Chitin Nanofibrils-Chitosan Composite Films: Characterization and Properties

In this research, an attempt to prepare a prototype of fully biodegradable nanocomposite films for food packaging was made by using commercial chitosan (CS) and chitin nanofibrils (CN). If food products could be packaged in these innovative films instead of paper (cellulosic) ones, the speed of deforesting in Europe will be diminished, thus improving the ecological situation and climate. In the paper, properties of the CS/CN films are described. The prototype films have been prepared from aqueous viscous CS/CN slurries by casting technique. The effect of many operating variables on morphology and properties of the nanocomposite CS/CN films such as sorption of water vapors, oxygen permeability, contact angle, mechanical stability and thermostability is analyzed and discussed. The examined variables are CN content, type of plasticizers (polyglycerols) and their content, type of metal ions such as Mg+2, Ca+2, Ba+2 and type of various additives (gelatin, lignin and monolignols) or surface modifiers (polylactides, polyglycerol polyricinoleate). Special attention was paid to the study of the effect of the storage time of the slurries on their aging and mechanical characteristics of CS/CN films.