Dynamic ionic crosslinks enable high strength and ultrastretchability in a single elastomer

By Yohei Miwa, Junosuke Kurachi, Yu Kohbara, S. Kutsumizu. Communications Chemistry, 2018

143 citations recorded by the source corpus.

Maintenance-free self-healing elastomers that switch their mechanical properties on demand would be extremely useful materials for improving the functionalities, safety, energy efficiency, and lifetimes of many kinds of products and devices. However, strength and stretchability are conflicting properties for elastomers because the inherent crosslinking density of a polymeric network is unchangeable. For example, heavily crosslinked elastomers are strong, but poorly stretchable. Here we report an ionically crosslinked polyisoprene elastomer in which the ionic moieties are continually hopping between ionic aggregates at room temperature. Thus, the network is dynamic. This elastomer spontaneously self-heals without the input of external energy or healing agents. Furthermore, it behaves like a strong elastic material under rapid deformation, but acts like a highly stretchable and viscoelastic material under slow deformation. Our ionic elastomer shows a variety of notable mechanical properties, including high fracture strength (≈7 MPa), good toughness (≈70 MJ m−3), and ultrastretchability (>13,400%).Imparting both high strength and stretchability in polymers is challenging as it requires changing the crosslinking density of the polymer network. Here, Miwa et al. use an ionic elastomer with dynamic crosslinks to achieve high strength under rapid deformation but high stretchability under slow deformation in a single material.

Subfields: Biomedical Engineering, Polymers and Plastics

View Paper: https://www.semanticscholar.org/paper/f9dd955c11c7506133057bfbbe4ac54fa607b705