Enhancing the properties of starch-based blends through the synergistic effect of polyethylene brassylate

This study investigates strategies to enhance the dispersion and homogeneity of cassava starch (CS) within polybutylene succinate (PBS) matrices aiming to improve the processability, cost-effectiveness, and biodegradability of the blends. Triphasic blends of PBS/CS/polyethylene brassylate (PEB) were prepared with CS contents of 10, 30, and 50 wt %, and compared to corresponding biphasic PBS/CS blends. The impact of PEB addition on crystallinity, thermal behavior, morphology, rheological properties, mechanical performance, and disintegration characteristics of the blends was thoroughly evaluated. The incorporation of PEB weakened the intermolecular hydrogen bonds within the starch structure, facilitating the integration. This resulted in a reduction of starch particle size, enhanced dispersion within the PBS matrix, and improved interfacial interaction, even at a high CS content of 50 wt %. The presence of starch restricted the mobility of PBS chains, hindering its crystallization and lowering the crystallization temperature. Notably, the triphasic blends exhibited significant enhancements in mechanical properties, increasing the Young's modulus and tensile strength by 122 % and 105 %, respectively, at high CS loadings compared to the biphasic counterparts. Morphological analysis revealed improved phase homogenization in the triphasic systems, attributed to the plasticizing effect of PEB at the blend interface. However, at low CS concentrations, the addition of PEB decreased the viscosity of the blends compared to neat PBS. These findings demonstrate that PEB is an effective compatibilizer, significantly enhancing the processability and mechanical performance of starch-based blends. Consequently, these materials show strong potential to replace conventional plastics in applications such as rigid packaging, disposable tableware, and agricultural films. • PEB improves starch dispersion and distribution in PBS matrix. • Triphasic blends show better interfacial compatibility even at high starch content. • Young's modulus and tensile strength increase with high starch content. • Thermoplastic starch reduces PBS crystallization. • PEB acts as a compatibilizer and plasticizer in PBS/starch blends.