PVOH-Bentonite Nanocomposites for Medical and Packaging Applications

ROMINA OLLIER PRIMIANO; JIMENA SOLEDAD GONZALEZ; VERA ALEJANDRA ALVAREZ

Praga

Conferencia; 7th International Conference on Nanostructured Polymers and Nanocomposites; 2012

Clay based nanocomposites show notable improvements in several properties in comparisonwith a polymer or conventional micro-composites, such as increased strength and heat resistance and decreased gas permeability and flammability1. The hydrophilic character of clays promotes dispersion of these inorganic crystalline layers in water soluble polymers.Polyvinylalcohol (PVOH) is a synthetic water soluble polymer, non-toxic, with excellent film forming properties. It is characterized by strong hydrophilic and hydrogen bonding character. It has been studied for medical and biomedical applications, as well as for food packaging applications. It is also an interesting polymer for the synthesis of biocompatible high-strength hydrogels2. However, some applications are still restricted because of its high degree of swelling and solubility in water, and its limited mechanical properties. Some of these drawbacks can be improved by the incorporation of reinforcement like clays.In this work, PVA has been used for the synthesis of nanocomposites in different ways: films (by casting) and hydrogels (by freezing-thawing). In both cases, bentonite (clay) was used as reinforcement. PVOH/clay nanocomposites can be easily obtained because, as both of them are hydrophilic, the clay can be incorporated into the PVA without pre-treatments by simply dispersing the two components in water3. The aim of this work was to study the chemical, barrier and thermal properties of the nanocomposites in order to analyze the effect of clay incorporation on the general behavior of PVA matrices. It was determined that the incorporation of bentonite produce a decrease on the water vapour transmission rate which is very important for both selected applications. On the other hand, that filler was able to enhance the mechanical performance of neat PVA matrices measured by tensile properties.