through conformational rearrangements, hence the extrudate swelling results. With increasing wall shear stress, the shear deformational energy stored in the molecules also increases, leading to a corresponding increase in the swelling of an extrudate. At a given wall shear stress, the discrepancy in the property values of the iPP melt and the melts that had been filled with CYU203 at different loadings was comparatively the least.