A Simple Way to Control Small-Strain Cavitation in Die-Drawn Isotactic Polypropylene

Abstract

Increasing attention has been focused on smallstrain cavitation behavior of semicrystalline materials, due to the increased need of porous films with low cost and advanced chemical stability. The control of cavitation is crucial to the properties of the final product as well as the fabrication process. In this work, we proposed a simple way to regulate small-strain cavitation of isotactic polypropylene (iPP) samples via modifying the fraction of lamellae with their normal perpendicular to the stretching direction by stretching at 125 °C. Deformation at 125 °C could effectively reduce the fraction and the long period of those perpendicular lamellae in the iPP system without inducing smallstrain cavitation. When successively deformed at 50 °C, the modified samples exhibited weaker ability to initiate small-strain cavitation as determined by the USAXS techniques.

Specific deformation behavior of isotactic polypropylene films under a multiaxial stress field

“…2 Since cavitation can lighten materials and improve impact resistance, investigations of cavitation distributions in porous isotactic polypropylene ( it PP) films have been performed based on X-ray scattering and diffraction to control the mechanical properties. 3–5…”

“…2 Since cavitation can lighten materials and improve impact resistance, investigations of cavitation distributions in porous isotactic polypropylene (it PP) films have been performed based on X-ray scattering and diffraction to control the mechanical properties. [3][4][5] Uniaxial stretching deformation is one of the most prevalent mechanical deformation methods used to evaluate the mechanical properties of polymers. This is because the measurement can be performed simply, and the instrument is commercially available.…”