Development of Cellulose-Reinforced Bio-Composites for Sustainable and Highly Durable Footwear

In recent years, the footwear industry has faced significant scrutiny as a major contributor to global climate change, accounting for approximately 1.4% of global greenhouse gas emissions. Consequently, stringent international environmental regulations, such as the European Union’s Ecodesign for Sustainable Products Regulation (ESPR), are shifting the market paradigm toward mandatory carbon-footprint reduction and sustainable materials. Traditionally, footwear components like midsoles and outsoles have heavily relied on petroleum-derived elastomers—including polyurethane (PU) and ethylene-vinyl acetate (EVA)—to satisfy demanding specifications for cushioning and structural durability; however, their lifecycle inflicts severe environmental burdens, ranging from fossil-resource depletion to microplastic accumulation upon disposal.

In response to stringent global environmental regulations and carbon-neutrality initiatives, this study addresses the fabrication and characterization of cellulose-applied bio-composite materials applicable to sustainable footwear components, such as midsoles and outsoles. To substitute conventional petroleum-based elastomers, recycled cellulose fibers, serving as eco-friendly natural fillers, were incorporated into a bio-based polyol resin matrix.

The surface and interfacial morphologies of the fabricated bio-composites were characterized using scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FT-IR). Concurrently, key mechanical properties relevant to footwear standards—including tensile strength, tear strength, abrasion resistance, and rebound resilience—were systematically evaluated.