phonon dispersion

A study of vibrational dynamics of poly (a-n-butyl-b-l-aspartate) (panbla)

Poly(-N-butyl--L-aspartate) (PANBLA) is nylon-3 derivative in which an alcoxycarbonyl group has been stereoregularly attached to -carbon of the repeating unit. Like poly(-isobutyl--L-aspartate) (PAIBLA) exists in two helical forms, namely hexagonal form (13/4 helix) and tetragonal form (4/1 helix), were characterized by X-ray diffraction. The hexagonal form appears to be poorly crystalline and it could not be obtained well oriented. On the other hand tetragonal form turns to be highly crystalline.