Preparation and Properties of Polypropylene-Based Nanocomposite Films for Food Packaging

Packaging of foods in high barrier and strong materials is essential to attain food safety, and nanocomposite technology leads in search of the above kind of packaging material. The effect of compatibilizer (1.6, 5, 10, 15 and 18.4%), nanoclay (0.6, 2, 4, 6 and 7.4%) and thickness of film (35, 50, 75 100 and 120 mu m) on oxygen transmission rate (OTR), water vapour transmission rate (WVTR), tensile strength and per cent elongation of polypropylene (PP)-based nanocomposite films was studied using response surface methodology. The maximum reduction in OTR of PP-based nanocomposite films over the control was 21.4% in treatment having 10% compatibilizer, 4% nanoclay and 120 mu m thickness. A maximum of 28.1% reduction in WVTR for the treatment with 5% compatibilizer, 2% nanoclay and 100 mu m thickness over the control was achieved. The regression models were developed for the prediction of OTR and WVTR of nanocomposite films. The maximum increase in the tensile strength of PP-based nanocomposite films over the corresponding control was 71.7%. The elongation percentage of nanocomposite films was less than the control and increased with increase of thickness of film and decrease of both nanoclay and compatibilizer. Treatment having 5% compatibilizer, 2% nanoclay and 100 mu m thickness of nanocomposite films showed better barrier and strength characteristics than other treatments. This paper helps to design the packaging films according to the requirement of foods to be stored using the developed regression models. Copyright (C) 2011 John Wiley & Sons, Ltd.