The Shape Memory Properties and Actuation Performances of 4D Printing Poly (Ether-Ether-Ketone)

Abstract

Shape-memory polymers (SMPs) have gradually emerged in the mechanism and biomedical fields and facilitate the upgrading of industrial mechanisms and the breakthrough of technical bottlenecks. However, most of the SMPs are infeasible in harsh environments, such as aerospace, due to the low glass transition temperature. There are still some works that remain in creating truly portable or non-contacting actuators that can match the performances and functions of traditional metal structures. Polyether-ether-ketone (PEEK) with a high glass transition temperature of 143 °C is endowed with outstanding high-temperature resistance and radiation-resistant properties and shape memory behavior. Thus, we explore the shape-memory properties and actuation performances of high-temperature PEEK in bending behaviors. The shape-recovery ratio, actuation speed and force under different programming conditions and structure parameters are summarized to complete the actuation capacities. Meanwhile, a metallic ball transported by shape-memory PEEK and deployed drag sail with thermo-responsive composite joints were shown to verify the potential in aerospace.

Toward 4D Printing of Shape Memory Polymers Based on Polyaryletherketone/NVP/PEGDA through Molecular Engineering and Direct Ink Writing 3D Printing

“…PAEK exhibited a high modulus of 2–2.5 GPa, but a relatively lower elongation at break of less than 4.5%, with the strength ranging from 30.4 to 45.6 MPa. Obviously, the mechanical properties of the shape memory PAEKs (σ = 25–70 MPa) were comparable to those reported, − ,,,, suggesting that the addition of PEGDA and NVP did not significantly reduce the strength, and were much stronger than PEDGA/NVP hydrogels . The cross-linker PEGDA400/PEGDA600 was pivotal in adjusting the mechanical properties.…”

“…Due to the good fluidity of melted PAEK at 350–400 °C, a series of work on free-form precision molding of PAEK has been reported using fused deposition modeling (FDM) 3D printing. − The emergence of this new manufacturing technology has also opened up new ideas for researchers, such as Zhang et al, , who achieved a shape fixing rate and a recovery rate of 99 and 87.8% for PEKE SMPs by optimizing printing parameters and completed the electric drive by embedding chromium–nickel wire. Although 3D printing PAEK through FDM has demonstrated the capacity to extrude and rapidly shape the material with excellent shape fidelity after extrusion, as well as the potential to achieve up to 100 MPa of strength through the optimization of print parameters or material modifications, printing PAEK without internal defects still remained a persistent challenge. ,, Nevertheless, direct ink writing (DIW) 3D printing technology allowed the polymer ink to be extruded in a liquid state, which prevented the defects caused by temperature changes and enabled the printed objects with higher precision (micron-level). , Meanwhile, it is worth noting that the DIW printing inks required a proper rheological behavior, including the shear-thinning effect and thixotropy to maintain the printing fidelity. , …”

“…Given the numerous advantages offered by 4D printing, including the ability to produce prototypes featuring intricate or precisely defined structures with designable actuation, and its extensive range of potential applications, ,, there has been a growing focus on achieving 4D printing for PAEK. Nevertheless, DIW 3D printing with enhanced interfacial adhesion and reduced defects based on the longer contact time before solidification offered a viable alternative to 3D printed PAEK prototypes. , On the other hand, the solubility was another hindrance for PAEK to achieve DIW 3D printing.…”

Recent trends in thermo‐responsive elastomeric shape memory polymer nanocomposites

“…For polyaspartimide‐urea, a similar trend was seen 148 . Shape memory capabilities can also be revealed by altering the significant engineering polymer polyetheretherketone (PEEK) 149 . PEEK's programming is opposed to normal PEEK‐based tubing, having transition temperatures of about 340°C for activating the SME.…”

“…148 Shape memory capabilities can also be revealed by altering the significant engineering polymer polyetheretherketone (PEEK). 149 PEEK's programming is opposed to normal PEEK-based tubing, having transition temperatures of about 340 C for activating the SME. An SME occurs at around 200 C (depending on the selection of metal counter ions) when ionic moieties are introduced into PEEK (via sulfonation).…”