Development and characterization of commercial biodegradable films using blown film extrusion technology

摘要

The aim of this study was to develop commercial polylactic acid (PLA), PLA + polyethylene glycol (PEG) and PLA + polybutylene adipate terephthalate (PBAT)-based biodegradable films using blown film extrusion technology. The films produced were characterized for morphological, structural, optical, mechanical and thermal properties. The haze %, tensile strength, oxygen transmission rate (OTR), water vapour transmission rate (WVTR) parameters were varied from 10.65% to 28%, 48.3 to 56.49 MPa, 194.55 to 318.25 cc/m(2)/day and 175 to 318.18 (gm/m(2)/day) respectively for developed films. The study showed that better haze properties in biofilm are achived by compatibilizing with PEG. Thermal degradation of virgin PLA takes place in a single weight loss step with degradation peak at 349.77 degrees C compared to PLA + PBAT blended that took two weight loss step. Fourier-transform infrared spectroscopy study was used to monitor the absorption peak shifts in specific regions to determine the known functional group interactions of the PLA with various types of materials. In all the films the absorbtion peaks appeared at 1451.2-1451.7 and 2921.2-2944.3 cm(-1) corresponding to asymmetrical deformation of C-H bond. The stretching of C=O band vibration appeared at 1745.2-1745.7 cm(-1) in PLA, PLA + PEG and PLA + PBAT film. From the fracture scanning electron microscope micrographs, there was smooth surface texture for films, and no interfacial differences were visible indicating the presence of a single phase and structural integrity of the films. The developed packaging films were subjected to MA packaging study with capsicum and found to be at par with low-density polyethylene + linear low-density polyethylene in maintaining the texture, colour and overall market quality.