TY - JOUR
T1 - Knoevenagel C═C Metathesis Enabled Glassy Vitrimers with High Rigidity, Toughness, and Malleability
AU - Wang, Sheng
AU - Feng, Hongzhi
AU - Li, Bofan
AU - Lim, Jason Y.C.
AU - Rusli, Wendy
AU - Zhu, Jin
AU - Hadjichristidis, Nikos
AU - Li, Zibiao
N1 - Publisher Copyright:
© 2024 The Authors. Published by American Chemical Society.
PY - 2024/6/12
Y1 - 2024/6/12
N2 - Thermosets, characterized by their permanent cross-linked networks, present significant challenges in recyclability and brittleness. In this work, we explore a polarized Knoevenagel C═C metathesis reaction for the development of rigid yet tough and malleable thermosets. Initial investigation on small molecule model reactions reveals the feasibility of conducting the base-catalyzed C═C metathesis reaction in a solvent-free environment. Subsequently, thermosetting poly(α-cyanocinnamate)s (PCCs) were synthesized via Knoevenagel condensation between a triarm cyanoacetate star and a dialdehyde. The thermal and mechanical properties of the developed PCCs can be easily modulated by altering the structure of the dialdehyde. Remarkably, the introduction of ether groups into the PCC leads to a combination of high rigidity and toughness with Young’s modulus of ∼1590 MPa, an elongation at break of ∼79%, and a toughness reaching ∼30 MJ m3. These values are competitive to traditional thermosets, in Young’s modulus but far exceed them in ductility and toughness. Moreover, the C═C metathesis facilitates stress relaxation within the bulk polymer networks, thus rendering PCCs excellent malleability and reprocessability. This work overcomes the traditional limitations of thermosets, introducing groundbreaking insights for the design of rigid yet tough and malleable thermosets, and contributing significantly to the sustainability of materials.
AB - Thermosets, characterized by their permanent cross-linked networks, present significant challenges in recyclability and brittleness. In this work, we explore a polarized Knoevenagel C═C metathesis reaction for the development of rigid yet tough and malleable thermosets. Initial investigation on small molecule model reactions reveals the feasibility of conducting the base-catalyzed C═C metathesis reaction in a solvent-free environment. Subsequently, thermosetting poly(α-cyanocinnamate)s (PCCs) were synthesized via Knoevenagel condensation between a triarm cyanoacetate star and a dialdehyde. The thermal and mechanical properties of the developed PCCs can be easily modulated by altering the structure of the dialdehyde. Remarkably, the introduction of ether groups into the PCC leads to a combination of high rigidity and toughness with Young’s modulus of ∼1590 MPa, an elongation at break of ∼79%, and a toughness reaching ∼30 MJ m3. These values are competitive to traditional thermosets, in Young’s modulus but far exceed them in ductility and toughness. Moreover, the C═C metathesis facilitates stress relaxation within the bulk polymer networks, thus rendering PCCs excellent malleability and reprocessability. This work overcomes the traditional limitations of thermosets, introducing groundbreaking insights for the design of rigid yet tough and malleable thermosets, and contributing significantly to the sustainability of materials.
UR - http://www.scopus.com/inward/record.url?scp=85194466266&partnerID=8YFLogxK
U2 - 10.1021/jacs.4c03503
DO - 10.1021/jacs.4c03503
M3 - Article
C2 - 38803151
AN - SCOPUS:85194466266
SN - 0002-7863
VL - 146
SP - 16112
EP - 16118
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 23
ER -