The authors have an ongoing research interest in the application of Fourier transform infrared spectroscopy to the study of compatible polymer blend systems and, in particular, the role of intermolecular interactions in compatibilization. It was considered essential to obtain an independent measurement of the lower critical solution temperature (LCST) of the particular polymer blends used in our studies. Not having conventional light scattering equipment, it was decided to attempt to use our Raman spectrometer for these purposes. In this communication we describe the simple method employed and present preliminary results from three polymer blend systems. The results exceeded our expectations. The onset of phase separation is obvious, and the experimentally determined LCSTs are in accord with previously published data.
M. M. Coleman, D. J. Skrovanek, and P. C. Painter, "A Simple Method for Determining the Lower Critical Solution Temperature of Polymer Blends Using a Raman Spectrometer," Appl. Spectrosc. 38, 448-450 (1984)