Reprocessable and Self‐Healing Shape Memory Epoxy Resin Based on Biphenyl Mesogen and Siloxane

Abstract

Shape memory epoxy resin has a high potential for applications in various fields such as space deployable structures and actuators. In order to meet the requirements of application and extend the materials' service life, it is highly desirable to develop a shape memory epoxy resin with good properties of shape memory, reprocessing, and self-healing. In this work, a shape memory epoxy resin based on the orientable biphenyl mesogen and the dynamic siloxane is fabricated successfully via anion ring-opening polymerization. The resulting epoxy resin exhibits excellent shape memory performance, good reprocessing ability, good self-healing property, and triple shape memory effect (triple-SME).

Fast Dynamic Siloxane Exchange Mechanism for Reshapable Vitrimer Composites

“…The first report on siloxane chemistry in the context of dynamic materials was published by Zheng and McCarthy in 2012, followed by a number of studies with a focus on the use of both siloxane ,,− and silyl ether ,− chemistries in CANs. The studies on silyl ether chemistry explored the silyl ether metathesis reaction as well as the internal catalysis by a γ-NH functionality or hydroxyl groups to fabricate the corresponding materials.…”

Reprocessable, Self-Healing, Thermadapt Shape Memory Polycaprolactone via Robust Ester–Ester Interchanges Toward Kirigami-Tailored 4D Medical Devices

“…A variety of unexpected and sophisticated 3D shapes are readily available by combining origami or kirigami with plasticity. ,, Besides 3D printing SMPs, designing thermadapt SMPs has become the most popular route to achieve 4D deformation, in which an object evolves with time into a designable 3D permanent shape when exposed to a predetermined stimulus. At present, a large number of the thermadapt SMPs with various SEMs had been elegantly engineered, employing a variety of dynamic covalent chemistries including transesterification, ,,, transcarbamoylation, , disulfide change, − Diels–Alder reaction, − siloxane exchange, , a selenide bond, , and an imine bond. ,, The thermoadapt SMPs with various 4D structures exhibit a wealth of potential advantages, such as soft robots, , information encryption, , actuators, ,, and tissue engineering scaffolds …”

An extended shoving model for dynamic fluctuation of glass transition in amorphous polymer towards cooperative shape-memory effect

“…The repulsion force has been identified as the driving force [29], and the average lateral distance of the CRR is gradually enlarged with an increase in the repulsion Table 1. Values of parameters used in equation (2.10) for epoxy SMP [33]. force during the shoving process.…”

“…To verify the effectiveness of the proposed model based on equation (2.10), the experimental data of strain-temperature behaviours of epoxy SMP [33] were used, and the corresponding analytical results obtained using equation (2.10) are plotted in figure 6 a . All the parameters used in the calculation based on equation (2.10) are listed in table 1, where A = 1, r 1 = 1 × 10 −9 m, T ref = 300 K, T * = 750 K, T 0 = 375 K and G = 3 GPa [32,40].…”

“…The effect of CRR volume on the phase transition has been formulated using the strain function, which has been further employed to develop a constitutive stress–strain equation based on the extended Maxwell model [32]. Finally, the effectiveness of the proposed model's analytical result has been verified using the experimental results reported in the literature [33–36], and good agreements between these analytical and experimental results of amorphous SMPs are achieved.…”