Tuning the thermal and mechanical behavior of poly (butylene succinate) through annealing for eco-insulation applications

This work explores the effects of low-temperature annealing (40 °C-80 °C) on the physical, thermal, and mechanical performance of poly(butylene succinate) (PBS) for thermal insulation applications. A comprehensive suite of analyses, including differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), mechanical testing, and transient plane source (TPS) thermal measurements, were used to evaluate the annealing-induced changes. Temperature‑dependent structural changes were observed, where annealing at 40 °C improved lamellar ordering, while 60 °C promoted amorphous phase formation. Annealing at 60 °C yielded the lowest crystallinity and density, resulting in enhanced thermal resistivity (10.55 (m.K)/W), corresponding to a thermal conductivity of 0.095 W/(m.K), the lowest water absorption (0.232%), and reduced thermal diffusivity—features desirable for insulation. Conversely, annealing at 40 °C enhanced compressive and tensile properties by improving lamellar packing, whereas annealing at 80 °C increased crystallinity and thermal stability but introduced surface cracks. Notably, this is the first systematic study to investigate the influence of annealing below 90 °C on unfilled PBS on insulation performance. The findings demonstrate that mild thermal post-processing can optimize PBS properties for sustainable building materials, balancing energy-efficient fabrication with functional performance.