Structure and Defects in Sanidic Liquid Crystalline Polymers. 1

Abstract

A series of polymeric "sanidic" materials were investigated and a number of criteria developed which must be fulfilled in order to classify these materials as liquid crystalline. By a combination of electron diffraction and high-resolution imaging, the biaxial phase is shown to consist of poorly developed microcrystals embedded in a liquid-like amorphous matrix. Only some materials are able to form a liquid crystalline phase at higher temperatures, but this phase is uniaxial.

The impact of new microscopical methods on the investigation of polymers. 2. Electron crystallography and high resolution imaging

“…The method has been used to obtain the structure of monomeric analogues of the discotic triphenylene ethers and esters [43,44] as well as sanidic aromatic polymeric amides [45,46]. This is now standard practice in theoretical chemistry and many degrees of accuracy can be attained, ranging from force field calculations via semi-empirical quantum mechanical methods to the ab initio methods.…”

“…Examples of successful structure determinations using a combination of electron diffraction, high resolution imaging and molecular modeling are the liquid crystalline polymers and their monomeric analogues [31, [43][44][45] as well as several linear polysaccharides [13,14,25,331.…”

“…Because of beam-sensitivity, the correct transfer function cannot be found experimentally by defocusing but has to be calculated beforehand [43,45]. Because of beam-sensitivity, the correct transfer function cannot be found experimentally by defocusing but has to be calculated beforehand [43,45].…”

“…On the basis of the electron diffraction pattern from the sample, a decision is made as to which spatial frequencies are to be transferred and the appropriate phase contrast transfer function chosen [43,45,95,99]. On the basis of the electron diffraction pattern from the sample, a decision is made as to which spatial frequencies are to be transferred and the appropriate phase contrast transfer function chosen [43,45,95,99].…”

Synthesis and Liquid Crystalline Properties of Hyperbranched Aromatic Polyesters Consisting of Azoxybenzene Mesogens and Polymethylene Spacers

“…[1][2][3][4][5][6][7] In contrast, the side chain LCPs [8][9][10][11][12][13] contain the mesogenic units in the side branches or as pendants. Many papers [1][2][3][4][5][6][7] have been published during the past quarter of a century on the structure-property relationships of main chain LCPs. Thanks to those research efforts, the structure-property relationship of the main chain and side chain LCPs are rather well established.…”