M. G. Kulthe;R. K. Goyal
Abstract
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) ...
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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.
S. Gokul Raj; G. Ramesh Kumar
Abstract
Single crystals of pure and Deuterated L-alanine have been grown by both slow cooling and seed rotation techniques. The grown nonlinear optical crystals were subjected to single crystal X-ray diffraction for determining its lattice parameters and morphology. Thermal expansion measurements were carried ...
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Single crystals of pure and Deuterated L-alanine have been grown by both slow cooling and seed rotation techniques. The grown nonlinear optical crystals were subjected to single crystal X-ray diffraction for determining its lattice parameters and morphology. Thermal expansion measurements were carried for the Deuterated crystals of L-alanine using thermomechanical analyzer in order to ascertain the strain tensors along the three mutually perpendicular crystallographic directions. Microhardness study was also undergone on deuterated L-alanine single crystals on a prominent plane for determining the mechanical strength of the grown crystals. The results have been discussed in detail.
