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  • Polymer and Materials Science  (474)
  • 1980-1984  (474)
  • 1982  (239)
  • 1981  (235)
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 26 (1981), S. 509-519 
    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 deterioration of polyolefin, poly(ethylene terephthalate), and polyamide films under soil burial conditions extending up to 32 months has been investigated. Based on changes in their elongation at break, the films can be ranked in order of increasing sensitivity to degradation: Polyester ≃ polypropylene 〈 low-density polyethylene ≃ high-density polyethylene 〈 nylon 6.6. The degraded nylon 6.6 and polyethylene films were characterized by infrared and luminescence spectroscopy and scanning electron microscopy, as well as by wet analysis for hydroperoxides. From a comparison with the well-known oxidative sensitivity of nylon 6.6 in oxygenated water at slightly elevated temperatures, the rapid deterioration of nylon 6.6 film during soil burial was also concluded to be an oxidative process. The somewhat smaller, but significant, embrittlement of the polyethylenes studied could not be simply explained by thermal oxidation (with only trace oxidation products detectable) or microbiological attack (deterioration being unaffected by surface activation to enhance wettability).
    Additional Material: 5 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 16 (1982), S. 381-398 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Numerous hypotheses exist to explain observed blood-materials interactions. It is the purpose of this article to test two popular hypotheses, namely, the minimum interfacial free energy hypothesis and the optimum polar/apolar ratio hypothesis. Methacrylate polymers and copolymers were characterized using the captive bubble underwater contact angle method; bulk water content was determined by gravimetric methods; streaming potential measurements were made; and surface roughness and possible particulate contamination were evaluated by reflected light microscopy. In vitro blood tests include whole blood clotting time measurements on polymer-coated tubes; centrifugal force platelet adhesion on polymer-coated coverslips; and a measure of the partial thromboplastin time, Russell's viper venom time (Stypven time), and the prothrombin time of native whole blood exposed to polymer-coated microscope slides. Results suggest that platelet adhesion correlates in the opposite direction of whole blood clotting time and partial thromboplastin time, emphasizing the need for a multiparameter approach to blood-materials testing. Based on these tests the minimum interfacial free energy hypothesis is not supported. In fact, the data suggest the opposite to be true. It is apparent that platelet adhesion can be a misleading indicator of blood compatibility. Neither hypotheses can explain the apparent conflict between the platelet adhesion data and the coagulation time data.
    Additional Material: 9 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 19 (1981), S. 2817-2834 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermal degradation behavior of poly(1,3-phenylene isophthalamide) and poly(chloro-2,4-phenylene isophthalamide) was investigated with the aid of some appropriate model compounds. The pyrolysis products of these materials were identified by gas chromatography (GC), gas chromatography/Fourier transform infrared spectroscopy (GC/FT-IR), and gas chromatography/mass spectrometry (GC/MS). The residual chars were characterized by IR spectroscopy. Thermogravimetric analysis (TGA) was applied to study the effect of end-group concentration on the degradation characteristics of the two polyamides. Kinetic parameters that describe the thermal degradation of the polyamides were also evaluated by TGA. The results of this investigation suggest that the thermal decomposition of these aromatic polyamides involves homolytic as well as hydrolytic cleavages of the amide units.
    Additional Material: 13 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 19 (1981), S. 321-334 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Optical-absorption, fluorescence, and Raman spectra for solutions, suspensions, and precipitates of poly(1,6-di-p-toluene sulfonoxy-2,4-hexadiyne) in and from nitrobenzene, acetone, and chloroform are presented. These are interpreted in terms of the occurrence of two forms of the polymer chain; a quasicrystalline form with properties close to those of single crystal polymer and a chain-extended form occurring in solution and colloidal particles, with an absorption energy of about 2.5 eV (20,000 cm-1). No evidence is found for the presence of very short polymer chains in partially polymerized monomer at low conversion. The relationship of these results to those for deformed single crystals is briefly discussed.
