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  • 1
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 184 (1983), S. 651-668 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Two series of polyurethane zwitterionomers based on 4,4′-methylene-di(phenyl isocyanate) (MDI), N-methyl diethanolamine (MDEA)Systematic IUPAC name: 2,2′-(methylimino)diethanol., and either 1350 molecular weight hydroxyl terminated polybutadiene or 1000 molecular weight poly(tetramethylene oxide)Systematic IUPAC name: poly(oxytetramethylene). were synthesized. Zwitterionization was accomplished by quaternizing the tertiary amine of MDEA with 1,3-pro-panesultone. In Both series, IR analysis suggests that the sulfonate ion SO3- associates with the counter ion on the chain extender and the acidic hydrogen of the urethane linkage. Ammonium sulfonation shifts the soft segment Tg of polyether-based material to lower temperatures suggesting that ionization improves microphase separation. The soft segment Tg of the polybutadiene system is unaffected by ionization. IR dichroism measurements show that with increasing ammonium sulfonation both the hard and soft segments in the polyether-polyurethane zwitterionomers orient to a greater extent with deformation. In contrast, in the poly-butadiene-based zwitterionomers the orientability of the hard segment decreased with ionization while the soft segment showed significant chain alignment. Coupling the dichroism measurements to stress-strain results suggests that the hard segment domains of the polyether-polyurethane system possess more of an interconnected structure, while the polybutadiene-poly-urethane system contains hard segment domains which are largely isolated. The formation of different morphologies in the two systems of zwitterionomers may be due to the different interdomain surface tensions.
    Additional Material: 12 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 185 (1984), S. 2429-2435 
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Small angle neutron scattering experiments were performed on a blend of deuterated and protonated hydroxyl terminated oligo(oxytetramethylene)s. The oligomer had a number-average molecular weight of 1000. The experimental data were fitted to a Debye function in order to obtain the radius of gyration of the chains. The measured radius of gyration, which was corrected for molecular weight distribution, was found to compare well with the values reported in the literature for poly(oxytetramethylene) in a theta solvent, as measured by viscosity methods and extrapolated to a molecular weight of 1000. Thus, this short oligomeric species has a random coil configuration. The weight-average molecular weight determined from the SANS data was 1540, compared with a value of 1450 determined from high performance liquid chromatography. This implies that no isotopic segregation of the deuterated and protonated species occurs.
    Additional Material: 3 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 6 (1962), S. S23 
    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.
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 10 (1966), S. 1837-1844 
    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 viscoelastic properties of some polyester-urethanes are compared with the properties of other polymers. The behavior observed is anomalous in that these polyurethanes exhibit an unusually high value of modulus well above their Tg, unaccounted for by either crosslinking or crystallinity. Various experiments including incorporation of plasticizes of widely varying chemical composition have suggested interpretation of the system as a block copolymer, each block having its own Tg. Each of the two types of blocks seems to associate with similar blocks from other molecules.
    Additional Material: 5 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 21 (1977), S. 3035-3061 
    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 compatibility, morphology, and mechanical properties of poly-∊-caprolactone (PCL) blended with poly(vinyl chloride), nitrocellulose, and cellulose acetate butyrate are described in this study. Methods used in this investigation included differential scanning calorimetry, dynamic mechanical testing, small-angle light scattering, light microscopy and stress-strain testing. Blends of PCL with poly(vinyl chloride) (PVC) are shown to be compatible in all proportions. In the PCL concentration range 40-100%, the PCL crystallizes in the form of negative spherulites. The spherulites were found to be volume filling with as much as 35% PVC. The nitrocellulose blends with PCL exhibited the glass transition behavior of a compatible system over the composition range of 50-100% PCL. At lower PCL concentrations, phase separation was apparent. The PCL crystallinity was present only in the nitrocellulose blends with more than 50% PCL, and it was in the form of rod-like super-structures. Blends of PCL with cellulose acetate butyrate were shown to be phase separated, with one phase having nearly equal proportions of the two polymers. The PCL crystallinity was in the form of negative spherulites and was formed with PCL compositions as low as 50%. Stress-strain results show polycaprolactone to be an effective plasticizer for poly(vinyl chloride) and the cellulose derivatives studied.
