Materials science anisotropic behavior

As can be seen in H, Kelkers l) excellent review on the history of liquid crystals, investigations on liquid crystalline polymers already exist before F. Reinitzer in 1888 gave the very first description of a low molar mass liquid crystal (1-l.c.). While, however, 1-l.c. s have become an extensive field of research and application during the past decades, these activities on l.c. polymers have come rather late. The research on l.c. polymers during the last years is mainly joined with activities in material science and tries to realize polymers with exceptional properties. These exceptional properties are expected because of the combination of the physical anisotropic behavior of l.c. and the specific properties of macromolecular material. 

In this chapter we have described the mesomorphic behavior and ionic conductivities of ionic liquid-based liquid crystalline materials. These ion-active anisotropic materials have great potentials for applications not only as electrolytes that anisotropically transport ions at the nanometer scale but also as ordered solvents for reactions. Ionic liquid crystals have also been studied for uses as diverse as nonliner optoelectronic materials [61, 62], photoluminescent materials [78], structuredirecting reagents for mesoporous materials [79, 80] and ordered solvents for organic reactions [47, 81]. Approaches to self-organization of ionic liquids may open a new avenue in the field of material science and supramolecular chemistry. 

McCullough, R. L. Anisotropic Elastic Behavior of Crystalline Polymers, Treatise on Material Science and Technology. New York Academic, pp. 453-540, 1977. 

On a material science level, thermoplastics also have different behaviors than many other materials. For starters, most thermoplastics are anisotropic that is, they have different properties when measured in different directions. They also have different behavior in compression than they do in tension. And their mechanical behavior is nonlinear, in that their behavior does not follow the traditional linear stress-strain relationship seen in metals. This means the classic engineering equations for structural calculations are not always accurate. 

Polymer science is a specialized field of materials science that focuses on the study of polymers. In addition to the unique characteristics of thermoplastics described earlier (anisotropic behavior, nonlinear elastic response, etc.), polymer science also has a unique language (Figure 3.6). Just like the word plastic has many meanings, many of the words used in polymer science have many meanings. In this section, we will review some of the more important terms, in order to provide a platform for subsequent discussion. 

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