Thermal and Structural Characterization Behavior of Electron Beam Irradiated Rubber/Clay Nanocomposites

Abstract

ABSTRACTThe effect of electron beam irradiation on the structure, thermal, and morphological properties of ethylene propylene diene monomer (EPDM)/clay and styrene butadiene rubber (SBR)/clay nanocomposites prepared by melt‐blending method has been investigated. The organomodified clay and irradiated rubber/clay samples were characterized using X‐ray diffraction (XRD), energy‐dispersive X‐ray (EDX), and thermogravimetric analysis (TGA). EDX and TGA data confirmed the modification of clay particles using cetyltrimethyl ammonium bromide (CTAB). The XRD patterns of the as‐prepared nanocomposites showed an indication of the presence of exfoliated clay layers at lower clay content whereas a phase‐separated (agglomeration) of organomodified clay layers was present at higher clay content. XRD data of unmodified clay/EPDM composites (EPDM–CCs) indicated that the rubber chains are not intercalated into the silicate galleries, that is, unmodified clay particles are simply incorporated into EPDM matrix in agglomerated states. EPDM–CNs and SBR–CNs nanocomposites show an exfoliated and/or a mixture of intercalated/exfoliated structures at lower (3–5 phr) and higher (10 phr) clay contents, respectively. TGA studies showed that the organomodified clay/rubber nanocomposites show a higher thermal stability in comparison with the unmodified clay/rubber composites. The improvement in the thermal properties is attributed to the organomodification of clay particles as well as the intercalation of rubber chains within silicate layers. In addition, EPDM–CNs nanocomposites exhibit a higher thermal stability than EPDM–CNs nanocomposites. © 2013 Wiley Periodicals, Inc. Adv Polym Technol 2014, 33, 21396; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21396