Synthesis and Characterization of Styrene-Butadiene Rubber-Clay Nanocomposites with Enhanced Mechanical and Gas Barrier Properties

Abstract

Five styrene-butadiene rubber (SBR)/clay nanocomposite or hybrid systems were synthesized via mechanical mixing of SBR using a Brabender mixer and a 2-roll mill in the presence of unmodified sodium montmorillonite (Na-MMT) clay, MMT modified with octadecylamine (C18amine), MMT modified with a zwitterionic surfactant, octadecyldimethyl betaine (C18DMB), and MMT modified with a polymerizable cationic surfactant, vinylbenzyl octadecyldimethyl ammonium chloride (VODAC) or vinylbenzyl dodecyldimethyl ammonium chloride (VDAC). The surfactant chain length and functional groups affected the dispersion of clay nanolayers in the matrix and the overall properties of the nanocomposites. X-ray diffraction (XRD) revealed peaks corresponding to intercalated structures; transmission electron microscopy (TEM) observations agreed well with XRD assessment of the composites. SBR/VODAC-MMT system exhibited the best dispersion among the nanocomposites studied. VODAC-MMT was partially exfoliated in SBR matrix and the average aspect ratio of the nanolayer stacks or aggregates was high (20). Depending on the amount of clay, considerable mechanical reinforcement and gas barrier enhancement were achieved in nanocomposites over pure rubber. Tensile strength in excess of 18MPa was observed in SBR nanocomposites with 30 phr C18 organoclays. The storage modulus at 25C increased by a factor of four by incorporating 10 phr VODAC-MMT in SBR. The most pronounced oxygen barrier enhancement was again observed in SBR/VODAC-MMT nanocomposite with the reduction of permeability by 60% at silicate volume fraction of 0.06. The superior performance of nanocomposites containing VODAC-MMT is attributed to the presence of the vinyl-benzyl group and 18 carbon-atom tail in the surfactant leading to high compatibility with SBR and nano-scale dispersion in the SBR matrix.

Transport performance in novel elastomer nanocomposites: Mechanism, design and control

“…The most pronounced oxygen barrier enhancement resulted in a SBR/vinylbenzyl octadecyldimethyl ammonium chloride-MMT nanocomposite with a 60% reduction in permeability at a clay fraction of 6 vol%. This observation was attributed to the presence of the vinyl-benzyl group and 18 carbon-atom tail in the surfactant, leading to high compatibility with SBR and nanoscale dispersion in the SBR matrix [314]. The dispersion states of the organo-clay in the rubber nanocomposites based on either brominated poly(isobutylene-co-para-methylstyrene) (BIMSM) or brominated isobutene-isoprene rubber (BIIR) and an organo-clay with or without carbon black were quantified based on the projected aspect ratios.…”

Performance of PDMS membranes in pervaporation: Effect of silicalite fillers and comparison with SBS membranes

“…Hence, the necessity of introducing fillers such as zeolites into the polymeric network seemed to be interesting and became the aim of scientific investigation [18,19]. It was already shown that nanofillers other than zeolites have a beneficial effect in other membrane processes such as pressure driven filtration [20] and gas separation [21]. The 0021-9797/$ -see front matter Ó 2010 Elsevier Inc. All rights reserved.…”

“…The 0021-9797/$ -see front matter Ó 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.jcis.2010.02.023 effect of filler concentration in such membranes is subject to specific studies in which diverse effects have to be investigated, such as fouling resistance [22] separation and permeability [23] or gas solubility [21]. In the latter publication, a solution-diffusion model equation was used to describe fluxes; a similar approach could be followed for pervaporation, although other, more complex transport equations would be required for pervaporation, and typical time lag effects would not be seen.…”

A comparison between the effects of gamma radiation and sulfur cure system on the microstructure and crosslink network of (styrene butadiene rubber/ethylene propylene diene monomer) blends in presence of nanoclay

“…But recently, reinforcing the rubber compounds with nanoparticles, in particular nanoclay, due to its easier accessibility and its special structure in comparison with other nanoparticles, has received a great deal of attention (Gopi et al, 2011;Karger-Kocsis and Wu, 2004;Ma et al, 2004;Monfared and Jalali-Arani, 2015;Nematollahi et al, 2014;Thomas and Stephen, 2010;Zhang et al, 2000). The use of organo modified clay (OC) in the SBR (Ahmed et al, 2000;Meneghetti et al, 2008;Sadhu and Bhowmick, 2004) and ethylene-propylene-diene monomer (EPDM) rubber (Gatos and Karger-Kocsis, 2005;Zheng et al, 2004) has been reported by the researchers. For instance, Meneghetti et al (2008) used different OC to reinforce SBR and reported that the surfactant chain length and its functional groups are the factors which affected the clay layers dispersion.…”

“…The use of organo modified clay (OC) in the SBR (Ahmed et al, 2000;Meneghetti et al, 2008;Sadhu and Bhowmick, 2004) and ethylene-propylene-diene monomer (EPDM) rubber (Gatos and Karger-Kocsis, 2005;Zheng et al, 2004) has been reported by the researchers. For instance, Meneghetti et al (2008) used different OC to reinforce SBR and reported that the surfactant chain length and its functional groups are the factors which affected the clay layers dispersion. Gatos and KargerKocsis (2005) investigated the effect of different amine based intercalants on the dispersion of the OC in EPDM/OC nanocomposite vulcanized by means of the sulfur curing system.…”