Incorporation of up to 30 phr of high abrasion furnace (HAF) carbon black into a thermoplastic elastomer of composition 100 phr maleated EPDM rubber, 10 phr ZnO, 1 phr stearic acid and 30 phr zinc stearate, improves its physical properties like modulus and tear resistance. While the glass-rubber transition temperature (T-g) of the thermoplastic elastomer occurring around -37 degrees C remains unaltered in the presence of the filler, the ionic transition (T-i) occurring around +50 degrees C is shifted to higher temperature. Furthermore, tan delta at T-g decreases but tan delta at T-i increases due to filler incorporation. It is believed that, besides the interaction between the backbone chains and the filler particles, the ionic domains in the thermoplastic elastomer interact with the polar sites of the filler particles presumably by hydrogen bond formation.