Raman spectra of polyethylene glycol/cellulose acetate butyrate biopolymer blend

Abstract

In order to investigate their crystalline structure conformations, several ratio combinations of polyethelene glycol (PEG)/cellulose acetate butyrate (CAB) were studied by Raman spectroscopy. PEG/CAB spectral features due to the composition dependence revealed the gradual transformation from crystalline PEG-like structure to the amorphous CAB-like structure as increasing the ratio of CAB. Bands appeared in the C-H stretching area of 3000- 2700 cm-1 and C-H bending area of 1500-1400 cm-1 clearly exposed the transition of the PEG to the CAB-spectral features with the transition point at about PEG/CAB (30/70). Band at 1737 cm-1 in the C=O stretching area of 1800-1650 cm-1 described the existence of a very weak hydrogen bond arise between PEG and CAB. In the C-O-C area of 1000-800 cm-1, drastic spectral change suggested that the hydrogen bond interaction takes place in the back bone of PEG.