Comparative analysis of the structure of two thermotropic LC copolyesters

Investigation of the Structural Deformation Mechanisms Induced by Microindentation in a Thermotropic Liquid Crystalline Copolyester Using Synchrotron X-ray Microdiffraction

“…13,[19][20][21][22][23] The radial profile in Figure 2c was obtained by integrating the intensity of the equatorial reflection along the azimuth direction within an annulus segment of ∼3°a s shown in Figure 2b. The asymmetry of the main peak is generally attributed to the presence of two strongly overlapping peaks that cannot be individually resolved, suggesting pseudohexagonal (P H ) symmetry [17][18][19][20][21][22][23] (orthorhombic lattice with a ) 3 1/2 b). This phase observed at room temperature is generally believed to be a typical signature of compression-molded or as-extruded samples.…”

“…This phase observed at room temperature is generally believed to be a typical signature of compression-molded or as-extruded samples. [17][18][19][20][21][22][23] A fit was correspondingly achieved using three Lorentzian functions and a first-order background polynomial. The two main peaks, indexed as 110 PH and 200 PH , were found respectively at q ) 14.05 and 14.88 nm -1 (d 110 ) 4.45 Å, d 200 ) 4.22 Å, respectively), which is in good agreement with values found by other authors.…”

“…The two main peaks, indexed as 110 PH and 200 PH , were found respectively at q ) 14.05 and 14.88 nm -1 (d 110 ) 4.45 Å, d 200 ) 4.22 Å, respectively), which is in good agreement with values found by other authors. [17][18][19][20][21][22][23] It should be noted that since the structure is essentially nonperiodic along the c-axis, the assignment of the l index of hkl reflections only refers, in our case, to the layer line number. The shoulder around q ) 19 nm -1 is thought to be an extension of the 211 PH reflection which was found at q ) 19.68 nm -1 (d ) 3.19 Å).…”

“…Those have been extensively studied lately because of exceptional mechanical properties and, therefore, important potential industrial applications in high-performance materials. 7 The microstructure of these materials has been principally studied using electron microscopy [8][9][10][11][12] (EM) and small/wide-angle X-ray scattering (SAXS/WAXS) [13][14][15][16][17][18][19][20][21][22][23][24] techniques. The latter have also been used extensively to assess structural changes upon annealing [19][20][21][22][23] and during crystallization.…”

Mesomorphism in polymers and its mechanotropic variety for polyethylene in binary polymer blends based on it

“…More than 10 families of totally aromatic copolyesters of statistical structure of both domestic and foreign make have been investigated in detail at present [4][5][6][7][8]. A comparative analysis of the phase composition and temperature evolution of the structure of this class of rigid-chain HMWCs in which the chain is constructed based on monomer links of different architecture, which destroy the regular packing of macromolecules in both the longitudinal direction and that perpendicular to the chain axes, with monomers of equal and different length, and containing and not containing side groups has shown the following:…”