Open Access

Marco Adrian Pelaez Vera

• The growing demand for sustainable and biodegradable materials for biomedical and environmental applications have driven significant research into polymer foams. This study investigates the impact of hydrothermal pretreatment on the expansion behaviour of poly(D,L-lactide-co-glycolide) (PLGA, 75:25) composites foamed using supercritical carbon dioxide (scCO2) with the addition of three mineral fillers Wollastonite, Rice husk ash and Bentonite at concentrations of 25 and 33.3 wt.%. PLGA composites underwent two processing routes: direct foaming and hydrothermal pretreatment followed by foaming. The expansion efficiency, pore morphology, and structural stability were systematically evaluated through volumetric analysis and scanning electron microscopy. Results indicated a notable improvement in foam expansion and pore uniformity for composites subjected to hydrothermal treatment + foaming, particularly with wollastonite and bentonite as additives. Hydrothermal pretreatment facilitated CO2 diffusion and enhanced nucleation, generating more uniform and interconnected porous structures. However, samples containing rice husk ash exhibited variable responses, achieving the highest overall expansion factor without HT pretreatment, suggesting complex filler-polymer interactions. This study demonstrates that hydrothermal pretreatment, combined with carefully selected mineral additives, significantly influences the structural and expansion characteristics of PLGA foams. These findings advance the design and fabrication of biodegradable porous materials with tailored properties for targeted biomedical and environmental applications.