Biobased Epoxy Nanocomposites

Biobased epoxy nanocomposites can be reinforced with organo montmorillonite clay and carbon fibers obtained from poly(acryl-onitrile) (45). To get the organically modified clay into the glassy biobased epoxy networks, a sonication technique was used. In this way, clay nanoplatelets were obtained that were homogeneously dispersed and completely exfoliated in the matrix. 

The mechanical properties showed an increase of 0.9 GPa for the storage modulus at 30°C when 5% of exfoliated clay nanoplatelets were added. In contrast, the glass transition temperature, decreases with the addition of the organoclay nanoplatelets (45). 

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Few examples of nanocomposites in which the cellulosic nanostructure is used in biobased thermosets can be also foimd. Due to the fact that these environment friendly composites suffer from several limitations, such as low mechanical properties due to low strength in reinforcement plus inadequate interfacial strength, and that cellulose nanostructures have been shown to have significant potential as a reinforcement, the possibility of using cellulose nanofibers as reinforcements in a bio-derived resin was revised. In Masoodi et al. [200], cellulose nanofibers were used as reinforcements in the forms of layered films, while in Lee et al. [201] the stability of the gas-soybean oil foam templates and the mechanical properties of the polymer nanocomposite foams are enhanced upon the addition of bacterial cellulose nanofibrils. Other examples of biobased thermosets containing cellulosic nanoreinforcements are the work of Shibata [202] in which the use of a biobased epoxy was revised, and systems in which cellulose nanocrystals are incorporated in biobased polyurethanes [203,204], Few examples exist also in the literature on the polymerization of furfuryl alcohol in presence of CNR [205,206] in these papers, the authors established the feasibility of producing furfuryl... 

Miyagawa, H., Mohanty, A., Drzal, L.T., Misra, M., 2004a. Effect of clay and alumina-nanowhisker reinforcements on the mechanical properties of nanocomposites from biobased epoxy a comparative study. Industrial Engineering Chemistry Research 43, 7001-7009. 

Wang, R., Schuman, T., Vuppalapati, R.R., Chandradhekhara, K., 2014. Fabrication of biobased epoxy-clay nanocomposites. Green Chemistry 16, 1871—1882. 

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. 

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