Chiral side chain polymers isotropic smectic phase

AMORPHOUS, OPTICALLY ISOTROPIC MESOPHASE OF CHIRAL SIDE-CHAIN POLYMERS WITH A HIDDEN LAYER STRUCTURE—THE ISOTROPIC SMECTIC PHASE... 

The chiral side chain polymers derived from asymmetric esters of terephthalic acid and hydroquinone can form (in a broad temperature range, including ambient temperature) an unusual mesophase (the isotropic smectic phase, IsoSm ) characterized by high transparency and optical isotropy within the visible wavelength range, combined with a hidden layered smectic ordering and some elements of helical superstructure at shorter dimensions of 10 to 250 nm. The short-pitch TGB A model seems to be the most adequate for the mesophase structure. 

Amorphous, Optically Isotropic Mesophase of Chiral Side-Chain Polymers with a Hidden Layer Structure— The Isotropic Smectic Phase 148... 

P8 M is not the only polymer forming the isotropic smectic phase. To date, we have observed formation of that phase for a half-dozen chiral polymethacrylates and polysiloxanes. Table 5.1 summarizes the chemical structure and phase behavior of synthesized side-chain homopolymers, which carry chirally substituted side chains derived from asymmetric esters of terephthalic acid and hydroquinone. Such a structure with alternating orientation of carboxylic link groups seems to favour the formation of the IsoSm phase, whereas isomeric derivatives of p-hydroxybenzoic acid, where all carboxylic links have the same orientation, form only conventional Sm A and Sm C phases. Molar mass of all the synthesized homo- and copoly(meth)acrylates is within the range of 1 to 2-10 g mol the poiysilox-anes have the average degree of polymerization, p 35. 

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