Raman spectroscopy study of poly(trimethylene terephthalate) crystallization

Raman spectroscopy was used to study the crystalline states of poly(trimethylene terephthalate) (PTT). There were significant spectral differences between the PTT melt and the crystallized PTT. The 909 cm(-1) band, associated with the C-C stretching of the trimethylene glycol residue, was found to be a suitable band for quantitative measurements of PTT crystallinity. Both the 847 and 1176 cm(-1) benzene ring breathing modes could be used as the internal reference bands, however, the use of the 1176 cm(-1) band was more sensitive to crystallinity changes. Two other C-C glycol residue stretching bands, 1116 and 1103 cm(-1), were found to relate to the crystalline and amorphous phases, respectively, from annealing experiment.