Abstract
The analysis of the effect of the temperature history on the morphology, and the shear relaxation behavior of two commercial PA6 material (BS400N, and NS4A1) is presented. The material was first brought into the molten state and then solidified along the two distinct temperature histories, simulating the conditions during the manufacturing process, such as injection molding, or extrusion. Morphological analysis, using the optical microscope with polarized light, revealed significantly different structure in the two groups of specimens. The shear relaxation experiments, performed at six different temperatures, were used to characterize the mechanical properties of these specimens. The time-temperature superposition principle was used to construct the master curves, which determine the long/time behavior of the materials. Comparison of the master curves showed that the mechanical properties of PA may vary, depending on temperature history during the manufacturing, close to 80% in strength, and more than 1000 times in long-time behavior!
