Simultaneous Synchrotron X-ray Diffraction and Stress−Strain or Stress−Relaxation Experiments for the Study of Parallel and Perpendicular Orientation in a Liquid Crystalline Polymer

2008 ◽  
Vol 41 (2) ◽  
pp. 421-428 ◽  
Author(s):  
Juan P. Fernández-Blázquez ◽  
Antonio Bello ◽  
María L. Cerrada ◽  
Ernesto Pérez
1991 ◽  
Vol 227 ◽  
Author(s):  
Joonhyun Nam ◽  
Tomohiro Fukai ◽  
Thein Kyu

ABSTRACTA thermotropic liquid crystalline copolymer consisting of bisphenol E diacetate, isophthalic acid and 2,6-naphthalene dicarboxylic acid was blended with polyether imide by dissolving in a mixed solvent of phenol/1,1,2,2-tetrachloroethane in a ratio of 60/40 w/w and co-precipitating the ternary solution in non-solvent (methanol). Wide-angle x-ray diffraction and differential scanning calorimetry studies revealed that the blends were completely amorphous with a single glass transition temperature. The single phase was probably entrapped during solvent removal, but these mixes were unstable and phase separated upon heating. Mesophase structure developed in the LCP rich region with continued annealing. The evolution of crystalline texture was monitored by time-resolved wide-angle x-ray diffraction following a temperature jump from ambient to 265 °C. The recrystallization process of LCP was found to slow down in the blend state relative to that of the neat LCP.


2010 ◽  
Vol 428-429 ◽  
pp. 144-149
Author(s):  
Xiao Dong Chen ◽  
Nan Qiao Zhou ◽  
Hai Zhang

A thermotropic liquid crystalline polyurethane (LCPU) was synthesized by the polyaddition reaction of 3,3'-dimethyl-4,4'-biphenylene diisocyanate (TODI) with 4,4-bis(6-hydroxyhexoxy)biphenyl (BHHBP). The liquid crystalline behavior of the polymer was investigated by differential scanning calorimetry (DSC), polarized optical microscopy (POM), wide angle X-ray diffraction (WAXD). The LCPU exhibited a nematic phase with a threaded texture and had a wide mesophase temperature range. And thermogravimetric analysis (TGA) indicated the decomposition temperature of the LCPU was >300°C. The observation of POM showed that the LCPU was a thermotropic nematic liquid crystalline polymer at certain temperature range.


2012 ◽  
Vol 116 (32) ◽  
pp. 9846-9859 ◽  
Author(s):  
Mario Encinar ◽  
Aránzazu Martínez-Gómez ◽  
Ramón G. Rubio ◽  
Ernesto Pérez ◽  
Antonio Bello ◽  
...  

2007 ◽  
Vol 40 (3) ◽  
pp. 703-709 ◽  
Author(s):  
Juan P. Fernández-Blázquez ◽  
Antonio Bello ◽  
Ernesto Pérez

1995 ◽  
Vol 52 (1) ◽  
pp. 671-680 ◽  
Author(s):  
R. E. Geer ◽  
S. B. Qadri ◽  
R. Shashidhar ◽  
A. F. Thibodeaux ◽  
R. S. Duran

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