LDPE-Soybean Seed Extrusion Process

Low-density polyethylene (LDPE) contributes significantly to plastic waste accumulation due to its non-biodegradable nature. One promising approach to mitigate this issue is blending LDPE with biodegradable materials. In this study, LDPE was blended with soy-based bioplastic using a single- screw extrusion process with variations in barrel temperature, screw rotation speed, and bioplastic composition. The extruded pellets were subsequently molded into thin sheets and subjected to biodegradation testing using a soil burial method, as well as morphological characterization using scanning electron microscopy (SEM). The experimental results indicate that extrusion parameters significantly influence the biodegradation behavior of LDPE–soy bioplastic composites. Taguchi analysis revealed that the optimal processing conditions were a barrel temperature of 95 °C, a screw speed of 50 rpm, and a soy bioplastic content of 20 wt%. Under these conditions, the composites exhibited the highest biodegradation performance. SEM observations showed the presence of bioplastic agglomeration and heterogeneous morphology due to uneven dispersion of the soy bioplastic phase within the LDPE matrix. These microstructural characteristics were found to contribute positively to the biodegradation behavior of the composites. The findings demonstrate that controlled extrusion processing is an effective strategy for producing partially biodegradable LDPE-based materials with enhanced environmental performance.