STUDY OF SYNTHESIS PARAMETERS OF CONDUCTIVE PLA/CASTOR OIL/GRAPHITE FILAMENTS FOR APPLICATIONS IN ELECTROCHEMICAL SENSORS
Conductive filaments; 3D printing (FDM); Electrochemical sensors
Additive manufacturing, especially 3D printing by Fused Deposition Modeling (FDM), has emerged as a promising technology for the production of functional components due to its versatility, low cost, and ability to fabricate complex geometries. However, commercial polymer filaments present limitations regarding electrical conductivity, restricting their use in electrochemical applications. In this context, this work aims to develop and characterize conductive filaments based on PLA, castor oil, and graphite, synthesized through chemical and physical routes, targeting their application as 3D-printed electrodes for dopamine detection. For this purpose, the composites were prepared by solvent-based and thermo-shear mixing methods, subsequently extruded into 1.75 mm filaments, and processed in a 3D printer. The materials obtained were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermal analyses (TGA and DSC), dynamic mechanical analysis (DMA), and electrochemical tests by cyclic voltammetry. Preliminary results indicated that the filaments showed good dimensional uniformity, mechanical flexibility attributed to castor oil, and stable printing without fractures, in addition to adequate graphite dispersion in the polymeric matrix. As future steps, the evaluation of electrical properties and electrochemical performance of the electrodes will be deepened, especially in dopamine detection at different concentrations, aiming to demonstrate the feasibility of the proposed formulation for sustainable and low-cost sensor applications.