Key words: supercritical carbon dioxide, polylactide, atomic force microscopy of polymers
Microstructure and properties of amorphous D,L-polylactide processed different routes
in supercritical carbon dioxide (SC-CO2) are studied. Atomic force microscopy analysis
demonstrated polymer plasticization that follows its swelling in SC-CO2 and leads to
significant internal structure changes caused by polylactic acid supramolecular
transformations. A developed pore structure formation and an accompanying increase
of polylactide void volume are directly related to a destruction of initial intermolecular
polymer bonds during the release of carbon dioxide. These changes are reflected in
significant (1.7—5-fold) increase of exothermal effects detected by differential scanning
calorimetry in the temperature ranges between -30 °C and -10 °C and around 30—40 °C.
doi:10.1134/S1990793114070057