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  • 1
    Electronic Resource
    Electronic Resource
    Thermoplasticization of cellulose acetates by grafting of cyclic esters (1999)
    Springer
    Cellulose 6 (1999), S. 193-212 
    Details
    ISSN: 1572-882X
    Keywords: cellulose acetate ; plasticization ; graft copolymerization ; ring‐opening polymerization ; biodegradable plastics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract A plasticization method for cellulose acetates (CAs) based on the selective grafting of ε‐caprolactone (CL) and L-lactide (LACD) has been developed. The selective‐grafted products could be prepared by ring opening polymerization in the melt state at 140°C using stannous octoate as catalyst, where CAs with remaining hydroxyl groups worked as initiator. Plasticization of CAs by this selective grafting can solve the problem encountered in the previous reports (Yoshioka et al., 1996, 1998) that the bleeding of unreacted monomers and homo‐oligomers from the inside of molded articles to their surface was often found. By using adequate reaction conditions, the grafting reaction proceeded rapidly and could be completed within 10–30 min. LACD is grafted more rapidly than CL onto CAs, producing relatively rigid and brittle products in the earlier stages and elastomer‐like ones in the later stages. Transparent amorphous molded articles were obtainable depending on the reaction conditions. The analysis of the structure of the grafted side chains by means of high resolution NMR spectroscopy showed that, although the grafted side chains are composed of large amounts of ε‐oxycaproyl or lactidyl block polymer portions depending on the reaction conditions, a large amount of randomly polymerized parts coexist in the grafted chains, which confer high thermoplasticity, elasticity and amorphous nature to the grafted products obtained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009221730934
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  • 2
    Electronic Resource
    Electronic Resource
    Composites of wood andtrans-1,4-isoprene rubber 1: Mechanical, physical, and flow behavior (1999)
    Springer
    Journal of wood science 45 (1999), S. 38-45 
    Details
    ISSN: 1611-4663
    Keywords: Trans-1,4-isoprene rubber (TIR) ; Maleic anhydride-modified TIR ; Wood flour ; Compatibilizer Composite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The modification oftrans-1,4-isoprene rubber (TIR) with maleic anhydride (MAH) was conducted in a kneader at 150°C, 30–70 rpm, for 10 min without using peroxide. The resultant MAH-modified TIR (MTIR) was then evaluated as a compatibilizer for TIR-wood flour (WF) composites. A control composite composed of TIR and WF only was also prepared. The presence of WF in the TIR-WF composite worsened the tensile and some physical properties. The addition of 5% MTIR as a compatibilizer to the whole composite improved the mechanical and the physical properties and increased the flow temperature and the melt viscosity. The improved composite had a 2.5 times increase in tensile strength and absorbed considerably less water than did the control composite. The SEM micrograph proved that interaction and adhesion between TIR and WF could be improved by the MTIR compatibilizer. The composites of TIR-MTIR-WF melts were of pseudoplastic nature, and their flows obeyed the Ostwald de Waele power law equation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00579522
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  • 3
    Electronic Resource
    Electronic Resource
    Plasticization of cellulose derivatives by reactive plasticizers II: characterization of plasticized cellulose acetates and their biodegradability (2000)
    Springer
    Journal of wood science 46 (2000), S. 22-31 
    Details
    ISSN: 1611-4663
    Keywords: Plasticization ; Cellulose acetate ; Dibasic acid anhydride ; Monoepoxide ; Biodegradability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract A plasticization method for cellulose acetates (CAs) has been developed that is based on the reaction with dibasic acid anhydrides and monoepoxides during the melting processing. As a continuation of the discussion in the previous report, additional evidence is presented for the role of grafting oligoesters onto cellulose acetates to prevent the bleeding of homo-oligoesters from the inside of molded articles to their surface. Based on these results, a method for enhancing the amount of grafting has been pursued by varying the combination of dibasic acid anhydrides and monoepoxides. The resulting reactive meltprocessing method allows preparation of biodegradable cellulosic plastics using practical process conditions. Higher biodegradability has been found for the oligoester-grafted CAs than for the unmodified parent CAs.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00779549
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  • 4
    Electronic Resource
    Electronic Resource
    Preparation of higher aliphatic acid esters of wood in an N2O4-DMF cellulose solvent mediumPresented in part at the 25th Annual Meeting of the Japan Wood Research Society, 5 April 1975, Fukuoka, Japan. (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 24 (1979), S. 2347-2359 
    Details
