Preparation of low-temperature-resistant and high-toughness bio-based polyamides and the application of their microcellular foams in the field of thermal insulation

Lightweight, friction-resistant polyamide foam with exceptional mechanical properties represents a novel material with significant potential. In this study, we synthesized a series of high-toughness, bio-based polyamide materials characterized by low melting points, extensive processing temperature ranges, and robust low-temperature resistance. This was achieved through the copolymerization of bio-based components, including glutaraldehyde, sebacic acid, and caprolactam. Subsequent foaming using supercritical CO 2 was performed, substantially reducing foaming conditions and broadening the foaming range. Optimal foaming conditions were simulated, resulting in the production of various polyamide foams with differing foaming multiplicities, all exhibiting impressive tensile strength, compressive strength, low-temperature resistance, and friction resistance. Additionally, this study simulated the thermal insulation performance of polyamide foams across a wide array of practical working conditions. The results demonstrated that these foams possess low thermal conductivity and excel in actual thermal insulation performance. Therefore, they present significant promise as energy-saving and environmentally friendly materials in applications such as building thermal insulation, electrical insulation, and protective systems. As a sustainable solution, these bio-based polyamide foams hold great potential for advancing energy efficiency in construction, thermal management of electrical appliances, and protective applications.