    Additional Material: 17 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 23 (1979), S. 201-214 
    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 diffusivities of simple gases through a series of polyurethane block copolymers of differing aromatic urethane content and type of soft segment were measured using a quadrapole mass spectrometer as a detecting device. Although an Arrhenius expression generally described the temperature dependence of diffusion in this system, a discontinuity was observed in the Arrhenius plots for some materials, and the discontinuity was found to be related to the onset of the glass transition in the hard domains. Increasing the hard segment content of the materials decreased the diffusivity due to the increase in the activation energy of diffusion. Increasing the soft segment length brought about a decrease in the activation energy with an increase in diffusivity. Polyster urethanes had lower activation energies for diffusion than polyether urethanes of similar hard segment composition. Finally, as the penetrant diameter was increased, a decrease in the diffusivity and an increase in the activation energy was noted.
    Additional Material: 7 Ill.
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 26 (1981), S. 2989-3006 
    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 objective of this research was to study the morphology and properties of PVC-polyurethane blends. Studies on blends of a segmented polyether polyurethane with PVC were carried out utilizing differential scanning calorimetry, Rheovibron, stress-strain, infrared peak position studies, and infrared dichroism experiments. This thermodynamically incompatible system was made kinetically compatible by precipitation from tetrahydrofuran (THF) solutions. THF-dioxane solution casting and melt processing produced an incompatible system. The compatible polyurethane-PVC system contains a well-mixed PVC-polyether matrix phase as evidenced by Tg shifts, orientation characteristics, and infrared peak position changes. The aromatic urethane segments which exhibit microphase separation in the pure polyurethane are not solubilized by blending with PVC by any of sample preparation methods used in this study.
    Additional Material: 13 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. 4735-4744 
    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: Experimental measurement of the change in coefficient of friction with sliding distance of a carbon-black-reinforced rubber on either glass or Perspex surfaces increases monotonically to a constant value as required by Saibel's theory. However, this general stochastic model does not allow for a fully satisfactory physical interpretation of the effects of run-in on rubber friction. The present measurements for rubber on a glass surface agree well with those of Roth and co-workers reported many years ago. The observation of these effects on Perspex does not appear to have been reported previously. It is found that a material, probably stearic acid or zinc stearate, is deposited from the rubber onto a glass surface when the rubber slides on it.
    Additional Material: 7 Ill.
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 30 (1985), S. 2115-2135 
    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 series of polydimethylsiloxane-urea acrylate prepolymers was synthesized by reacting aminopropyl-terminated polydimethylsiloxane (ATPS) with isocyanatoethyl methacrylate (IEM). The oligomers were cured using ultraviolet radiation in the presence of different reactive diluents. Three systems were prepared with varying ATPS soft segment molecular weight. All of the samples were transparent. However, microphase separation was indicated by the observation of two glass transition temperatures attributed to separate ATPS and IEM/reactive diluent phases. Increasing ATPS molecular weight led to a lower rubbery phase transition temperature and a smaller rigid phase volume fraction. These effects were reflected in lower modulus and tensile strength at room temperature, and higher elongation at break. An increase in the reactive diluent content resulted in an increase in Young's modulus and the ultimate tensile strength of these materials. Increasing reactive diluent content caused the rubbery phase transition peak to decrease in magnitude without changing its position and shifted the hard segment transition to higher temperature. The tensile strengths and moduli of these materials were higher than those reported in the literature for other polydimethylsiloxane and urethane acrylate materials.
    Additional Material: 14 Ill.
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  • 10
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Novel poly(enonsulfides) were prepared with inherent viscosities as high as 1.35 dL/g by nucleophilic addition of various aromatic dithiols to 1,1′-(1,3- or 1,4-phenylene)bis(3-phenyl-2-propyn-1-one) in m-cresol at 25-40°C. A tough clear yellow film with a tensile strength of 11,300 psi and a tensile modulus of 466,000 psi at 25°C was cast from a chloroform solution of the polymer prepared from 1,3-dithiobenzene and 1,1′-(1,4-phenylene)bis(3-phenyl-2-propyn-1-one). The poly(enonsulfides) exhibited Tg's as high as 180°C and weight losses of approximately 10% at 331°C in air. The synthesis and characterization of several poly(enonsulfides) are discussed.
    Additional Material: 3 Ill.
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