Rheological behavior of semi-aromatic transparent polyamide

The rheological behaviors of semi-aromatic transparent polyamide (SATPA) melt are investigated using a capillary rheometer. The effects of shear rate, shear stress, and temperature on the apparent viscosity (eta)a of SATPA are discussed. A correlation of non-Newtonian index with temperature is obtained. The results show the shear thinning of SATPA; meanwhile (eta)a decreases with increasing temperature and shear rate, and the viscous flow activation energy is further obtained from temperature dependence of the samples. It was concluded that the apparent viscosity (eta)a is sensitive to temperature at lower shear rate owing to the higher viscous flow activation energy; on the contrary, the influence of temperature effect on the apparent viscosity becomes minor at higher shear rate due to the lower viscous flow activation energy.