Results 161 to 170 of about 1,132 (188)

Effects of molecular weight on polybutene-1 cold crystallization from polybutene-1/polypropylene blend

Polymer, 2019
Abstract The influence of molecular weight on the polymorphic behavior of polybutene-1 (PB-1) in cold crystallization from PB-1/iPP (isotactic polypropylene) blend has been investigated. Twelve PB-1/iPP blend samples of 90/10 (w/w) composition were prepared from three PB-1s and four iPPs with molecular weight of 77–711 kg/mol and 12–580 kg/mol ...
Zhaohui Su, Zhaohui Su, Zhenxing Zhong, Zhenxing Zhong   +3 more
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Time dependent crystallinity of polybutene‐1

Polymer Engineering & Science, 1966
AbstractIsotactic Polybutene‐1 can exist in 4 different crystalline phases of varying stability of which two are of greatest importance because they are involved in solidification from the melt initially, the melt cools into an unstable crystalline phase which gradually and spontaneously transforms into a stable, stronger, stiffer, more crystalline ...
S. Y. Choi, J. P. Rakus, J. L. O'Toole
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Annealing Behavior of Isotactic Polybutene-1

Journal of Macromolecular Science: Part A - Chemistry, 1987
The annealing behavior of isotactic polybutene-1 (PB-1) has been studied by differential scanning calorimetry and wide-angle x-ray diffraction. On annealing at 110°C, PB-1 yields thick crystals melting at -140°C which are mainly of Form I. An increase in the heat of fusion (ΔHf) and crystallinity is found for annealing times up to 12 h at 110°C; at ...
Kishore, K, Vasanthakumari, R
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Annealing of polybutene‐1 single crystals

Journal of Polymer Science Part A-2: Polymer Physics, 1968
AbstractThe effects of thermal treatment in the 70–90°C. region on polybutene‐1 crystals, prepared by precipitation from dilute pentyl acetate solutions and with lath, hexagonal, and square morphologies, have been studied by using electron microscopy.
D. R. Morrow, A. E. Woodward
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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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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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