University Chemistry

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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

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