高等学校化学学报

高等学校化学学报 ›› 2002, Vol. 23 ›› Issue (12): 2378.

• 研究论文 • 上一篇    下一篇

高低温处理对乙基纤维素稀溶液特性的影响

李利2, 杨琥2, 程时2   

  1. 1. 南京师范大学化学与环境科学学院, 南京210097;
    2. 南京大学化学化工学院, 南京210093
  • 收稿日期:2001-09-07 出版日期:2002-12-24 发布日期:2002-12-24
  • 通讯作者: 李　利(1970年出生),男,博士,副教授,从事高分子物理及应用高分子的研究.E-mail:lili@email.njnu.edu.cn E-mail:lili@email.njnu.edu.cn
  • 基金资助:

    江苏省科技厅社会发展基金(批准号:BS2000015)资助

Influence of Heating and Freezing on the Hydrodynamic Properties of Ethyl Cellulose Dilute Solution

LI Li2, YANG Hu2, CHENG Rong-Shi2   

  1. 1. College of Chemistry & Environmental Science, Nanjing Normal University, Nanjing 210097, China;
    2. College of Chemistry & Chemical Engineering, Nanjing University, Nanjing 210093, China
  • Received:2001-09-07 Online:2002-12-24 Published:2002-12-24

PDF (PC)

被引次数

6

摘要： 利用自行设计的封闭式粘度计以及体积排除色谱(SEC)研究了循环冷冻及加热处理对四氢呋喃(THF)稀溶液中乙基纤维素(EC)分子流体力学性质的影响,探讨了处理前后溶液中EC分子组成及构象变化,发现对EC的THF稀溶液进行循环冷冻后溶液的粘度有所减小,但样品的SEC保留体积没有明显变化.这说明溶质分子的流体力学体积略有下降,这种下降主要是冷冻处理促使溶质分子结晶所致.加热处理可使溶液中EC分子的流体力学体积下降更为明显,溶液的粘度有较大的减小.这说明加热可能会引起EC分子发生侧基脱除,增大了分子形成氢键的能力,导致溶质分子发生团聚.

关键词: 乙基纤维素, 稀溶液, 循环冷冻, 加热, 粘度, 体积排除色谱

Abstract: A closed viscometer was designed for viscosity measurement of volatile solvent-based solutions. The influence of freezing-thawing and heating on the hydrodynamic properties of EC molecules was studied by viscometry and size exclusion chromatographic (SEC) analysis. The change of molecular structure and conformation of EC molecules in solution after treatments is discussed. Freezing-thawing treatment reduces the viscosity of EC dilute solutions. However, it doesn't make any significant change of the SEC retention volume of EC sample in THFsolvent. This suggests that the apparent hydrodynamic volume of EC molecules slightly decrease. Heating treatment reduces the apparent hydrodynamic volume of EC molecules more evidently. The viscosity of EC solution decreases obviously after heating treatment.

Key words: Ethyl cellulose, Dilute solution, Freezing-thawing, Heating, Viscometry, Size exclusion chromatographic

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