scholarly journals Molecular Orientation Behaviors with Optical Measurement and X-Ray Diffraction for Strip-Biaxially Stretched Syndiotactic Polypropylene Films.

1999 ◽  
Vol 56 (7) ◽  
pp. 445-455 ◽  
Author(s):  
Keiji NAGAYA ◽  
Yasushi HATANO ◽  
Sadao HIBI ◽  
Tsuneo KAWAKAMI ◽  
Yousuke KAKIZAKI ◽  
...  
Polymer ◽  
1993 ◽  
Vol 34 (24) ◽  
pp. 5029-5037 ◽  
Author(s):  
Claude-Paul Lafrance ◽  
Paul Chabot ◽  
Marie Pigeon ◽  
Robert E Prud'homme ◽  
Michel Pézolet

2003 ◽  
Vol 11 (1) ◽  
pp. 51-56 ◽  
Author(s):  
K. Nakayama ◽  
T. Masuda ◽  
A. Cao ◽  
J. Vega-Baudrit ◽  
R. Pereira

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.


2013 ◽  
Vol 8 (3) ◽  
pp. 155892501300800
Author(s):  
Prabhakar Gulgunje ◽  
Gajanan Bhat ◽  
Joseph Spruiell

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.


1991 ◽  
Vol 24 (17) ◽  
pp. 4948-4956 ◽  
Author(s):  
Claude Paul Lafrance ◽  
Michel Pezolet ◽  
Robert E. Prud'homme

2008 ◽  
Vol 47-50 ◽  
pp. 1169-1172 ◽  
Author(s):  
Si Zhu Wu ◽  
Feng Zhang ◽  
Xiao Xiao Hou ◽  
Xiao Ping Yang

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.


2003 ◽  
Vol 18 (11) ◽  
pp. 2639-2643 ◽  
Author(s):  
Yoshiro Kaneko ◽  
Nobuo Iyi ◽  
Juraj Bujdák ◽  
Ryo Sasai ◽  
Takektoshi Fujita

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.


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