Electrical and Mechanical Investigations on Polyvinyl Chloride Filled with HAF Black

• Published in: Journal of reinforced plastics and composites 2009-07, Vol.28 (14), p.1763-1773
• Main Authors: El-Nashar, D.E., Eid, M.A.M., Abou Aiad, T.H., Abd-El-Messieh, S.L.
• Format: Article
• Language: English
• Subjects: Applied sciences; Composites; Exact sciences and technology; Forms of application and semi-finished materials; Polymer industry, paints, wood; Technology of polymers
• ISSN: 0731-6844; 1530-7964
• DOI: 10.1177/0731684408090377

Polyvinyl chloride (PVC) was chosen to be loaded with various amounts of high abrasion furnace black (HAF). The mechanical as well as electrical properties of the prepared composites were investigated. The dielectric properties of these composites were investigated in the frequency range 102—10 5 Hz at a temperature range of 30—1208C. In addition to the conductivity term, the experimental data of the dielectric losses ε'' were analyzed using a computer program based on both Havriliak—Nagami and Fröhlich equations into two relaxation processes. The first relaxation process in the lower frequency range could be attributed to the Maxwell—Wagner effect. The second relaxation could be attributed to the combination of the large scale mobilization of the chains i.e., the glass—rubber relaxation process in addition to a contribution of the motion of the large aggregates caused by the movement of the main chain, which are expected to be formed by the addition of different ingredients to PVC such as a plasticizer. The percolation threshold concentration, which is the concentration after which the conductivity increases many orders of magnitude with very little increase in the filler amount for PVC/HAF composites, depends upon the measuring temperature, whether it is below or above the glass transition of the polymer matrix. Stress—strain plot, hardness, and other mechanical properties such as stress at yield, stress at rupture, strain at yield, strain at rupture, and Young's modulus were investigated at room temperature. This investigation led to the conclusion that all the mechanical properties are improved by increasing HAF content and reaches its optimum values at about 30 phr HAF loading. On the other hand, the addition of HAF black by concentration up to 40 phr increases the electrical conductivity to be 10-10 Sm-1 at 30°C and 10-9 Sm-1 at 120°C which highly recommends such composites to be used in antistatic applications as the suitable range of electrical conductivity for such application is 10-9—10-14 S m-1.