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  • 1
    Electronic Resource
    Electronic Resource
    The early stages of isotactic polypropylene oxidationPresented in part at the 140th Meeting of the American Chemical Society, Chicago, Illinois, September, 1961. (1963)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 7 (1963), S. 959-969 
    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 initial stages of isotactic polypropylene oxidation were investigated by oxidizing at 130°C. to various extents up to 10 ml. of oxygen consumed per gram of polymer. The development of infrared absorption bands in the carbonyl regions was followed, as increasing amounts of oxidation occurred. The oxidation uptake curves showed that both autocatalytic rate and induction time depended primarily on the thickness of the sample, contrary to the case of polyethylene. This indicated the initiation process was primarily diffusion controlled for samples of the thickness range studied. The presence of copper shortened the induction times and increased the autocatalytic rate. In this case, the dependency of the induction time on thickness was less. Dielectric data showed that polypropylene became unsuitable electrically at about the point where the autocatalytic oxidation set in. It was also found that the effects of prior exposure to oxidative conditions were cumulative to a considerable extent, and thus resulted in shorter induction times.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1963.070070314
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  • 2
    Electronic Resource
    Electronic Resource
    Polyesters of hydroxybenzoic acids (1959)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 2 (1959), S. 198-202 
    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: Polymers and copolymers were prepared from the acetoxy derivatives of m- and p-hydroxybenzoic acids. Molecular weights of over 20,000 were obtained for poly(m-hydroxybenzoic acid) and copolymers containing up to 60% para isomer. These polyesters were crystalline, and the degree of crystallinity increased as the para isomer content was increased. Blocks of the high-melting, insoluble poly(p-hydroxybenzoic acid) tend to form in copolymers containing a high proportion of the para isomer because of the difference in reactivity of the two isomers. Copolymers containing at least 55% of the meta isomer are soluble in several classes of solvents. The copolymers do not have sharply defined melting points, but have softening temperatures ranging from 150°C. to over 300°C. Tensile strengths of approximately 10,000 psi and elongations of about 6% to 40% were obtained. The polymers were relatively stable to oxidative degradation, but not to hydrolysis.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1959.070020512
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  • 3
    Electronic Resource
    Electronic Resource
    Oxyluminescence of polymers. II. Effect of temperature and antioxidants (1964)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 8 (1964), S. 997-1006 
    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 oxyluminescence of polypropylene and polyethylene stabilized with various amounts of 4,4′-thiobis(3-methyl-6-tert-butylphenol) were studied and compared with oxygen uptake data. It was found that there was a correlation, although not linear, between the two methods. In the case of the stabilized polypropylenes, a pronounced aging effect was noticed. The oxyluminescent behavior of stabilized polyethylene was somewhat different from that of stabilized polypropylene. The temperature coefficients of the oxyluminescence of polypropylene, polyethylene, nylon 6, polystyrene, polyurethane and polymethyl methacrylate were obtained. From these data the apparent activation energies for the light-emitting reaction were calculated. For the olefin polymers, these values are close to the activation energies of the oxidative degradation reaction obtained by other means. Both polyethylene and polymethyl methacrylate have different activation energies below their transition points as compared to higher temperature, indicating a different mode of reaction in the solid state from that occurring in the melt. An interesting transition luminescence, which was more pronounced in the absence of oxygen, was observed in the case of polyethylene.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1964.070080235
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  • 4
    Electronic Resource
    Electronic Resource
    The determination of the relative isotactic content of polypropylene by extraction (1960)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 4 (1960), S. 219-224 
    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: Attention is called to the variables effecting the extraction of polypropylene. Under controlled conditions, the extraction of polypropylene with first diethyl ether and then n-heptane will give reproducible results. It is necessary to extract with heptane in an atmosphere of nitrogen. The values obtained by the extraction procedure described are regarded as relative measures of the amounts of isotactic, stereoblock and atactic material present in a sample. Extraction with n-heptane alone by this procedure also gives the same value of relative isotacticity. Infrared studies showed that the ether soluble fractions were essentially atactic, while the n-heptane-soluble or stereoblock material possessed a degree of order corresponding to 20-40% isotactic polypropylene.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1960.070041114
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  • 5
    Electronic Resource
    Electronic Resource
    Oxyluminescence of polymers. I. General behavior of polymersThis paper was presented in part before the Polymer Division of the American Chemical Society at the 142nd meeting, Atlantic City, New Jersey, September 12, 1962. (1964)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 8 (1964), S. 985-995 
    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 faint emission of light by various classes and types of polymers when heated in the presence of oxygen, oxyluminescence, was studied by means of a photomultiplier tube and sensitive microammeter. Among the polymers with a carbon-carbon backbone, the polymers having the greater number of tertiary carbon atoms generally showed greater intensities of luminosity. Polystyrene was a notable exception to this generalization. The shape of the luminosity versus time curves varied with the type of polymer. It was also found that the emission of light did not stop instantly when the oxygen atmosphere was replaced by an inert gas, but rather followed an exponential type of decay. The rate of decay appeared to be different with different types of polymers. The intensities of luminescence and the times required to reach maximum or steady state luminescence were compared with oxygen uptake data for various polymers. In general there was a qualitative, but not necessarily quantitative correlation between the luminous intensities and polymer stabilities in the presence of oxygen.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1964.070080234
