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Weng L.,Xiangtan University | Weng L.,Key Laboratory of Advanced Functional Polymer Materials of Colleges and Universities of Hunan Province | Yan J.-J.,Xiangtan University | Yan J.-J.,Key Laboratory of Advanced Functional Polymer Materials of Colleges and Universities of Hunan Province | And 9 more authors.
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2013

A series of novel polymerized ionic liquids (PILs) contained imidazolium, poly (2,5-bis{[6-(1-butyl-3′-imidazolium)hexyl] oxy carbonyl}styrene salts) (denoted as P1X-, X -ï£ Br-, BF4 -, PF 6 - and TFSI-) were successfully synthesized via radical polymerization. The chemical structures of the monomers and their corresponding PILs were confirmed by 1H NMR, 13C NMR, and Fourier transform infrared spectroscopy. Thermogravimetric analysis results showed that these PILs had excellent thermal stability. The phase transitions and liquid-crystalline (LC) behaviors of these polymers were investigated by differential scanning calorimetry, polarized light microscopy (PLM), and wide-angle X-ray diffraction. The combined experimental results showed that all the PILs could form hexagonal columnar (φH) LC ordered structures because of the strong interaction between the anions and cations in the side groups except for P1TFSI-. The conductivities of monomers and PILs were sketchily investigated, and monomers had higher conductivities than those of conprespoding PILs. For comparison, we have synthesized a polymer without counter-anion, but similar to the chemical structure of P1X-, poly (2, 5-bis{[6-(4-butoxy-4′-oxy phenyl) hexyl] oxycarbonyl} styrene) (denoted as P2). In this case, phenyl took place of imidazolium of side chain, and LC ordered structure did not form. The comparison between P1X- and P2 suggested that ion played an important role in the constructing of LC ordered structure. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 Polymerized ionic liquids (PILs) based on a "jacketing" effect containing imidazolium with different counter-anions were successfully designed and synthesized via radical polymerization. With a combined "jacketing" effect and appropriate interaction between the anions and cations, the whole molecular chain of PILs would be considered a hierarchical cylinder, and this cylinder can further form hexagonal columnar (ΦH) LC ordered structures. Copyright © 2013 Wiley Periodicals, Inc. Source


Zhu M.,Key Laboratory of Advanced Functional Polymer Materials of Colleges and Universities of Hunan Province | Liu W.,Key Laboratory of Advanced Functional Polymer Materials of Colleges and Universities of Hunan Province | Xiao J.,Key Laboratory of Advanced Functional Polymer Materials of Colleges and Universities of Hunan Province | Ling Y.,Key Laboratory of Advanced Functional Polymer Materials of Colleges and Universities of Hunan Province | Tang H.,Key Laboratory of Advanced Functional Polymer Materials of Colleges and Universities of Hunan Province
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2016

A series of OEGylated random copolypeptides with similar main-chain lengths and different oligo(ethylene glycol) (OEG) molar content and chain lengths were prepared from triethylamine initiated ring-opening polymerization (ROP) of OEGylated γ-benzyl-L-glutamic acid based N-carboxyanhydride (OEGmBLG-NCA, m=2, 3) and γ-benzyl-L-glutamic acid based N-carboxyanhydride (BLG-NCA). 1H NMR analysis verified copolypeptides structures and determined the OEG molar content (x). FTIR analysis further confirmed the molecular structures, indicated α-helical conformations of copolypeptides in the solid-state, and revealed H-bonding interactions between OEG pendants and alcoholic solvents. The copolypeptides exhibited a reversible upper critical solution temperature (UCST)-type phase behavior in various alcoholic solvents (i.e., methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol) depending on the x values and OEG side-chain lengths (m). Variable-temperature UV-vis analysis revealed that the UCST-type transition temperatures (Tpts) of the copolypeptides in alcohols decreased as x or m value increased or as polymer concentration decreased. Tpts of copolypeptides with high x values (x≥0.50) increased as the number of methylene of the alcoholic solvent increased from 3 (i.e., 1-propanol) to 5 (i.e., 1-pentanol). © 2016 Wiley Periodicals, Inc. Source

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