University of Illinois Urbana-Champaign

Hindered urea bond for the design of dynamic materials

Ying, Hanze

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YING-DISSERTATION-2017.pdf

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https://hdl.handle.net/2142/97648

Description

Title
Hindered urea bond for the design of dynamic materials
Author(s)
Ying, Hanze
Issue Date
2017-01-04
Director of Research (if dissertation) or Advisor (if thesis)
Cheng, Jianjun
Doctoral Committee Chair(s)
Cheng, Jianjun
Committee Member(s)
  • Braun, Paul
  • Sottos, Nancy
  • Kilian, Kristopher
  • Moore, Jeffrey
Department of Study
Materials Science & Engineerng
Discipline
Materials Science & Engr
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
Ph.D.
Degree Level
Dissertation
Date of Ingest
2017-08-10T20:32:21Z
Keyword(s)
  • Dynamic covalent chemistry
  • Hindered urea bond (HUB)
  • Dynamic polymers
  • Self-healing
  • Hydrolyzable
  • Malleable thermoset
Abstract
Dynamic covalent bonds (DCBs) featuring reversible bonding/debonding properties have found various applications in dynamic materials designs such as self-healing, malleable, shape-memory or environmentally-adaptive materials. However, most DCBs developed so far require either catalyst or harsh environments to facilitate bond reversion and involve special building blocks for synthesis. Here we seek to develop a novel platform for dynamic materials design using a new type of DCB – hindered urea bond (HUB). Differing from normal urea bond, HUB bears bulky substituents on one of the nitrogen atom, which distorts the atomic co-planarity, weakens the bonding stability, and allows reversible dissociation of HUB to isocyanate and hindered amine. The dynamic properties of HUB enables the design of self-healing polymeric elastomers/malleable thermosets through bond exchange and hydrolyzable polymers through quenching of dissociative intermediate – isocyanate. HUB shows many advantages in dynamic materials designs compared with other DCB systems in terms of simplicity, dynamicity, tunability and cost.
Graduation Semester
2017-05
Type of Resource
text
Permalink
http://hdl.handle.net/2142/97648
Copyright and License Information
Copyright 2016 Hanze Ying

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