Nanocomposites based on PVA

ROMINA OLLIER; VERA ALVAREZ; JIMENA GONZÁLEZ

Congreso; eular; 2011

Nanocomposites are a new class of composites, for which at least one dimension of the dispersed particles is in the nanometer range. In the case of polymer-clay nanocomposites, they posse unique properties which are attributed to their nanometer size features and the extraordinarily high surface area of the dispersed clay [1]. Nowadays, poly (vinyl alcohol) (PVA) has received great attention in different areas and due to its excellent properties such as: non-toxicity, water-solubility, biodegradability and biocompatibility properties. PVA is characterized by strong hydrophilic and hydrogen bonding character [2]. It has excellent film and hydrogel forming abilities; thermal stability; chemical resistance, transparency and flexibility, and because of those, it is widely used in several applications such as paper coating, textile sizing, packaging, biomedical devices and membrane preparation [3-4]. However, some applications are still restricted because of its high degree of swelling and solubility in water, and its limited mechanical properties [5]. Some of these drawbacks can be improved by the incorporation of reinforcement like claysor layered silicates, which are popular fillers for various polymeric materials. Their crystalline net consists of bidimensional layers where a central octahedral layer of either alumina or magnesia is joined to two external tetrahedrons of silica in such a way that the oxygen ions of the octahedral layer also belong to the tetrahedral layers [6-7]. Among these clays, the use of bentonite is interesting because, added to their environmental and economic importance; their natural abundance and mechanical and chemical resistances make them very useful as polymeric material reinforcements.