Internal hydrogen bonding of imines to control and enhance the dynamic mechanical properties of covalent adaptable networks

Creep resistance in doubly crosslinked dynamic covalent networks

“…43 Sacrificial hydrogen bonds were incorporated into an acrylate vitrimer by Zhang et al and showed a 4.4 times increase in the tensile strength with only a 20% addition of acrylamide. 44 Finally, Du et al 45–47 have explored the integration of hydrogen-bonding moieties into boronate ester vitrimers. Rather than using the hydrogen bonds for sacrificial energy damping, the authors designed the vitrimer backbone around the incorporation of the hydrogen bond-forming pendent group.…”

Thermoswitchable catalysis to inhibit and promote plastic flow in vitrimers

“…On the other hand, because proton transfer equilibria are at the root of many vitrimer systems, such detailed studies provide useful insights that can be extrapolated to different types of vitrimeric materials, such as polyiminebased networks. 39,65,66 It should be noted that the nitrogen lone pair of the VU moiety is involved in a conjugated system and is thus deactivated as a base. Therefore, the "iminium" intermediate in acid catalysed VUs is obtained aer proton transfer onto the alkene moiety of the enamine.…”