BrΦnsted酸性离子液体掺杂聚苯胺的无溶剂制备及其表征

SOLVENT-FREE PREPARATION AND CHARACTERIZATION OF POLYANILINE DOPED WITH BRΦNSTED ACIDIC IONIC LIQUIDS

首先合成了两种带—SO3H官能团的Brφnsted酸离子液体([MIMPS][HSO4]和[PYPS][HSO4]),然后分别以这两种带—SO3H官能团的Brφnsted酸性离子液体做为掺杂剂,在无溶剂条件下通过机械化学聚合反应制备了掺杂导电态聚苯胺.由于带—SO3H官能团的Brφnsted酸性离子液体中H+可以单独以离子形式存在,因此可形成质子化导电态的翠绿亚胺盐,并以红外光谱、紫外可见-近红外、X-射线衍射、循环伏安和四探针技术等测试方法对聚苯胺进行了结构和性能表征.PANI-[MIMPS][HSO4]的结晶性、电导率和电化学活性要优于PANI-[PYPS][HSO4].

Two Brcnsted acidic ionic liquids with an alkyl -SO3 H functional group, 1-methylimidazoliumpropanesulfonic acid hydrogen sulfate （ [ MIMPS] [ HSO4 ] ） and pyridiumpropanesulfonie acid hydrogen sulfate （[PYPS] [ HSO4 ] ） were firstly synthesized. And then the polyamiline （PANI） doped with these Bronsted acidic ionic liquids were synthesized by a solvent-free mechanochemical mute. The structures and properties of PANI-[MIMPS] [HSO4] and PANI-[PYPS] [HSO4] were characterized. Because Bronsted acidic ionic liquid has four kinds of ionic form, in which hydrogen ion can exist independently, anilinium salt formed after the aniline was mixed with the ionic liquid. Reactions between anilinium salt and the oxidant, ammonium peroxydisulfate, resulted in PANI formation on grounding the reactants in a mortar. FTIR and UV-Vis-NIR spectroscopy indicated that PANI was formed in its doped, conductive emeraldine oxidation state and this was consistent with the green color of the products. The molar ratio of aniline monomer to ionic liquid was systematically varied in order to optimize the electrical conductivity of PANI. When the aniline monomer to ionic liquids ratio was 1 ： 1, the highest electrical conductivity for the PANI- [ MIMPS ] [ HSO4] （ 10.3 S/cm） and PANI- [ PYPS ] [ HSO4 ] （ 8.8 S/em） was obtained, respectively. The XRD patterns of the resultant PANI showed two broad peaks at 10.1°,27.1°,two sharp peaks at 20.60,25.4% and a weak peak at 29.1°, indicating that the resulting polymers were in the form of a highly doped emeraldine salts and have good crystallinity. Cyclic vohammograms of PANI showed two clear oxidation peaks in the forward scan and prominent reduction peaks in the reverse scan. The results demonstrated PANI-[ MIMPS] [ HSO4 ] had better erystallinity, conductivity and electrochemical activity compared with PANI-[ PYPS] [ HSO4 ]. Keywords Brcnsted acidic ionic liquids, Solvent-free, Meehanochemical, Polyaniline