Barrier properties rubber nanocomposites

Rubber-clay nanocomposites are particularly attractive for potential applications where enhanced barrier properties are desired. Organoclays for rubber intercalation were prepared... 

Furthermore, another advantage of nanofillers is not only to reinforce the rubber matrix but also to impart a number of other properties such as barrier properties, flammability resistance, electrical/electronic and membrane properties, and polymer blend compatibility. In spite of tremendous research activities in the field of polymer nanocomposites during the last two decades, elastomeric nanocomposites... 

The barrier properties of starch nanocrystals/natural rubber nanocomposites were also investigated [39]. For these systems, the water vapour transmission rate, the diffusion coefficient of oxygen, the permeability coefficient of oxygen and its solubility, were measured. It was observed that the permeabiUty to water vapour, as well as to oxygen, decreased when starch nanocrystals wctc added These effects were ascribed to the platelet-like morphology of the nanocrystals. 

Barrier properties of a rubber matrix are remarkably improved thanks to clay addition. The tortuous path model is proposed to explain this phenomenon. In a NR/Mt nanocomposite prepared from emulsion blending, 1, 2 and 3 phr of clay led to more than 35% and to about 45% and 50% reduction of oxygen permeability, respectively. " 3 phr of OC (Mt/ didodecyl methyl amine) gave a 50% reduction of the oxygen permeability and a 40% reduction of toluene absorption at 20 °C. About 10% and 15% reduction of oxygen permeability were obtained with 5 and 10 phr of OC, respectively, and 30% reduction of toluene absorption was achieved with 15% OC, at 30 °C. ... 

Wu et prepared NR/clay nanocomposites by directly co-coagulating the rubber latex and clay aqueous suspension. This preparative process is very simple, convenient and elfective. SEM showed good dispersion of clay in the NR matrix, and these novel NR/clay nanocomposites exhibited excellent mechanical and gas barrier properties. 

As reported in Section 23.3, research on rubber nanocomposites has remarkably increased over the last decades, both in the academic and industrial worlds. Nanofillers bring about appreciable improvements of the following properties of a rubber matrix mechanical, rheological, barrier, thermal, degradation, flame resistance. 

The Nielsen model has been a popular theory, originally used to explain polymer lay nanocomposites. This model is used to describe the tortuosity effect of plate-like particulates of filled rubber polymer composite on the gas permeation. An increase in barrier properties of gas permeation of rubber polymer nanocomposites is a result of the impermeable nature of filler particles which creates a long path of penetrant molecule by directing them around the particle. 

C. Nah, M. A. Kader, Barrier Properties of Rubber Nanocomposites. In S. Thomas, R. Stephen (Eds.), Rubber Nanocomposite Preparation, Properties and Applications, John Wiley and Sons (Asia) Pte Ltd., Singapore, 2010, 499. 

Use of nanoparticles as fillers in mbbers is highly relevant because end use applications of rubber compounds require filler reinforcement. Most of the literature on rubber nanocomposites is based on the use of nanoclay as the filler. It has been shown that incorporation of nanoclay in synthetic rubbers, like styrene butadiene rubber (SBR), chloroprene rubber (CR), nitrile rubber (NBR), ethylene propylene diene monomer (EPDM) mbber etc. enhances the mechanical, anti-ageing and barrier properties. 

The group of Gu Z. in the 2009, reported the behavior of styrene butadiene/ rubber/organo-bentonite nanocomposite prepared from latex dispersion, content was lower than 12 mass%. The results showed were that presence of organo-bentonite in the nanocoposite affects direct in the thermo stability, mechanical properties and swelling behavior, which was attribute to the good barrier properties of the dispersed nanoparticles. The dispersion is an important factor that can affect various properties such as thermal stability [81]. 

In recent years, lamellar nanofiUers have been established as the most important filler type for barrier and mechanical reinforcement. Dal Point et al. reported a novel nanocomposite series based on styrene-butadiene rubber (SBR latex) and alpha-zirconium phosphate (a-ZrP) lamellar nanofiUers. The use of surface modified nanofiUers improvement the mechanical properties. However, no modification of the gas barrier properties is observed. The addition of bis(triethoxysilylpropyl) tetrasulfide (TESPT) as coupUng agent in the system is discussed on the nanofiUer dispersion state and on the fiUer-matrix inteifacial bonding. Simultaneous use of modified nanofillers and TESPT coupling agent is found out with extraordinary reinforcing effects on both mechanical and gas barrier properties [123]. 

H.N. Azlina, H.A. Sahrim, R. Rozaidi, R. Bahri, Y. Yamamoto, S. Kawahara, Oxygen barrier properties of new thermoplastic natural rubber nanocomposites. Polymer - Plastics Technology and Engineering 50 (15) (2011) 1564—1569. 

Y. Zhang, Q. Liu, S. Zhang, Y. Zhang, H. Cheng, Gas barrier properties and mechanism of kaolin/styrene-butadiene rubber nanocomposites, Applied Clay Science, ISSN 0169-1317 111 (July 2015) 37-43. http //dx.doi.Org/10.1016/j.clay.2015.03.001. 

J. Ok Jo, P. Saha, N.G. Kim, C.H. Choi, J.K. Kim, Development of nanocomposite with epoxidized natural rubber and functionalized multiwalled carbon nanotubes for enhanced thermal conductivity and gas barrier property. Materials Design, ISSN 0264-1275 83 (October 15, 2015) 777-785. http //dx.doi.Org/10.1016/j.matdes.2015.06.045. 

Gatos KG, Karger-Kocsis J (2007) Effect of the aspect ratio of siheate platelets on the mechanical and barrier properties of hydrogenated acrylonitrile butadiene rubber (HNBR)/layeted silicate nanocomposites. Eur Polym J 43 1097-1104... 

Bras, J., Hassan, M.L., Bruzesse, C., Hassan, E.A., El-Wakil, N.A., Dufresne, A., 2010. Mechanical, barrier, and biodegradability properties of bagasse cellulose whiskers reinforced natural rubber nanocomposites. Industrial Crops and Products 32, 627—633. 

Natural rubber (NR)-rectorite nanocomposite was prepared by co-coagulating NR latex and rectorite aqueous suspension. The TEM and XRD were employed to characterize the microstructure of the nanocomposite. The results showed that the nanocomposite exhibited a higher glass transition temperature, lower tan d peak value, and slightly broader glass transition region compared with pure NR. The gas barrier properties of the NR-rectorite nanocomposites were remarkably improved by the introduction of nano scale rectorite because of the increased tortuosity of the diffusive path for a penetrant molecule. The nanocomposites have a unique stress-strain behavior due to the reinforcement and the hindrance of rectorite layers to the tensile crystallization of NR [36]. 

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