Nanocomposite technology

The impact of the nanocomposite technology on polymers is huge, reflected in enhanced properties of the resulting PNs, such as enhanced mechanical, barrier, solvent-resistant, and ablation properties.12 The effect of nanocomposite technology on the thermal and fire performance of the polymers is primarily observed in two important parameters of the polymers (1) the onset temperature (7( ,nsct) in the thermogravimetric analysis (TGA) curve—representative of the thermal stability of the polymer, and (2) the peak heat release rate (peak HRR) in cone calorimetric analysis (CCA)—a reflection of the combustion behavior (the flammability) of the polymer. The Tonset will be increased and the peak HRR will be reduced for a variety of polymers when nanoscale dispersion of the nanoadditive is achieved in the polymer matrix. 

Clays, natural or synthetic, are the most widely investigated and understood nanoadditives used to enhance the flame retardancy of polymers through nanocomposite technology, because of their unique properties, particularly the ease of surface treatment and application in polymer matrices. Clay can be cationic and anionic materials, in accordance with the charge on the clay layers. In this chapter, the focus is on two kinds of clays montmorillonite (MMT), a naturally occurring cationic clay that belongs to the smectite group of silicates, and LDH, an anionic clay that does occur naturally but for which the synthetic form is more common. Other clays will also be mentioned as appropriate. 

Because of the unique combination of mechanical, electrical, and thermal properties, the CNTs have been excellent candidates to substitute or complement the conventional nanofillers in the fabrication of multifunctional PNs. The first PNs using CNTs as the nanoadditive was reported in 1994.20 By far, the CNTs have been the second most investigated nanoadditives to reduce the flammability of the polymers through nanocomposite technology. A difficulty of the application of the CNTs in polymers is the dispersion of CNTs in the matrix polymer, and the high cost of the CNTs is another problem. 

The impact of nanocomposite technology on flame retardance (the thermal and fire resistance) of the polymers, as mentioned in Section 11.1, is primarily reflected in two important parameters (1) the ronset in the TGA curve—representative of the thermal stability of the polymer and (2) the peak HRR in the curve of CCA—reflection of the combustion behavior (the flammability) of the... 

In the field of flame retardancy only a few papers paid attention to the interfaces until the appearance of nanocomposites [7,8], Nanocomposite technologies adapted the use of both the surfactants and the multilayer interfacial structures (introducing maleic anhydride grafted macromolecular interlayer) [9,10], A simplification is, however, characteristic to most of the works dealing with nanostructured FR polymers the importance of dispersion is considered, neglecting the other special interfacial requirements of FR. 

Morgan, A. B. Fire performance of polymer + fiberglass reinforced composites with and without polymer nanocomposite technology, Proceedings of 19th Annual BCC Conference on Flame Retardancy, Stamford, CT, June 9-11, 2008. 

It is well known that small molecules can be removed from larger molecules using inorganic materials such as molecular sieves. However, this approach contaminates the polymer with inorganic particulates. The only literature teaching this approach are Russian patents claiming the addition of silica gel [27] and mont-morillonite clay [28] to absorb styrene from PS. The advances in nanocomposite technology in recent years may allow further development of this approach. 

Both phases (the matrix and the filler) must be homogeneously distributed and the sizes of particles must be uniform and well controlled. Layered fillers such as montmorillonite are finding growing applications many of which involve the use of nanocomposite technology. One example of intercalation process to produce membrane resulted in the development of nanocomposite with controlled ion mobility "... 

Fillers are usually considered to be opaque materials but they can play an important role in high technology optical devices. This is possible due to the use of very small particles of controlled size obtained through application of nanocomposite technology. 

The pol5mier nanocomposite field has been studied heavily in the past decade. However, polymier nanocomposite technology has been around for quite some time in the form of latex paints, carbon-black filled tires, and other pol5mier systems filled with nanoscale particles. However, the nanoscale interface nature of these materials was not truly understood and elucidated until recently [2 7]. Today, there are excellent works that cover the entire field of polymer nanocomposite research, including applications, with a wide range of nanofillers such as layered silicates (clays), carbon nanotubes/nanofibers, colloidal oxides, double-layered hydroxides, quantum dots, nanocrystalline metals, and so on. The majority of the research conducted to date has been with organically treated, layered silicates or organoclays. 

Paulis M, Leiza JR (2009) In Mittal V (ed) Advances in polymer nanocomposites technology Nova, New York, chap 5... 

Utracki, L. A. (2004). Basic Elements of Polymeric Nanocomposite Technology, In Clay-Containing Polymeric Nanocomposites, pp. 73-96, Rapra Technology Limited, England. 

Nanocomposite technology using small amounts of silicate layers can lead to improved properties of thermoplastic elastomers with or without conventional fillers such as carbon black, talc, etc. Mallick et al. [305] investigated the effect of EPR-g-M A, nanoclay and a combination of the two on phase morphology and the properties of (70/30w/w) nylon 6/EPR blends prepared by the melt-processing technique. They found that the number average domain diameter (Dn) of the dispersed EPR phase in the blend decreased in the presence of EPR-g-MA and clay. This observation indicated that nanoclay could be used as an effective compatibilizer in nylon 6/EPR blend. X-ray diffraction study and TEM analysis of the blend/clay nanocomposites revealed the delaminated clay morphology and preferential location of the exfoliated clay platelets in nylon 6 phase. 

Njuguna J, Pena I, Zhu H et al (2009) Opportunities and environmental health challenges facing Integration of polymer nanocomposites technologies for automotive applications. Int J Polym Technol 1 113-122... 

In order to make biopolymers more attractive for commercial end-use applications, it is necessary to enhance the thermomechanical properties through the utilisation of nanocomposite technology. In the last decade, polymer nanocomposites have become a global research interest, due to the superior advances in polymer characteristics by the addition of nano-scale materials (preferably in the range 10-100 nm) into the polymer matrix [13]. Due to the nanoscopic dimensions and extreme aspect ratios of the nanofillers, this results in six interrelated characteristics, which defines the type of nanocomposite. These are (1) low-percolation threshold ( 0.1-2 vol%), (2) particle to particle correlation (orientation and position) arising... 

Mittal, V. (2010). Advances in Polymer Nanocomposites Technology (ed. V. Mittal), Nova Science Publishers, New York. 

The field of clay-polymer nanocomposite technology is attracting a great amount of attention (169). Among clay minerals, the 2 1 natural clay mineral montmorillonite has been used for clay nanocomposite applications. The structure of nanocomposites, the dynamics of confined polymer clay nanocomposites using NMR and computer simulations, rheology of clay nanocomposites have been... 

It is evident that the suggested concept does not use starting nanomaterial which has to be blended with the matrix instead, the reinforcing nanofibrils are created from the blending of two polymers, one of them later playing the role of reinforcement. In this way, the most common problem of dispersion, encountered in nanocomposite technology,... 

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