Organo-modified layered silicate nanocomposites of EPDM–chlorobutyl rubber blends for enhanced performance in γ radiation and hydrocarbon environment

Abstract

In this work, blends of ethylene propylene diene monomer rubber and chlorobutyl rubber were reinforced with organo-modified layered silicate (nanoclay) to enhance their performance in radiation as well as hydrocarbons environments. The mechanical properties of the nanocomposites increased (up to 57%) and solvent transport coefficients decreased (by 30%) with increasing nanoclay content. The enhancement in properties was attributed to the dispersion of nanoclay platelets in the ethylene propylene diene monomer–chlorobutyl rubber blends and the chemical interaction between nanoclay and the polymer which were confirmed by morphological and spectroscopic analysis, respectively. The effect of nanofiller content on the mechanical properties, solvent uptake and thermal degradation of blends exposed to gamma radiation was investigated by irradiating the nanocomposites with gamma rays for cumulative doses of 0.5, 1 and 2 MGy. The ethylene propylene diene monomer–chlorobutyl rubber nanocomposites with 5 phr nanoclay had the best retention of mechanical properties and solvent sorption coefficients on exposure to radiation. Depending on the dose of cumulative radiation exposure, chain scission and/or crosslinking occurred in the nanocomposites, resulting in varying degrees of changes in properties.

Intensive study on structure transformation of muscovite single crystal under high-doseγ-ray irradiation and mechanism speculation

“…According to Bragg's formula ( nλ = 2 d sin θ ), for the refined lattice plane and measurement condition, n and λ are constant. In this case, increased θ means reduced d [72]. In other words, low-dose irradiation declines the interlayer space, resulting in shrinking.…”

Synergistic enhancement of mechanical, viscoelastic, transport, thermal, and radiation aging characteristics through chemically bonded interface in nanosilica reinforced EPDM‐CIIR blends

“…The free radicals generated after irradiation, in presence of molecular oxygen, react to form oxygenated groups (hydroxyl and peroxyl radicals). 9 The compounds like carboxylic acids, hydroperoxides, ketones containing carbonyl, and hydroxyl functional groups associates to oxygenated products. The hydroperoxide formed after reaction of peroxyl group with hydrogen atoms in rubber chains cleavages to form two new free radicals viz.…”

“…7 In the case of nanofiller reinforced elastomers, apart from the above, nanofiller-rubber interactions, shape and size of nanofiller, aspect ratio, and dispersion of nanoparticles also play significant role in determining the properties. 8,9 The improvement in properties of nano-reinforced polymer can be ascribed to the larger interfacial interaction between nanoparticle and matrix, arising from the large specific surface area of the nanofiller. 7,10 Among the nanoparticles, nanosized silicon dioxide, or nanosilica (SiO 2 ), is a good candidate for reinforcement of rubbers owing to their high stability, lower toxicity, and capability to be modified with a range of functional groups.…”

Manifestation of the silicate filler additives and electron beam irradiation on properties of SBR/devulcanized waste tire rubber composites for floor tiles applications

“…Rubber blends have established increasing consideration from numerous researchers around the world. 19 Silica (silicon dioxide) is the most bountiful mineral on the Earth. 20 Silica can be utilized as filler for rubber, 21 which is utilized in the manufacture of numerous products, like tires and other industrial materials.…”