取代基对糖类衍生物亲二氧化碳性的影响

Influence of substituent on CO_2-philicity dependence of sugar derivatives

在高压可视釜中用等温合成法研究了298.1和303.1K时二氧化碳（CO2）中7种糖类衍生物的相行为。样品质量分数区间为0~0.09。以恒温时样品在CO2中开始溶化的压力值作为判断亲CO2性高低的标准。葡萄糖衍生物中α-甲基-2,3,4,6-四-O-乙酰-D-吡喃葡萄糖苷和β-甲基-2,3,4,6-四-O-丙酰-D-吡喃葡萄糖苷的潮解点最低,为3.4~3.6MPa。二糖衍生物中,蔗糖八乙酸酯很好地溶解于高压CO2。除D-纤维二糖八乙酸酯外,其余6种样品都可以在较温和的压力（2.5~6.5MPa）下溶化在CO2中。α-甲基-2,3,4,6-四-O-乙酰-D-吡喃葡萄糖苷、β-甲基-2,3,4,6-四-O-丙酰-D-吡喃葡萄糖苷和蔗糖八乙酸酯有望发展为高效的CO2相变物理吸附剂。

The phase behaviors of seven sugar derivatives with a mass fraction of 0.0-0.09 in carbon dioxide were investigated by isothermal synthetic method at 298.1K and 303.1K in a high pressure view cell. The pressure under which samples deliquesced in isothermal cases suggested the CO2-philic intensity. The results illustrated that among all the glucopyranose-based CO2-philes, methyl 2,3,4,6-tetra-O-acetyl a-D-glucopyranoside and methyl 2,3,4,6-tetra-O-propionyl β-D- glucopyranosideis deliquesced at the lowest pressure （3.4-3.6MPa）. Sucrose octaacetate and disaccharide derivative were highly soluble in high pressure carbon dioxide. Except D-cellobiose octaacetate,the rest six all solubilized in carbon dioxide under modest pressure （ 2.5 - 6.5 MPa）. Methyl 2,3,4,6-tetra-O-aeetyl α-D-glucopyranoside, methyl 2,3,4,6-tetra-O-propionyl β-D-glucopyranoside and sucrose oetaacetate were promising candidates for effective phase-change absorbents for CO2.