Investigation of Thermal Transition and Mechanical Properties of NR/SBR Composites Filled with Carbon Blacks and MWCNT

The effects of loading two different grades of carbon blacks (CBs) including highly structured CB, named SCCB, and conventional CB, i.e. N330, as well as multi-walled carbon nanotube(MWCNT), on the mechanical and thermal transition properties of natural-rubber(NR)/styrene-butadiene-rubber(SBR) blend with weight ratio of 60/40 were studied. Composites were compounded by two-roll mill and then cured by sulfur vulcanizing system using compression molding. The tensile properties and dynamic mechanical analysis (DMA) were examined. The tensile strength and modulus of the nanocomposites were improved as a result of incorporation of both CBs and MWCNT. However, the biggest improvements are relevant to SCCB and MWCNT. The results of DMA showed a single loss factor (tanδmax) along with a shoulder with no changes in the glass transition temperature (Tg), while the biggest decrease belongs to SCCB filled rubber. The results lead us to conclude that the bound rubber and occluded rubber governs the mechanical properties of CB filled rubber, while the higher mechanical properties along with big aspect ratio dominate the MWCNT filled rubber.

کلیدواژه ها:

Carbon black ، Multi-walled carbon nano-tube ، Natural rubber ، Styrene-butadiene rubber ، Mechanical properties ، Thermal transition properties