Preparation and properties of ethylene propylene diene rubber/multi walled carbon nanotube composites for strain sensitive materials

Conducting rubber composites of ethylene propylene diene M-class rubber (EPDM) were prepared with multi walled carbon nanotubes (MWCNTs) and organo-clay, Cloisite® 15A to develop flexible strain sensitive materials. The composites were prepared with a constant amount of organo-clay and various amounts of MWCNTs from 5 to 50 wt.%. Organo-clay led to improved dispersion of MWCNTs in the rubber matrix. Upon increasing the MWCNT contents, the tensile strength, stiffness and electrical conductivity of the composites increased significantly but the elongation at break decreased in the EPDM/MWCNT composites. The organo-clay was able to improve tensile strength, stiffness, elongation at break and electrical conductivity of the composites. The non-symmetric linear resistance change was observed by the composites under deformation.