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  • 6
    Electronic Resource
    Electronic Resource
    Modification of crosslinking effects in cotton fabrics by swelling and methylation (1965)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 9 (1965), S. 2311-2318 
    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 effects of crosslinking on cotton fabric are changed when the cotton has been chemically modified before crosslinking with an inert substituent, such as the methyl group. The main action of the inert substituent is to preserve swelling ability by hindering fiber deswelling after methylation and during crosslinking. At the levels of modification used, the crosslinking reaction appears to proceed normally, with no effects from reduction in the number of reactive cellulosic hydroxyl groups.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1965.070090622
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  • 7
    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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  • 8
    Electronic Resource
    Electronic Resource
    Graft copolymers of starch. III. Copolymerization of gelatinized wheat starch with acrylonitrile. Influence of chain modifiers on copolymer compositionProd. No. 1476 (1967)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 11 (1967), S. 457-463 
    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: A study was made of the influence of selected chain modifiers on both the molecular weight of grafted polyacrylonitrile and the grafting frequency of the starch-polyacrylo-nitrile graft copolymer. Gelatinized wheat starch was used with ceric ammonium nitrate as the initiator. The organic chain modifiers investigated were ethyl mercaptan, 1-dodecanethiol, methyl ethyl ketone, acetaldehyde, and chloroform. Sodium chromate, cupric bromide, cupric nitrate, cupric acetate, and cupric chloride were also tested as chain modifiers. In the presence of cupric chloride, there was a tenfold reduction in the molecular weight of grafted polyacrylonitrile; however, fewer chains were grafted to the starch backbone than were observed without cupric chloride.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1967.070110312
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  • 9
    Electronic Resource
    Electronic Resource
    Crystallinities of copolymers of ethylene and 1-alkenes (1988)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 26 (1988), S. 1271-1286 
    Details
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Random copolymers of ethylene with 1-butene, 1-octene, and 1-octadecene have been prepared using a homogeneous vanadium-based catalyst system. Comonomer contents determined by 13C-NMR analysis of polymer solutions are in the range 1-10 mol%. Crystallinities were estimated by means of density measurements, x-ray diffraction, differential scanning calorimetry, laser Raman spectroscopy, and CPMAS 13C-NMR spectroscopy. The results are compared with those obtained for heterogeneous copolymers of ethylene containing 1-4 mol% 1-butene. As the comonomer content is increased, the crystallinity decreases. The dimension perpendicular to the 110 plane in orthorhombic crystallites decreases linearly with crystallinity. This decrease in crystallite size is accompanied by an increase in the size of the orthorhombic unit cell. For copolymers containing large amounts of 1-octene and 1-octadecene, a second crystalline form appears. Differences in estimates of crystallinity are discussed in terms of looser packing in highly branched copolymers and the extent to which the second crystalline form participates in the phase structure.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1988.090260611
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  • 10
    Electronic Resource
    Electronic Resource
    X-ray studies on the deformation of an aromatic polyimideThe work reported here was partially done at the Stanford Synchrotron Radiation Laboratory, which is supported by the Department of Energy, Office of Naval Energy, Office of Basic Energy Science, and the National Institute of Health, Biotechnology Resource Program, Division of Research Resources. (1987)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 25 (1987), S. 1129-1148 
    Details
    ISSN: 0887-6266
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The deformation of the aromatic polyimide poly{N,N′-bis(phenoxyphenyl)-pyromellitimide} (PMDA-ODA) has been investigated by x-ray scattering. PMDA-ODA, which exhibits a smecticlike ordering in the bulk can be elongated up to 70% at room temperature without a distinct yield point. Under strain, the diffraction pattern of the intramolecular spacing occurring at a Bragg spacing of 15.4 Å is elliptical. The ellipticity shows that the molecule changes its repeat distance along the chain axis. This may result from bond angle and bond length distortions. Consistent with this is a rapid recovery well below the glass transition temperature where all but 20% strain is recovered. This localized extension, however, cannot account fully for the macroscopic deformation applied, and, as such, a global orientation of the chains occurs, as evidenced by the arcing of the diffraction profiles. The retention of the intrachain reflection indicates that bundles of chain segments ordered in a smectic fashion orient as a unit maintaining a lateral chain-segment alignment. Finally, the scattering vector at which a small-angle scattering reflection occurs was found to be correlated to the coherence length determined by a Scherrer analysis of the ca. 15.4 Å intramolecular reflection. As the strain increased, the intensity and spacing of the small-angle scattering reflection increased parallel to the stretching direction and decreased perpendicular to this. This suggests that the origin of the small-angle scattering reflection arises from electron density fluctuations along the chain axis, as is typically seen in semicrystalline polymers.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/polb.1987.090250513
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