A study of the polymerization of styrene by Rayleigh-Brillouin spectroscopy

Abstract

The Rayleigh-Brillouin spectrum has been used to probe the kinetics of the thermal polymerization of styrene. The behaviour of the velocity and attenuation of hypersound in the medium is consistent with frequency-dependent bulk and shear viscosities. The characteristic relaxation times are dependent on the degree of polymerization. The relaxation times continuously increase as the polymerization proceeds. In the initial stages of the experiment the measured sound velocity and absorption coefficients correspond to the zero frequency values, and as the polymerization proceeds these quantities go over to the infinite frequency values.