Modeling tensile modulus of nanoclay-filled ethylene–propylene–diene monomer/styrene–butadiene rubber using composite theories

摘要

Abstract Nanocomposites of ethylene–propylene–diene monomer (EPDM)/styrene–butadiene rubber (SBR) (80/20) filled with different content of nanoclay 0–10 phr (parts per hundred rubber) were prepared on the two-roll mill. Tensile modulus was studied using composite theories. Transmission electron microscopy showed the existence of intercalated, aggregated, and partially exfoliated structures. The tensile modulus of nanocomposites was studied by the Guth, Halpin–Tsai, and modified Halpin–Tsai equation, which is generally used for composites reinforced through fiber-like or rod-like fillers. Composite models are mostly used in particulate-reinforced polymers, particularly in non-rigid polymer matrices. The aspect ratios of nanoclay platelets in nanocomposites were determined by statistically analyzing transmission electron micrographs. The modulus reduction factor is a vital role in the enhancement of predicted theoretical values of the tensile modulus. Taking account of the lower influence of the platelet-like filler to tensile modulus than the fiber-like filler, the modulus reduction factor for the platelet-like fillers of 0.66, determined by fitting experimental data, is introduced into the above three equations. Because of the necessity for the development and reduction of characterization of these materials for diverse applications, modeling of rubber-based nanocomposites has become a hot issue in recent years. Mechanical modeling of rubber nanocomposites is critical for studying Young's modulus using various composite theories. Moreover, the effect of nanoclay addition on tensile properties of EPDM/SBR–nanoclay composite was tested. Percentage increase in tensile strength and elongation at break are 80 and 27, respectively.