Reinforcement of diene elastomers by organically modified layered silicates

Abstract

Nanocomposites were prepared based on diene rubbers and layered clays modified with an alkyl quaternary ammonium cation (organoclay). A diene rubber, either polybutadiene, or synthetic or naturally occurring polyisoprene or styrene-butadiene copolymer, was melt blended with either a preformed organoclay or with a mixture of pristine clay and ammonium cation. Besides isolated lamellae, nanocomposites showed the presence of crystalline organoclays with intercalated organic layers made only by low molecular mass substances, essentially the ammonium cation, and no evidences for the intercalation of polymer chains were observed. Dynamic-mechanical properties of sulphur cured compounds with carbon black as the main filler and a minor amount of organoclay were investigated. The organoclay was found to bring about a reduction of Mooney viscosity, an increase of storage modulus at low temperature as well as an increase of thermoplasticity.

Rubber‐Clay Nanocomposites

“…Data that the show the remarkable Payne effect of RCN, increasing with the clay content, were reported for NR [104] and IR [67] as the rubber matrices. A strong reduction of the dynamic modulus was observed also by increasing the temperature [50]. The 2-D melting of the paraffinic chains substituents of the compensating ion [105] was commented as a possible explanation [66,101].…”

“…The melt blending of a pristine Mt with a rubber leads to composites with undispersed agglomerates, as demonstrated for NR [46][47][48][49], IR [50], BR [51][52][53], E-SBR [48,54], E-SBR/NBR blend [55], EPDM [56] as the rubbers. Analogous results were presented with fluorhectorite and attapulgite as the clays.…”

“…In SBR as the matrix, a hybrid sepiolite-silica filler system was adopted [116]. Hybrid OC/CB filler systems were used in the following matrices: SBR [117][118][119], brominated poly(isobutylene-co-paramethylstyrene) rubber [117], IR [50,57,120], NR [67,121] NR/SBR blend [122], chlorobutyl rubber [123], ENR [124], EPDM [125] (Malas and Das, 2012). In some of these works [50,57,[120][121][122], CB was used at a level typical of commercial applications (higher than 50 phr).…”

Exfoliated/Intercalated Rubber/Organo‐Montmorillonite Nanocomposites: Preparation and Characterization

“…In the literature studies on nanocomposites based on natural rubber (NR),3–9 unsaturated synthetic rubbers [butadiene rubber (BR),9–13 styrene‐butadiene rubber (SBR),14–18 acrylonitrile butadiene rubber (NBR)19, 20] and ethylene‐propylene rubber (EPDM)21, 22 can be found.…”

“…However, in the frame of industrial relevant conditions, rubber‐based compounds containing carbon black as the main filler and a minor amount of organoclay have been also prepared, cured and characterized. Cure kinetics and morphology as well as final properties, such as mechanical and dynamic‐mechanical behavior, are usually investigated 9, 18…”