New approach for preparation of dry natural rubber nanocomposites through acid-free co-coagulation: Effect of organoclay content

摘要

Natural rubber (NR) vulcanizates exhibit good mechanical properties compared to vulcanizates of synthetic rubbers. Incorporation of a conventional filler at higher loadings to NR enhances its modulus, while reduction in tensile strength and elongation. This paper presents a new strategy for development of a NR-clay nanocomposite with enhanced mechanical properties by incorporation of lower loadings (2-8 phr) of cetyl trimethyl ammonium bromide modified montmorillonite clay (OMMT-C) under acid-free environment. The effect of OMMT-C loading on cure characteristics, rubber-filler interactions, crosslink density, dynamic mechanical thermal properties, and mechanical properties were evaluated. Incorporation of OMMT-C accelerated the vulcanization process and enhanced mechanical properties. X-ray diffraction analysis and scanning electron microscopy images revealed that the formation of intercalated clay structures at lower OMMT-C loadings, and clay aggregates at higher loadings. A nanocomposite at OMMT-C loading of 2 phr exhibited the best balanced mechanical properties, and was associated with highest crosslink density and rubber-filler interactions. (C) 2018 Wiley Periodicals, Inc.