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  • 5
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Biopolymers 21 (1982), S. 2265-2277 
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Human fibrinogen was treated with thrombin in the presence of fibrinoligase (Factor XIIIa) and calcium ion at pH 8.5, ionic strength 0.45, and the ensuing polymerization was interrupted at various time intervals (t) both before and after the clotting time (tc) by solubilization with a solution of sodium dodecylsulfate and urea. Aliquots of the solubilized protein were subjected to gel electrophoresis on polyacrylamide gels after disulfide reduction by dithiothreitol and on agarose gels without reduction. The degree of γ-γ ligation was determined from the former and the size distribution of ligated oligomers, for degree of polymerization x from 1 to 10, from the latter. In some experiments, thrombin was inhibited, after partial polymerization, by p-nitrophenyl-p′-guanidinobenzoate. From these, it was concluded that for thrombin concentration ≤0.013 units/mL and fibrinoligase ≥30 mg/L, oligomer assembly is rapid compared with peptide A release and ligation is rapid compared with assembly. Under these conditions, the theory of the first paper of this series describes rather well the time dependences of the degree of γ-γ ligation, the weight fractions of monomer and small oligomers, and the number- and weight-average degrees of polymerization after solubilization of the staggered overlapped assemblies, each of which splits to give two strands of end-to-end ligated oligomers. The theory assumes that the second A peptide is released by thrombin more rapidly than the first by a factor q, which, from the experimental data, is determined to be 16. The subsequent assembly into staggered overlapped oligomers follows the statistics of linear polycondesation taking into account the presence of both difunctional and monofunctional combining units. For higher thrombin or lower fibrinoligase concentrations, ligation fails to keep pace with oligomer assembly, and the size distributions after solubilization show a higher proportion of very small and a lower proportion of larger ligated oligomers, owing to separation of the staggered overlapped assemblies into smaller fragments.
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 26 (1981), S. 591-602 
    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: Reticulated polystyrene-divinylbenzene (PSt-DVB) copolymer membranes or thin sheets were prepared using two different methods. The first method employed a nonsolvating diluent which dissolves the monomer but precipitates the polymer. This resulted in skinned membranes with the skin being nonporous, being either crenelated or smooth. The second method used paraffin wax as the inert phase. The wax was precipitated by cooling, followed by polymerization of the styrene. The wax was then solvent extracted. This resulted in a reticulated structure both on the surface and in the interior of the membrane. The resulting products from the two methods were compared using scanning electron microscopy. The objective of this study was to prepare a skinless, macroporous, crosslinked polystyrene, as polymer I for the preparation of novel interpenetrating polymer network (IPN) materials.
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 26 (1981), S. 1941-1949 
    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 adhesive bond of allyl 2-cyanoacrylate between steel substrates has been analyzed and compared to that of ethyl 2-cyanoacrylate. Mechanical strength as well as thermomechanical, calorimetric, thermogravimetric, and dynamic mechanical response was observed. It was demonstrated that the allyl 2-cyanoacrylate bonds exhibit improved temperature resistance owing to the formation of heat-induced crosslinks in the adhesive layer, resulting in much improved lap-shear strengths. Scanning electron microscopy of the fracture surfaces showed that plastic deformation occurred in the allyl 2-cyanoacrylate adhesive after thermal aging, while interfacial and brittle failure dominated all other cases.
    Additional Material: 9 Ill.
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 27 (1982), S. 3591-3595 
    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: Oligomers are potentially useful as well characterized models for studying the chemical and physical properties of their long chain homologues. These model compounds are often available only as mixtures which must be separated. This separation may be accomplished using chromatographic techniques, i.e., GPC. Polydispersity (Mw/Mn) is often used as a criteria for the extent to which separation has been achieved. Values of polydispersity of 1.01-1.03 are considered indicative of very narrow fractions in the high polymer area. A purpose of this paper is to show that such low values of polydispersity are misleading when applied to oligomers containing 2-20 repeat units. Further, the existence of a single “sharp” melting endotherm is not necessarily proof that one has separated out a single molecular weight component. An intimate mixture of different molecular weight oligomers can give a single narrow endotherm.
