Study of the distribution of molecular orientation in highly oriented polyethylene by x-ray diffraction

1991 ◽  
Vol 24 (17) ◽  
pp. 4948-4956 ◽  
Author(s):  
Claude Paul Lafrance ◽  
Michel Pezolet ◽  
Robert E. Prud'homme
Keyword(s):  
Molecular Orientation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oriented Polyethylene

Study of the distribution of the molecular orientation in thick polyethylene samples by X-ray diffraction, infra-red dichroism and Raman spectroscopy

Polymer ◽  
1993 ◽  
Vol 34 (24) ◽  
pp. 5029-5037 ◽  
Author(s):  
Claude-Paul Lafrance ◽  
Paul Chabot ◽  
Marie Pigeon ◽  
Robert E Prud'homme ◽  
Michel Pézolet
Keyword(s):  
Raman Spectroscopy ◽  
Molecular Orientation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Infra Red

scholarly journals Orientation Effect in Poly (Butylene Succinate) Fibers

2003 ◽  
Vol 11 (1) ◽  
pp. 51-56 ◽  
Author(s):  
K. Nakayama ◽  
T. Masuda ◽  
A. Cao ◽  
J. Vega-Baudrit ◽  
R. Pereira
Keyword(s):  
Molecular Orientation ◽  
Fiber Structure ◽  
X Ray Diffraction ◽  
Velocity Measurements ◽  
Screw Extruder ◽  
Butylene Succinate ◽  
X Ray ◽  
Single Screw ◽  
Single Screw Extruder ◽  
Structure Morphology

Fibers of poly (butylene succinate) (PBS) were prepared using a single screw extruder at various take-up speeds. Changes in fiber structure, morphology and physical properties were investigated using sonic velocity measurements and X-ray diffraction. High take up speeds enhanced some of the properties of PBS fibers as a consequence of changes in molecular orientation and crystallinity. Spherulites of PBS were also obtained at 90°C.

scholarly journals Influence of Molecular Orientation on the Melting Behavior of Poly(phenylene sulfide) Fibers

2013 ◽  
Vol 8 (3) ◽  
pp. 155892501300800
Author(s):  
Prabhakar Gulgunje ◽  
Gajanan Bhat ◽  
Joseph Spruiell
Keyword(s):  
Differential Scanning Calorimetry ◽  
Molecular Orientation ◽  
Polarized Light ◽  
Melting Behavior ◽  
Probable Mechanism ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Phenylene Sulfide

The influence of molecular orientation on the melting behavior of draw-annealed poly(phenylene sulfide) fibers is investigated in the present paper. Tools used to probe the investigation were differential scanning calorimetry, polarized light optical microscopy, wide angle X-ray diffraction, and small angle X-ray diffraction. It is shown that molecular orientation in the crystalline and amorphous regions play a key role in crystal rearrangement during melting. A probable mechanism by which amorphous orientation influences crystal rearrangement is also discussed.

Stretching-Induced Orientation for Improving the Mechanical Properties of Electrospun Polyacrylonitrile Nanofiber Sheet

2008 ◽  
Vol 47-50 ◽  
pp. 1169-1172 ◽  
Author(s):  
Si Zhu Wu ◽  
Feng Zhang ◽  
Xiao Xiao Hou ◽  
Xiao Ping Yang
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanofibers ◽  
Molecular Orientation ◽  
High Performance ◽  
Carbon Composites ◽  
X Ray Diffraction ◽  
Fiber Alignment ◽  
X Ray ◽  
N2 Atmosphere ◽  
Potential Precursor

Partially aligned and oriented polyacrylonitrile(PAN)-based nanofibers were electrospun from PAN and CNTs/PAN in the solution of dimethylformamide(DMF) to manufacture the carbon nanofibers. The as-spun nanofibers were hot-stretched in a temperature controlled oven to enhance its crystallinity and molecular orientation. Therefore it were stabilized at 250 ( under a stress, and carbonized at 1000 ( in N2 atmosphere by fixing the length of the stabilized nanofiber to convert them into carbon nanofibers. With the hot-stretched process and with the content of CNTs, the mechanical properties will be enhanced correspondingly. The crystallinity of the stretched fibers confirmed by X-ray diffraction has also increased. For PAN nanofibers, the improved fiber alignment and crystallinity resulted in the increased mechanical properties, such as the modulus and tensile strength of the nanofibers. It was concluded that the hot-stretched nanofiber and the CNTs/PAN nanofibers can be used as a potential precursor to produce high-performance carbon composites.

Molecular orientation of methylene blue intercalated in layer-charge-controlled montmorillonites

2003 ◽  
Vol 18 (11) ◽  
pp. 2639-2643 ◽  
Author(s):  
Yoshiro Kaneko ◽  
Nobuo Iyi ◽  
Juraj Bujdák ◽  
Ryo Sasai ◽  
Takektoshi Fujita
Keyword(s):  
Methylene Blue ◽  
Molecular Orientation ◽  
Layer Charge ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Charge Densities ◽  
Clay Surface ◽  
Host Materials

The effect of the layer-charge density of clay on the orientation and aggregation of a cationic dye, methylene blue (MB), in MB/clay films was investigated using a series of layer-charge-controlled montmorillonites as host materials. Polarized ultraviolet-visible spectroscopy and x-ray diffraction were used for the characterization of the arrangement and orientation of dye cations in host interlayer spaces. It was revealed that high charge densities of layers induced the formation of relatively ordered and homogeneous phases with dye dimers. The reduction of the charge led to the formation of disordered, mixed phases with large amounts of monomers (isolated dye cations). Dimers and monomers were slightly tilted against the plane of the clay surface, and their angles were not affected by the layer charge.

X-Ray Diffraction Studies of Crystallization in Elastomers

1956 ◽  
Vol 29 (2) ◽  
pp. 438-450 ◽  
Author(s):  
Leroy E. Alexander ◽  
Stanley Ohlberg ◽  
G. Russell Taylor
Keyword(s):  
Natural Rubber ◽  
Molecular Orientation ◽  
Room Temperature ◽  
Geiger Counter ◽  
Preferred Orientation ◽  
X Ray Diffraction ◽  
X Ray ◽  
A Value ◽  
Integrated Intensity ◽  
Beam Monitor

Abstract In general, extension of an elastomer results in a degree of preferred orientation of the molecular chains composing the amorphous phase. Therefore the amorphous fraction of a partially crystalline elastomer must be related to the integrated intensity of the amorphous diffraction halo rather than to the intensity at any one azimuth. A noteworthy exception is natural rubber, for which simple meridional measurements suffice. A Geiger-counter apparatus, with beam monitor and temperature-controlling accessories, is described for making accurate measurements of the x-ray intensities scattered at any azimuth and at small or moderate Bragg angles. Measurements of crystallinity in natural rubber are in essential agreement with the findings of previous workers. When polybutadiene is extended at room temperature, molecular orientation occurs, but little if any crystallization. Measurements at lowered temperatures show that the crystalline fraction becomes appreciable at about 0° C and that it increases with further reduction of temperature and with increasing extension ratio. Preferred orientation of the crystalline regions in extended polybutadiene has been measured quantitatively with the object of providing jointly with birefringence measurements a value of the birefringence of a single crystal of polybutadiene.

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