ABSTRACT
This chapter addresses the growth of a bubble due to diffusion of volatile material from the bulk of the liquid and its vaporization into the gasesous phase at the bubble surface. It discusses bubble growth controlled by mass transfer. A crucial stage in the devolatilization process is that of the growth of bubbles containing vapor of the volatile material to be separated from the polymer. Bubble growth is enhanced by large values of FM that is high temperatures, low pressures, and large differences between the concentrations at infinity and at the bubble surface. Bubble growth during devolatilization may be also controlled by the viscosity of the polymer melt, which are typically orders of magnitude higher than that of water. E. J. Barlow and W. E. Langlois derived analytical expressions for the extreme cases of the initial and final stages of bubble growth.
