Transport mechanism and diffusion kinetics of kerosene through polynorbornene rubber/natural rubber blends

Blends of polynorbornene rubber and natural rubber with varying compositions were made and their swelling behavior in kerosene at 35, 45 and 55 °C were examined by conventional weight-gain method. Transport parameters such as diffusion, permeation and sorption coefficients were estimated for each blend systems, and the data obtained were utilized in the determination of activation energies of diffusion (ED) & permeation (EP) and enthalpy of sorption (ΔHs). Moreover, the kinetics of sorption was also studies and it was found that the transport behavior of blends systems changed from anomalous to Fickian to quasi Fickian diffusion for the penetrating molecules. PB-03 at 35 °C showed perfect Fickian diffusion behavior. Besides this, theoretical modeling of diffusion was carried out which revealed that the experimental data were best satisfied with Peppas-Sahlin model. SEM analysis was also carried out to identify the morphology of the blends. Furthermore, mechanical testing was also performed for unswollen, swollen and deswollen blends samples to evaluate the stability of rubber blends.