Morphology and rheological properties of nanocomposites based on nitrile rubber and organophilic layered silicates

Abstract

Organo‐montmorillonite/nitrile rubber (NBR) nanocomposites were prepared by a melt intercalation process. The characteristics of NBR nanocomposites were determined by an oscillating disk rheometer and transmission electron microscopy. The cure characteristics were investigated according to the change in clay content and clay types. This study confirmed that organo‐montmorillonite/NBR nanocomposites have various cure characteristics, namely minimum torque, maximum torque, scorch time and curing time, according to the change in clay content and clay types. In particular, as the chain length of the modifier used for the treatment of Na+‐MMT following vulcanization increases, scorch time and optimum curing time are reduced. This is because, as the chain length of the modifier increases, organo‐MMT is distributed more equally during the formation of the nanocomposites. As swelling increases, the chain length of the clay modifier expands and then constitutes a better barrier. 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].…”

“…Data were reported for RCN based on various rubbers, such as BR [60], SBR [60], NBR [60], BIMS [74] and fluoroelastomer [75]. A compensating cation with longer alkyl chains led to a reduction of Mooney viscosity, that was not observed with a short chain substituent [76].…”

Micro-structural evolution of rubber/clay nanocomposites with vulcanization process

“…As shown in Figure 6, the clay exists in the form of granules, and large aggregates appear in EPDM-T 0 (uncured EPDMCN). The dispersion state of clay improved markedly in EPDM-T 10 . The clay exists largely as fine filaments 10 nm in thickness and 160 nm in length.…”

“…BIIR-T 0 contains the least amount of clay aggregates, and the size of the aggregates was the smallest (about 20 nm in thickness and 500 nm in length). The amount of clay aggregates increases significantly in BIIR-T 10 .…”

“…There are many factors that impact the microstructure of RCNs prepared by melt compounding. Previous studies have shown that the type of intercalant [9][10][11][12], the compounding conditions (shear stress and temperature) [13,14], as well as the polarity of the rubber [15] have sig-…”