Side-chain liquid-crystalline polyester

James DF and Walters K, "A Critical Appraisal of Available Methods for the Measurement of Extensional Properties of Mobile Systems" in Collyer AA (Ed), "Techniques in Rheological Measurement", Chapman Hall, London, 1993. Jin S, "Synthesis and Characterization of Side-Chain Liquid Crystalline Polyesters and Polyurethanes", PhD Thesis, Delft, 1995. 

Hvilsted, S., Andruzzi, E, Kulinna, C., Siesleg H. W., and Ramanujam, P. S. Novel side-chain liquid crystalline polyester architecture for reversible optical storage. Macromolecules 28, 2172 (1995). 

Hvilsted, S. Andruzzi, F. Kulirma, C. Siesler, H. W. Ramanujam, P. S. (1995). Novel Side-Chain Liquid Crystalline Polyester Architecture for Reversible Optical Storage. Macromolecules, 1995, 28,2172-2183. 

Alignment of Side-Chain Liquid-Crystalline Polyesters Under Laser Irradiation... 

Holme, N. C. R., Nikolova, L., Ramanujam, P. S., and Hvilsted, S. An analysis of the anisotropic and topographic gratings in a side-chain Liquid crystalline azobenzene polyester. Appl. Phys. Lett. 1997, 70, pp. 1518-1520. 

The synthesis and some thermal properties of three series of block copolymers comprising both main-chain and side-chain liquid-crystalline (LC) blocks in the same macromolecular structure are described. The former block is a semiflexible LC polyester (block B), and the latter is an LC polymethacrylate (block A) containing a variously substituted mesogenic unit. The two structurally different blocks were partly phase-separated within the glassy and LC states and underwent distinct phase transitions. Significant deviations of the transition enthalpies relative to those of the corresponding homopolymers suggest the occurrence of a more or less diffuse interphase which may depend on the nature of the mesophase formed. 

A common method for polyester formation is via trans-esterification. The procedure described below uses a procedure that is modified from that described in Sorenson. In this case, aromatic di-acid 5 and di-ester 4 monomers are reacted together in the melt. During the polymerization, the molecular weight grows while volatile side-product is continuously removed from the reaction vessel by means of a vacuum pump. Scheme 2 describes the formation of a main-chain liquid crystalline poly(ester ether) containing... 

Liquid crystalline polyesters with 3-methylphthalimide and chromophore side chains, having good orientation stability and mechanical properties, were claimed for making nonlinear optical devices like filters, polarisers, waveguides and others [274]. 

C. Noel and J. Virlet, "DSC, Miscibility and X-ray Studies of the Thermotropic Liquid Crystalline Polyesters with Aromatic Moieties and Flexible Spacers in the Main Chain", in "Liquid Crystals and Ordered Fluid, A. Griffin and A. Johnson eds., Plenvim Press, New-York, vol. 1+, 1+01 (198I+) Finkelmann, "Synthesis, Structure, and Properties of Liquid Crystalline Side Chain Polymers", in "Polymeric Liquid Crystals", A. Ciferri, W.R. Krigbaum and R.B. Meyer eds. Academic Press, New-York (I982)... 

The procedures which employ the intrachain scattering to evaluate the molecular orientation parameters have been applied successfully to main-chain and side-chain liquid crystal polymers and to non-crystalline polymers in general. - They have recently been reviewed by Windle. We shall explore their use through the example of a semi-rigid thermotropic co-polyester The X-ray... 

Another variant of liquid crystalline polyesters are side chain LC polyester. Usually side chain LC polymers are used for functional purposes such as holographic writing, non-linear optics, optical information storage, photo-addressable film, optical switch etc. 

These modifications include variations on the length of the spacer which connects the azobenzene and the polymeric chain in side-chain azopolymers, or the electronic nature of substituents at the azobenzene moiety (Ruhmann, 1997). This requires the synthesis of appropriate monomers. Conventional techniques can be used for the polymerization of azobenzene monomers. For instance, step polymerization has been used by Hvilsted and co-workers to synthesize different series of liquid crystalline polyesters with potential applications in reversible optical data storage. These polyesters have a side-chain architecture, which synthesis is represented in Fig. 16.6 (Hvilsted et al, 1995). Being a modular synthetic approach, the influence of different structural parameters on the photoinduced optical properties can be evaluated in relatively simple manner. 

AND LIQUID CRYSTALLINE POLYESTERS WITH FLEXIBLE SIDE CHAINS... 

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