Effect of ionizing radiation on the properties of acrylonitrile butadiene rubber/clay nanocomposites

Abstract

The effects of electron beam irradiation dose (50–150 kGy) and the concentration of montmorillonite (MMT) clay (3–10 parts per hundred part of rubber (phr)) on the properties of acrylonitrile butadiene rubber (NBR) have been investigated. The dispersion of the layered silicates was assessed by x-ray diffraction and transmission electron microscopy. The morphology of NBR nanocomposites showed exfoliated clay layers at low clay content and a combination of exfoliated and intercalated clay layers at high clay content. The mechanical properties of NBR composites such as tensile strength (TS) and tear strength were remarkably improved by the incorporation of organoclay and electron beam irradiation, while elongation at break (E _b) was decreased. The increase in the TS of NBR nanocomposites increases with the increase in the clay content up to 10 phr, whereas the optimum gel content and TS of NBR composites were observed at 50 kGy irradiation dose. Thermogravimetric analysis studies showed that NBR/organo-MMT nanocomposites have higher decomposition temperatures in comparison with the NBR/Na⁺-MMT at 50 kGy irradiation dose.