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

Abstract

ABSTRACTThis 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.