Results 201 to 210 of about 23,452,503 (249)

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
openaire   +2 more sources

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
openaire   +2 more sources

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
openaire   +2 more sources

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
openaire   +2 more sources

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
openaire   +2 more sources

Nucleation of crystallization in molten isotactic polybutene‐1

Journal of Polymer Science Part A-2: Polymer Physics, 1968
AbstractDroplet experiments have been performed on polybutene‐1. It was found that this polymer can be cooled to room temperature without homogeneous nucleation of crystallization. It was also found that when the polymer was heterogeneously nucleated, form I (as well as form II) could be crystallized directly from the melt.
D. Turnbull, Joanne R. Burns
openaire   +2 more sources

Thermally Induced Phase Transition of Polybutene-1 from Form I′ to Form II through Melt Recrystallization: Crucial Role of Chain Entanglement

Macromolecules, 2023
Lingling Ni, Chenxuan Sun, Shanshan Xu, Wangkai Xiang, Yong-Ze Pan, Bao Wang, Ying Zheng, Chengtao Yu, Pengju Pan   +8 more
semanticscholar   +1 more source

Kinetics of Nucleation and Growth of Form II to I Polymorphic Transition in Polybutene-1 as Revealed by Stepwise Annealing

, 2016
Kinetics of II to I polymorphic transformation in isotactic polybutene-1 (PB-1) and its annealing temperature and time dependencies have been investigated by means of differential scanning calorimetry and in situ wide-angle X-ray diffraction techniques ...
Yongna Qiao, Qiao Wang, Yongfeng Men
semanticscholar   +1 more source

Stretching-Induced Melting and Recrystallization Polymorphism Revealed in Polybutene-1

Macromolecules, 2023
Wei Li, Dai Zhang, Chunjing Qv, Rui-Xiong Zhao, Zhenzhen Ma   +4 more
semanticscholar   +1 more source