Hindered urea bond for the design of dynamic materials

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.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Materials Science & Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2017

Author dc:creator

• Ying, Hanze

Contributors dc:contributor

• Cheng, Jianjun
• Braun, Paul
• Sottos, Nancy
• Kilian, Kristopher
• Moore, Jeffrey

• Dynamic covalent chemistry
• Hindered urea bond (HUB)
• Dynamic polymers
• Self-healing
• Hydrolyzable
• Malleable thermoset

Statement dc:rights

• Copyright 2016 Hanze Ying

Language dc:language

en

Handle dc:identifier

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

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/97648