- Controlled functionalization of poly(4-methyl-1-pentene) films for high energy storage applications
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A new family of poly(4-methyl-1-pentene) ionomer [PMP-(NH3)xA-y] (x = 1, 2, 3 and A = Cl-, SO42-, PO43-, y = NH3 content) modified (NH3+)xAx- ionic groups has been synthesized. The ionomers were synthesised using either a traditional Ziegler-Natta or a metallocene catalyst for the copolymerisation of 4-methyl-1-pentene and bis(trimethylsilyl)amino-1-hexene. A systematic study was conducted on the effect of the subsequent work-up procedures that can prevent undesirable side reactions during the synthesis of the [PMP-(NH3)xA-y] ionomers. The resulting PMP-based copolymers were carefully monitored by a combination of nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), mechanical properties, dielectric properties, and electric displacement-electric field (D-E) hysteresis loop measurements. Our results reveal that the [PMP-(NH3)xA-y] ionomer films show a significantly enhanced dielectric constant (~5) and higher breakdown field (~612 MV m-1) as compared with pure PMP films. Additionally, these PMP-based films show good frequency and temperature stabilities (up to 160 °C). A reliable energy storage capacity above 7 J cm-3 can be obtained, and is twice the energy storage capacity of state-of-the-art biaxially oriented polypropylene films, which can be attractive for technological applications for energy storage devices.
- Zhang, Min,Zhang, Lin,Zhu, Meng,Wang, Yiguang,Li, Nanwen,Zhang, Zhijie,Chen, Quan,An, Linan,Lin, Yuanhua,Nan, Cewen
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supporting information
p. 4797 - 4807
(2016/04/08)
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- New polyethylene based anion exchange membranes (PE-AEMs) with high ionic conductivity
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This paper discusses a new class of high performance polyethylene-based anion exchange membranes (PE-AEMs) that contain a wide concentration range of pendant (flexible) ammonium chloride (NR3+Cl-) groups and with or without a cross-linked PE matrix structure. The chemistry involves a metallocene-mediated polymerization of ethylene, silane-protected α,ω-amino-olefin [CxN(SiMe3)2], with or without styrenic diene (cross-linker), to form ethylene/C xN(SiMe3)2 copolymers and ethylene/C xN(SiMe3)2/diene terpolymers, respectively. The resulting co- and ter-polymers were completely soluble in common organic solvents and were solution-casted into uniform films (thickness, 50-70 μm; without backing material) and then thermal cross-linked in ethylene/C xN(SiMe3)2/diene case, further interconverting the silane-protected amino groups into the desired -NR3 +Cl- groups (R: H, CH3, and C3H 7) under solid state conditions. The resulting PE-NR3 +Cl- and cross-linked x-PE-N(CH3) 3+Cl- membranes were systematically studied to understand how the PE structure (-NR3+Cl- concentration, R group, cross-linking density, etc.) affects ionic conductivity, water uptake, film stability, and ion selectivity. For comparison, several commercially available AEMs were also examined. Evidently, an x-PE-N(CH 3)3+Cl- membrane, with 28.1 mol % -N(CH3)3+Cl- groups and 0.2 mol % cross-linkers, shows moderate water swelling and outperforms all commercial membranes with exceptionally high ionic conductivities of 119.6 mS/cm in 2 N HCl solution and 78.8 mS/cm in 2 N HCl-0.2N CuCl solution at room temperature.
- Zhang, Min,Kim, Hyung Kyu,Chalkova, Elena,Mark, Fedkin,Lvov, Serguei N.,Chung, T. C. Mike
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experimental part
p. 5937 - 5946
(2012/03/08)
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