Clay-based polymer bionanocomposites

M Wicklein, B AlcUntara, A.C.S., and Aranda, P. (2013) Bionanocomposites based on fibrous clays. Prog. Polym. Sci.,... 

Bionanocomposites are an ecological alternative to conventional nanocomposites based on petroleum-derived polymers, as they are based on biodegradable polymers obtained from renewable resources. Biomass is the source of agropolymers like starch and cellulose and also of monomers used to chemically synthesize polymers like polylactic acid (PLA). Other kinds of biopolymers, e.g., xanthan gum and poly (hydroxyalkanoates), are produced by microorganisms. Even though most of the bionanocomposites reported in the hterature are based on layered sihcates, the number of examples illustrating the use of fibrous clays in the preparation of new bionanocomposites is growing rapidly. 

PCL, is an important APES with many potential applications in biomedical and environmental fields [144]. This polymer was the first one to be studied in bionanocomposite when in the early 1990s, GianneUs group from Cornell University (Ithaca, NY, USA) started to work on the elaboration of PCL-based nanocomposites by intercalative polymerization [295]. Since then, a vast number of bionanocomposites have been prepared [87]. Several groups used intercalation, master batches, and in situ polymerization of PCL with clays to produce a variety of nanocomposites as can be seen in Table 11.2. Not only clays, but also various types of nanoreinforcements such as cellulose [296] and StNs [297, 298], chitin [299] nanowhiskers, carbon nanotubes [300, 301], and silica nanoparticles [302] have been used to prepare bionanocomposites with PCL. 

Biodegradable polymers such as PVA, PVAc, and PGA have been used in bio-nanocomposites, but to a less extent compared to polymers such as PCL, PLA, and PHB. Nonetheless, these polymers, among other factors, can be used as model to prepare bionanocomposites with hydrophilic material such as clays and CNWs. Moreover, nanobiocomposites based on these polymers can be potentially used as bioscaffolds for cell growth among other applications. 

---