Effect of Vulcanization System Type on the Morphology and Mechanical Properties of EPDM/CNT Nanocomposite Foams

Nanocomposite foams based on ethylene propylene diene monomer terpolymer (EPDM), reinforced with a hybrid system of carbon black and multi-walled carbon nanotubes (MWCNTs), were prepared using different amounts of MWCNTs, foaming agent, and two curing systems of sulfur and peroxide. Carbon black facilitated the uniform dispersion of MWCNTs within the rubber matrix and enhanced the interaction between the nanoparticles and matrix. The mechanical properties and morphology of the foams, as well as the influence of rubber composition, were systematically investigated. CNTs contributed as heterogeneous nucleation sites, resulting in higher cell density and a more uniform morphology with reduced cell size, which were analyzed using a modified classical nucleation theory. Increasing CNT content reduced the scorch time due to the high thermal conductivity of nanoparticles and improved the thermal stability of the samples. Additionally, the compression strength and energy dissipation capacity of the samples were enhanced. The key novelty of this work lies in the systematic comparison of sulfur and peroxide curing systems in controlling CNT-driven heterogeneous nucleation in EPDM foams, combined with a curvature-modified nucleation theory. The results provide a practical framework for optimizing structure–property relationships in lightweight elastomeric composites for engineering applications.

کلیدواژه ها:

EPDM foam ، Multi-walled carbon nanotubes ، carbon black ، Hybrid nanocomposites ، Heterogeneous nucleation