摘要
This paper investigates the possibility of attaining sulphonated poly(phenylene oxide) (SPPO) with a relativelyhigher sulfonation degree. To achieve this aim, the approach we adopt is to improve the solubility of the final product in themixed solvent so that the sulfonation may take place between the bulk solutions and PPO powders even at higher sulfonationdegree. It is shown that the addition of a proper amount of dimethyl formide (DMF) to the conventional PPO-chloroformsystem can actually enhance the sulfonation effect. The solvent composition is then correlated with the sulfonation degreebased on the solubility parameters. It is interesting to find that solubility parameters between the mixed solvent and theprecipitated products keep an approximately unchanged value at about 4.9, which is just equal to that when pure chloroformis used, though the solubility parameters of both solvents increase with the content of DMF in solution. This may be the mainreason why the addition of DMF can reduce the precipitation and improve the ion exchange capacity (IEC) of SPPOpolymer.
This paper investigates the possibility of attaining sulphonated poly(phenylene oxide) (SPPO) with a relativelyhigher sulfonation degree. To achieve this aim, the approach we adopt is to improve the solubility of the final product in themixed solvent so that the sulfonation may take place between the bulk solutions and PPO powders even at higher sulfonationdegree. It is shown that the addition of a proper amount of dimethyl formide (DMF) to the conventional PPO-chloroformsystem can actually enhance the sulfonation effect. The solvent composition is then correlated with the sulfonation degreebased on the solubility parameters. It is interesting to find that solubility parameters between the mixed solvent and theprecipitated products keep an approximately unchanged value at about 4.9, which is just equal to that when pure chloroformis used, though the solubility parameters of both solvents increase with the content of DMF in solution. This may be the mainreason why the addition of DMF can reduce the precipitation and improve the ion exchange capacity (IEC) of SPPOpolymer.
基金
The authors graefully acknowledge financial support from the National Natural Science Foundation of China (29976040), Natural Science Foundation of Anhui Province (99045431), Key Foundation of Anhui Educational Comrnittee (2000j1255zd), the Foundation of
