Side-chain polymer liquid crystals structural considerations

SIDE-CHAIN POLYMER LIQUID CRYSTALS STRUCTURAL CONSIDERATIONS... 

Until now there was no obvious correlation found between the monomer structure and the resulting pol qner phase. No.theorr retical structural conditions were described which would result in a liquid crystalline polymer with a definite ordered phase e.g. with a nematic a smectic or a cholesteric phase as in conventional liquid crystals. Although previous examples have established (8 9) the existence of enantiotropic liquid crystalline side chain polymers additional considerations are in order for a systematic synthesis of such polymers. 

The chemical structure of the polymers determines whether the molecules can form rigid rods. If the backbone of the polymer is composed of rigid structures then it tends to form main chain liquid crystals. If, however, the side chains are rigid, then the polymer will tend to form side chain liquid crystals. From practical considerations, these two properties are of prime interest. The structures are illustrated in Fig. 2.15. 

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