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  • 11
    Electronic Resource
    Electronic Resource
    Graft copolymers of starch. I. Copolymerization of gelatinized wheat starch with acrylonitrile. Fractionation of copolymer and effect of solvent on copolymer compositionPresented in part at the 149th meeting of the American Chemical Society, Detroit, Michigan, April 1965.Prod. No. 1353 (1966)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 10 (1966), S. 929-937 
    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 starch-polyacrylonitrile graft copolymer prepared from gelatinized wheat starch with ceric ammoninm nitrate as the initiator has been freed of ungrafted polyacrylonitrile and separated into fractions by extraction with dimethylformamide, γ-butyrolactone, and dimethyl sulfoxide. The copolymer fractions obtained differed appreciably in level of add-on, molecular weights of grafted chains, and grafting frequency. To determiue the molecular weights of grafted chains, the starch part of the copolymer was effectively removed by hydrolysis with α-amylase. It was necessary to dissolve or swell the polymer in dimethyl sulfoxide and freshly precipitate it by addition to water before enzymatic hydrolysis. In studying the effect of reaction medium on copolymer composition, there was less ungrafted homopolymer formed and a higher yield of graft copolymer possessing more frequent grafts with water than with aqueous dimethylformamide or aqueous ethylene glycol. Polymer solubility, the results of control polymerizations of acrylonitrile in the absence of starch, and the detection of glucose endgroups on the polyacrylonitrile liberated from the fractionated polymer by hydrolysis are presented as evidence that the copolymers obtained are true grafts rather thau intimate mixtures.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1966.070100610
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  • 12
    Electronic Resource
    Electronic Resource
    Graft copolymers of starch and poly(2-hydroxy-3-methacryloyloxypropyltrimethyl-ammonium chloride). Preparation and testing as flocculating agentsPaper presented at the 158th National Meeting of the American Chemical Society, New York, September 1969. (1970)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 14 (1970), S. 2601-2609 
    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 title monomer (I) has been graft polymerized onto whole wheat starch with both ceric ammonium nitrate and ferrous ammonium sulfate-hydrogen peroxide initiation. Three graft copolymers, which contained 4.5, 12.1, and 15.2% grafted poly(I), were characterized as to molecular weight of grafted branches and grafting frequency. Graft polymerization was proved by fractional precipitation. Graft copolymers were tested as flocculating agents for diatomaceous silica and nonmagnetic iron ore. The graft copolymers with 12.1 and 15.2% grafted poly(I) compared favorably in flocculating ability with a commercial high molecular weight cationic polyacrylamide.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1970.070141015
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  • 13
    Electronic Resource
    Electronic Resource
    Graft copolymers of starch with mixtures of acrylamide and the nitric acid salt of dimethylaminoethyl methacrylate (1972)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 16 (1972), S. 2835-2845 
    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: Mixtures of acrylamide and the nitric acid salt of dimethylaminoethyl methacrylate (DMAEMA·HNO3) have been graft polymerized onto unmodified wheat starch with ferrous ammonium sulfate-hydrogen peroxide initiation. Graft polymerizations were carried out with both unswollen starch granules and granules that had been swollen by heating in water to 60°C. Ungrafted synthetic polymers were removed from graft copolymers by cold-water extraction and were characterized by their M̄n and DMAEMA·HNO3 content. Graft copolymers were characterized with respect to per cent add-on, M̄n and DMAEMA·HNO3 content of grafted polymer, and grafting frequency. Ungrafted synthetic polymers contained a mole percentage of DMAEMA·HNO3 equal to or greater than that present in the initial monomer mixtures; whereas in most grafted polymers the mole-% DMAEMA·HNO3 in the grafted branches was less than that in the starting monomers. At all monomer ratios examined, polymer grafted to swollen starch granules contained a higher percentage of DMAEMA·HNO3 then polymer grafted to unswollen starch. The influence of starch granule swelling on the molecular weight and frequency of grafted branches was correlated with the composition of the initial monomer mixture. It was determined that the effect of granule swelling on graft copolymer structure would be minimal when 25-30 mole-% DMAEMA·HNO3 was used. In an acetonitrile-water solvent system, reactions with 20 and 50 mole-% DMAEMA·HNO3 produced graft copolymers with less DMAEMA·HNO3 in grafted branches than corresponding graft polymerizations run in water. The flocculation of 3% aqueous suspensions of diatomaceous silica was examined with selected starch graft copolymers.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1972.070161110
