A convenient method to determine the Rayleigh ratio with uniform polystyrene oligomers

The Rayleigh ratio of toluene at 25°C for a wavelength of 632.8 nm was determined by static light scattering measurement of a certified polystyrene reference material PS 2400 with exactly evaluated or certified mass-average molecular mass (Mw). At first, static light scattering measurements were carried out for PS 2400 in toluene with a literature value of the Rayleigh ratio of toluene. Then, corrections of degree of depolarization, density fluctuations, and molecular mass dependence of refractive index increment were applied to the observed Mw of PS 2400 to obtain apparent Mw. Finally, from the ratio between the apparent Mw and the certified Mw, the Rayleigh ratio of toluene was reevaluated. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99:1953–1959, 2006