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  • 1
    Electronic Resource
    Electronic Resource
    Rheooptical Studies of Racemic Poly(γ-benzyl glutamate) Liquid Crystals (1980)
    s.l. : American Chemical Society
    Macromolecules 13 (1980), S. 867-871 
    Details
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ma60076a019
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  • 2
    Electronic Resource
    Electronic Resource
    Dependence of the packing structure of mesogenic groups on the flexible spacer length of liquid-crystalline side-chain polymers (1989)
    s.l. : American Chemical Society
    Macromolecules 22 (1989), S. 1141-1144 
    Details
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ma00193a024
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  • 3
    Electronic Resource
    Electronic Resource
    Phase transition and the packing structure of the side mesogenic groups of liquid crystalline side-chain copolymers (1991)
    Springer
    Polymer bulletin 25 (1991), S. 597-602 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Copolymers consisting of cholesteryl 11-methacryloyloxy-undecanoate (ChMO-10) and t-buthyl methacrylate (t-BMA) were studied by DSC method and by small angle X-ray scattering method (SAXS). Although homopolymer (pChMO-10) has two different packing structures which are a single-layer packing structure and a two-layer packing one, copolymers (co-pChMO-10-t-BMA) have only the single layer packing one in their mesophase. Furthermore, transition entropy at a clearing point of co-pChMO-10-t-BMA (80/20) is larger than that of pChMO-10. Adequate distance of the mesogenic groups in the direction of a short axis of the mesogenic groups, produced by introduction of non-mesogenic units, seems to stabilize the single-layer packing structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00293520
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  • 4
    Electronic Resource
    Electronic Resource
    Dynamic viscoelastic behavior of cholesteric liquid crystalline side-chain copolymers (1991)
    Springer
    Polymer bulletin 25 (1991), S. 611-617 
    Details
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The rheological behavior of the cholesteric side-chain copolysiloxane whose two kinds of mesogenic groups consist of cholesteryl units and biphenyl benzoate units was investigated for three different compositions: 31:69, 35:65, 37:63 (in mol%). On the frequency dependence diagram of G′ for the copolymers at various temperatures, G′ decreases with decreasing frequency. The slope of G′ in a higher frequency region at lower temperatures (110°–130°C) is similar to that in the flow region of amorphous polymer melts. However, the slope of G′ in a lower frequency region at higher temperatures (140°–160°C) is relatively small, and the G′ curves in this region can not be superposed on to a single master curve. This deviation seems to be due to change in stability of the domain structure of the cholesteric phase. Furthermore, on the temperature dependence curve of G′, G′ showed a maximum near T c1 . This maximum of G′ curve seems to be caused by molecular organization of a blue phase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00293522
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  • 5
    Electronic Resource
    Electronic Resource
    Time-temperature superposition of time-dependent birefringence for low-density polyethylenePaper presented at the International Symposium on Macromolecular Chemistry, Tokyo and Kyoto, Japan, October 3, 1966. (1967)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 5 (1967), S. 1067-1078 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The time-dependent birefringence has been measured simultaneously with the stress relaxation on quenched and annealed low-density polyethylene at various temperatures from 10 to 70°C. The strain-optical coefficient increases generally with increasing time, and approaches the equilibrium value, which depends upon the temperature. When the strain-optical coefficient at a fixed time is plotted against temperature, it first increases and then decreases after passing through a maximum at Tmax with increasing temperature. The higher the degree of crystallinity, the higher are the equilibrium values of the strain-optical coefficient and Tmax. The curves for strain-optical coefficient versus time and relaxation modulus versus time below Tmax can be superposed well by a horizontal shift along the abscissa. The optical shift factor obeys the original WLF equation, while the mechanical shift factor is much larger than the optical one. The molecular mechanisms corresponding to this dispersion of the strain-optical coefficient and viscoelastic αc absorption peak near Tmax are discussed.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1967.160050607
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  • 6
    Electronic Resource
    Electronic Resource
    Rheo-optical studies of high polymers. XIV. Study of the deformation mechanism in polymer blends of polypropylene with ethylene-propylene rubber (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 171-182 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: To clarify the deformation mechanism in polyblends of polypropylene with ethylene-propylene rubber having different compositions, simultaneous measurements of the infrared dichroism with stress and strain under a constant rate of strain of 1.64%/min have been carried out. The orientation function of the crystallographic c axis of polypropylene in the blends has been obtained as a function of strain ranging from 0 to 20% and of polypropylene content ranging from 0.3 to 1.0. These results have been compared with the temperature dependences of the dynamic Young's modulus and of the loss modulus, as well as of stress-strain curves for the same blends. The modulus data analyzed by Kerner's equation reveal the occurrence of phase inversion at polypropylene contents higher than about 0.5, and this is supported by the infrared dichroism data. The strong effect of quenching on crystalline structure and mechanical properties of pure polypropylene has also been elucidated.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070114
