Effect of carbon fiber on electrical conductivity and mechanical properties of PLA matrix composites

• 1、College of Chemistry and Chemical Engineering, Hunan University, 410082
• 2、 College of Material Science and Engineering, Central South University of Forestry and Technology, 410004
• 3、College of Material Science and Engineering, Central South University of Forestry and Technology, 410004

Abstract：Polylactic acid (PLA) is a commonly used fused deposition molding (FDM) printed filament, but it can not conduct electricity. In this paper, carbon fiber (CF) was used as the conductive agent to modify PLA. CF/PLA based FDM conductive composites were prepared by single screw melt blend extrusion method.The effects of carbon fiber content on the electrical and mechanical properties of the composites were investigated emphatically.The properties of the composites were tested by digital multimeter, melt flow rate tester and universal tester, etc.The results showed that with the increased of carbon fiber content, the electrical conductivity, tensile modulus and bending modulus of the composites increased, the impact strength, elongation at break and bending strength first increased and then decreased, while the tensile strength decreased. The suitable carbon fiber content was determined to be 10wt%. At this case, the tensile strength and bending strength of the composites were 42.0 MPa and 69.5 MPa respectively, and the conductivity reached 10^(-4)S/cm, which was 10 orders of magnitude higher than that of pure PLA.

Keywords： Chemical engineering 3D printing PLA based conductive composites Carbon fiber FDM filaments Melt blending