文摘
A novel borate ester (BE)-grafted carboxylated acrylonitrile butadiene rubber (XNBR) was synthesized. From Fourier transform infrared, 1H NMR and elemental analyses, the borate ester was successfully grafted to XNBR, resulting in a more flexible XNBR chain as revealed by differential scanning calorimetry. The binding energies of boron, oxygen, lithium and chlorine atoms of XNBR-g-BE–LiClO4 are quite different from those of XNBR or LiClO4. Meanwhile, the wavenumbers of COBOC, CO and CH vibrations of the benzene ring shift towards lower values and a new shoulder peak for CN at about 2260 cm−1 emerges. By integrating fitting peak areas of CN groups and ClO4−, the fractions of CN group and ClO4− bidentate bonding in XNBR-g-BE–LiClO4 are much higher than in NBR–LiClO4. Based on these experiments, a possible dissociation mechanism is proposed in which the boron atom of XNBR-g-BE receives electron pairs from ClO4−, releasing partial positive charge of Li+ to bind with CN group.
