Hindered urea bond for the design of dynamic materials

Ying, Hanze

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

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

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

Copyright and License Information

Copyright 2016 Hanze Ying

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