Effect of gas-phase tortuosity on the mechanical properties of low-density polyolefin open-cell foams at low- and high-strain rates

This paper describes the mechanical behavior in compression, at both low- and high-strain rates, of several low-density open-cell polyolefin-based foams with different gas phase interconnectivities and different levels of gas-phase tortuosity. The mechanical properties of the open-cell polyolefin foams have been compared with two different references: an open-cell low tortuous foam based on flexible polyurethane and closed-cell polyolefin foams. One the one hand, at low-strain rates, it has been observed that the mechanical performance is controlled by the open-cell content and the properties of the polymeric matrix, being the influence of tortuosity small. On the other hand, the influence of the level of tortuosity is critical to high-strain rates. In fact, it has been demonstrated that open-cell polyolefin foams with high tortuosity (HT) present an unexpected mechanical behavior, showing excellent mechanical properties, which are even similar to that of closed-cell polyolefin materials with the same chemical composition. Therefore, low-density polyolefin foams with HT have a unique mechanical performance strongly influenced by the strain rate. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48468.