of acid as activator for KMnO4 and different parameters affecting on the grafting process, e. g. reaction temperature, reaction time, and monomer concentration, are investigated to ascertain the optimum conditions of the grafting process.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 41 (1990), S. 581-583 
    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: Auf Holzzellstoff wurde unter Verwendung eines Kaliumbromat-Redox-Systems Methylmethacrylat gepfropft. Die Einflüsse von Monomerkonzentration, Reaktionszeit, Initiatorkonzentration und Flottenverhältnis auf den Pfropfrad, die Menge des gebildeten Polymers und das Wasserrückhaltevermögen des gepfropften Zellstoffs wurden untersucht. Die optimalen Bedingungen für die Pfropfreaktion wurden ermittelt.
    Notes: Paper wood pulp was grafted with methyl methacrylate using the potassium bromate redox system. The effects of monomer concentration, reaction time, initiator concentration, and liquor ratio on the graft yield, polymer loading, and water retention value of the grafted samples were studied. The optimum conditions of the grafting reaction were determined.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 38 (1987), S. 93-95 
    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: Methylmethacrylat wurde nach der Cerionenmethode unter Stickstoff beziehungsweise Luft auf Baumwoll-Linters gepfropft. Der Einfluß eines Zusatzes von einigen organischen Lösungsmitteln zum Reaktionsmedium wurde unter-sucht, und die optimalen Pfropfbedingungen wurden festgestellt.
    Notes: Grafting of methyl methacrylate onto cotton linters by the ceric ion method was carried out under nitrogen and air atmospheres. The effect of addition of some organic solvents to the reaction medium was studied, and optimum grafting conditions were established.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 39 (1988), S. 719-722 
    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 Bagasse- und Holzzellstoff hergestellte Papierblätter wurden mit Lösungen von Poly(methylmethacrylat) in Aceton behandelt. Der Einfluß der Härtungstemperatur auf die physikalischen Eigenschaften wurde untersucht. Die Ergebnisse zeigen, daß durch diese Behandlung die Festigkeitswerte und die Wasserdampfdurchlässigkeit der Papierblätter verbessert werden. Der Grad der Verbesserung hängt vom Anteil des auf dem Papier verbliebenen Polymers sowie von Dauer und Temperatur der Härtung ab.
    Notes: Bagasse and wood pulp paper sheets were treated with poly(methyl methacrylate) solutions in acetone. The effect of curing temperature on the physical properties is studied. The results show that the treatment improves the strength properties and water vapour permeability of the paper sheets. This improvement depends on the percentage of retained polymer, curing temperature and time.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 40 (1990), S. 731-739 
    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: Infrared spectra of treated cotton linters and bleached cotton stalk pulp with different concentrations of ethylene diamine and zinc chloride solution are studied. The structural changes brought about by these treatments have been studied from infrared spectral diagrams. It is found that the crystallinity index calculated from the infrared spectral data of these treated pulps decreases with increasing concentration of ethylene diamine and zinc chloride. The decrease in the crystallinity index (Crl) of the treated pulp with zinc chloride is higher than in case of treatment with ethylene diamine (EDA). The detectable frequency change at the hydrogen bonded OH of cotton linters by treatment with zinc chloride and ethylene diamine reflects the contributions of this bond in the swollen pulp. The dielectric study of these treated pulps confirmed the molecular structural changes determined from IR spectroscopic study.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 33 (1987), S. 2915-2924 
    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 lignin separated from the spent liquor of soda pulping of rice straw can replace a part of phenol in the condensation reaction with formaldehyde in a basic medium to form phenol lignin-formaldehyde (PL-F) resol resin. The production of phenol lignin-formaldehyde resol resin was carried out in two stages: First was the formation of the adduct (lignin phenol) using different lignin percentages; second was the condensation of the adduct with formaldehyde. Reaction variables, i.e., molar ratio of formaldehyde to phenol lignin, polymerization time, amount of sodium hydroxide as a catalyst, and polymerization temperature in the polymerization step were studied. Solubility of the produced resol resin in different solvents, its viscosity, and yield were determined. Lignin could replace up to 40% of phenol in the produced resin. Infrared spectra of the prepared resin were determined. Structural similarity of phenol-formaldehyde to phenol lignin-formaldehyde resin was shown. Also, relative absorbance of characteristic bands of the resins were calculated and claimed too much on the effect of reaction parameters on the prepared resins.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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