Ionic cross-linked methacrylic copolymers for carbon fiber reinforced thermoplastic composites

Methacrylic copolymers have high potential as matrix polymers for carbon fiber reinforced thermoplastics (CFRTPs) due to their superior mechanical properties and the versatility of the monomers. However, the methacrylic copolymers have low solvent resistance, compared to epoxy, polyamide, and polypropylene, due to their un-cross-linked amorphous structure. Therefore, an improvement of the solvent resistance by the introduction of metal salts into methacrylic copolymer matrices for CFRTPs was investigated. Infrared spectroscopy, dynamic mechanical analyses and small-angle X-ray scattering clarified that an ionic cross-linked structure was formed. Low-viscosity mixtures of the methacrylic monomers with the metal salts, as a precursor of the matrices for CFRTPs, were easily impregnated into CF fabrics and were then copolymerized within the CF fabrics. Both the flexural strength and shear adhesive strength of the CFRTPs using the in situ polymerized methacrylic ionomer cross-linked with sodium ions were sufficiently high, even after 12 h immersion in methyl ethyl ketone

Branched Alkyl Functionalization of Imidazolium-based Ionic Liquids for Lithium Secondary Batteries

Room temperature ionic liquids (ILs) are the appealing research target as electrolytes for lithium batteries. The cation and anion structure of ILs influences their physical and chemical properties. In this study, an electron-donating branched substituent was introduced into imidazolium cations to promote charge delocalization and to improve the reduction stability of ILs. The ILs with branched substituent group at the third position of imidazolium cation, 1-allyl-3-isobutylimidazolium bis(fluorosulfonyl)amide ([ABisoIm][FSA]) and 1-allyl-3-tert-butylimidazolium bis(fluorosulfonyl)amide ([ABtertIm][FSA]), exhibited lower cathodic potential (−2.54 and −2.79 V vs. Fc/Fc+, respectively). [ABisoIm][FSA] and [ABtertIm][FSA] showed sufficiently high ionic conductivity (4.85 and 3.66 mS/cm at 298 K, respectively), although the viscosity increased with the introduction of bulky branched substituent. Lithium secondary batteries composed of electrolytes using [ABisoIm][FSA] and [ABtertIm][FSA] showed stable charge-discharge behavior