The
rapid development of flexible electronic devices has resulted
in serious electronic pollution, which has aroused great attention
in recent years. This study focuses on the development of dynamic
cross-linking poly(dimethylsiloxane) (PDMS) elastomers with covalent
adaptive network structures that can be recycled by a solvolytic approach
to address this challenge. The elastomer is prepared through the addition
reaction between amine-terminated PDMS, isophorone diisocyanate, and
2-aminobenzimidazole followed by cross-linking with hexamethylene
diisocyanate trimer. The secondary ureidobenzimidazole (SUBI) moieties
formed by benzimidazole and isocyanate groups can undergo a six-membered-ring
transition state, enabling automatic dissociation and reformation
character at room temperature. Hydrogen-bonded aggregates formed by
SUBI moieties work as physical cross-linking units to protect urea
bonds from dissociation, which endows the materials with excellent
creep-resistant performance. Decomposition of the aggregates by solvation,
releasing the SUBI moieties, is mainly responsible for the recycling
process. Wearable electronic devices with a microcrack structure for
vibratory monitoring are assembled through 3D printing nanosilver
paste onto the elastomer with predesigned structure. The excellent
recycling performance can be transferred from the PDMS substrate to
the devices, which enables the separation of PDMS and nanosilver,
providing promising principles to develop facile degradable materials
at room temperature for fabricating recyclable wearable electronic
devices.