Convenient Method of Chain-Growth Polycondensation for Well-Defined Aromatic Polyamides

2005 ◽  
Vol 26 (12) ◽  
pp. 979-981 ◽  
Author(s):  
Tsutomu Yokozawa ◽  
Daichi Muroya ◽  
Ryuji Sugi ◽  
Akihiro Yokoyama
Keyword(s):  
Convenient Method ◽  
Chain Growth ◽  
Aromatic Polyamides

Inductive Effect-Assisted Chain-Growth Polycondensation. Synthetic Development frompara-tometa-Substituted Aromatic Polyamides with Low Polydispersities

2005 ◽  
Vol 127 (29) ◽  
pp. 10172-10173 ◽  
Author(s):  
Ryuji Sugi ◽  
Akihiro Yokoyama ◽  
Taniyuki Furuyama ◽  
Masanobu Uchiyama ◽  
Tsutomu Yokozawa
Keyword(s):  
Inductive Effect ◽  
Chain Growth ◽  
Aromatic Polyamides

Self-initiated Chain-growth Polycondensation for Aromatic Polyamides

2004 ◽  
Vol 33 (3) ◽  
pp. 272-273 ◽  
Author(s):  
Tsutomu Yokozawa ◽  
Ryuji Sugi ◽  
Toshinobu Asai ◽  
Akihiro Yokoyama
Keyword(s):  
Chain Growth ◽  
Aromatic Polyamides

Well-Defined Star-Shaped Aromatic Polyamides from Chain-Growth Polymerization of Phenyl 4-(Alkylamino)benzoate with Multifunctional Initiators

2005 ◽  
Vol 38 (13) ◽  
pp. 5526-5531 ◽  
Author(s):  
Ryuji Sugi ◽  
Yoshio Hitaka ◽  
Akihiro Yokoyama ◽  
Tsutomu Yokozawa
Keyword(s):  
Chain Growth ◽  
Aromatic Polyamides

Electron Microscopic Observation of the Longitudinal Organization of Poly (p-Phenylene Terephthalamide) Fibers

1982 ◽  
Vol 40 ◽  
pp. 680-681
Author(s):  
Li Li-Sheng ◽  
L.F. Allard ◽  
W.C. Bigelow
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Microscopic Observation ◽  
Electron Microscopic Observation ◽  
Electron Microscopic ◽  
Aromatic Polyamides ◽  
Radial Arrangement ◽  
Scanning Electron ◽  
Better Than

The aromatic polyamides form a class of fibers having mechanical properties which are much better than those of aliphatic polyamides. Currently, the accepted morphology of these fibers as proposed by M.G. Dobb, et al. is a radial arrangement of pleated sheets, with the plane of the pleats parallel to the axis of the fiber. We have recently obtained evidence which supports a different morphology of this type of fiber, using ultramicrotomy and ion-thinning techniques to prepare specimens for transmission and scanning electron microscopy.

Thickness and composition determinations from T.E.M. specimens using both x-ray and backscattered electron data

1984 ◽  
Vol 42 ◽  
pp. 576-577
Author(s):  
M.D. Ball ◽  
H. Lagace ◽  
M.C. Thornton
Keyword(s):  
Electron Microscope ◽  
Atomic Number ◽  
Transmission Electron Microscope ◽  
Convenient Method ◽  
Flow Chart ◽  
X Ray ◽  
Intensity Measurements ◽  
Transmission Electron ◽  
Electron Intensity ◽  
Backscattered Electron

The backscattered electron coefficient η for transmission electron microscope specimens depends on both the atomic number Z and the thickness t. Hence for specimens of known atomic number, the thickness can be determined from backscattered electron coefficient measurements. This work describes a simple and convenient method of estimating the thickness and the corrected composition of areas of uncertain atomic number by combining x-ray microanalysis and backscattered electron intensity measurements.The method is best described in terms of the flow chart shown In Figure 1. Having selected a feature of interest, x-ray microanalysis data is recorded and used to estimate the composition. At this stage thickness corrections for absorption and fluorescence are not performed.

Stereo imaging in the shadow electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 120-121
Author(s):  
W. C. T. Dowell
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Convenient Method ◽  
Patent Application ◽  
Standard Technique ◽  
Stereo Imaging ◽  
Stereo Images ◽  
Specimen Height

Stereo imaging is not new to electron microscopy. Von Ardenne, who first published transmission pairs nearly forty hears ago, himself refers to a patent application by Ruska in 1934. In the early days of the electron microscope von Ardenne employed a pair of magnetic lenses to view untilted specimens but soon opted for the now standard technique of tilting the specimen with respect to the beam.In the shadow electron microscope stereo images can, of course, be obtained by tilting the specimen between micrographs. This obvious method suffers from the disadvantage that the magnification is very sensitive to small changes in specimen height which accompany tilting in the less sophisticated stages and it is also time consuming. A more convenient method is provided by horizontally displacing the specimen between micrographs. The specimen is not tilted and the technique is both simple and rapid, stereo pairs being obtained in less than thirty seconds.

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