TY - JOUR

T1 - Shape memory-assisted self-healing of dynamic thiol-acrylate networks

AU - Alabiso, Walter

AU - Hron, Tiago Manuel

AU - Reisinger, David

AU - Bautista-Anguís, Daniel

AU - Schlögl, Sandra

N1 - Publisher Copyright: © 2021 The Royal Society of Chemistry.

PY - 2021/10/12

Y1 - 2021/10/12

N2 - Self-healing polymers are tremendously attractive due to their ability to repair macroscopic damage and defects, thus opening doors to sustainable and reliable functional polymers. In this scope, vitrimers are in the spotlight, as dynamic polymer networks exhibiting unique properties such as self-healing ability, recyclability and malleability. The possibility of intrinsically healing macroscopic damage on the molecular scale repeatedly is undoubtedly appealing, although it would strongly benefit from an additional driving force bringing the surfaces of larger defects together. Herein, we present a study on the synergistic combination of physical and chemical healing of a thiol-acrylate vitrimeric photopolymer based on thermo-activated transesterification by pursuing a close-then-heal approach. By following shape-memory assisted self-healing (SMASH), we used the shape-memory properties of thiol-acrylate photopolymers to physically close a scratch, whilst chemical healing was obtained via thermo-activated dynamic exchange reactions of the –OH groups and ester moieties available in the network. We prepared formulations with varying thiol content and characterised their mechanical, chemical, and shape memory properties and healing efficiency. We provide a comprehensive picture of the role of physical recoil, bond exchanges and network mobility on self-healing efficiency as well as its limitations. By appropriate network design, defects with a size of 50–150 μm can be rapidly closed, and healing efficiency up to 90% can be reached in terms of ultimate tensile strength, thus demonstrating the potential of SMASH for vitrimers.

AB - Self-healing polymers are tremendously attractive due to their ability to repair macroscopic damage and defects, thus opening doors to sustainable and reliable functional polymers. In this scope, vitrimers are in the spotlight, as dynamic polymer networks exhibiting unique properties such as self-healing ability, recyclability and malleability. The possibility of intrinsically healing macroscopic damage on the molecular scale repeatedly is undoubtedly appealing, although it would strongly benefit from an additional driving force bringing the surfaces of larger defects together. Herein, we present a study on the synergistic combination of physical and chemical healing of a thiol-acrylate vitrimeric photopolymer based on thermo-activated transesterification by pursuing a close-then-heal approach. By following shape-memory assisted self-healing (SMASH), we used the shape-memory properties of thiol-acrylate photopolymers to physically close a scratch, whilst chemical healing was obtained via thermo-activated dynamic exchange reactions of the –OH groups and ester moieties available in the network. We prepared formulations with varying thiol content and characterised their mechanical, chemical, and shape memory properties and healing efficiency. We provide a comprehensive picture of the role of physical recoil, bond exchanges and network mobility on self-healing efficiency as well as its limitations. By appropriate network design, defects with a size of 50–150 μm can be rapidly closed, and healing efficiency up to 90% can be reached in terms of ultimate tensile strength, thus demonstrating the potential of SMASH for vitrimers.

UR - http://www.scopus.com/inward/record.url?scp=85117282292&partnerID=8YFLogxK

U2 - 10.1039/d1py00925g

DO - 10.1039/d1py00925g

M3 - Article

AN - SCOPUS:85117282292

VL - 12.2021

SP - 5704

EP - 5714

JO - Polymer Chemistry

JF - Polymer Chemistry

SN - 1759-9954

IS - 39

ER -