Evaluation of the role of devulcanized rubber on the thermomechanical properties of expanded ethylene‐propylene diene monomers composites

Abstract

Various amounts of both devulcanized (DR) and non‐devulcanized (NDR) recycled rubber were melt compounded with a virgin ethylene‐propylene diene monomer (EPDM) rubber. The resulting compounds were then expanded by using azodicarbonamide. The role played by the presence of DR or NDR on the thermomechanical properties of the obtained materials was evaluated. Electron scanning microscope micrographs highlighted that DR particles were better encapsulated within the EPDM matrix with respect to the corresponding NDR ones. Moreover, a better interfacial adhesion was observed with DR, probably due the re‐vulcanization process in which the free crosslinking sites that typically characterize DR could form linkages with the EPDM matrix. Tensile impact behavior of expanded EPDM/recycled rubber blends highlighted a strong improvement of the normalized total absorbed energy, of the normalized impact strength and of the elongation at break with respect to the neat expanded EPDM for all the investigated compositions, and especially with a DR content of 20 wt%. The preparation of expanded EPDM containing considerable amounts of devulcanized rubber was, therefore, demonstrated to be a practical route to reduce the costs and improve the properties and the environmental sustainability of rubber products.

Mechanical Properties of Silicone Rubber Enhanced Microcellular EPDM Foams Based on Supercritical CO2Foaming Technology

“…Moreover, the mechanical properties of microcellular SR/EPDM foams in this paper are higher than those of EPDM foams reported in existing literature. [ 2,40–42 ]…”

Study on preparation of highly dispersed graphite composite expandable polystyrene foam by homogeneous dissolution‐suspension polymerization with waste polystyrene

“…In conventional suspension polymerization, the low compatibility of graphite with styrene monomer and its own agglomeration tendency prevent the homogeneous dispersion of graphite in the organic phase, resulting in instability of the polymerization process. [33][34][35][36][37] In suspension polymerization, the monomer and graphite are suspended as small droplets in the dispersion medium for polymerization. In small droplets, styrene monomer (0.909 g/cm 3 ) and graphite (2.09-2.33 g/cm 3 ) are subjected to different gravitational and centrifugal forces of rotation and revolution due to their different densities.…”

Microcellular ground tire rubber/ethylene vinyl acetate compounds: Mechanical properties and structure relationships

“…[8] In this regard, the effect of GTR on the functional properties of some foamed polymers such as low-density polyethylene (LDPE), [9,10] polypropylene (PP), [11][12][13][14][15][16] polyurethane (PU), [17][18][19] among others has been reported. [20,21] Those studies indicated that the incorporation of elastomeric filler as GTR powder into polyolefin enhanced the structural and mechanical properties of the foamed compounds.…”