The impact of industrial methyl diethanolamine solution on the aging of cured ethylene‐propylene‐diene monomer and butyl rubber compounds, and associated blends with potential applications in rubber‐made sealants within gas refinery environments

Abstract

AbstractThis study investigates the impact of aging in methyl diethanolamine (MDEA) solution on cured rubber compounds comprising ethylene‐propylene‐diene monomer rubber (EPDM), butyl rubber (IIR), and blends, utilizing nano (nZnO) and conventional (ZnO) zinc oxides as curing activators. The analysis reveals that MDEA solution induces degradation in the rubber matrix by grafting amine and amide groups onto the rubber backbone, particularly affecting unsaturated units in diene monomers in EPDM and isoprene units in IIR. The Fourier‐transform infrared (FTIR) analysis validated the addition of these functional groups. Aging contributed to the formation of a thin rubber layer covering carbon black particles, likely due to un‐crosslinking and rubber chain scission, resulting in changes in bound rubber as observed in scanning electron microscopy (SEM) images. Tensile strength and elongation at break typically decreased with aging, with EPDM compounds exhibiting the highest initial tensile strength and IIR compounds demonstrating superior initial elongation. Hardness remains largely unaffected by aging. This study showed the detrimental effects of MDEA exposure on rubber compounds, emphasizing the critical importance of material selection and property tailoring for specific applications in MDEA‐rich environments, such as gas refineries.