Petrény Roland, Tóth Csenge, Horváth Aurél, Mészáros László
Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp 3 H-1111 Budapest, Hungary.
ELKH-BME Research Group for Composite Science and Technology, Műegyetem rkp. 3, H-1111 Budapest, Hungary.
Heliyon. 2022 Aug 17;8(8):e10287. doi: 10.1016/j.heliyon.2022.e10287. eCollection 2022 Aug.
In this study, we developed electrically conductive nano- and hybrid composites with a poly(lactic acid) (PLA) matrix for different melt processing technologies. We used short carbon fiber and multi-walled carbon nanotube reinforcements to enhance electric conductivity. We prepared the composite compounds with twin-screw extrusion; then the compounds were processed via injection molding and fused filament fabrication. We showed that electric conductivity only slightly increased by when only carbon nanotubes were added to the PLA matrix. However, when carbon fibers were added to the nanocomposites, the higher shear during melt mixing helped the uniform dispersion of the carbon nanotubes, resulting in a highly conductive reinforcement network in the composite. On the other hand, the hybrid reinforcement resulted in higher viscosity, making melt processing difficult and the material also became more brittle. Therefore, we added an oligomeric lactic acid plasticizer to the hybrid composites, and produced specimens by injection molding and 3D printing. The tensile strength increased by 140% and the elongation at break increased by 56%, and at the same time, the electrical conductivity of the material remained at a high level.
在本研究中，我们针对不同的熔融加工技术，开发了以聚乳酸（PLA）为基体的导电纳米复合材料和混杂复合材料。我们使用短碳纤维和多壁碳纳米管增强材料来提高导电性。我们通过双螺杆挤出制备复合料；然后通过注塑成型和熔丝制造对这些复合料进行加工。我们发现，仅向PLA基体中添加碳纳米管时，电导率仅略有增加。然而，当向纳米复合材料中添加碳纤维时，熔融混合过程中更高的剪切力有助于碳纳米管均匀分散，从而在复合材料中形成高导电增强网络。另一方面，混杂增强材料导致粘度更高，使熔融加工变得困难，并且材料也变得更脆。因此，我们向混杂复合材料中添加了低聚乳酸增塑剂，并通过注塑成型和3D打印制备了试样。拉伸强度提高了140%，断裂伸长率提高了56%，同时，材料的电导率保持在较高水平。
