Mesogen-jacketed block copolymers

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... 

Wan et al. used TEMPO-mediated polymerizations to prepare liquid crystalline (LC) polymers [147,148]. pSt-TEMPO was chain extended with a mesogen-jacketed LC monomer, 2,5-bis [(4-methoxyphenyl)oxycarbonyl] styrene (MPCS, Fig. 9) to form a rod-coil diblock copolymer. The resulting copolymer had an Mn=19,500 with an Mw/Mn=1.48. There was tailing to lower molecular weights, indicating the presence of some unreacted macroinitiator, but after extraction with cyclohexane, the remaining macroinitiator was removed, leaving pure block copolymer. H and 13C HMR analysis indicated the presence of both blocks, as did DSC analysis, which showed two Tgs,one at 117.2 °C (pMPCS) and... 

The final section describes the synthesis and properties of new main-chain and side-chain liquid-crystdline block copolymers, mesogen-jacketed LCPs, and liquid-crystaJline thermosets, which offer a unique... 

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... 

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