Mesogen-jacketed liquid-crystalline

Wu et al. reported on a rod—coil diblock copolymers based on mesogen-jacketed liquid crystalline polymer as the rod block and polystyrene as the coil block (Scheme 6).82 Styrene was polymerized by TEMPO mediated radical polymerization, followed by sequential polymerization of 2,5-bis[4-methoxyphenyl]oxy-carbonylstyrene (MPCS) to produce the rod—coil diblock copolymer (20) containing 520 styrene and 119 MPCS repeating units. The rod—coil copolymer was observed to self-assemble into a core—shell nanostructure in a selective solvent for polystyrene... 

Figure 4.19. Banded texture of a mesogen-jacketed liquid crystalline polymer. The shearing direction is perpendicular to the direction of the parallel bands.

More recently in the study of another series of mesogen-jacketed liquid crystalline polymers we found (Zhang et al, 1996) that the frozen-in nematic order (formed from evaporation of the solvent or when precipitated from solution) in the non-crystalline polymers will disappear when they are heated up to the temperature region of the glass transition. The DSC curves of these polymers shows again only the glass transition, however instead of a jump a broad endothermic peak appears. Obviously in such cases the glass transition and the transition of the nematic-to-amorphous are superimposed. 

IR dichroism is also used to obtain the orientation of mesogenic units relative to the main chain in side-chain type liquid crystalline polymers. One example was given by Xu et al. (1993). The polymer studied by them was a mesogen-jacketed liquid crystalline polymer shown below ... 

While the IR dichroism and NMR studies can give information about the conformation at individual bonds, the small-angle neutron scattering (SANS) measures the global conformation of the polymers (Cotton et al., 1974). SANS has been successfully utilized, for example by Hardouin and coworkers (Hardouin et al, 1991 Leroux et al, 1993), to establish the evolution with the temperature of the global shape of some mesogen-jacketed liquid crystalline polymers from isotropic to the nematic phase. A pseudobinary system of fully protonated polymer (P4,4,4) with the same polymer... 

Zhang, L. Chen, S. Zhao, H. Shen, Z. Chen, X. Fan, X. Zhou, Q., Synthesis and Properties of a Series of Mesogen-Jacketed Liquid Crystalline Polymers with Polysiloxane Backbones. Macromolecules 2010,43,6024-6032. 

Synthesis and Chain R dity of Mesogen-Jacketed Liquid-Crystalline Pofymers Based on Poly(2,5-disubstituted-styrene)... 

Zhou Q-H, Zheng J-K, Shen Z, Fan X-H, Chen X-F et al (2010) Synthesis and hierarchical self-assembly of rod-rod block copolymers via click chemistry between mesogen-jacketed liquid crystalline polymers and helical polypeptides. Macromolecules 43 5637-5646... 

Mesogenic-Jacketed Liquid Crystalline Polymers (MJLCPs)... 

Fig. 16.11 Example of mesogenic-jacketed liquid crystalline polymers (Chen et al. 2010)...

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Chen XF, Shen Z, Wan XH, Fan XH, Chen EQ, Ma Y, Zhou QF (2010) Mesogen-jacketed liquid crystalline polymers. Chem Soc Rev 39 3072-3101 Choi EJ, Kim EC, Ohk CW, Zin WC, Lee JH, Lim TK (2010) Synthesis and mesomtuphic properties of main-chain polymers containing V-shaped bent-core mesogens with acute-subtended angle. Macnunolecules 43 2865-2872 Collings JP, Hird M (1997) Introduction to liquid oystals chtanistry and physics. Taylor and Francis, London... 

Gopalan P, Andruzzi L, Li XF, Ober CK (2002) Fluorinated mesogen-jacketed liquid-crystalline polymers as surface-modifying agents design, synthesis and characterization. Macromol... 

Ye C, Zhang HL, Huang Y, Chen EQ, Lu YL, Shen DY, Wan XH, Shen ZH, Cheng SZD, Zhou QF (2004) Molecular weight dependence of phase structures and transitions of mesogen-jacketed liquid crystalline polymers based on 2-vinylterephthalic acids. Macromolecules 37 7188-7196... 

Zhang L, Chen S, Zhao H, Shen Z, Chen X, Fan X, Zhou Q (2010) Synthesis and properties of a series of mesogen-jacketed liquid crystalline polymers with polysiloxane backbones. Macromolecules 43 6024-6032... 

Zhu YF, Zhang ZY, Zhang QK, Hou PP, Hao DZ. Qiao YY, Shen Z, Fan XH, Zhou QF (2014) Mesogen-jacketed liquid crystalline polymers with a polynorbOTnene main chain green synthesis and phase behaviors. Macromolecules 47 2803-2810... 

Zhu YF, Tian HJ, Wu HW, Hao DZ, Zhou Y, Shen ZH, et al. Ordered nanostruetures at two different length scales mediated by temperature a triphenylene-containing mesogen-jacketed liquid crystalline polymer with a long spacer. J Polym Sci A Polym Chem 2014 52 295-304. 

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