Microstructure development and dynamic-mechanical properties of polybutadiene rubber/nanoclay: Effect of curing system

Abstract

This study investigates the fabrication and characterization of polybutadiene rubber (BR) nanocomposites incorporating organoclay (OC) through melt mixing with a focus on the microstructure development and properties of the cured materials using sulfur curing and electron beam irradiation. The role of epoxidized natural rubber (ENR50) as a compatibilizer to improve interfacial interactions is explored. X-ray diffractometer (XRD) and scanning electron microscopy (SEM) analyses confirm the intercalation structure of clay nanoplates within the nanocomposites. Mechanical properties measurements highlight the enhancement of tensile strength and elongation at break with increasing nanoclay content in sulfur-cured nanocomposites while in the case of the irradiated samples the tensile strength increased as the nanoclay content increased from 3 to 7 wt% up to a dose of 150 kGy after which it decreased with further dose increments and exhibit a dose-dependent behavior. Dynamic Mechanical Analysis (DMA) reveals a strong chain-nanoparticle interaction with irradiated samples at 150 kGy displaying superior storage modulus and reduced loss factor compared to sulfur-cured counterparts. Furthermore, the incorporation of ENR50 as a compatibilizer proved beneficial in enhancing the interaction between the BR chains and the modified nanoclay. These findings offer valuable insights into the design and performance of rubber nanocomposites for advanced applications.