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  • 14
    Electronic Resource
    Electronic Resource
    Graft copolymers by simultaneous 60Co-irradiation of starch, acrylamide, and N,N,N-trimethylaminoethyl methacrylate methyl sulfate (1974)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 18 (1974), S. 2205-2209 
    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
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1974.070180726
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  • 15
    Electronic Resource
    Electronic Resource
    Graft copolymers of starch and mixtures of acrylamide and acrylic acid (1976)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 20 (1976), S. 3201-3204 
    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
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1976.070201123
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  • 16
    Electronic Resource
    Electronic Resource
    Graft polymerizations of acrylonitrile and methyl acrylate onto starch and cellulose at different stirring speeds (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 29 (1984), S. 4449-4453 
    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
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1984.070291278
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  • 17
    Electronic Resource
    Electronic Resource
    Saponification of wheat straw-g-polyacrylonitrile (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 33 (1987), S. 907-913 
    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: Wheat straw-g-polyacrylonitrile (PAN), containing 40% PAN, was saponified with sodium hydroxide and isolated under three sets of saponification and work-up conditions. Each reaction mixture was separated into a water-soluble and a water-insoluble fraction, which were individually analyzed for percentages (by weight) of synthetic polymer (saponified PAN), cellulose, hemicellulose, and lignin. Water solubles amounted to 14-24% of the total product and contained 70-74% synthetic polymer, the remainder being hemicellulose and lignin. Although water-insoluble fractions contained 52-54% saponified PAN, their water absorbencies were low (14-17 g H2O/g polymer). Treatment of these fractions with the enzyme cellulase converted 55-62% of the total cellulose of glucose.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1987.070330319
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  • 18
    Electronic Resource
    Electronic Resource
    Graft polymerization of acrylonitrile onto wheat straw (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 33 (1987), S. 899-906 
    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: Acrylonitrile was graft polymerized onto ground, water-washed wheat straw using Fe2+-H2O2 as initiator. Reaction conditions were selected to minimize homopolymer formation and maximize the amount of polyacrylonitrile (PAN) grafted to straw. Polymerizations typically yielded straw-g-PAN containing 30-35% PAN. A two-step fractionation scheme was developed for determining the relative amounts of PAN grafted to cellulose, hemicellulose, and lignin. This scheme involved (1) delignification of straw-g-PAN with sodium chlorite followed by removal of lignin-grafted PAN by extraction with dimethylformamide (DMF), and (2) hydrolysis of the hemicellulose component with 1 N trifluoroacetic acid followed by DMF extraction of hemicellulose-grafted PAN. Product remaining after these two treatments was assumed to be cellulose-g-PAN. When relative amounts of PAN grafted to cellulose, hemicellulose, and lignin were compared with relative percentages of these components present in wheat straw, the percentage of total PAN grafted to lignin was less than its relative percentage in straw, whereas that grafted to hemicellulose was considerably more. Although the use of Ce4+ as initiator gave little or no polymer with whole, water-washed straw, grafted polymerization occurred when delignified straw was used as substrate. Relative amounts of PAN grafted to cellulose and hemicellulose were not greatly different from those observed with Fe2+-H2O2 initiation onto whole straw.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1987.070330318
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  • 19
    Electronic Resource
    Electronic Resource
    Graft polymerization of vinyl acetate onto starch. Saponification to starch-g-poly(vinyl alcohol) (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 23 (1979), S. 229-240 
