Torsion Tests on Polypyrrole-Coated Specimens: An Approach to Its Mechanical characterization

Abstract

The innovative use of conductive polymers, such as polypyrrole (PPy), in medical applications represents an alternative solution for scenarios where the motor and sensory functionality of the human body is compromised. Their mechanical properties are determined by the synthesis methodology utilized to obtain the polymer. Studies show a variation in the elastic modulus ranging from 96 kPa through chemical synthesis up to 2.41 kPa through electropolymerization. This study develops an approach for characterizing the mechanical properties of polypyrrole generated by chemical synthesis. Polylactic acid (PLA) samples coated with PPy were tested under torsion, and their behavior was compared with that of unmodified PLA specimens. The stress-strain diagrams of both sets of samples were similar. Although the values of the shear modulus for pure PLA (340 MPa) and PPy-coated PLA (288 MPa) show a clear difference, the variation is attributed to factors such as the low thickness of the coating and the porosity in the cross-sectional area of the 3D-printed PLA samples.