3. Swelling and barrier properties of nanocomposites

The swelling properties of a polymer film by liquid or vapor, or its gas barrier properties, are important issues, particularly for packaging applications. To perform a packaging function, a material must have suitable mechanical, optical and barrier properties. While the mechanical properties of nanocellulose have been studied for many years, it is only very recently that its barrier properties have attracted interest. Most materials used for packaging, especially food packaging, are essentially derived from non-biodegradable petrochemical polymers. The main reasons for their use are their ease of shaping, low cost and excellent barrier properties, particularly with regard to liquids. However, these performances are not always valid for water vapor, odors, flavors and fragrances. In addition, the low permeability of cellulose may be accentuated by the highly crystalline nature of cellulose...