Polymer-matrix composites; electrical conductivity; optical microscopy; hardness.
Department of Metallurgy and Materials Science, College of Engineering, Shivaji Nagar, Pune 411 005, India
Adv. Mater. Lett., 2012, Current Issue, 3 (3), pp 246-249
Publication Date (Web): Jun 10, 2012
Copyright © IAAM-VBRI Press
Polymer matrix composites filled with metals are widely studied for the applications in electrostatic dissipation (ESD) and electromagnetic interference (EMI) shielding. In view of this, the electrical conductivity and the microhardness of the polymer matrix composites based on poly(vinyl chloride) (PVC) as matrix and copper (Cu) as reinforcement were determined. The composites were prepared using ball milling followed by hot pressing. Both constituents PVC and Cu were mixed together in a dry condition at room temperature for 12 h, 24 h and 36 h and then blended powder was hot pressed at 175 °C and 50 MPa. The Cu content was varied from 0 to 40 wt% (9.3 vol%) in the matrix. Optical microscope showed good dispersion of Cu particles in the matrix and the degree of Cu dispersion increased with increasing ball milling time. The electrical conductivity of the composites increased approximately six orders of magnitude for 9.3 vol% Cu composite. A percolation threshold was obtained at 3.7 vol% Cu. The microhardness increased by more than 18 % compared to the pure matrix. For a given loading of Cu, the electrical conductivity and the microhardness of the composites increased with increasing ball-milling time. This was attributed to the better and uniform dispersion of the Cu particles in the matrix at higher ball milling time.
Polymer-matrix composites, electrical conductivity, optical microscopy, hardness.