Fabrication and characterization of microalgae-based additive ethylene vinyl acetate composites as sustainable...

A microalgae-based ethylene vinyl acetate (EVA) composite was developed to enhance recyclability and reduce environmental impact, offering a sustainable alternative for bioplastic applications. Comprehensive bioplastic analysis starts from rheometric, heat press molding, mechanical, morphology, and particle size distribution, and follows by thermal property characterization, such as thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), hardness, crosslinking density and melt flow index in this study. At first, Chlorella sorokiniana PY, processed via spray or freeze drying, significantly improved the melt flow index of recycled EVA foam by 2-5 times. Thermal analysis confirmed that the incorporation of microalgae can maintain EVA stability during processing at 180 °C. Rheological studies revealed that the addition of 10-50 phr microalgae altered the crosslinking behavior, extending foam expansion by 8.8-16.7 times compared to pure EVA. Spray-dried composites exhibited 1.4-1.5 times higher tensile strength than freeze-dried counterparts while preserving acceptable hardness. Furthermore, composites derived from microalgae that cultured in wastewater reduce carbon emissions by 63 % at the optimal loading. This study demonstrated the potential of microalgae-EVA composites as sustainable, high-performance bioplastics for applications in footwear, packaging, and consumer products.