Development of modified expanded graphite-filled solution polymerized styrene butadiene rubber vulcanizates in the presence and absence of carbon black



Expanded graphite (EG) consists of a huge number of partially exfoliated graphite sheets with the thickness of most of the sheets in the nanometer range. This study analyses the effect of EG and modified EG (MEG) on the mechanical, thermal, and dynamic mechanical properties of solution styrene butadiene rubber (SSBR) with and without carbon black (CB). The surface of the EG was modified to enhance its dispersion in the SSBR matrix. In addition, oil-extended carboxylated styrene butadiene rubber (XSBR) was used as a compatibilizer to disperse MEG in the base nonpolar SSBR matrix. XSBR/MEG nanocomposites have been prepared by solution mixing. The obtained nanocomposites were incorporated into the SSBR matrix in the presence of CB by melt blending. Morphological properties of the nanocomposites revealed intercalation of MEG sheets in the SSBR matrix. Nanocomposites containing MEG in the presence of CB show improvement in mechanical, thermal, and dynamic mechanical properties. POLYM. ENG. SCI., 54:33–41, 2014. © 2013 Society of Plastics Engineers