Dynamic mechanical properties of VAMAS polycarbonate/polyethylene blends

As part of the Versailles Project on Advanced Materials and Standards Technical Working Party on Polymer Blends, the dynamic mechanical properties of polycarbonate/linear low density polyethylene (PC/LLDPE) blends were measured. Ten laboratories participated in the round robin tests. As a whole, the inter‐laboratory agreement of data is good, particularly when results are obtained using the same apparatus (especially a Rheovibrom DDV‐III EA). The results clearly show the nonmiscibility of the parent components. The influence of frequency is also obvious but difficult to characterize because of the narrowness of the frequency range explored. The Takayanagi model applies very well for the calculation of the storage moduli as a function of composition and morphology. The most specific result is probably that of the processing orientation effect: There is no visible influence of flow orientation on dynamic tensile moduli of the parent polymers, but there is a significant difference in the moduli measured in the direction of extrusion and in the transverse direction for the blends at temperatures above 0°C. The difference is greatest for the high PE‐concentration blend.