大学化学 >> 2021, Vol. 36 >> Issue (12): 2102009.doi: 10.3866/PKU.DXHX202102009

化学实验 上一篇    下一篇

润物无声,启迪创新——从“冷冻聚合制备高分子量聚合物”综合实验谈起

金邦坤1, 何卫东2,*()   

  1. 1 化学国家级实验教学示范中心(中国科学技术大学), 合肥 230026
    2 中国科学技术大学高分子科学与工程系, 合肥 230026
  • 收稿日期:2021-02-05 录用日期:2021-03-30 发布日期:2021-04-15
  • 通讯作者: 何卫东 E-mail:wdhe@ustc.edu.cn
  • 作者简介:何卫东, Email: wdhe@ustc.edu.cn
  • 基金资助:
    2019年中国科学技术大学教学改革研究项目(2019xjyxm032);2020年安徽省教学改革研究项目(2020jyxm2288)

Teaching and Learning of a Comprehensive Experiment on Synthesis of Ultrahigh Molecular Weight Polymers through Cryo-Polymerization

Bangkun Jin1, Weidong He2,*()   

  1. 1 National Demonstration Center for Experimental Chemistry Education (University of Science and Technology of China), Hefei 230026, China
    2 Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026, China
  • Received:2021-02-05 Accepted:2021-03-30 Published:2021-04-15
  • Contact: Weidong He E-mail:wdhe@ustc.edu.cn

摘要:

冷冻聚合是一种新发展的聚合反应实施方法,其聚合温度低于反应介质的凝固点,聚合场所为冻结聚合体系中的液相微区,液相微区的体积百分数约为10%。因为聚合温度低、液相微区的单体浓度很高,所以冷冻聚合是制备高/超高分子量聚合物的有效方法。本实验分别实施丙烯酰胺和丙烯酸的冷冻聚合,通过改变冷冻聚合条件调控聚合物的分子量,使用稀溶液黏度法测定所得聚合物的分子量。通过该实验,帮助学生理解自由基聚合分子量控制的基本原理,学会灵活运用Mayo方程,引导学生关注实验细节、掌握实验技巧、学会实验设计。

关键词: 综合性实验, 冷冻聚合, 分子量控制, 超高分子量, 聚丙烯酰胺, 聚丙烯酸

Abstract:

Cryo-polymerization is a newly developed polymerization technique. Its polymerization temperature is below the freezing point of the medium and the polymerization locus is indeed the liquid microphase (about 10%, volume percent) embedded in the frozen bulk. Due to the low polymerization temperature as well as the highly concentrated monomer in the polymerization locus, cryo-polymerization facilitates the preparation of (ultra) high molecular weight polymers. In this experiment, the cryo-polymerization of acrylamide and acrylic acid is performed separately, the molecular weight of the obtained polymer is modulated by varying polymerization parameters and determined by the dilute solution viscometry method. This experiment can prompt students to grasp the primary principle to control molecular weight of radical polymerization, utilize Mayo equation flexibility and learn some laboratory skills through watching out the experimental details, leading to acquisition of the ability to design experiment.

Key words: Comprehensive experiment, Cryo-polymerization, Molecular weight control, Ultra-high molecular weight, Polyacrylamide, Poly(acrylic acid)

MSC2000: 

  • G64