Nitrile rubber nanocomposites

Chayan, Das, Bharat, K. Preparation and studies of nitrile rubber nanocomposites with silane modified silica nanoparticle. Research Journal of Recent Sciences 1, 357-360 (2012)... 

R.L. Sala, T.M. Arantes, E. Longo, E.R. Leite, C.M. Paranhos, E.R. Camargo, Evaluation of modified silica nanoparticles in carboxylated nitrile rubber nanocomposites. Colloids and Surfaces A Physicochemical and Engineering Aspects, ISSN 0927-7757 462 (November 20, 2014)45-51. http //dx.doi.Org/10.1016/j.colsurfa.2014.08.012. 

Thomas P, Jose ET, George G, Thomas S, Joseph K (2013) Dynamic mechanical and rheological properties of nitrile rubber nanocomposites based on Ti02, Ca3(P04)2 and layered silicate J Compos Mater 1... 

Recently, nanocomposites were prepared with different grades of nitrile rubber with acrylonitrile contents of 19%, 34%i, and 50%i, with SBR (23%i styrene content), and with polybutadiene rubber with Na-montmorillonite clay. The clay was modified with... 

Sanchez studied the functionalization of oxidized SWCNTs and MWCNTs dispersed in thermoplastic elastomers based on poly(butylene terephthalate) (PBT)/ poly(tetramethylene oxide) (PTMO). These nanocomposites showed good dispersion and enhancement in thermo-oxidative stability [27]. 1 % of pristine multi-walled carbon nanotube (MWCNTs) were dispersed in silicon rubber. The SR nanocomposites showed 28 % better thermal stability and 100 % improvement in the ultimate tensile strength is achieved as compared with the pristine polymer matrix counterpart [28]. Also ionic liquids have been tested to improve the dispersion and thermal stability of MWCNTs in polychloroprene rubber (CR) showing improvement in these properties [29]. On the other hand the effect of carbon nanofiber on nitrile rubber was studied. It has been found that the nanofiber increase the thermal stability and decrease the flammability [4]. 

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. 

Synthetic mbbers are characterized by good thermal stability due to its stmcture, for this reason the rubbers have very important applications. The nitrile rubber (NBR) is a polymer used in applications requiring resistance to high temperatures of oil. Balachandran et al. reported behavior NBR-nanoclay nanocomposites, showing that the temperature at which degradation occurs is increased by adding the nanoclays [74]. 

In 2013, cellulose nanocrystals (CNs) were fabricated from sulfuric acid hydrolysis of cottonseed finter. The crystals were then utifized to prepare nitrile rubber (NBR)/CNs nanocomposites by mixing a water suspension of CNs and the NBR latex directly. CNs formed a strong filler-filler network in the NBR matrix which resulted in an obvious Payne effect [110]. 

Gilman et al. found similar reductions in the PHRR of clay nanocomposites. They prepared 6 wt% intercalated nanocomposites with Cloisite 15A dispersed in a nitrile rubber-modified bisphenol A epoxy-based vinyl ester (mod-bis-A) or a combination of bisphenol A and novolac epoxy-based vinyl ester (bis-A/novolac). The PHRR was reduced by 25 and 39% for mod-bis-A and bis-A/novolac, respectively. The clay promoted charring in fact, no residue was obtained for the neat resins, while in the nanocomposites the residue yields were 8 wt% (mod-bis-A) or 9 wt% (bis-A/novolac). The heat of combustion, specific extinction area, and carbon monoxide yields were unchanged. 

Rybinski P, Janowska G (2012) Thermal properties and flammability of nanocomposites based on nitrile rubbers and activated halloysite nanotubes and carbon nanofibers. Thermochim Acta 549 6-12... 

Rubber nanocomposites can be based on many rubber matrices, for example (clay reinforcement) natural rubber [41] or synthetic mbber materials such as styrene-butadiene rubber [42], nitrile-rubber [43], EPDM [44] or polyurethane [45, 46],... 

Kim JT, OhTS LDH (2003) Preparation and characteristics of nitrile rubber (NBR) nanocomposites based on organophilic layered clay. Polym Int 52 1058... 

Gatos, K.G., Szazdi, L., Pukdnszky, B., and Karger-Kocsis, J. (2005) Controlling the deintercalation in hydrogenated nitrile rubber (HNBR)/organo-montmorillonite nanocomposites by curing with peroxide. Macromolecular Rapid Communications,... 

It has been found that the interaction of intercalated and/or exfoliated nanoparticles may restrict the mobility of the matrix polymer chains, which lead to an increase of Tg values, as observed in nanocomposites of polyamide-12-layered silicates [102], nitrile rubber-organophilic montmorillonite [103], natural rubber-montmorillonite [104], and EVA-day [105]. A slight increase with the organosurface treatment in Tg values was noticed in poly(vinyl chloride)-clay [106,107], poly(vinyl chloride)-CNTs [108], polyurethane-montmorillonite [109-111], LLDPE-layered tetrasilisic fluoromica [112], PP-montmorillonite [113-115], PP-sUica [116], and styrene-butadiene rubber [117]. 

On the other hand, the results of a DSC analysis performed to investigate the curing process of nitrile rubber (NBR)-layered clay nanocomposites showed a... 

Nitrile rubber (NBR)-clay nanocomposites were prepared by different methods.The NBR-clay nanocomposites exhibited excellent gas barrier properties. Compared to gum NBR vulcanizate, the oxygen index of the NBR-clay nanocomposites slightly increased. " ... 

Wu Y-P, Jia Q-X, Yu D-S, Zhang L-Q, Structure and properties of nitrile rubber (NBR)-clay nanocomposites by co-coagulating NBR latex and clay aqueous suspension , J. Appl. Polym. ScL, 2003 89 3855-8. 

Nitrile rubber (NBR)-clay nanocomposites have been successfully prepared with mainly exfoliated and partially-intercalated structures in some cases, and intercalated structure in others. The preparation of NBR-clay has been reported via different processing techniques such as melt intercalation (internal blending), solution blending, ball milling of surfactant treated layered clay in emulsified solution and followed by latex shear blending, and by co-coagulating the nitrile mbber latex and layered silicate aqueous suspension followed by two-... 

Compared to the vast literature on most of the thermoplastic or thermosetting polymer-clay nanocomposites, reports of rubber-clay nanocomposites are much more limited. Much more research is needed to understand the complex nature of these nanocomposites and to identify the factors that have the most significant influence on their physical, mechanical, thermal, barrier, and dynamic mechanical properties. The several examples of rubber-clay nanocomposite that have been covered in this chapter indicate that to date rubber nanocomposite research has largely concentrated on the natural rubber, ethylene propylene diene rubber, styrene-butadiene rubber, and nitrile rubbers. The main factors found to influence final properties were type of clay and its treatment, clay... 

Choudhury et al. [36] in their work on hydrogenated nitrile butadiene rubber (HNBR)-nanoclay systems showed the thermodynamic aspects of nanocomposite formation using the mean-field-lattice-based description of polymer melt intercalation, which was first proposed by Vaia and Giannelis [37]. Briefly, the free... 

M. Kotal, S.K. Srivastava, A.K. Bhowmick, Thermoplastic polyurethane and nitrile butadiene rubber blends with layered double hydroxide nanocomposites by solution blending. Polymer International 59 (1) (2010) 2-10. 

Examples of nanocomposites that fit the tortuous path model relatively well include work by Shah et al. [2] with low-density polyethylene (LDPE) and ionomer, and by Gatos and Karger-Kocsis [3] with a nanocomposite of nitrile butyl rubber (NBR) and organofluorohectorite... 

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