PREPARATION OF PLA/NANOCELLULOSE DEGRADABLE ENVIRONMENTALLY FRIENDLY FOOD PACKAGING MATERIALS

The pressure of energy and environmental protection in the world is gradually increasing, and food packaging is developing in the direction of energy saving and environmental protection. Because of its renewable and degradable properties, polylactic acid (PLA) has become an important material for green food packaging materials. Modification of polylactic acid with nanocellulose (NCC), which is also a biodegradable high-strength filler particle, can obtain better performance composite packaging material. In this paper, three kinds of composite materials, ENCC-g/PLA composite material, NCC/mPLA/PLA composite material and NCC/PLA composite material, were prepared by solution casting method. The crystallographic properties, thermal properties and mechanical properties of the prepared composites were analyzed by wide-angle X-ray diffraction analysis (WAXD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TG). Studies have shown that the crystallinity of ENCC-g/PLA composites is nearly 12% higher than that of NCC/PLA composites. ENCC-g is prepared under the condition that ENCC is 1/1 and methyl acrylate (MA)/butyl acrylate (BA) is 3/1. The composites are prepared with 2% by mass of ENCC-g and PLA. Comprehensive mechanical properties and tensile properties are 38.95% and 33.59% higher than those of pure PLA and NCC/PLA composites with the same ratio, respectively, and the elongation at break is slightly lower than that of pure PLA. The mechanical properties of the prepared composite material can well meet the basic requirements of food packaging materials, and the application of degradable materials can well avoid environmental pollution caused by plastic products.