The effects of bubble behavior were investigated for two polymers, polymethylmethacrylate (PMMA) and polypropylene (PP), in spheres of diameter 0.3 cm. Input parameters for this model are shown in Table 1. Values were obtained where available from the Polymer Handbook [52]. For this study of bubble effects on a pyrolysis model, material properties are considered constant in time and space, with the exception of polymer viscosity. The variation of polymer viscosity with temperature is determined by the WLF model [53]:
|
| (67) |
Table 1: Nominal parameter values for polypropylene (PP) and polymethylmethacrylate (PMMA).
