Dielectric, mechanical, and thermal characterization of high-density polyethylene composites with ground tire rubber

Abstract

The mass manufacture of tires and the difficulty in storing or disposing them constitute a serious environmental problem. At present, various recycling methods for tires are used, such as grinding, which separates the steel and fibers from the vulcanized rubber, then using the rubber in numerous industrial applications such as pavements, insulators, footwear, etc. The aim of this article focuses on finding a new application for the ground tire rubber (GTR). This would allow including GTR in industrial applications of recycled high-density polythene (HDPE). Tire dust and HDPE thermoplastic have been mixed, and the maximum accepted values of GTR concentration that can be admitted while keeping dielectric, mechanical, and thermal properties within acceptable values, as well as initial polymer microstructure, have been checked. In addition, the suitability of the compounds for antistatic applications is studied. The recycled tire dust which results from the industrial milling processes has been divided by sieve in three different categories according to the size of the particles (<200, 200–500, and >500 mm). This has then been mixed with HDPE in different GTR concentrations (0%, 5%, 10%, 20%, 40%, 50%, and 70%) in order to establish its conduct through electrical, mechanical, thermal, and microstructure tests, which will be held in a temperature range 30–120 C, and with a frequency range 1 10 2 and 3 106 Hz. The thermal tests determined the enthalpies and fusion temperatures which allow for the observation of changes in crystalline and microstructure of the matrix, and finally, the fracture surfaces of the compound samples have been evaluated using scanning electron microscopy.