有机硅骨架阴离子交换树脂的合成及应用

Synthesis and Application of Anion Exchange Resin with Organic Silicone-Containing Dendrimers

以等摩尔的γ-氨丙基三乙氧基硅烷与γ-氯丙基三乙氧基硅烷于140℃反应12h,脱盐后再与1.2倍摩尔的γ-氯丙基三乙氧基硅烷150℃反应16h,得叔胺硅氧烷预聚物,该预聚物在甲苯-甲醇-水混合溶剂中进一步聚合成含N高度交联的有机硅聚硅氧烷树脂骨架。骨架与溴乙烷在120℃的封管反应20h,生成强碱性阴离子交换树脂(PNC树脂),交换量可达1.55mmol·g-1。该树脂用碳酸氢根转型后于固定床反应器中在95℃、1.2MPa、环氧乙烷与水摩尔比18、空速1.0h-1下催化环氧乙烷水合反应,连续运行72h,环氧乙烷转化率可达96.9%,乙二醇选择性可达97.1%;交换容量损失率小于2%,溶胀率为零。

The equal molar amount of γ-aminopropyltriethoxysilane and γ-chloropropyltriethoxysilane were heated together at 140℃ for 12 h, in the following steps the salt formed in the reaction was removed and another over 20% （molar volume） of γ-chloropropyltriethoxysilane was added with continuous stirring at 150℃ for 16 h, then the tertiaryaminotriethoxysilane was synthesized. The obtained silane was further polymerized in the mixed solvent of toluene-methanol-water, and a high cross-linked organic polysiloxane skeleton linked with tertiary amino groups was formed. Putting the above polymer and bromoethane in a sealed tube, heating them to 120℃ and reacting for 20 h, a strong-base anion exchange resin with high exchanging capacity （1.55 mmol.g^-1） was prepared. After the prepared resin was treated by sodium bicarbonate solution, its catalytic application for ethylene oxide （EO） hydration was carried out at 85℃ for 72 h with the water/EO ratio of 18, the space velocity of 1.0 h^-1 and operating pressure of 1.2 MPa. The results show that the EO conversion reaches 96.9%, the ethylene glycol （EG） selectivity achieves 97.1%, the percentage loss of exchanging capacity is lower than 2% and no swelling is observed.