Water absorption behaviour for IIR/EPDM loaded with carbon black

This study investigates and quantifies the water absorption behaviour of hydrophobic carbon black in the 75IIR/25EPDM blend by keeping 5 × 2.5 × 0.2 cm samples in distilled water over three months. We utilise HAF (N-326) at concentrations of 50, 60, and 70 phr as filler for 75IIR/25EPDM blend. Samples are masticated carefully and then molded under a hot hydraulic press. The effect of water absorption by un-filled and filled samples is described using two fitting models: the logistic and the two-exponential growth models. The results show the water absorption has non-Fickian behaviour for all samples, and water uptake increases continuously. The rate of the uptake is found to be minimum for the sample with HAF-concentration of 60 phr.