Preparation of poly (butylene adipate-co-butylene terephthalate) microspheres via foam-transfer and investigation of their degradation behavior

Abstract

Degradable polymer microspheres hold considerable significance for their application in everyday consumer products. In this study, poly (butylene adipate-co-butylene terephthalate) (PBAT) microspheres were synthesized using an improved solvent evaporation method via foam-transfer, and their degradation behavior was subsequently comprehensively examined. Experimental outcomes revealed that optimal conditions, including a PVA concentration of 2.0 wt %, a stirring rate of 600 rpm, a polymer/solvent ratio of 1:16, and a temperature of 45°C, yielded PBAT microspheres through the foam-transfer method with an impressive yield of up to 90 wt %. The degradation of PBAT microspheres was influenced by various factors, including environmental conditions, particle size, and structure. Specifically, PBAT microspheres exhibited heightened degradation when immersed in an acidic environment, possessing smaller particle sizes and a more intricate structure. In a water environment with a pH of 4, PBAT microspheres displayed a degradation rate of 36.16 wt % over a 90-day period. Furthermore, PBAT microspheres with particle sizes ranging from 20 to 30 μm showcased a degradation rate of 49.54 wt % after a 90-day immersion in water at 25°C. Notably, microspheres characterized by substantial porosity, with a porogen to polymer ratio of 180 wt %, exhibited a remarkable degradation rate of 61.66 wt % under the same conditions. As a result, this study offers a promising solution to address the issue of microplastic pollution in everyday consumer products.