Electrical, mechanical and thermal properties of polyvinyl chloride composites filled with aluminum powder

摘要

In this work, the electrical, mechanical and thermal properties of polyvinyl chloride (PVC) composites filled with different content of aluminum powder varying from 0 to 40 wt.% have been prepared. The dielectric properties of these composites were investigated in the frequency range 100Hz-100kHz at temperature range from 30 to 98 ℃. The percolation threshold concentration, which is the concentration after which the conductivity increases many orders of magnitude with very little increase in the filler content for PVC/Al composites depends upon the measuring temperature, whether it is below or above the glass transition of the polymer matrix. The highest value of the electrical conductivity, σ, of the composites was found to be in the order of 10~(-8) S cm~(-1), this value recommend such composites to be used in electrostatic dissipation applications as the range of conductivity for such application should be in the range of 10~(-5)-10~(-9)Scm~(-1). The mechanical strength values decrease with increasing the aluminum content. It was also noticed that, both tensile strength and elongation at break values have been slightly decreased after annealing at 100 ℃. The scanning electron microscope (SEM) micrographs of PVC containing different content of aluminum powder indicate that at the higher aluminum concentration (20 and 30 wt.%) large agglomerates of aluminum particles dispersed within the PVC, yielding a conductive path through the composite. The thermal stability of the prepared composite samples increases with increasing Al content.