Development and Characterization of TPS / LDPE Blends and Composites Reinforced With Açaí Fibers: Structural, Mechanical, Photodegradation and Biode

ABSTRACT

Due to inherent limitations in properties, processability, and application range of thermoplastic starch (TPS), developing alternative strategies to improve performance and versatility is essential. In this study, TPS was blended with low‐density polyethylene (LDPE) and reinforced with açaí fibers (AF) to produce TPS/LDPE blends and TPS/LDPE/AF composites using maleic anhydride (MA) as a compatibilizer. The materials were processed by extrusion and compression molding and characterized in terms of physicochemical, mechanical, and degradation properties. FTIR and XRD analyses confirmed intermolecular interactions among TPS, LDPE, and AF, and an increase in crystallinity associated with the incorporation of LDPE and AF. Thermal analyses demonstrated improved thermal stability and good compatibility between TPS, LDPE, and AF. Mechanical tests showed significant improvements in tensile strength and elastic modulus, despite the presence of porosity observed by scanning electron microscopy. The blends and composites also exhibited partially hydrophobic behavior. Photodegradation tests indicated an increase in the carbonyl index compared to neat TPS, while the addition of AF provided a photoprotective effect attributed to its lignin content. In biodegradation assays, the materials showed mass losses ranging from 44% to 65% after 816 h. Overall, the developed materials represent a promising sustainable alternative, combining improved mechanical performance with environmentally compatible degradation.