Studies on the mechanical, barrier, optical, and characterization of photo-/biodegradable LDPE-PLA blend with nanoclay for packaging film application

Abstract

LDPE-poly-lactic acid (PLA) (60:40%) was melt blended with nanoclay (1, 2, and 3%) and benzophenone (3%) using maleic anhydride-grafted LLDPE (LLDPE- g-MAn; 3%) as compatibilizer in a twin screw compounding extruder. Tubular blown films extruded using Dr Collins blown film extruder were subjected to various mechanical tests like tensile strength, elongation at break, and so on, optical tests, and permeability tests for oxygen and water vapor. The tensile strength was increased as the nanoclay percentage was increased (upto 2 wt%) and the elongation at break was decreased. Tear strength was increased, burst strength was decreased, and the dart impact strength was constant. The coefficient of friction was little decreased. The haze was increased and luminous transmittance was decreased. Water vapor transmittance and oxygen gas permeability were decreased. Scanning electron microscope images were taken to determine the morphological changes on the samples. Characterization by X-ray diffraction was carried out to analyze the shift in peak when nanoclay was blended at various proportions. In conclusion, LDPE with benzophenone is photodegradable and PLA is biodegradable. Hence, in this study, LDPE-PLA (60:40%) with benzophenone (3%) is photo-/biodegradable. Inclusion of nanoclay increased the mechanical properties like tensile strength, tear strength, and barrier properties. Furthermore, nanoclay improves the compatibility apart from LLDPE- g-MAn.