Structure and high-resolution thermogravimetry of liquid-crystalline copoly(p-oxybenzoate-ethylene terephthalate-p-benzamide)

1999 ◽  
Vol 48 (12) ◽  
pp. 1277-1287 ◽  
Author(s):  
Xin-Gui Li ◽  
Mei-Rong Huang ◽  
Yuliang Yang
Author(s):  
Patricia M. Wilson ◽  
David C. Martin

Efforts in our laboratory and elsewhere have established the utility of low dose high resolution electron microscopy (HREM) for imaging the microstructure of crystalline and liquid crystalline polymers. In a number of polymer systems, direct imaging of the lattice spacings by HREM has provided information about the size, shape, and relative orientation of ordered domains in these materials. However, because of the extent of disorder typical in many polymer microstructures, and because of the sensitivity of most polymer materials to electron beam damage, there have been few studies where the contrast observed in HREM images has been analyzed in a quantitative fashion.Here, we discuss two instances where quantitative information about HREM images has been used to provide new insight about the organization of crystalline polymers in the solid-state. In the first, we study the distortion of the polymer lattice planes near the core of an edge dislocation and compare these results to theories of dislocations in anisotropic and liquid crystalline solids. In the second, we investigate the variations in HREM contrast near the edge of wedge-shaped samples. The polymer used in this study was the diacetylene DCHD, which is stable to electron beam damage (Jc = 20 C/cm2) and highly crystalline. The instrument used in this work was a JEOL 4000 EX HRTEM with a beam blanidng device. More recently, the 4000 EX has been installed with instrumentation for dynamically recording scattered electron beam currents.


1995 ◽  
Vol 60 (11) ◽  
pp. 1869-1874 ◽  
Author(s):  
Anatoly E. Nesterov ◽  
Yuri S. Lipatov ◽  
Vitaly V. Horichko

The phase separation in the blends of poly(methyl methacrylate) and liquid-crystalline polymer (copolymer of ethylene terephthalate and p-hydroxybenzoic acid) has been studied by the light scattering method and the cloud point curves have been obtained. Simultaneously some morphological features of the blends have been observed. It was found that the initial blends are in the state of forced compatibility and that thermally induced phase separation occurs by the mechanism of spinodal decomposition but presumably in the non-linear regime.


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