Improved Self-Healing of Polyethylene/Carbon Black Nanocomposites by Their Shape Memory Effect

Abstract

In this work, the improved self-healing of cross-linked polyethylene (PE) (cPE)/carbon black (CB) nanocomposites by their shape memory effect (SME) is investigated. CB nanoparticles are found to be homogeneously dispersed in the PE matrix and significantly increase the strength of the materials. Compared with the breaking of linear PE (lPE) at the melting temperature (T(m)), the cPE and cPE/CB nanocomposites still have high strength above T(m) due to the formation of networks. The cPE and cPE/CB nanocomposites show both high strain fixity ratio (R(f)) and high strain recovery ratio (R(r)). Crystallization-induced elongation is observed for all the prepared shape memory polymer (SMP) materials and the effect becomes less remarkable with increasing volume fraction of CB nanoparticles (v(CB)). The scratch self-healing tests show that the cross-linking of PE matrix, the addition of CB nanoparticles, and the previous stretching in the direction perpendicular to the scratch favor the closure of the scratch and its complete healing. This SME-aided self-healing could have potential applications in diverse fields such as coating and structure materials.

Microfibrillated cellulose-reinforced bio-based poly(propylene carbonate) with dual shape memory and self-healing properties

“…3,[18][19][20][21][22] For instance, Rown reported a structurally dynamic polydisulfide network which could exhibit both shape memory and healable properties. 18 Zhao also investigated the improved self-healing property of cross-linked polyethylene/carbon black nanocomposites by shape memory effect (SME).…”

Shape Memory-Enhanced Electrical Self-Healing of Stretchable Electrodes

“…The results suggested obvious enhancing effect of the pre-stretching on the healing behaviors. According to the previous report on the self-healing improved by the shape memory pre-stretching, the enhancement may attribute to the release of the strain energy driving the local shape recovery and favoring the closure of the scratch and its complete healing [12,13]. The SEM images, shown in Figure 2d-f, clearly disclosed that the thermal stimulation made the scratch gap closer and reconstructed the conductive pathways of the AgNWs.…”

“…and its complete healing [12,13]. The SEM images, shown in Figure2d-f, clearly disclosed that the thermal stimulation made the scratch gap closer and reconstructed the conductive pathways of the AgNWs.…”

Triple shape memory effect of foamed natural Eucommia ulmoides gum/high‐density polyethylene composites

“…Such properties give SMPs marked potential regarding deployable space structures, biological applications, smart dry adhesives, and other smart devices . Shape memory polymers typically comprised 2 phases: a fixed phase and a reversible phase . The fixed phase, usually used to hold the permanent shape, can be composed of chemical and physical crosslink points, while the reversible phase (eg, amorphous or crystalline phase) contributes to shape deformation and recovery due to the change in molecular chain mobility above specific temperature (eg, glass transition temperature or melting temperature), which is typically referred to as the “switch temperature” ( T sw ) …”

“…There have been relatively few studies on multiple or triple SMEs based on vulcanized EUG or its blends, however. Similar to low crosslinked EUG, polyethylene as a kind of general polymer can also be used to prepare shape memory and self‐healing materials via light crosslinking …”