The swelling test was carried out in accordance to ISO 1817. The cured specimens with dimensions of
30 mm 5 mm 2 mm were weighed using an electrical balance, then, immersed in toluene for 72 h at room temperature (25 C) in a dark environment. After the conditioned period, the swollen specimen was extracted and reweighed.The specimens were then dried in an oven at 70 C until constant weight was obtained. The Lorenz and Park equation [9] was applied in order to study the rubberfiller interaction. The weight of toluene uptake per gram of rubber hydrocarbon (Q) was ultimately calculated as per Equations (1) and (2) below: