Biodegradation rate control with blends of poly(butylene succinate) and poly(butylene succinate-co-adipate)

• Biodegradable PBS and PBSA were blended by the solvent casting method to produce PBS/PBSA blend films. • DSC measurements of PBS/PBSA blend films confirmed compatibility in the amorphous form and phase separation during crystallization. • Enzymatic degradation tests showed that the opposite phenomena of accelerated and inhibited degradation were observed depending on the blend ratio. • Structural morphology, including a proposed third phase, governed the degradation behavior • The degradation rate of PBS/PBSA blends can be tuned by adjusting the blend composition. Biodegradable plastics are attracting attention as a potential solution to mitigate global plastic waste, and therefore, biodegradable plastics with different degradation rates are in demand for various applications. In this study, two biodegradable plastic materials, poly(butylene succinate) (PBS) and poly(butylene succinate- co -adipate) (PBSA), were blended using a solvent casting method to produce PBS/PBSA blend films. The thermophysical properties of the prepared films were measured by differential scanning calorimetry, and the results confirmed compatibility in the amorphous form and phase separation during crystallization. Polarization microscopy revealed a linear relationship between the spherulite growth rate and the blend ratio. Enzymatic degradation tests indicated accelerated and inhibited degradation, which further suggested the presence of PBS spherulite crystals with PBSA incorporated inside. Overall, we demonstrated control over the plastic degradation rate by appropriately blending PBS and PBSA, thus highlighting the potential for modulating biodegradability using simple polymer blend techniques.