Mesophase Formation of Cellulosics

Rod-like macromolecules or semi-flexible chains such as cellulosics with a certain rigidity may form thermotropic and, in highly concentrated solution with suitable interactions, lyotropic liquid-crystalline phases. 

Rory [29] proposed a lattice theory that accommodates chain flexibility in liquid-crystalline polymers in a later version. The critical concentration for mesophase formation depends for freely jointed rods on the aspect ratio of the individual Kuhn segment, that is, instead of the contour length, the axial ratio of is used for the calculation. The critical volume fraction of the polymer V is determined by the aspect ratio x, and Eq. (8) was derived as 

The phase separation of the solution is driven by the entropy of forming a liquid-crystalline phase at a high polymer concentration. However, Maier and Saupe [30] concluded that the formation of a nematic phase arises from orientation-dependent interaction of induced dipoles. From these considerations, it appears that both entropy and enthalpy contribute to the stability of mesophases, although in a different ratio for large and small molecules. Asymmetric at- 

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