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim [u.a.] : Wiley-Blackwell
    Materials and Corrosion/Werkstoffe und Korrosion 33 (1982), S. 155-163 
    ISSN: 0947-5117
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Triphenylmethanfarben als Korrosionsinhibitoren für Aluminium-Kupfer-Legierungen in SalzsäureDie Inhibierung der Korrosion von Aluminium B 26 S in Salzsäure durch Triphenylmethan-, Anthrachinon- und Acridinfarben wurde unter Berücksichtigung von Säurekonzentration, Inhibitordosierung, Versuchsdauer und Temperatur untersucht. Im allgemeinen nimmt bei konstanter Säurekonzentration der Hemmwert von Malachitgrün, Methylviolett 6 B and „light green“ mit der Inhibitorkonzentration zu, während der von Fuchsinbase und Kristallviolett mit zunchmender lnhibitorkonzcntration geringer wird. Bei konstanter Inhibitorkonzentration nimmt andererseits die Wirksamkeit aller untersuchten Verbindungen (mit Ausnahme von Methylviolett 6 B und Acridinorange) mit steigender Säurekonzentration zu. Der Hemmwert aller untersuchten Verbindungen steigt im Temperaturbereich 20-50°C mit der Temperatur, während kein Einfluß der Versuchsdauer zu erkennen ist. Bei einer lnhibitorkonzentration von 0,1% in 0,5 M Salzsäure nimmt der Hemmwert in der folgenden Reihe zu: Fuchsinsäure (32%) 〈 Acridinorange 〈 Fuchsinbase (39%) 〈 Alizarinrot S (46%) 〈 Methylviolett 6 B (50%) 〈 Malachitgrun (64%) 〈 Kristallviolett (70%) 〈 „light green“ (80%).Die Wirkung der Inhibitoren scheint durch Absorption nach einer Langmuir-Adsorptionsisotherme bedingt zu sein. Das wird durch die Korrosionspotentiale bestätigt; allerdings dürfte bei galvanostatischer Polarisation die Kathode bevorzugt polarisiert werden.
    Notes: The inhibition of the corrosion of B 26 S aluminium in HCl solutions by triphenylmethane, anthraquinoid and acridine dyes has been studied in relation to the concentration of acid and inhibitor, duration of immersion and temperature. In general, at constant acid concentration, the inhibiting efficiency of malachite green, methyl violet 6 B and light green increases, whereas that of fuchsine base and crystal violet decreases as the inhibitor concentration increases. At constant inhibitor concentration the efficiency of all the compounds except methyl violet 6 B and acridine orange increases with increasing acid concentration. The inhibitive efficiency of all the compounds increases with temperature in the range 20-50°C, but no dependence can be recognized on the duration of immersion. At an inhibitor concentration of 0.1% in 0.5 M HCl the efficiency increases in the order: fuchsine acid (32%) 〈 acridine orange ≤ fuchsine base (39%) 〈 alizarin red S (46%) 〈 methyl violet 6 B (50%) 〈 malachite green (64%) 〈 crystal violet (70%) 〈 light green (80%).The inhibitors appear to function through adsorption following the Langmuir adsorption isotherm. From the corrosion potentials the inhibitors appear to function through general adsorption but under galvanostatic polarisation conditions, the cathode appears to be preferentially polarised.
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 105 (1982), S. 83-90 
    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: 2-Hydroxypropylmethacrylat wurde mit Ethylacrylat und n-Butylacrylat in Masse bei Temperaturen zwischen 60 und 100°C copolymerisiert unter Verwendung von Benzoylperoxid als Initiator. Die Zusammensetzung der Copolymeren wurde durch Hydroxylgruppenbestimmung analysiert; die Copolymerisationsparameter wurden nach der Kelen-Tüdös-Methode berechnet. Die Arrheniusparameter wurden abgeleitet, und die Grenzviskositäten und das thermische Verhalten der Copolymeren wurden ebenfalls untersucht.
    Notes: 2-Hydroxypropyl methacrylate has been copolymerized with ethyl acrylate and n-butyl acrylate in bulk at temperatures between 60 and 100°C using benzoyl peroxide as initiator. The compositions of copolymers have been analyzed by hydroxyl determination; the reactivity ratios have been calculated by Kelen-Tüdös method. Arrhenius parameters have been derived. The intrinsic viscosities and the thermal behaviours of the copolymers were also studied.
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