Impregnation of clove extract (Eugenia Caryophyllus) in blends of polycarbonate/poly(L-lactic acid) via supercritical CO2
Polymers that release natural extracts are used in active packaging for food, wound care, cosmetics, and agriculture. The impregnation process by supercritical CO2 (scCO2) is more sustainable than conventional ones, allowing the extract to be incorporated into the polymer. Clove extract (Eugenia Caryophyllus) has antibacterial, antifungal, antiviral, and insecticidal properties and contains four main compounds. Previous work impregnated this extract in polycarbonate (PC) and poly(L-lactic acid) (PLLA) and showed that pressure, temperature, and polymer influence the amount of impregnated extract and its release. In this work, we seek to impregnate PC/PLLA blends (100/0; 75/25; 50/50; 25/75; 0/100) and to study how the composition of the blend impacts the amount of impregnated extract and its composition in the headquarters. The films were characterized by differential calorimetric analysis (DSC) to identify phase separation and microstructure modification. Films of the blends were prepared after extrusion and pressing. They were impregnated at 60°C and 20 MPa. The amount of impregnated extract was determined gravimetrically. Infrared spectra confirmed the presence of the extract. DSC analyses of non-impregnated and impregnated films showed the extract's impact on the blends' thermal properties.