Mechanical and sorption behaviour of organo-modified montmorillonite nanocomposites based on EPDM - NBR Blends

Abstract Nanocomposites of blends based on ethylene propylene diene monomer (EPDM) rubber and acrylonitrile butadiene copolymer (nitrile rubber or NBR) rubber was prepared by melt compounding in an internal mixer using maleic anhydride as compatibilizer. The blends were reinforced with varying amount (0, 2, 4, 6 and 8 phr (parts per 100 parts rubber)) of organomodified montmorillonite (nanoclay). The nanocomposites were vulcanized at 170°C for the optimum cure time in hydraulic compression press to obtain approximately 2mm thick sheets. Morphological analysis using X-ray diffraction and Atomic Force Microscopy confirmed intercalation and exfoliation of nanoclay at lower concentration and slight agglomeration at higher concentration. Consequently, owing to the large surface area and strong matrix – reinforcement interaction, the mechanical properties improved with increasing nanofiller content. The barrier properties, characterized by diffusion, sorption and permeation coefficients also improved with increasing nanoclay content. However, at higher concentration of nanoclay, both mechanical and barrier properties showed slight decline due to formation of agglomerates.