Shape memory and self‐healing behavior of styrene–butadiene–styrene/ethylene‐methacrylic acid copolymer (SBS/EMAA) elastomers containing ionic interactions

Abstract

Ionic interactions were introduced to styrene-butadiene-styrene (SBS) through blending with ethylene-methacrylic acid copolymer (EMAA) and zinc oxide (ZnO), and a following in situ neutralization reaction between the carboxyl groups of EMAA and ZnO. The resultant SBS/EMAA (60/40 wt %) blends containing zinc carboxylate crosslinks exhibited high modulus and strong long-time relaxation characteristics. With 74% of the carboxyl groups neutralized (zinc cation fraction of 1.7 wt %), the tensile strength of the blends was increased from 14.6 to 16.6 MPa, and the stress at 100% extension was increased from 4.8 to 8.1 MPa. The melting temperature of EMAA was utilized to trigger the shape memory behavior of SBS/EMAA, and the reversible ionic bonds endowed SBS with better shape memory and self-healing performance. The shape-fixing ratio and recovery ratio of SBS were increased from 90.2 and 56.5% up to 93.3 and 84.2%, respectively. When the cut surfaces of SBS/EMAA/Zn samples were brought back into contact and annealed at 100 C for 1 h, the strength and the elongation at break were recovered by 36 and 21%, respectively. This introduction of ionic interactions through the EMAA-ZnO neutralization reactions imparts new functions to SBS thermoplastic elastomers.

Coupling Dynamic Covalent Bonds and Ionic Crosslinking Network to Promote Shape Memory Properties of Ethylene-vinyl Acetate Copolymers

“…After heat treatment at 130 • C for 30 min, the residual strains were 100% recovered for all samples. However, the dissipating energy did not completely recover, and the recovery ratios of the stress at 200% extension and the dissipating energy increased sequentially from mEVA to DA1 to ZnMA 10 wt % to DA1-ZnMA 10 wt %, which was different from the results of SBS/EMAA blends [34], in which the irreversible deformation at large strain was due to the introduction of the crystalline EMAA. For ZnMA 10 wt % and DA1-ZnMA 10 wt %, the stresses at 200% extension were completely recovered attributed to excellent recovery ability of these reversible crosslinks.…”

A Fast Self‐Healing Magnetic Nanocomposite for Magnetic Actuators

“…The former mainly includes DA chemistry, [ 15–17 ] disulfide bonds, [ 18–20 ] imine bonds, [ 21,22 ] boron‐based bonds. [ 23–25 ] The latter mainly refers to hydrogen bonding, [ 26–29 ] host‐guest interactions, [ 30–32 ] ionic interactions, [ 33,34 ] and metal‐ligand interactions. [ 11,35–37 ]…”

Self‐healing polymer blend based onPETGandEMAA

“…20,[23][24][25] As emphasized, EMAA is one of the most studied ionomers with healing abilities. 1,21,26,27 In their works, Kalista et al 19 studied the self-healing of EMAA in ballistic tests and have observed that the incorporation of aliphatic carboxylic acids into EMAA increased the elastomeric behavior and elastic healing of the samples due the change of the ionomeric clusters mobility. Moreover, those authors observed that, when the ionic clusters were plasticized, the rate of recovery was increased, and the behavior was attributed to the reestablishment of ionic clusters through the reorganization of Coulombian interactions.…”

“…As emphasized, EMAA is one of the most studied ionomers with healing abilities 1,21,26,27 . In their works, Kalista et al 19 studied the self‐healing of EMAA in ballistic tests and have observed that the incorporation of aliphatic carboxylic acids into EMAA increased the elastomeric behavior and elastic healing of the samples due the change of the ionomeric clusters mobility.…”