    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: Graft polymerizations of vinyl acetate onto granular corn starch were initiated by cobalt-60 irradiation of starch-monomer-water mixtures, and ungrafted poly(vinylacetate) was separated from the graft copolymer by benzene extraction. Conversions of monomer to polymer were quantitative at a radiation dose of 1.0 Mrad. However, over half of the polymer was present as ungrafted poly-(vinyl acetate) (grafting efficiency less than 50%), and the graft copolymer contained only 34% grafted synthetic polymer (34% add-on). Lower irradiation doses produced lower conversions of monomer to polymer and gave graft copolymers with lower % add-on. Addition of minor amounts of acrylamide, methyl acrylate, and methacrylic acid as comonomers produced only small increases in % add-on and grafting efficiency. However, grafting efficiency was increased to 70% when a monomer mixture containing about 10% methyl methacrylate was used. Grafting efficiency could be increased to over 90% if the graft polymerization of vinyl acetate-methyl methacrylate was carried out near 0°C, although conversion of monomers to polymer was low and grafted polymer contained 40-50% poly(methyl methacrylate). Selected graft copolymers were treated with methanolic sodium hydroxide to convert starch-g-poly(vinyl acetate) to starch-g-poly(vinyl alcohol). The molecular weight of the poly(vinyl alcohol) moiety was about 30,000. The solubility of starch-g-poly(vinyl alcohol) in hot water was less than 50%; however, solubility could be increased by substituting either acid-modified or hypochlorite-oxidized starch for unmodified starch in the graft polymerization reaction. Vinyl acetate was also graft polymerized onto acid-modified starch which had been dispersed and partially solubilized by heating in water. A total irradiation dose of either 1.0 or 0.5 Mrad gave starch-g-poly(vinyl acetate) with about 35% add-on, and a grafting efficiency of about 40% was obtained. A film cast from a starch-g-poly(vinyl alcohol) copolymer in which homopolymer was not removed exhibited a higher ultimate tensile strength than a comparable physical mixture of starch and poly(vinyl alcohol).
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1979.070230121
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  • 20
    Electronic Resource
    Electronic Resource
    Graft polymerization of acrylamide and 2-acrylamido-2-methylpropanesulfonic acid onto starch (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 24 (1979), S. 2015-2023 
    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: Mixtures of acrylamide and 2-acrylamido-2-methylpropanesulfonic acid (AASO3H) were graft polymerized onto starch by cobalt-60 irradiation, and the water absorbency and water solubility of the resulting products were determined. The conversion of monomers to polymer was nearly quantitative when pregelatinized wheat starch and a water solution of the two monomers were simultaneously irradiated (simultaneous irradiation conditions). Products with high water absorbency were obtained with equal weights of starch and total monomers when acrylamide:AASO3H ratios ranged from 9:1 to 1:3. Water solubility of these polymers was over 50%. Neither of the two monomers gave absorbent polymers when graft polymerized individually onto starch. Although highly absorbent products were also obtained at a total monomer:starch ratio of 2:5, ratios of 1:5 and lower gave products with poor absorbency. Neutralization of AASO3H with sodium hydroxide before graft polymerization drastically reduced both the water solubility and absorbency of the final products. A reaction with granular starch was also carried out under simultaneous irradiation with a total monomer:starch ratio of 2:5 and with equal weights of the two monomers. Conversion of monomers to polymer was once again nearly quantitative. To obtain good water absorbency from this granular product, it was necessary to first neutralize the AASO3H portion with alkali, then disperse the polymer in hot water, and finally dry the resulting water dispersion. Graft copolymers with good water absorbency were also obtained by adding preirradiated starch to a water solution of acrylamide and AASO3H, although only partial conversions of monomers to polymer were realized. Selected products from the various graft polymerizations were fractionated by extraction with either water or a 1% solution of sodium chloride. The synthetic polymer content of the resulting fractions and the percentage of AASO3H in the synthetic portion of each polymer were determined. The Mn of some of the synthetic polymers was also determined after removal of carbohydrate by enzymatic hydrolysis.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1979.070240909
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