The fourth dimension in 4D printing comprises the ability of materials to recover their shape with time by utilizing 3D printing in combination with shape memory polymers. The focus of this work is on 3D printing of physically crosslinked thermoplastic polymers, which allow a reversible transformation from a temporary to an original shape by an external stimulus temperature, thus realize 4D printing. In this context, (AB)_n segmented copolyetherimides consisting of perylene and poly(ethylene glycol) (PEG) segments are synthesized and characterized regarding their thermal and rheological properties in view of 3D printing. The perylene imide segments act as reversible physical crosslinks which disassemble between 100 and 200 °C. The PEG segments exhibit a low melting temperature around 40 to 60 °C and are semi‐crystalline at room temperature. The results show that this type of (AB)_n segmented copolyetherimide combines reliable 3D printing performance, which is indicated by low warp deformation and excellent interlayer bonding. With a blend of two copolymers, it is able to realize 4D printing.

中文翻译：

---

（AB）n用于4D打印的分段共聚醚酰亚胺

4D打印的第四个维度包括材料通过与形状记忆聚合物结合使用3D打印来随时间恢复其形状的能力。这项工作的重点是物理交联的热塑性聚合物的3D打印，通过外部刺激温度，它可以从临时形状恢复为原始形状，从而实现4D打印。在这种情况下，（AB）_n合成了由per和聚（乙二醇）（PEG）链段组成的嵌段共聚醚酰亚胺，并根据3D打印对其热和流变性进行了表征。per酰亚胺链段充当可逆的物理交联键，可在100至200°C之间分解。PEG链段的熔点较低，约为40至60°C，在室温下呈半结晶状态。结果表明，这种类型的（AB）_n嵌段共聚醚酰亚胺具有可靠的3D打印性能，这表现为低翘曲变形和出色的层间粘合力。通过将两种共聚物共混，可以实现4D打印。