Vibrational analysis of poly(L‐lactic acid)

The Raman and IR spectra of poly( L ‐lactic acid) in the amorphous and semicrystalline states were recorded from 3600 to 100 cm −1 . Complete vibrational assignments are proposed. In the Raman spectra, the splittings of the v C=O stretching and the δCCO bend are characteristic of the crystalline phase and the presence of the two lines at 923 and 520 cm −1 indicates a 10 3 helical conformation.