Thermal Modulation of Microstructure and Dielectric Properties in Poly(butylene succinate)-Biocomposites for EMI and Communication Applications

The increasing demand for environmentally sustainable materials in electronic and communication systems has driven interest in biodegradable polymers with functional electrical properties. In this study, poly(butylene succinate) (PBS) and lignocellulosic fiber–reinforced composites were developed and modified through controlled thermal exposure to tailor their microstructural and dielectric characteristics. The role of crystallinity and interfacial polarization in governing dielectric behavior, electrical insulation, and electromagnetic interference (EMI) response was systematically examined. The results indicate that thermally induced microstructural ordering effectively suppresses polarization losses, enhances electrical resistivity, and improves environmental stability under humid conditions. The materials exhibited high resistivity (up to 1.5 × 1014 Ω·cm), along with reduced capacitance (2.57 pF) and faster signal propagation (1.76 × 108 m/s), demonstrating suitability for low-delay communication systems. In addition, the composites exhibit stable frequency-dependent electromagnetic attenuation supported by improved thermal transport and structural stability.