In this work, the latent thermal cationic initiators triphenyl benzyl phosphonium hexafluoroantimonate (TBPH) and benzyl-2-methylpyrazinium hexafluoroantimonate (BMPH) were newly synthesized and characterized with IR, 1 H NMR, and P NMR spectroscopy. The thermal and mechanical properties of difunctional epoxy [diglycidyl ether of bisphenol A (DGEBA)] resins cured by 1 phr of either TBPH or BMPH were investigated. The DGEBA/TBPH system showed a higher curing temperature and a higher critical stress intensity factor than the epoxy/BMPH system. This could be interpreted in terms of the slow thermal diffusion rate and bulk structure of the four phenyl groups in TBPH. However, the decomposition activation energy derived from the Coats-Redfern method was lower for epoxy/TBPH. This result was probably due to the fact that a broken short-chain structure was developed by the steric hindrance of TBPH in the difunctional epoxy resin.
Carbon-based electric double-layer capacitors are being evaluated as potential energy-storage devices in an expanding number of applications. In this study, samples of carbon black (CB) treated at different temperatures ranging from 650°C to 1100°C were used as electrodes to improve the efficiency of a capacitor. The surface properties of the heat-treated CB samples were characterized by X-ray photoelectron spectroscopy and X-ray diffraction. The effect of the heat-treatment temperature on the electrochemical behaviors was investigated by cyclic voltammetry and in galvanostatic charge-discharge experiments. The experimental results showed that the crystallinity of the CBs increased as the heat-treatment temperature increased. In addition, the specific capacitance of the CBs was found to increase with the increase in the heat-treatment temperature. The maximum specific capacitance was 165 F·g-1 for the CB sample treated at 1000 o C.
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