Recently, Professor Zhang Shuangbao's research group at the School of Materials Science and Technology published a paper titled "Engineering strong and tough wood fiber/polyhydroxybutyrate bio-composite: Synergistic modification, performance optimization, and mechanistic insights" in Composites Part B: Engineering (F=12.7), a top journal in the field of materials science.

Polyhydroxybutyrate (PHB), with excellent biodegradability, shows great promise as a green substitute for fossil-based thermoplastics. However, the high production cost of PHB, along with its fragility and thermolability characteristics, hinders its broader applications. Composite fabrication based on polymer blending technology is a highly efficient and flexible strategy for overcoming the drawbacks of PHB. It can be ideal for versatility in manufacturing, enabling easy modification of formulas to fulfill a wide range of demands.

The conflict between mechanical strength and toughness of polyhydroxybutyrate (PHB) based composites remains challenging for its advancing development and application. The research group reported a straightforward and effective synergistic modification approach for preparing WF/PHB bio-composites with optimal multiple performances. Mixture design of experiments and characterizations were employed to investigate the positive synergistic effect of the poly(hydroxybutyrate-grafted-maleic anhydride) (PHB-g-MA) and poly(butylene succinate) (PBS) throughout the process of modification of the bio-composites. Three optimized formulations, the maximum strength formulation (MSF), the maximum toughness formulation (MTF), and the optimal formulation (OPTF) were selected based on the design criteria. Mechanistic analysis reveals that PHB-g-MA not only improves the interface compatibility between WF and the matrix but also promotes the uniformity dispersion of PBS toughener within the WF/PHB bio-composite. However, exceeding or imbalanced proportions of PHB-g-MA and PBS adversely affect the synergistic modification of multiple performances in the WF/PHB bio-composites. The OPTF yielded WF/PHB bio-composites with significantly improved mechanical properties, reflected in impact strength (+210.7 %), bending toughness (+165.6 %), and elongation at break (+110.8 %), along with gains in modulus of rupture (+25.6 %) and tensile strength (+22.4 %). Furthermore, compared to MSF and MTF, the OPTF effectively balances the conflict of enhancing strength and toughness while also exhibiting superior performance in processability, water resistance, dynamic elastic properties, and thermal stability. This work reveals the synergistic mechanism of PHB-g-MA and PBS modification in enhancing WF/PHB bio-composites, providing an easy and promising pathway for high-performance, eco-friendly, and sustainable WF/PHB bio-composite development.

Dr. Chen Zhenghao, from the School of Materials Science and Technology is the first author of the paper. Professor Zhang Shuangbao and Dr. Li Hui from Washington State University are the co-corresponding authors. Beijing Forestry University is the signature unit of the first author.

This study was funded by the National Key Research and Development Program of China (2023YFD2202102); the National Natural Science Foundation of China (32171707); the National Natural Science Foundation of China (32371979); the National Natural Science Foundation of China (32101607); the China Scholarship Council (202206510012).

Paper link: https://doi.org/10.1016/j.compositesb.2025.112174

Written by Chen Zhenghao, Zhang Shuangbao
Translated and edited by Song He
Reviewed by Yu Yangyang