Structuring polymer blends with bicontinuous phase morphology. Part II. Tailoring blends with ultralow critical volume fraction

A hypothesis providing a guideline for the development of immiscible polymer blends with co-continuous phase structure at very low critical volume fraction of one component is postulated and experimentally verified. Based on a number of simplifying assumptions the following relation was derived: φcr=k(λγ̇)1−z/(θb∗)z where λγ̇ is a Deborah number and θb∗ is a dimensionless break-up time. The equation parameters, k and z are constant that depend on the flow field hence on the blending equipment. For the studies an internal mixer with Walzenkneter-type 30 mixing shafts was used. For this equipment the experimental values of the equation parameters, k=1801 and z=2.01, were found.