The Effect of Rheological Properties of Polymer Melt on the Bubble Growth Dynamics of Polystyrene/CO2 Foaming System

Polymeric foams have porous structure composed of two phases: a solid matrix and a gaseous phase. The bubble growth phenomenon as second step in foaming process has an important role in final properties of the foam. So, in present study, the bubble expansion of Polystyrene/CO2 foaming system was modeled and compared to the experimental results. A single spherical bubble surrounded by an incompressible viscoelastic fluid (upper-convected Maxwell model) was considered as polymeric matrix. To calculate concentration profile in the shell, mass diffusion equations were solved. The predicted results showed that as increasing of the viscosity decreases the bubble growth rate. Furthermore, it was demonstrated that the decreasing of the relaxation time, could suppress the bubble expansion. It was depicted that predicted results were in good agreement with the experimental ones

کلیدواژه ها:

Polystyrene Foam ، Bubble Growth Dynamics ، Viscoelastic Fluid ، Mass Transfer ، Supercritical Carbon dioxide