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  • 7
    Electronic Resource
    Electronic Resource
    A rheo-optical study on the reformation of structure in racemic poly(γ-benzyl glutamate) liquid crystals (1984)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 24 (1984), S. 355-360 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    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: Transmitted light intensities were measured by means of the polarized light technique for the nematic liquid crystal phase of racemic poly(γ-benzyl glutamate) (PBG) in m-cresol at 25°C after cessation of steady flow at shear rates ranging from 0.2 to 110 s-1. Weight-average molecular weights of PBG used were 1.5, 2.1, and 2.6 × 105, while the concentrations varied between 20, 30, and 40 wt percent. Transmitted light intensities with crossed and parallel polarizers, Ix and I|, show wavy changes with time after cessation of steady flow, indicating the retardation decreases with time. An attempt was made to explain experimental results on the basis of a simple model, in which not only relaxation of molecular orientation but also effects of the wall and disclination were taken into account.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760240510
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  • 8
    Electronic Resource
    Electronic Resource
    Structure and physical properties of biaxially stretched polyethylene terephthalate sheet after heat-setting (1992)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 32 (1992), S. 481-487 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    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 consumption of hot-fillable poly(ethylene terephthalate) bottles is extremely large and is still increasing in Japan. This type of bottle is generally manufactured by the heat-set method using hot molds after stretch-blow molding. In this study, the method is simulated using a setting application in which sheets can be stretched constraining their sizes on a hot aluminum block. The crystallinities of the sheets are found to depend on the thermal history, i.e., the duration and temperature of the heat-set cycle. Heat-setting mitigates thermal-shrinkage of the sheets which is due to the increase in crystallinity or in the tense segments in the amorphous region. The structure of the heat-set sheet varies depending on the original stretched sheet. For a sample of low draw ratio, the crystallinity does not increase because of the heat-set. For a sample of medium draw ratio, the crystallinity increases greatly and the tense segments in the amorphous region also increase because of heat-set. For a sample of high draw ratio, the crystallinity increases a little but the numbers of the crystallite and tense segments in the amorphous region do not change with the heat-set.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760320705
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  • 9
    Electronic Resource
    Electronic Resource
    Investigation of the three region flow curve of polymeric liquid crystals by rheo-optical methods (1993)
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 33 (1993), S. 1022-1026 
    Details
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    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: Steady flow behavior of bulk liquid crystals and polymeric liquid crystals are summarized into a three region flow curve. Changes in the internal structure during deformation and flow were investigated by rheo-optical methods. Two different optical geometries were used. In one method, a light beam passed through perpendicular to the shear plate, and in the other method a light beam passed perpendicular to the edge of the lamina flow. The results indicate that the details of the internal texture do not necessarily appear in the rheological properties, such as viscosity, and that the molecular orientation mechanism under shear force is fundamentally different in a liquid crystal of rod-like molecules and a suspended solution of rod-like molecules. In the isotropic solution, the rod-like molecules float or are suspended in a solvent and are oriented by the flow field of the solvent fluid. However, in a liquid crystal, the torque propagates directly on the individual rod-like molecules, affecting their orientation. They flow as if it were a plastic solid.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pen.760331603
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  • 10
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    Dependence of the packing structure of mesogenic groups on the flexible spacer length of liquid-crystalline side-chain polymers (1989)
    American Chemical Society
    Details
    Publication Date: 1989-05-01
    Print ISSN: 0024-9297
    Electronic ISSN: 1520-5835
    Topics: Chemistry and Pharmacology , Physics
    Published by American Chemical Society
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