Crystalline Phases of Polymers

Finkelmann, H., and Jahns, E. (1989). Association and liquid crystalline phases of polymers in solution. In Polymer Association Structures, El-Nokaly, M. A. (Ed.), ACS Symposium Series 384, pp. 1-20. Am. Chem. Soc., Washington, DC. 

Association and Liquid Crystalline Phases of Polymers in Solution... 

The first part of the book discusses formation and characterization of the microemulsions aspect of polymer association structures in water-in-oil, middle-phase, and oil-in-water systems. Polymerization in microemulsions is covered by a review chapter and a chapter on preparation of polymers. The second part of the book discusses the liquid crystalline phase of polymer association structures. Discussed are meso-phase formation of a polypeptide, cellulose, and its derivatives in various solvents, emphasizing theory, novel systems, characterization, and properties. Applications such as fibers and polymer formation are described. The third part of the book treats polymer association structures other than microemulsions and liquid crystals such as polymer-polymer and polymer-surfactant, microemulsion, or rigid sphere interactions. 

In addition to barotropic liquid crystals of flexible polymers, there are also a few reports on the observation of the liquid crystalline phase of polymers containing no mesogenic units of rigid rods. Aharoni (1988), for example, was very lucky to have found a series of the following polymers that form a thermotropic liquid crystal phase. 

Table IV shows that the values of transition temperatures Tg j slightly decrease with increasing n, which is probably due to the effect of internal plas-tification and was frequently observed in the case of comb-like polymers (21), The evaluation of the thermal effect inherent In this transition for PChMAA-II gave the value of 0,76-0,08 cal/g, which agrees well with the values of heats of melting, corresponding to the liquid crystalline phase-isotropic melt transition for low-molecular liqtdd crystals ( ), However, in contrast to the latter, which, as a rule, crystallize during cooling (see, for example, Pi re 33. the liquid crystalline phase of polymers vitrifies while cooled (Figure 5). In other words, in the case of polymers, the structure of the liquid C3 ystalline phase...

The fiber diameter distribution was studied by microscopy (optical microscope, Hitachi TM-1000 scanning electron microscope). Fiber orientation was studied by using birefringence and polarization IR-spectroscopy (SPECORD M 80 IR-spectrometer). Crystalline phase of polymer was studied by differential scaiming calorimetry (DSC) (differential scanning calorimeter). The packing density of fibrous materials was calculated as a function of airflow resistance variation with a special manometric pressure unit [7]. 

Conformations in crystalline phase of polymers Cohesion energy... 

Below the glass transition temperature, the heat capacities of amorphous and crystalline phases of polymers Cpa and Cpc, respectively) are roughly identical ... 

El-Nokaly, M. A. (ed.), Polymer Association Structures Microemulsions and Liquid Crystals , ACS, Washington, DC, 1989. The book discusses formation and characterization of microemulsions and the liquid crystalline phase of polymer association structures. 

What are the common conformations found in the crystalline phase of polymer fibers ... 

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