Development of new approach based on Raman spectroscopy to study the dispersion of expanded graphite in poly(lactide)

A new approach has been developed to study the dispersion/delamination of expanded graphite (EG) in poly(lactide) (PLA) by using Raman spectroscopy. This technique is more sensitive and therefore fully complementary to more standard dispersion characterization techniques like SEM, TEM and X-ray diffraction. The incorporation of EG into PLA was carried out by a twin-screw micro-extruder. The effects of the dispersion and delamination of EG on the thermal and thermo-mechanical properties of polylactide-EG nanocomposites were investigated. In contrast to the standard techniques, Raman spectroscopy was able to show a partial exfoliation, which could therefore explain the slight improvement of the PLA-EG thermal and thermo-mechanical properties.