Results 161 to 170 of about 27,269,029 (232)

Differential thermal analysis of polybutene‐1

Journal of Polymer Science Part C: Polymer Symposia, 1964
AbstractThe three polymorphic forms of polybutone‐1 may be easily characterized by DTA: Form I has a DTA peak near 132°C; Form II has a peak near 118°C; and Form III has doublet peaks at 104° and 118°C. The kinetics of the room temperature transformation of Form II to Form I have been qualitatively investigated by DTA.
Bert H. Clampitt, Richard H. Hughes
openaire   +1 more source

Zur Toxikologie von Polybuten-(1)

F�hner-Weilands Sammlung von Vergiftungsf�llen Archiv f�r Toxikologie, 1968
Unter den Bedingungen eines halbjahrigen Futterversuchs (1% und 10% Gehalt) an Ratten fand sich kein Anhalt fur eine gesundheitliche Bedenklichkeit des Kunststoffs Polybuten-(1).
Gerhard Bornmann, Arnold Loeser
openaire   +1 more source

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
openaire   +1 more source

Multiple phase transitions of polybutene‐1

Journal of Polymer Science Part C: Polymer Symposia, 1966
AbstractMultiple phase transitions of polybutene‐1 in the form III modification have recently been the subject of discussion by a number of authors. The exact nature of the observed phenomena has remained in doubt, leading to the proposal of divergent theories.
C. Geacintov, R. B. Miles, H. J. L. Schuubmans   +2 more
openaire   +1 more source

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 ...
S. Abedi, N. Sharifi-Sanjani
openaire   +1 more source

Nucleation Mechanism for Form II to I Polymorphic Transformation in Polybutene-1

Macromolecules, 2020
By means of in situ small-/wide-angle X-ray scattering (SAXS/WAXS) techniques, nucleation mechanism for Form I crystals of polybutene-1 (PB-1) has been investigated by heating the early-stage polym...
Binghua Wang, K. He, Yaguang Lu, Yufeng Zhou, Jinlong Chen, C. Shen, Jingbo Chen, Yongfeng Men, Bin Zhang   +8 more
semanticscholar   +1 more source

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.
A. E. Woodward, D. R. Morrow
openaire   +1 more source

Hierarchical structure of polybutene-1 in crystal blocks resulting from the form II to I solid-to-solid transition as revealed by small-angle X-ray scattering

, 2020
Polybutene-1 (PB-1) exhibits excellent mechanical properties, while an unavoidable polymorphic transition from a metastable form II to the stable form I occurs after solidification from the molten state.
Yongna Qiao, M. Schulz, Hai Wang, Ran Chen, M. Schäfer, T. Thurn‐Albrecht, Yongfeng Men   +6 more
semanticscholar   +1 more source

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
J. P. Luongo, R. Salovey
openaire   +1 more source

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
openaire   +1 more source