Poly(vinyl alcohol)/cellulose composites for different applications

ROMINA OLLIER PRIMIANO; JIMENA SOLEDAD GONZALEZ; LEANDRO LUDUEÑA; CLAUDIO PEREZ; VERA ALEJANDRA ALVAREZ

Sitges

Simposio; Frontiers in Polymer Science.; 2013

Poly(vinyl alcohol) (PVA) has received great attention due to its unique physical and chemical properties. It is a nontoxic, water-soluble, and biocompatible synthetic polymer with strong hydrophilic and hydrogen bonding character. It has an excellent film and hydrogel forming ability, thermal stability, chemical resistance, good transparency and flexibility, and because of them it is widely used in several applications such as textile, packing, biomedical devices and membrane preparation; some applications are still restricted because of its solubility in water, and its limited mechanical properties. The preparation of a composite material that incorporates both biocompatibility and improved physical properties, by use of natural fillers, is of great importance. The use of cellulose, which is a natural polysaccharide with excellent mechanical properties, as reinforcement is attractive due to environmental and economic concerns. PVA hydrogels are excellent candidates for several applications, for example drug delivery devices, due to their high hydrofilicity and water uptake capability. PVA/nanocelluse hydrogels were obtained by freezing/thawing method, with different nanocellulose contents (1, 3, 5 and 7 wt.%). The nanocellulose was synthetized by acid hydrolysis from commercial microcellulose. These hydrogels were thermally, morphologically, physically and mechanically characterized. The obtained results indicate that the addition of nanocellulose enhanced the mechanical properties and the optimal concentration was found to be 3 wt.%. On the other hand, development of ecofriendly packaging materials is an important area of challenge for packaging technologies and the excellent properties of PVA make it appropriate for this application. PVOH/microcellulose composites were obtained in order to enhance the mechanical and barrier properties. Composites were prepared by casting technique using different amounts of cellulose: 5, 10 and 20 wt.%. The effect of the microfiller on the thermal, mechanical and water absorption properties of the matrix was determined. The microcomposite films showed an increase in the degree of crystallinity and elevated increase on modulus, as well as a decrease in water absorption.