2, 6-XylenoI (XOH) was oxidatively polymerized by Cu-partially-quaternized poly(vinylpyridine) (QPVP) complexes in a water-benzene system, the catalytic effects of the polymer-ligand and the mechanism of the polymerization were discussed. The Cu-QPVP complexes were soluble in water and the QPVP chelate which is formed above pH 5 was relatively stable in the range of pH 5~10. The oxidation was influenced by the pH of aqueous phase; the main product was biphenoquinone below pH 7, and was poly(phenyleneoxide) above pH 7. The maximum of the polymer yield was observed at pH 9; this fact is because of the following changes with the increase of the pH value in the system; i) the change of the composition of the complex, ii) the decrease of the concentration of the catalyst, iii) the decrease of the oxidation potential of the monomer. The polymerization did not proceed in either the water or the benzene solution. From this result and the solubility of the reactants, it was suggested that XOH is polymerized at the interface between water and benzene. The polymerization rate was larger in the Cu-QPVP system than in the Cu-Py system (Table 6), and then it is considered that QPVP acts as an emulsifier.
ASJC Scopus subject areas
- 化学 (全般)