Ultra-expanded microcellular shape memory polymer foams via supercritical foaming for recyclable oil absorption and improved thermal insulation

Abstract

Shape memory foams (SMFs) have garnered significant attention as smart, sustainable solutions for diverse applications, including environmental remediation and thermal insulation. However, their practical utility has often been constrained by limited expansion ratios resulted poor porosity, which hinder performance in key areas such as oil absorption and heat retention. In this study, we report the fabrication of ultralight SMFs based on the environmentally friendly supercritical foaming method. The exceptional miscibility of the polymer blends, validated by molecular dynamics analysis and thermo behaviors, enables the formation of foams with an extraordinarily high expansion ratio. This process yields microcellular structures with an ultralow density of 0.0265 g cm−3, significantly enhancing both the porosity and surface area of the material. The high expansion ratio directly translates to superior oil absorption capacity, as the increased pore volume and interconnected microstructure facilitate rapid uptake and retention of oils. Simultaneously, the expanded cellular architecture imparts outstanding thermal insulation properties, effectively minimizing heat transfer and energy loss. The excellent shape memory behavior and recyclability, further underscoring their potential for sustainable applications. This research introduces a robust and eco-friendly strategy for producing high-performance SMFs with unprecedented expansion ratios, offering a versatile approach for environmental protection and energy conservation. Graphical abstract: [Figure not available: see fulltext.]