Investigation on the kinetics of cure reaction of acrylonitrile–butadiene rubber (NBR)/polyvinyl chloride (PVC)/graphene nanocomposite using various models

Abstract

ABSTRACTThis research work is devoted to the study of the kinetics of the cure reaction of rubber nanocomposites based on the blend of acrylonitrile–butadiene rubber/poly(vinyl chloride) (NBR/PVC) (70/30) reinforced by graphene. Two series of nanocomposites were prepared using two grades of NBR [33 and 45% of acrylonitrile (ACN)] with a general‐purpose PVC. In each series, three graphene contents including 1, 2, and 3 phr were chosen in conjunction with neat polymer blend. The cure behaviors of the samples were quantified using rubber process analyzer and differential scanning calorimeter. The experimentally measured degree‐of‐cure and rate‐of‐cure were fitted to five different kinetic equations including Isayev, modified Isayev, Kamal and Ryan, autocatalytic, and model‐free approach. The parameters of these models were calculated. The accuracy of each model was checked by comparison of the predicted degree‐of‐cure and rate‐of‐cure with their corresponding experimental values. It is shown that by increasing the graphene content at constant ACN content, the activation energy is reduced while the rate‐of‐cure is increased. On the other hand, the activation energy is increased with increasing the ACN content at constant graphene content. Moreover, the results showed that Isayev model could not predict the curing behavior as accurate as of the other models due to the complex interaction between polymer with curing system and graphene. In addition, the analysis of the computed activation energy using the model‐free approached suggested that an advanced equation needs to be employed for the description of this parameter for rubber‐based nanocomposites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48632.