Extensional Viscosity of Immiscible Polymer Multi-Nanolayer Films: Signature of the Interphase

The measurement of interfacial mechanical or rheological properties in polymer blends is a challenging task, as well providing quantitative link between these and the nanostructure. Here, we perform systematic study extensional rheology multilayer films an immiscible pair, polystyrene poly(methyl methacrylate). We take advantage multi-nanolayer coextrusion to increase number interfaces up thousands, consequently magnifying response films. transient elongational compared additivity rule model based on summation contribution each one. At low strain rates, reproduces viscosity strain-thinning, while at larger extra stress exceeds prediction constant tension. This attributed interphase modulus order 1–10 MPa, which increases with rate following power law exponent 1/3. then efficient combination go beyond tension quantitatively measure blends.