微波辅助制备β-环糊精纳米海绵

Mcrowave-assisted synthesis of β-cyclodextrin nanosponges

摘要:

利用微波辐射法制备β-环糊精纳米海绵（NSCD）。以β-环糊精（β-CD）为单体，碳酸二苯酯（DPC）为交联剂，以反应时间、反应温度和物料摩尔比〔n（β-CD）:n (DPC）〕为自变量，产物收率为响应指标，通过响应曲面法建立Box-Behnken模型对工艺优化及预测，得到最优反应条件为：反应时间87 min，反应温度90 ℃，物料摩尔比 1:7.75，在该条件下产物收率为70.71%。利用FTIR、DSC、PXRD、SEM和BET等方法表征了产物结构。FTIR结果显示，在1760cm-1处出现新的羰基特征峰，表明β-CD与DPC交联成功；DSC测得分解温度在260℃左右；PXRD和SEM表明，微波法得到的产物其结晶度比传统加热法产物的结晶度更高；BET分析表明，随着物料DPC与β-CD物质的量比增加，产物比表面积增加，孔径减小。优化后的工艺方法相较于传统方法反应时间缩短至原来的1/4，收率提高约20%～30%。

Abstract:

The β-cyclodextrin nanosponge (NSCD) was synthesized by microwave irradiation method, using β-cyclodextrin (β-CD) as the monomers and diphenyl carbonate (DPC) as the cross linker. The Box-Behnken design of response surface methodology was used to evaluate the interactive effects of temperature, reaction time and the molar ratio〔n（β-CD）:n (DPC）〕on the yield of NSCD. The optimum reaction conditions were obtained as follows: the reaction time was 87 min; the reaction temperature was 90 ℃; the molar ratio was 1:1.75. Under the optimum reaction conditions, the product yield of 70.71% was obtained. The structure and physicochemical properties of the products are characterized by DSC, PXRD, SEM and BET. As the result, the characteristic peaks of carbonyl appeared at 1760 cm-1 in the FT-IR spectrum compared with that of fresh β-CD, which indicate the successful crosslinking of β-CD and DPC; The results of DSC showed the thermal degradation temperature of the NSCD was about 260 ℃ PXRD results shows that the as-synthesized NSCD obtained from our microwave-assisted method had higher crystallinity than those prepared with conventional heating method, consistent with our SEM results. The BET analysis showed an increase in the specific surface area of product as the molar ratio increase, while the pore size changed in the opposite tendency. The reaction time of the optimized process was nearly four times shorter than the traditional method and the yield was increased by 20%~30%.