Thermotropic side-chain liquid-crystalline

Thermotropic side chain liquid crystalline polymers, SCLCPs... 

The work presented here has demonstrated, for the first time, that the molecular organization of thermotropic-side chain-liquid-crystalline l.c. polymers could drastically influence the yield of a chemical reaction. 

Hydrosilylation reactions have been performed with PFSs containing Si-H functionalities to attach mesogenic azobenzene groups. This has allowed the preparation of calamitic thermotropic side-chain liquid crystalline materials that display a nematic mesophase between ca. 53 and 250... 

Deschenaux, R., V. Izvolenski, R Turpin, D. Guillon, and B. Heinrich. 1996. Ferrocene-containing thermotropic side-chain liquid-crystalline p>olymethacrylates. 

Cojocariu, C. and Rochon, P. (2005) Thermotropic side-chain liquid crystalline copolymers containing both mono- and bisazobenzene mesogens Synthesis and properties , Macromolecules, 38,9526-9538. 

Effect of the Polymer Backbone on the Thermotropic Behavior of Side-Chain Liquid Crystalline Polymers... 

A review of the literature demonstrates some trends concerning the effect of the polymer backbone on the thermotropic behavior of side-chain liquid crystalline polymers. In comparison to low molar mass liquid crystals, the thermal stability of the mesophase increases upon polymerization (3,5,18). However, due to increasing viscosity as the degree of polymerization increases, structural rearrangements are slowed down. Perhaps this is why the isotropization temperature increases up to a critical value as the degree of polymerization increases (18). 

Liquid crystallinity can be attained in polymers of various polymer architectures, allowing the chemist to combine properties of macromolecules with the anisotropic properties of LC-phases. Mesogenic imits can be introduced into a polymer chain in different ways, as outhned in Fig. 1. For thermotropic LC systems, the LC-active units can be connected directly to each other in a condensation-type polymer to form the main chain ( main chain liquid crystalline polymers , MCLCPs) or they can be attached to the main chain as side chains ( side chain liquid crystalline polymers , SCLCPs). Calamitic (rod-Uke) as well as discotic mesogens have successfully been incorporated into polymers. Lyotropic LC-systems can also be formed by macromolecides. Amphiphihc block copolymers show this behavior when they have well-defined block structures with narrow molecular weight distributions. 

Side-chain liquid-crystalline polymers with controlled molecular weights have been obtained by the polymerization of FM-25 with 1-22 (X = Br)/CuBr/ L-3 in the bulk at 100 °C, to examine the thermotropic transition as a function of the MWD.324 Second-order nonlinear optical materials with branched structure were prepared by the copper-catalyzed radical polymerization of FM-26 and FM-27 using hyperbranched poly[4-(chloromethyl)styrene] as a multifunctional initiator.325... 

Side-chain liquid crystalline polymers containing disk-like pendant mesogenic groups are well known to exhibit thermotropic columnar mesophases [65], the... 

The amorphous segment of microphase-separated amorphous/liquid crystalline block copolymers may influence the ordering of the mesogens at the interface, as well as the size and discreteness of that interface. Living copolymerizations are therefore being used to determine the effect of the morphology and domain size on the thermotropic behavior of side-chain liquid crystalline block copolymers. 

He X, Zhang H, Yan D, Wang X. 2003. Synthesis of side chain liquid crystalline homopolymers and triblock copolymers with p methoxyazobenzene moieties and poly(ethylene glycol) as coil segments by atom transfer radical polymer zation and their thermotropic phase behavior. J Polym Sci Part A Polym Chem 41 2854 2864. 

Thermotropic behavior of H-bonded side-chain liquid crystalline polymeric complexes. 

Thermotropic side-chain ionic liquid-crystalline polymers are particularly attractive when the aim is that of merging the liquid-crystalline characteristics of the low molecular weight mesogen side groups with the mechanical properties of the polymeric main chain. It is not surprising, then, that they attracted most of the research efforts in the polymeric ionic liquid crystals field. 

There are very few structural studies of thermotropic side-chain polymers under shear flow. Recent work [54] describes the neutron scattering by the liquid crystalline polymethacrylate labelled PMAOC4H9 (Sect. 4.1) in the SmA phase. Typical liquid crystal behavior was observed in which the layers orient... 

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