The effect of microwave irradiation on the molecular diffusion of the ethyl acetate (EA) into the blend of styrene-butadiene rubber (SBR)/ethylene-propylene-diene monomer rubber (EPDM).

This article focuses on the preparation and analysis of styrene-butadiene rubber (SBR) and ethylene-propylene-diene monomer rubber (EPDM) blends and compounds to improve mechanical performance and reduce costs in rubber-made articles. Using dynamic swelling experiments with ethyl acetate (EA) as a solvent, the study determined diffusion characteristics—diffusion coefficient (D), sorption coefficient (S), and permeability coefficient (P)—and developed a new quantitative method to evaluate the interphase thickness between polymers in the blend based on these diffusion parameters. Microwave irradiation effects on the blends and the influence of carbon black (CB) filler were also examined, showing that CB reduces solvent uptake due to bound rubber formation. The findings were validated by scanning electron microscopy (SEM) and atomic force microscopy (AFM), with AFM phase imaging used to quantitatively measure interphase thickness, which correlates inversely with polymer-polymer interaction parameters and directly with polymer-solvent interaction parameters.