Thermal and Mechanical Characterization of a Terpolymer Mixture of Devulcanized Recycled Ethylene-Propylene-Diene and Low-density Polyethylene

In this study, mixtures of low-density polyethylene (LDPE) and the recycled elastomeric terpolymer ethylene-propylene-diene (EPDM-r) were obtained. The EPDM-r was incorporated as obtained by the manufacturer (vulcanized) and also after being submitted to a devulcanization process using microwaves. The mixtures were obtained with the use of bis(alpha, alpha-dimethylbenzyl) peroxide. The elastomeric residue was characterized by gel content and scanning electron microscopy, before and after the devulcanization process. The mixtures obtained were characterized by thermogravimetric analysis, differential scanning calorimetry, and mechanical tests for resistance to traction and impact. The results of the analysis of the residues showed that the devulcanization process reduced significantly the gel content of the elastomer. The mixtures obtained demonstrated that the incorporation of vulcanized EPDM-r reduced the crystallization and fusion enthalpies, while conserving the crystallization and fusion characteristics of the thermoplastic. The mixtures showed a reduction in the deformation and traction strength; however, the incorporation of devulcanized EPDM-r led to a significant increase in the elasticity modulus values and the resistance to impact in relation to the pure LDPE.