    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: Esterification of wood meal with a series of aliphatic acid anhydrides and acid chlorides in a nonaqueous cellulose solvent, an N2O4-DMF solvent, has been studied. The N2O4-DMF-pyridine solution used as the reaction medium plays a role in destroying the molecular order of the cellulose within the wood, enabling the cellulose to be uniformly substituted by acyl groups along its chain. These uniformly distributed blocking groups result in the permanent decrystallization of the wood. The acyl blocking groups are best achieved by esterification using acid chlorides in the nonaqueous solvent. Acid chlorides, from caproyl to stearoyl chloride, were found to be much more effective as acylating agents than acid anhydrides, from propionic to caproic anhydride. Although no difference in reactivity can be recognized among the acid chlorides, the reactivity decreases with increase in the number of carbon atoms in the acyl group among the acid anhydrides.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1979.070241203
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  • 5
    Electronic Resource
    Electronic Resource
    Thermal softening and melting of esterified wood prepared in an N2O4-DMF cellulose solvent mediumPresented in part at the 25th Annual National Meeting of the Japan Wood Research Society, 5 April 1975, Fukuoka, Japan. (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 24 (1979), S. 2361-2368 
    Details
    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 thermal softening and melting of a series of esterified wood samples, whose preparation has previously been described,4 have been studied by measuring the deformation of the samples under constant load at a constant heating rate. The introduction of acyl groups into wood including part of the original crystal structure in cellulose makes the modified wood meal conspicuously thermoplastic. While untreated dry wood shows a thermal softening point (Ts) of ca. 260°C, esterified wood meal samples with acyl groups larger than caproyl have a Ts of around 100°C or less, and appeared to melt over the temperature range of 220° to 250°C. In this case, the melting occurs even with wood meal samples esterified with appropriate acid chlorides in an N2O4-DMF-pyridine medium only for 30 min at room temperature. This might be the first finding that wood meal is converted, as a whole, into a thermoplastic material which can melt without any accompanying detectable degradation.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1979.070241204
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  • 6
    Electronic Resource
    Electronic Resource
    Dielectric properties of cellulose acylates (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 29 (1984), S. 3981-3990 
    Details
    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: Thirteen kinds of cellulose acylates from the acetate to stearate were prepared by trifluoro acetic anhydride-fatty acid esterification, and their dielectric constant and loss were measured over wide temperature and frequency ranges. Two types of relaxation process (αd and βd) were recognized for all the acylates and an additional relaxation process (γd) was detected for the acylates with side chain length longer than that of the butyrate. These αd to γd processes were attributed to the micro-Brownian motion of the main chain (αd), the motion of oxycarbonyl group of the side chain (βd) and the motion initiated by minimum three methylene groups in addition to the oxycarbonyl group (γd), respectively. In the transition map for the βd process, inflection points were observed, and the temperature at the inflection point could be regarded as a freezing point of the micro-Brownian motion of the acyl side chain. In the temperature region above the inflection point, plots in transition map for all the acylates were found to be on the same straight line.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1984.070291230
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  • 7
    Electronic Resource
    Electronic Resource
    Dynamic viscoelastic properties in the molten state for cellulose acylates and (cellulose oligo-oxymethylene ether) acylates (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 34 (1987), S. 1217-1234 
    Details
    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 dynamic viscoelastic properties of cellulose acylates, its mixed acylates, and (cellulose oligo-oxymethylene ether) acylates (COM acylates) have been meausured in the molten state over wide ranges of frequency and temperature. The log G′ vs. log ω curves as well as the similar curves for the loss modulus G′ at various temperatures for cellulose acylates could not be superposed into respective master curves by use of the time-temperature superposition principle. This is considered to be caused from the orientation of cellulose acylates main chain in the molten state. In the case of cellulose mixed acylates, rheological simplicity was found but this was only the case on selected combinations of acyl groups. Most cellulose acylates, which were introduced oxymethylene chains (OM chains) in between glucopyranose ring and the acyl group, behaved as thermorheologically simple materials in the molten state. When the acyl groups become large, however, it is necessary to introduce long OM chains in order to get thermorheologically simple COM acylates in their molten state. Several studies have been made concerning the behavior of side chains, both the OM and the acyl chains, of COM acylates in the molten state.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1987.070340329
