Results 161 to 170 of about 23,507,238 (213)

Infrared characterization of polymorphism in polybutene‐1

Journal of Polymer Science Part A-2: Polymer Physics, 1966
AbstractThe transformations of the polymorphic forms of polybutene‐1 (I,II,III) were studied by infrared spectroscopy. Attenuated total reflectance spectra demonstrate that the II → I transformation occurs initially and most rapidly on the film surfaces. Electron irradiation experiments showed the II → I conversion can be suppressed by irradiation. The
R. Salovey, J. P. Luongo
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Local deformation in stretched polybutene‐1 spherulites

Journal of Polymer Science Part A-2: Polymer Physics, 1970
AbstractThe orientation of crystals in spherulites of modifications I and II of polybutene‐1 was studied by micro‐x‐ray diffraction. Changes in such micro‐x‐ray diffraction patterns were measured in various regions of the spherulites as a function of strain and time. The relationship between micro‐x‐ray diffraction from parts of spherulites and macro‐x‐
R. Y. Yee, Richard S. Stein
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Preparation of high isotactic polybutene-1

Journal of Applied Polymer Science, 2000
Polymerization of butene-1 (B-1) was carried out with a PP-TiCl3/Et2AlCl/methyl methacrylate (MMA) catalyst system in n-heptane. The influence of temperature, pressure, time and H2 on molecular weight, isotacticity, and catalytic activity were studied by viscometry, solubility in boiling diethyl ether, and measuring the polymer produced, respectively ...
N. Sharifi-Sanjani, S. Abedi
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Retardance of Form II to Form I Transition in Polybutene-1 at Late Stage: A Proposal of a New Mechanism

, 2018
The retardation of polybutene-1 form II to form I transition in the late stage has been investigated by means of time-resolved wide-angle X-ray diffraction.
Yongna Qiao, Hai Wang, Yongfeng Men
semanticscholar   +1 more source

Isotactic Polybutene-1 Single Crystals: Morphology

Journal of Applied Physics, 1964
Three crystalline modifications of isotactic polybutene-1 have been obtained from dilute solution in a variety of habits. These three crystalline modifications are: (a) tetragonal, (b) ``untwinned'' hexagonal, and (c) orthorhombic. The structure of the orthorhombic polymorph has not previously been reported.
V. F. Holland, Robert L. Miller
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Deformation and stress-induced transformation of polybutene-1

Journal of Macromolecular Science, Part B, 1989
Abstract The deformation at room temperature of thick (ca. 2 mm) and thin (ca. 1000 A) films of polybutene was characterized by electron microscopy and electron x-ray diffraction. The thin films, as studied, draw by micronecking whereas the thick films draw uniformly.
T. C. Hsu, Phillip H. Geil
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Thermodynamic properties of polybutene‐1 and butene‐1

Journal of Polymer Science Part A-2: Polymer Physics, 1967
Abstract : Using published specific heat data, the entropy, enthalpy, and Gibbs free energy of polybutene-1 (PB) were calculated over the temperature range 0 to 315K. The encraty, C sub p/T vs. T, calculated for PB exhibits a maximum at 60K and a small inflection at about 250K, which is associated with the glass transition.
M. C. Petree, R. W. Warfield
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Spontaneous Form II to I Transition in Low Molar Mass Polybutene-1 at Crystallization Temperature Reveals Stabilization Role of Intercrystalline Links and Entanglements for Metastable Form II Crystals

Macromolecules, 2018
As for the solid–solid transformation from form II to form I in polybutene-1, the intercrystalline links in amorphous phase and the temperature difference between crystallization and phase transition were thought to be essential in previous studies for ...
Yongna Qiao, Fei Yang, Ying Lu, Peiru Liu, Yue-sheng Li, Yongfeng Men   +5 more
semanticscholar   +1 more source

Laser‐excited Raman scattering in polybutene‐1

Journal of Polymer Science Part A-2: Polymer Physics, 1969
AbstractRaman spectra are described for the three crystalline modifications of polybutene‐1. The Raman frequencies are compared with infrared results and give good agreement. A normal‐coordinate analysis for A‐mode vibrations is presented for five possible helical conformations. The behavior of several calculated helix‐sensitive bands is characterized.
J. L. Koenig, S. W. Cornell
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Crystallization studies on deformed polybutene‐1 melts

Polymer Engineering & Science, 1971
AbstractAn apparatus was designed and built which allowed an investigation concerning the morphology and kinetics of crystallization of a deformed polybutene‐1 melt. The polymer was quenched from a temperature above its melting point to one of two crystallization temperatures.
Anthony Wereta, Costas G. Gogos
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