Graphical AbstractHighlights Surface tension of poly lactic acid was measured at high temperatures using Axisymmetric drop shape analysis profile (ADSA-P) pendant drop technique. Effect of supercritical carbon dioxide pressure on interfacial tension of poly lactic acid was investigated. * Corresponding author. Tel.: 519-888-4567 x35586 E-mail address: p4chen@uwaterloo.ca (P. Chen).