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  • 8
    Electronic Resource
    Electronic Resource
    Studies on composites from wood and polypropylenes. II (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 37 (1989), S. 645-659 
    Details
    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: Composites of polypropylene (PP) or maleic-anhydride-modified polypropylene (MPP) with refiner ground pulp (RGP) were prepared under various kneading conditions (mixing temperature, rate of rotation, and mixing time) and evaluated for their tensile strength (σmax), break elongation (∊max), and Young's modulus (E). Particularly, for the rate of rotation, fiber length distribution and its fibrillation were investigated in connection with mechanical properties of the composites. Also evaluated in this study was the effect of modifiers of PP on the properties. Modified PP that can be grafted or can have affinity to RGP was proved to improve the tensile strength of the molded composites as the RGP content increases, while the strength was decreased for PP-RGP composite without a modifier. MPP was also evaluated as a compatibilizer for the PP-RGP composites, and a tremendous improvement of tensile strength was achieved with MPP addition of only 2.5%, indicating that MPP can act as a compatibilizer in its system. These lines of evidence is interpreted to be caused from the improvement of the adhesion between RGP and PP through localizing MPP at the interface of these two components.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1989.070370305
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  • 9
    Electronic Resource
    Electronic Resource
    Liquefaction of wood in the presence of phenol using phosphoric acid as a catalyst and the flow properties of the liquefied wood (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 52 (1994), S. 1629-1636 
    Details
    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 liquefaction of wood in the presence of phenol using phosphoric acid as a catalyst and the flow properties of the obtained liquefied wood were investigated. It was found that phosphoric acid is a satisfactory catalyst for liquefying wood. The amount of phenol that reacts with the liquefied wood components (i.e., combined phenol) increases with an increase in liquefaction temperature, liquefaction time, catalyst content, or liquid ratio. By removing the free phenol, the resulting liquefied woods become novolaclike resins. The measurements of the flow properties of these liquefied woods reveal that the melts of liquefied woods behave as pseudoplastics and their flows obey the Ostwald de Waele power law equation. The amount of combined phenol within the liquefied wood and the presence of filler in the liquefied wood have great influence on their flow properties. The flowing temperature, activation energy, and zero shear viscosity of the liquefied woods show tendencies to increase with an increase in combined phenol. © 1994 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1994.070521111
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  • 10
    Electronic Resource
    Electronic Resource
    Physical properties of moldings from liquefied wood resins (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 55 (1995), S. 1563-1571 
    Details
    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 liquefied wood resins obtained by liquefying wood in the presence of phenol using phosphoric acid as a catalyst were applied to prepare the moldings by using hexamine as a hardener. The effects of the molding conditions and the moldings' compositions on flexural properties and water-sorption kinetics of the moldings were investigated. It was found that the liquefied wood resins had satisfactory and almost uniform curing reactivity, although they were composed of different kinds of wood components. The flexural properties of the liquefied wood moldings were enhanced with an increase in the amount of combined phenol within the liquefied wood and became comparable to those of the commercial novolak when the amounts of combined phenol were larger than 75%. Furthermore, it was also found that with an increase in the content of wood fillers the flexural properties of the liquefied wood moldings were enhanced more effectively than were the cases of the commercial novolak moldings, exhibiting that the liquefied wood resins could gain a greater reinforced effect from compounding with the wood fillers than did the commercial novolak resins, and the greater the amount of combined phenol, the higher the reinforcing performance of wood fillers. In addition, water-sorption measurements and the SEM observations of the moldings indicated that the liquefied wood resins had much greater hydrophilicity than that of the novolak and revealed a greater compatibility with wood fillers. © 1995 John Wiley & Sons, Inc.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1995.070551107
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