Rubber curing chemistry governing the orientation of layered silicate

Abstract

Abstract. The effect of curing systems on the orientation and the dispersion of the layered silicates in acrylonitrile butadiene rubber nanocomposite is reported. Significant differences in X-ray diffraction pattern between peroxide curing and sulfur curing was observed. Intense X-ray scattering values in the XRD experiments from peroxide cured vulcanizates indicate an orientation of the layers in a preferred direction as evinced by transmission electron micrographs. However, sulfur cured vulcanizates show no preferential orientation of the silicate particles. Nevertheless, a closer inspection of transmission electron microscopy (TEM) images of peroxide and sulfur cured samples shows exfoliated silicate layers in the acrylonitrile butadiene rubber (NBR) matrix. It was revealed in the prevailing study that the use of an excess amount of stearic acid in the formulation of the sulfur curing package leads to almost exfoliated type X-ray scattering pattern.

Investigation of correlation between dielectric parameters and nanostructures in aqueous solution grown poly(vinyl alcohol)-montmorillonite clay nanocomposites by dielectric relaxation spectroscopy

“…Synthesis and structural characterization of polymer-clay (organic-inorganic) nanocomposites (PCNs) are of technological interest due to significant improvement in the useful properties of composite materials over those of the pure polymer [1][2][3][4][5][6][7][8][9][10][11][12]. For the preparation of poly(vinyl alcohol) (PVA)-layered silicate nanocomposite, montmorillonite (MMT) clay is the most commonly used, which has hydrophilic property, and 2:1 phyllosilicate laminar structure.…”

Effects of carbon blacks with various structures on vulcanization and reinforcement of filled ethylene-propylene-diene rubber

“…Léopoldès's group found that higher 100% and 300% moduli were observed for the natural rubber filled with a modified carbon black, which was treated by oxidative gas [19]. Scanning electron microscope (SEM) is a technique used to probe the filled rubber [20,21]. The carbon black mainly exists as the primary aggregation in rubber [2,22].…”

Low frequency dielectric relaxation processes and ionic conductivity of montmorillonite clay nanoparticles colloidal suspension in poly(vinyl pyrrolidone)−ethylene glycol blends

“…Swelling of the clay is mainly due to solvent intercalation (absorption) in the clay galleries, and also because of the adsorption of solvent molecules on the hydroxylated aluminate clay surfaces through H-bond interactions, which results the clay exfoliation. The intercalated and exfoliated clay sheets in polymeric solvent results the organic-inorganic nanocomposites of highly complicated structures, which is responsible for the improved thermal, mechanical, gas barrier and electrical properties of the polymer-clay nanocomposites (PCNs) [6][7][8][9][10][11][12][13][14][15][16][17][18]. The investigation of broadband dielectric spectroscopy (BDS) of the materials covers nowadays the extraordinary spectral range from 10 -6 to 10 12 Hz [19].…”