Preparation and microcellular foaming of crosslinked polyethylene-octene elastomer by ionic modification

Polyethylene-octene elastomer (POE) has the advantages associated with thermoplastics and rubbers, and is therefore widely used in various fields. To achieve better performance, zinc oxide (ZnO) and stearic acid were introduced into maleic anhydride-grafted POE to create ionically crosslinked structures. Owing to these crosslinked structures, the tensile strength and creep resistance of POE were improved. After crosslinking, the viscoelastic properties of the polymer matrix were enhanced, thus stabilizing the cellular structure of the foams prepared by supercritical CO₂ foaming. When the foaming condition was 8 MPa and 55 °C, the cell size of the POE-10ZnO foam was reduced from 50 µm to 23 µm, and the cell density was improved by approximately an order of magnitude higher than that of neat POE foam. The cyclic resilience of the foams was also investigated. The results showed that the POE-10ZnO foam exhibited good rebound resilience and high compressive strength.