Mechanism-Driven Development of Dual-Acid Doped Poly(butylene succinate) Composites for Flexible Sensors with Integrated High Conductivity and Biodegradability

In order to reduce the pollution of electronic waste, mixed-acid-doped poly aniline (TSPANI) was prepared via in situ solution polymerization, while poly(butylene succinate) (PBS) was synthesized by direct esterification. TSPANI and PBS were then blended in solution to fabricate a conductive and biodegradable polymer composite film (TSPANI/PBS). TSPANI and PBS are combined through intermolecular interactions. The addition of an appropriate amount of TSPANI improves the mechanical properties of the film while enhancing its electrical conductivity. When the TSPANI content reaches 20%, the semicircular arc diameter is minimized, indicating the lowest charge transfer resistance of 3.16 MΩ and optimal electrical conductivity. The film maintains excellent conductivity even under bending and twisting conditions. Concurrently, the film surface exhibits significant collapse and pores compared to other proportions, resulting in a faster degradation rate─achieving 34.3% after 42 days of enzymatic degradation and 35.75% after 180 days of soil degradation. When tested under various pressures, human motion, joint movement, and other subtle pressures, the sensor based on this electrically conductive film could effectively capture these changes and generate corresponding current responses. Furthermore, compatibility simulations conducted via Materials Studio software systematically evaluated the interfacial interactions in the TSPANI/PBS composite system, elucidating at the molecular level the formation of a hydrogen-bonding network and its role in enabling proton-hopping transport and synergistic electron conduction. The development of this composite material serves as a promising alternative to nondegradable polymers, effectively mitigating electronic waste pollution and contributing significantly to environmental protection.