Simulation of polyimide fibers with trilobal cross section produced by dry-spinning technology

2015 ◽  
Vol 55 (9) ◽  
pp. 2148-2155 ◽  
Author(s):  
Gang Deng ◽  
Shihua Wang ◽  
Xin Zhao ◽  
Qinghua Zhang
Keyword(s):  
Cross Section ◽  
Polyimide Fibers ◽  
Dry Spinning

scholarly journals On the cross-section of shaped fibers in the dry spinning process: Physical explanation by the geometric potential theory

2019 ◽  
Vol 14 ◽  
pp. 102347 ◽  
Author(s):  
Zhanping Yang ◽  
Feng Dou ◽  
Tao Yu ◽  
Minfeng Song ◽  
Haoxuan Shi ◽  
...  
Keyword(s):  
Potential Theory ◽  
Cross Section ◽  
Physical Explanation ◽  
Dry Spinning ◽  
Spinning Process ◽  
The Cross ◽  
Shaped Fibers

The properties, morphology and structure of BPDA/ PPD/ BOA polyimide fibers

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Senbiao Huang ◽  
Zhongmin Gao ◽  
Xiaoye Ma ◽  
Xuepeng Qiu ◽  
Lianxun Gao
Keyword(s):  
Cross Section ◽  
Molecular Orientation ◽  
Microphase Separation ◽  
Amic Acid ◽  
Wet Spinning ◽  
Excellent Thermal Stability ◽  
X Ray ◽  
Polyimide Fibers ◽  
Spinning Process ◽  
Microfibrillar Structure

AbstractA family of random copoly(amic acid)s (coPAAs) containing the 2-(4- aminophenyl)-5-aminobenzoxazole (BOA) moiety were synthesized in DMAc, followed by dry-jet wet spinning process into as-spun PAA fibers. The modified polyimide (PI) fibers were obtained from PAA fibers after imidized and drawn in a furnace. The mechanical properties of fibers were improved by incorporating BOA into BPDA/PPD backbone. SEM photo showed that the cross-section of each stage fibers was round and voids free. Besides, the “skin-core” and microfibrillar structure were not observed. The thermal properties of PI fibers were also investigated. The results showed that the PI fibers owned excellent thermal stability, moreover, the dimensional stability and the microphase separation of fibers were improved by heat-drawn stage. The Tg were found to be around 290°C by TMA and DMA. The X-ray (WAXD and SAXS) experiments indicated that the longitudinal stacks, the molecular orientation and the structural homogeneity of PI fiber were improved in the preparation process of fibers.

Simulation of dry-spinning process of polyimide fibers

2009 ◽  
Vol 113 (5) ◽  
pp. 3059-3067 ◽  
Author(s):  
Gang Deng ◽  
Qingming Xia ◽  
Yuan Xu ◽  
Qinghua Zhang
Keyword(s):  
Polyimide Fibers ◽  
Dry Spinning ◽  
Spinning Process

Polyimide fibers prepared by dry-spinning process: imidization degree and mechanical properties

2013 ◽  
Vol 48 (22) ◽  
pp. 7863-7868 ◽  
Author(s):  
Yuan Xu ◽  
Shihua Wang ◽  
Zhentao Li ◽  
Qian Xu ◽  
Qinghua Zhang
Keyword(s):  
Mechanical Properties ◽  
Polyimide Fibers ◽  
Dry Spinning ◽  
Spinning Process

XUV Absorption Spectra of Carbon Ions

1988 ◽  
Vol 102 ◽  
pp. 71-73
Author(s):  
E. Jannitti ◽  
P. Nicolosi ◽  
G. Tondello
Keyword(s):  
Absorption Spectra ◽  
Cross Section ◽  
Theoretical Calculations ◽  
Photoionization Cross Section ◽  
Carbon Ions

AbstractThe photoabsorption spectra of the carbon ions have been obtained by using two laser-produced plasmas. The photoionization cross-section of the CV has been absolutely measured and the value at threshold, σ=(4.7±0.5) × 10−19cm2, as well as its behaviour at higher energies agrees quite well with the theoretical calculations.

Elastic Scattering in Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 252-253
Author(s):  
J. Langmore ◽  
M. Isaacson ◽  
J. Wall ◽  
A. V. Crewe
Keyword(s):  
Electron Microscopy ◽  
Elastic Scattering ◽  
Cross Section ◽  
Quantum Noise ◽  
Dark Field ◽  
Elastic Cross Section ◽  
Biological Molecules ◽  
Dark Field Microscopy ◽  
Field Systems ◽  
Effects Of Radiation

High resolution dark field microscopy is becoming an important tool for the investigation of unstained and specifically stained biological molecules. Of primary consideration to the microscopist is the interpretation of image Intensities and the effects of radiation damage to the specimen. Ignoring inelastic scattering, the image intensity is directly related to the collected elastic scattering cross section, σɳ, which is the product of the total elastic cross section, σ and the eficiency of the microscope system at imaging these electrons, η. The number of potentially bond damaging events resulting from the beam exposure required to reduce the effect of quantum noise in the image to a given level is proportional to 1/η. We wish to compare η in three dark field systems.

A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin

1973 ◽  
Vol 31 ◽  
pp. 698-699
Author(s):  
V. Mizuhira ◽  
Y. Futaesaku
Keyword(s):  
Cross Section ◽  
Tannic Acid ◽  
Elastic Fiber ◽  
The Other ◽  
New Approach ◽  
Tissue Block ◽  
Active Reaction ◽  
The Cross

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.

Electron Irradiation Effects in Polyoxymethylene Crystals Grown Inside Trioxane Crystals

1971 ◽  
Vol 29 ◽  
pp. 78-79
Author(s):  
J. P. Colson ◽  
D. H. Reneker
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Detailed Examination ◽  
The Other ◽  
Electron Micrograph ◽  
Irradiation Effects ◽  
Threefold Axis ◽  
Typical Sample ◽  
Polymer Crystals ◽  
Chain Axis

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.

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