Kinetic curves describing the processes of vulcanisation and pore formation of foam rubbers based on nitrile butadiene rubbers were studied. The curves were obtained using a D-MDR 3000 rheometer (MonTech) equipped with MonControl analytical software, which makes it possible, simultaneously with the measurement of the torque and tg δ, to determine the pressure in the chamber. The rubber compounds were noted for different stearic acid contents. The results of quantitative interpretation of the kinetic curves of processes of vulcanisation and pore formation in elastomeric materials are presented. Mathematical models for approximation of the curves of vulcanisation and pore formation, distinguished by high goodness of ft, are proposed. The relationship between the parameters of the models and the vulcanisation characteristics and the parameters of pore formation is established. The influence of the stearic acid content on processes of formation of the porous structure of foam rubbers based on blends of nitrile butadiene rubbers containing 27–30 wt% acrylic acid nitrile and polyvinyl chloride is shown.