Shear and extensional rheological characterization of poly(acrylonitrile)/halloysite nanocomposite solutions

• Low loadings of HNTs improve the life-time of PAN solution in extensional flow.
• Extensional viscosity of PAN fibers decreases with HNT content at high strain rates.
• CaBER is used to study the spinning behavior of HNT–PAN nanocomposites.

The shear and extensional flow properties of polyacrylonitrile (PAN) solution in the presence of halloysite nanotubes (HNTs) were investigated at an industrially relevant concentration of the polymer. In dynamic shear rheology, the elasticity and relaxation time of PAN solutions and the availability of heterogeneous PAN domains were found to increase with HNT content. Extensional flow behavior of PAN solutions were characterized using the capillary breakup extensional rheometry and increasing the amount of HNT content in the solution was found to increase the life-time of the filament and suppress strain hardening at high strains.

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