Bj. Kip et al., ORIENTATIONAL ORDER IN POLYETHYLENE FOILS - A POLARIZED RAMAN-SPECTROSCOPIC STUDY, Journal of Raman spectroscopy, 24(8), 1993, pp. 501-510
Polarized Raman spectroscopy was used to determine the order parameter
s of the orientational distribution function for a series of stretched
polyethylene foils with a relatively low degree of molecular orientat
ional order. By combining measurements of the foil under study and of
an isotropic polyethylene foil, simple backscattering experiments are
sufficient to determine the orientation order parameters of the foil w
ith molecular orientation. Practical considerations for obtaining pola
rized Raman spectra are discussed. The results are in good agreement w
ith the order parameters obtained by IR dichroism and wide-angle x-ray
diffraction. Differences between the various methods are discussed. T
he Raman method proves to be a relatively rapid method for obtaining i
nformation concerning the molecular orientation in polyethylene films.