含磺酸基之聚酯在水中溶解度相當大,當乙二醇,對苯二甲酸及5-磺酸鈉-間苯二甲酸之聚酯中磺酸鈉占10莫耳%時,溶解度爲12.6%(w/w)以上。加入丙三醇16莫耳%而磺酸鈉含量仍爲10莫耳%之聚酯則溶解度可降至0.1%(w/w)。此等聚合物之分子量估計在6000~10000之範圍。本聚合法爲使用醋酸鈣及三氧化銻爲催化劑,減壓下280℃聚合所得之樹脂。因丙三醇交連後所得樹脂在水中溶解度下降至可使用之範圍,因此將該樹脂與商品之離子交換樹脂Dowex 50之數據相對照,所得結果相當接近,而具有比Dowex 50優良之特性,在若干有機溶劑中之溶解度則較小。
The ion exchange resin was synthesized by the condansation of dimethyl terephthalate, with ethylene glycol, dimethyl sodium sulfoisophthalate, and glycerol. The water solubility of the resin increases with increasing the sulfo group. The ion exchange proverties of the synthesized resins containing different amount of sulfo group and glycerol are compared with those of commercial resin, Dowex 50.