Preparation and characterization of organoclay nanocomposites based on natural rubber

Abstract

Rubber compounds based on natural rubber (NR) reinforced with octadecylamine‐modified bentonite have been prepared via a vulcanization process and characterized by several techniques. The silicate nanolayers are exfoliated and uniformly dispersed in the polymer chains. Monsanto measurements have shown that the organoclay accelerates the vulcanization reaction and, furthermore, gives rise to a marked increase of the torque, indicating that the elastomer becomes more crosslinked in the presence of the organoclay. These results were corrobated by swelling measurements since a noticeable increase in the curing degree was observed when the organoclay was added to the rubber recipe. Moreover, thermodynamic parameters have shown an increase in the structural order of the nanocomposite. In addition, thermal analysis supports the assumption that the degree of curing of the elastomer increases when the organoclay is added to the elastomer. An appreciable increase of the involved heat during the curing reaction has been observed. Moreover, the Tg of the NR increases in the presence of the organoclay due to the confinement of the elastomer segment into the organoclay nanolayers, which restricts the mobility of the chains. Copyright © 2003 Society of Chemical Industry

Rubber Clay Nanocomposites

“…Many data were reported in the literature, supporting these conclusions, in rubbers such as NR (hexadecyltrimethyl ammonium, octadecyltrimethyl ammonium, tetraoctyl phosphonium, triphenyl vinylbenzyl phosphonium, octadecylamine chloridrate were used as intercalants) [81][82][83][84][85][86], SBR (Mt/octadecyltrimethylamonium) [87], (NBR (octylamine; dodecylamine and octadecylamine chloridrates were the intercalants) [76]. A reduction of the activation energy for sulphur based NR crosslinking was found by using a bentonite modified with octadecylamine chloridrate [83,88].…”

Processing and structure–property relationships of natural rubber/wheat bran biocomposites

“…where m e -cross-link density, mol/cm 3 ; V r -gel volume in the swollen sample; V 1 -solvent molar volume (toluene = 106.2 cm 3 /mol); v-polymer-solvent interaction parameter [in the calculations, it was assumed to be 0.393 (López-Manchado et al 2003)]. …”

Evaluating the effect of processing conditions and organoclay content on the properties of styrene-butadiene rubber/organoclay nanocomposites by response surface methodology

“…It is well known that the elongation at break of rubber nanocomposite depends on the morphology of nanocomposites. Due to slippage of rubber chains in the presence of the free surfactant of nanoclay in exfoliated or intercalated morphology, the elongation at break increases [25][26][27][28][29]. In other words, the surfactant can act as a lubricant in the nanocomposites.…”