Evaluation of the Biodegradability of a Composite Material Reinforced with Cellulose Acetate Nanofibers

The development of biodegradable composite materials offers a sustainable alternative to conventional synthetic polymers, particularly in short-lived applications. In this context, the incorporation of nanoscale reinforcements can improve mechanical properties without compromising the material's degradability. The purpose of this study was to evaluate the composting behavior of a composite material based on low-density polyethylene (LDPE), potato starch, and cellulose acetate nanofibers (NFCA). The material's degradability and mechanical stability were analyzed over 180 days according to the ASTM D5988 standard. The nanofibers were produced via electrospinning, yielding an average diameter of approximately 85 nm. The composite material was prepared using twin-screw extrusion followed by injection molding to produce ASTM D638 test specimens. The effects of biodegradation were evaluated through mass loss, CO₂ generation in a desiccator, tensile testing, Shore D hardness measurements, and microstructural analysis via scanning electron microscopy (SEM). The results demonstrated a progressive increase in CO₂ generation, particularly in the reinforced formulations (up to 111.76%). The formulation containing 3% NFCA exhibited the greatest mass loss (20.28%). Tensile testing revealed moderate reductions in maximum stress (1.66-8.44%), whereas hardness increased by up to 5.4% in the reinforced formulations. SEM analysis revealed increased porosity as the composting period progressed. The findings suggest that the incorporation of NFCA enhances biodegradative performance, as evidenced by increased CO₂ evolution, mass loss, and morphological changes during composting.