CIESC Journal ›› 2017, Vol. 68 ›› Issue (6): 2526-2534.DOI: 10.11949/j.issn.0438-1157.20170060

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Cyclohexane assisting preparation of starch esterification in supercritical CO2

LI Xidu, XIE Xinling, ZHANG Youquan, JU Quanliang   

  1. Guangxi Key Laboratory of Petrochemical Resources Processing and Process Intensification Technology, Guangxi University, Nanning 530004, Guangxi, China
  • Received:2017-01-13 Revised:2017-03-09 Online:2017-06-05 Published:2017-06-05
  • Contact: 10.11949/j.issn.0438-1157.20170060
  • Supported by:

    supported by the Natural Science Foundation of Guangxi (2014GXNSFAA118065)

环己烷辅助超临界CO2流体制备淀粉酯

李习都, 谢新玲, 张友全, 鞠全亮   

  1. 广西大学广西石化资源加工及过程强化技术重点实验室, 广西 南宁530004
  • 通讯作者: 张友全
  • 基金资助:

    广西自然科学基金项目(2014GXNSFAA118065)

Abstract:

Auxiliary effect of additives, such as cyclohexane, in supercritical CO2 fluid on the preparation of octenyl succinic acid cassava starch was investigated, and the types of additives, volume rate of additive to supercritical CO2, amount of esterification agent, reaction temperature, pressure and reaction time on the effect of degree of substitution and reaction efficiency were explored in a bath reactor set-up. The NMR, SEM and XRD were used to examine esterification groups, particle surface morphology and crystalline structure. The results revealed that the additive could improve the solubility of the supercritical CO2 medium to esterification agent, and the cyclohexane additive showed the optimal synergistic effect with reaction efficiency of about 3.0 times higher than that without the additive when 1.5% cyclohexane was added. Meanwhile, the optimum reaction conditions were found as follows: reaction temperature of 90℃, pressure of 12 MPa, time of 3 h and esterification agent of 4% with the degree of substitution and the reaction efficiency are 0.0191 and 61%, respectively, and even the reaction efficiency was up to 83% by using 2% esterification agent. Analysis of product structure characterization showed that the esterification groups were introduced into the starch molecules, and small particle characteristics and A-type crystal structure were still remained, but the particle surface morphology was partially destroyed and the crystallinity was reduced. All the results indicated that the cyclohexane can increase reaction efficiency and improve esterification reaction condition.

Key words: supercritical CO2, preparation, octenyl succinic acid starch, cyclohexane, esterification, auxiliary effect

摘要:

利用环己烷等助剂辅助超临界CO2流体制备辛烯基琥珀酸淀粉酯,研究助剂辅助效果,优化超临界酯化反应条件,并采用NMR、SEM和XRD等进行结构表征。结果表明:环己烷有助于改善超临界CO2对酯化剂的溶解性能,酯化反应效率约为无助剂时的3.0倍;反应温度、压力、时间及酯化剂用量等对反应也有重要影响,当温度90℃、压力12 MPa、酯化剂用量2%、时间3 h时,反应效率高达83%以上;酯化剂用量为4%时,取代度为0.0191,反应效率可达61%。结构表征发现淀粉分子中引入了酯化基团,产品依然保持淀粉颗粒特征和A型结晶结构,但颗粒表面遭到局部破坏,结晶度降低。以上结果说明,环己烷提高了超临界淀粉酯化反应效率,改善了酯化反应条件。

关键词: 超临界CO2, 制备, 辛烯基琥珀酸淀粉酯, 环己烷, 酯化, 辅助效果

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