Studying the roles of nanoclay and blend composition on the improved properties of natural rubber/chloroprene composites

Hybrid clay polymer nanocomposites (CPNs) based on blends of natural rubber (NR) and chloroprene rubber (CR) with different compositions (100/0, 95/5, 90/10, 85/15, 80/20), reinforced with various contents of organomodified montmorillonite (OMMT), were prepared by a two-roll mill via a vulcanization process. Curing data of the prepared compounds indicated a reduction in scorch time (t5) and optimum cure time (t90) with increasing the nanoclay content. Mechanical properties of samples were markedly enhanced upon nanoclay inclusion, due to the proper level of interactions established between nanoclay particles and the rubber matrix as it was evidenced by SEM photomicrographs. Results of X-ray diffraction proved the expansion of the interlayer distance, and transmission electron microscopy micrographs further confirmed that the prepared CPN samples exhibit intercalated/partially exfoliated structures. Moreover, the reinforcement effect of OMMT was reflected in the stress-induced crystallization and network structure of the CPNs based on the rubber-elasticity and tube model theories as well as rheological properties. POLYM. COMPOS., 2016. © 2016 Society of Plastics Engineers