A REFINED APPROACH TO BUBBLE NUCLEATION AND POLYMER FOAMING PROCESS -DISSOLVED-GAS AND CLUSTER-SIZE EFFECTS

A refined approach to bubble nucleation is presented and applied to po lymer foaming process, The integral overall energy balance and the int egral Clausius-Duhem inequality are used to analyze a bubble nucleatio n experiment. The computation of long-range intermolecular potential r esults in expressions for surface tension, work, and critical work for cluster formation, as functions of the Hamaker constant, molecular an d/or repeat unit interaction distance, molar fractions of each compone nt, and cluster radius, The variation of surface tension with cluster size, temperature, and pressure is determined in terms of well-known m acroscopic properties and compared with available experimental data. ( C) 1996 Academic Press, Inc.