Polyhydroxyalkanoates (PHA) are promising biodegradable polymers owing to their renewable origin and excellent biodegradability; however, their inherent brittleness limits broader engineering applications. In this study, biodegradable composite films were developed by incorporating maleic anhydride-modified starch (MS), poly(butylene adipate-co-terephthalate) (PBAT), and natural fiber powder into a PHA matrix to improve mechanical performance while maintaining environmental sustainability. The modified starch was prepared by graft modification and characterized using Fourier transform infrared spectroscopy (FTIR). Composite films were fabricated by solution casting and characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and tensile testing. Response Surface Methodology (RSM) was employed to optimize the formulation and evaluate the effects of PHA, modified starch, and PBAT on mechanical properties. The RSM model predicted an optimum composition of 90 wt.% PHA, 10 wt.% modified starch, and no PBAT addition, yielding the highest tensile strength among all tested formulations. Although PBAT is generally used to improve ductility, the optimized formulation demonstrated that superior tensile performance could be achieved without PBAT through the synergistic reinforcement of PHA and modified starch. In addition, the incorporation of natural fiber powder enhanced interfacial compatibility and thermal stability. Further analyses verified that modified natural fillers accelerated the degradation of composite films in both soil and water compared with filler-free films. These findings provide an effective material design strategy for developing high-performance biodegradable composites for sustainable packaging and advanced functional material applications.

Chair Professor Tsair-Wang Chung received his Ph.D. in Chemical Engineering from the University of Missouri–Columbia, USA, in 1993. He began his professional career as a Research Scientist at the Industrial Technology Research Institute (ITRI), Taiwan, in the same year, and was appointed Associate Professor of Chemical Engineering at Chung Yuan Christian University (CYCU), Taiwan, in 1995. Currently, Dr. Chung serves as a principal investigator focusing on the production and application of bioresources and functional biomass materials, bioenergy and sustainability, as well as separation and purification processes. He has authored or co-authored more than 220 scientific publications in peer-reviewed journals and international conference proceedings. His current research interests include sustainable biomass energy materials, mechanical devices for separation processes, and biomass upgrading technologies. Professor Chung has successfully established extensive international collaborations with universities and research institutions in Taiwan, Japan, Indonesia, and other regions, particularly in the fields of sustainable biomass materials, separation equipment, and the biomaterials industrial value chain. He has been recognized as one of the World’s Top 2% Scientists in Chemical Engineering by Stanford University in USA as a lifetime honor, and has received the First-Class Talent Scholar Award from the National Science and Technology Council in Taiwan.