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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of organic chemistry 29 (1964), S. 123-129 
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of organic chemistry 29 (1964), S. 221-222 
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 86 (1964), S. 298-299 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of organic chemistry 27 (1962), S. 2377-2383 
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 33 (1995), S. 143-157 
    ISSN: 0887-624X
    Keywords: anionic polymerization ; polybutadienes ; trialkyltin lithium ; trialkyltin termination ; 119Sn-NMR ; 2,1-initiation ; 1,2-napthoquinone ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Low molecular weight polybutadienes and styrene butadiene copolymers were anionically prepared with trialkyltin lithium initiator and end-capped with either hydrogen or a trialkyltin group. These polymers were prepared with a variety of microstructures. Analysis by 119Sn-NMR and comparison to model compounds showed no cis-1,4-initiation of the butadiene. The initiation sites found were trans-1,4- and both 2,1- and 1,2-additions of the tin-lithium bound to a 1,3-butadiene. At low levels of added polar modifier, the 2,1-addition predominated. The 119Sn-NMR spectra allowed the assignment of the sequence distribution associated with the nearest eight main chain carbon atoms (2-4 monomer units) adjacent to the tin end groups. No initiation could be detected involving the styrene comonomer, but incorporation of styrene was detected as the first or second unit after initiation. The reaction of the allyl-tin end groups of these polymers with 1,2-napthoquinone was followed by NMR and was used to assign the peaks associated with 1,2-addition of the trialkyltin lithium to 1,3-butadiene. © 1995 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 40 (1990), S. 989-996 
    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 molecular weight between crosslinks was measured as a function of the maximum extension to which samples of solution cast films of ABA triblocks were tested. These measurements were done by applying the kinetic theory of rubber elasticity to the retraction portion of a tensile hysteresis curve. The molecular weight between chain restrictions, as determined by extrapolation to 0% elongation, was found to be identical to the entanglement molecular weight normally associated with the polybutadiene or polyisoprene that was used for the center block. The disentanglement of the small amount of AB diblock present could also be followed by fitting the data collected to what could be pictured kinetically as a simultaneous first-and second-order loss of crosslink density.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 48 (1993), S. 1621-1633 
    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: Tensile retraction measurements have been made on the same SBR filled with 50 phr of 10 different carbon blacks. The slopes and intercepts determined from the plots against λmax were determined in three different elongation ranges. These carbon blacks were chosen to have a variety of different surface areas and structures such that the influence of these features on the slopes and intercepts could be measured. The tensile retraction parameters determined were also evaluated at elevated temperatures and Arrhenius plots were made. The activation energies calculated from these plots showed that the structure and surface area of the carbon blacks had no effect on the process being measured. A series of different molecular weight SBRs were also made by anionic techniques to have 0, 1, and 2 tributyltin end groups. The changes in the constants determined from tensile retraction measurement on these cured filled stocks were explained in terms of the number of loose end groups still present after reaction with the carbon black. © 1993 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 8
    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 preparation, analysis, testing, and structure determination of ultrahigh impact rubber-toughened polycaprolactams (nylon 6) are described. Partially unsaturated hydrocarbon rubbers were used for this purpose. They were functionalized by reaction either in solution or in bulk with maleic anhydride to give rubbery “ene” adducts containing varying amounts of pendnet succinic anhydride. Tough, rigid, thermoplastic engineering resins with notched Izod impact strengths of 750-1000 J/m were prepared by briefly melt-blending these adducts with nylon 6. Properties of the blends could be affected by the type and amount of elastomer used, the anhydride content, the type of nylon, the mixing conditions and the test conditions. Fractionation by coacervation in m-cresol/cyclohexane of a typical resin containing 20% by weight of functionalized rubber showed approximately 35% of a rubber-nylon graft, along with a few percent of free rubber dispersed in the nylon 6 matrix. A comb-block copolymer structure for the graft and a model for its formation are proposed, consistent with analyses of the fractions. Some of the blends prepared with partially hydrogenated medium vinyl polybutadiene-maleic anhydride adducts displayed a retention of impact properties at low temperatures which was superior to that obtainable with a similarly prepared EPDM-modified nylon 6. Transmission electron microscopy of a blend containing an anhydride-modified hydrogenated medium vinyl polybutadiene showed a morphology consisting of a nylon matrix containing finely dispersed, irregularly shaped, 0.03-0.55 μm rubber domains in which were found even smaller domains of nylon.
    Additional Material: 6 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 42 (1991), S. 1727-1738 
    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: Tensile retraction measurements have been made on unfilled rubbers cured with either sulfur or dicumyl peroxide to different levels of crosslink density. The rubbers chosen were emulsion and solution polymerized anionic SBRs, cis-polybutadiene, natural rubber, and anionic 1,4-polybutadienes of different molecular weight. The measured molecular weight between crosslinks (Mc) at each extension gave a smooth curve when plotted against the maximum extension (Λmax) used for the measurement. This curve was separated into three linear regions that characterize the cured rubber. The first region, above about 30% elongation, gave a Λmax = 1 intercept that decreased with either increased polymer Mn or increased level of curatives. Subtracting this calculated crosslink density from the measured crosslink density below about 30% elongation gave another smooth curve when plotted against Λmax. A second linear relationship was described in the general range of 5-30% elongation. Below about 5% elongation, a third linear relationship was found. This line was determined from the differences between the calculated and the observed crosslink densities in the lowest strain region of the intermediate strain plot. Possible explanations of these three linear regions have been made. Supporting evidence was gained from temperature-dependent experiments as well as from correlation of experimental results with polymers of different values of Tg.
    Additional Material: 9 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 19 (1975), S. 1931-1937 
    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: Isoprene-urea and butadiene-urea block polymers have been prepared by reaction of isocyanate-terminated prepolymers with diamines and diisocyanates. It was found that the per cent of blocked urea in these copolymers is dependent on the isocyanate-diamine stoichiometry. Stress-strain data were obtained on sulfur-cured copolymers. Stress levels at any given extension were directly dependent on the urea content, however, ultimate strength was maximized at about 35 wt-% urea. Slight variations in urea structure produced rather dramatic changes in the modulus of these cured elastomers. Diamine-diisocyanate stoichiometry did not affect the physical properties of these cured copolymers at equal or excessive diamine concentrations. However, at excess diisocyanate levels, elastomeric properties deteriorated rapidly. Finally, stress-strain properties were affected by polymerization solvent. Copolymers prepared in hexane gave higher values of stress at low strains than corresponding elastomers prepared in toluene. These latter results are explained in terms of the nonaqueous emulsion in which the urea blocks form.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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