Polymer/clay nanocomposites nanocomposite fabrication

This chapter aims to review the developments of biobased polymer/clay nanocomposites comprising general fabrication techniques and optimization of mixture homogeneity in solutions. Furfliermore, the effects of interactions between biopolymer matrices and nanoclays on structural, mechanical, and thermal properties, and biode-gradabUity of currently available biobased polymer nanocomposites are reviewed. Finally, future trends are also summarized for such nanocomposites with great enhancements of mechanical, thermal, and biodegradable properties. 

To achieve improved dispersibUity of nanoclay fillers within polymer systems, three familiar methods are commonly used, namely, melt intercalation, solution intercalation, and in situ polymerization. The melt-intercalation method is based on the melting point of polymer matrices and is applied by annealing above the melting point of the polymer (Reddy et al., 2013). This method has been chosen by industrial sectors to produce polymer/clay nanocomposites. However, it is not apphcable to the fabrication of biobased polymer/clay nanocomposites based on thermosetting materials such as epoxy and polyester due to their high viscosities (Wypych and Satyanarayana, 2005 Wang et al., 2014). Therefore, the fabrication of biobased thermosetting polymer/clay nanocomposites is mainly based on solution intercalation or in sim polymerization. 

Concerns regarding the toxicity and environmental effects of polymer-based nanocomposites, such as those derived from clay nanoparticles or carbon nanotubes, throughout their life cycle, from formulation, polymerisation, compounding, fabrication, use, disposal and degradation, are described. The potential of nanoparticles to enter the body by skin contact or inhalation is discussed. Accession no.927669... 

Soft nanohybrid materials with novel organic-inorganic network structures, such as nanohydrogels, soft nanocomposites (solid), and their derivatives are described in the chapter Soft Nanohybrid Materials Consisting of Polymer-Clay Networks. Synthesis of polymer hybrids based on metal-oxide nanoparticles are discussed in Fabrication of Metal Oxide-Polymer Hybrid Nanocomposites. Some properties and applications of these hybrid nanocomposites are also discussed in this chapter. 

The reported fabrication of biopolymer/clay nanocomposites by in situ polymerization can be seen in Table 6.5 with the solubility of clay nanofiUers in biobased polymer matrices, indicating better dispersion using this method. 

In-depth discussions of clay and clay surface treatment, fabrication, and characterization of nanocomposites are provided, and particular emphasis is placed on the proper use and interpretation of analytical techniques, helping the reader to avoid artifacts in their own work. With commercial appUca-tions discussed throughout, this is an ideal reference for those working in polymer science. 

Since the development of nylon 6/clay nanocomposites by Kojima et al. [3,4] has been successful in tremendously reducing gas permeabihty, a large number of studies on polymer/organoclay nanocomposites have been reported. There are three different approaches possible to fabricate nanocomposites of polymers. The first one is the solution process. Clay is hydrophilic so that it can... 

Storage moduli are greatly increased in the low-frequency region in the case of SPS/OPS nanocomposites due to the retarded relaxation dynamics of polymer chains in a confined geometry. [9,17] Exfoliated nanocomposites fabricated by adding Cloisite lOA (Southern Clay Products, Inc.) showed... 

It was shown that the clay dispersion was improved with increasing compatibilizing agent, but at the expense of the polymer processability into filaments. Nevertheless, there was no evidence of intercalation or exfoliation, irrespective of the nature of compatibilizer or clay modifier, nor strong improvements of LOI. Despite the absence of formation of true nanocomposites, filaments were sufficiently strong to be knitted into fabrics and presented slower burning behavior than the pure polymer. 

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