Supersoft, Stretchable, Tough, and Adhesive Elastomers with Dual Metal‐Ionic Crosslinked Double‐Network Structure

Abstract

Soft, stretchable, tough, and adhesive elastomers are developed based on the metal‐ionic crosslinked double network structure, where the metal ion coordination of sulfonated poly(phenylene oxide) (SPPO) is used for the first network and the soft chemical crosslinked poly(ethyl acrylate) (PEA) is used for the second network. The influence of SPPO content on the tensile, cyclic tensile, adhesive, and rheological behavior of the elastomers is systematically investigated. It is observed that the elastomers are immensely soft and stretchable with tunable modulus from 0.038 to 0.086 MPa, fracture strain of ≈1400%, fracture stress in the range 0.20–1.2 MPa, work of extension of 0.72–5.6 MJ m−3, fast self‐recovery of 5 s after experiencing 200% strain, and robust adhesive behavior on glass substrates with interface debonding energy ≈35.2 J m−2. The mechanical behavior of the double‐network elastomers at the macroscopic scale is related to the dynamic breaking and reforming of the metal‐ion coordination at the molecular scale in the first network. This study provides a facile approach for the synthesis of elastomers with multidimensional mechanical behavior and broadens the applications of the elastomers in the field of flexible electronic devices, soft robotics, among others.

Recent Progress in Double Network Elastomers: One Plus One is Greater Than Two

“…They use Al-COOH ion binding to construct a strong polymer network and EU-iminodiacetate (IDA) coordination to construct another weak yet dynamic network structure, resulting in a strong, self-healing IPN elastomer. Similarly, a tough, flexible, stretchable, and adhesive DN elastomer is developed based on metal-ion cross-linking by Jiang et al [108] The first sacrificial network is a sulfonated poly (phenoxy) (SPPO) metal-ion cross-linked network, while the second is a chemically cross-linked poly(ethyl acrylate) (PEA) network (Figure 9a). The hydration of SPPO and the formation of interchain ionic complexation promote the expansion and shrinkage of the elastomer in water and FeCl 3 solution, respectively (Figure 9b).…”

“…e) Adhesive properties of the DN elastomers. Panels (a)-(e) are reproduced with permission [108]. Copyright 2019, Elsevier.…”

High‐Performance Supramolecular Adhesives

“…In addition to mentioned strategies, the interpenetrating polymer network is also beneficial to improving the mechanical properties. [ 42 ] It has been previously confirmed that the interpenetrating network is superior to the single network when comparing peak stress and fracture toughness. [ 43 ] Moreover, the mechanical strength can be significantly improved by incorporating nano‐particle and nano‐fiber.…”

Mechanically Robust Dual-Crosslinking Elastomer Enabled by a Facile Self-Crosslinking Approach

“…( b ) Summary of mechanical properties of the SCDCEs. ( c ) Ashby plot of the mechanical properties of SCDCEs and recently reported acrylate-based elastomers [ 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ]. Cyclic stress–strain curve of SCDCE-0.3 ( d ), SCDCE-0.5 ( e ) and SCDCE-0.8 ( f ).…”