Dielectric properties of various polymers (PVC, EVA, HDPE, and PP) reinforced with ground tire rubber (GTR)

Abstract

Mass production of tires as well as its difficult storage or elimination is a real environmental problem. Various methods for recycling tires are currently used, such as mechanical crushing, which puts vulcanized rubber, steel, and fibers apart. The rubber may be used in several industrial applications such as flooring, insulations, and footwear. The present paper focuses on finding a new application for old used tires [ground tire rubber (GTR)]. To this end, tires dust has been mixed with various thermoplastic polymers such as polyvinyl chloride (PVC), high-density polyethylene (HDPE), ethylene vinyl acetate (EVA), and polypropylene (PP). We have checked the maximum GTR concentration values admitted by these compounds while keeping dielectric properties within acceptable values and therefore remaining suitable for industrial applications in the manufacturing of insulators for electrical wires. In particular, tires dust with particles size p<200 μm has been mixed with the polymers in four different GTR concentrations of 5%, 10%, 20%, and 50% to establish its performance through dielectric tests performed within a range of temperatures from 30°C to 120°C, and with frequencies from 1×10-2 to 3×106 Hz, and analyzing conductivity, permittivity, dielectric loss factor, and relaxations. At last, the fracture surfaces of the composite samples have been evaluated using scanning electron microscopy (SEM).