Abstract Thermoelectric (TE) composite wires with polylactic acid (PLA) as the matrix and Bi0·5Sb1·5Te3 (BST) as the filler are synthesized by extruding. The effects of silane coupling agent KH570, plasticizer ATBC, and conductive additive multi-walled carbon nanotubes (MWCNTs) on the composition, TE, and mechanical properties of the composite wires are systematically studied. It is necessary to add KH570 into the composite wires to make the actual BST loading the same as the designed value. The addition of ATBC greatly increases the flexibility of the composite wires and improves the wires' mechanical properties. When the BST loading increases from 35.8 to 87.5 wt%, the flexural modulus increases from 1684.0 to 4379.8 MPa and the flexural strength monotonically decreases from 50.1 to 13.4 MPa. In aspect of TE properties, the power factor PF of the composite wires increases with the increase of the BST loading, and the maximum Seebeck coefficient reaches 200 μV K−1. When MWCNTs are added into the composite wires, the electrical conductivity is significantly enhanced and thus the PF of the wires is raised. The highest PF of 11.3 μW m−1 K−2 is obtained for the wire containing 81.3 wt% BST and 4 wt% MWCNTs. A TE figure of merit ZT of 0.011 is obtained at room temperature. The excellent TE properties and satisfactory mechanical properties of the BST/PLA composite wires make them a promising candidate used for 3D printing of TE devices.

中文翻译：

---

用于3D打印的PLA/Bi0·5Sb1·5Te3复合线材的热电和机械性能

摘要 以聚乳酸（PLA）为基体，Bi0·5Sb1·5Te3（BST）为填料的热电（TE）复合线材通过挤出成型合成。系统地研究了硅烷偶联剂 KH570、增塑剂 ATBC 和导电添加剂多壁碳纳米管 (MWCNTs) 对复合导线的成分、热电偶和机械性能的影响。需要在复合线中加入KH570，使实际BST载荷与设计值一致。ATBC的加入大大提高了复合线材的柔韧性，改善了线材的机械性能。当 BST 负载量从 35.8 wt% 增加到 87.5 wt% 时，弯曲模量从 1684.0 增加到 4379.8 MPa，弯曲强度从 50.1 增加到 13.4 MPa。在 TE 特性方面，复合导线的功率因数PF随着BST负载的增加而增加，最大塞贝克系数达到200 μV K-1。当多壁碳纳米管被添加到复合导线中时，其导电性显着增强，从而提高了导线的 PF。对于含有 81.3 wt% BST 和 4 wt% MWCNT 的导线，获得了 11.3 μW m-1 K-2 的最高 PF。在室温下获得了 0.011 的 TE 品质因数 ZT。BST/PLA 复合线材优异的热电性能和令人满意的机械性能使其成为用于热电设备 3D 打印的有前途的候选材料。导电性显着增强，从而提高了导线的PF。对于包含 81.3 wt% BST 和 4 wt% MWCNT 的导线，获得了 11.3 μW m-1 K-2 的最高 PF。在室温下获得了 0.011 的 TE 品质因数 ZT。BST/PLA 复合线材优异的热电性能和令人满意的机械性能使其成为用于热电设备 3D 打印的有前途的候选材料。导电性显着增强，从而提高了导线的PF。对于含有 81.3 wt% BST 和 4 wt% MWCNT 的导线，获得了 11.3 μW m-1 K-2 的最高 PF。在室温下获得了 0.011 的 TE 品质因数 ZT。BST/PLA 复合线材优异的热电性能和令人满意的机械性能使其成为用于热电设备 3D 打印的有前途的候选材料。