Preparation and properties of rapidly plasticized poly (butylene succinate)/mechanically activated cassava starch biocomposite

Overcoming limitations of poly (butylene succinate) (PBS) and enabling non-toxic, rapid production could lay the foundation for expanding applications in various fields. In this work, mechanically activated cassava starch (ACS) was used to augment the toughness of PBS and reduce the plasticization time of starch. The composite was prepared by melt blending PBS with two types of activated cassava starch particles (native starch and ACS) and acetyl tributyl citrate (ATBC) as a non-toxic plasticizer. X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FTIR), scanning electronic microscope (SEM), and differential scanning calorimetry (DSC) were used to investigate the structural changes, compatibility, and dispersibility of ACS particles in PBS. The results showed that under high-speed shear and grinding, the hydrogen bonds within ACS molecules were severely disrupted and the amorphous regions increased, leading to improved compatibility with PBS. Under the plasticization of ATBC, the cross-section of ACS composites was smoother. DSC results showed that addition of ACS significantly reduced crystallinity of PBS/ACS composites. Mechanical properties results showed that impact strength and elongation at break of PBS/ACS-12A were, respectively, increased by 125% and over 5 times compared with that of PBS. Water absorption test and contact angle test demonstrate a significant improvement in the water resistance of PBS/ACS. This study provides a simple and feasible method for preparing low-cost PBS biocomposites, and their extensions are expected to further replace general-purpose plastics in daily application.