Ameliorating the comprehensive performance of rigid polyurethane foam insulating materials by green cork for building energy conservation

Biomass-modified polyurethane (PU) foam materials are vital to promote the sustainable development, but the balance between their mechanical strength and thermal insulating ability remains a challenge compared to the petrochemical-based PU foams. Herein, an appropriate amount of cork is introduced to fabricate PU composite foams with good thermal insulating performance and mechanical strength. The added cork could act as a nucleating agent during the foaming process, further tailor the foam structure and enhance their comprehensive performance. The optimal composite foams containing the peak cork usage of 24 % also belong to the high-efficiency insulating materials, with a thermal conductivity of 0.043 W m⁻¹ K⁻¹, a tensile strength of 0.17 MPa, a bending strength of 0.16 MPa, and good impact resistance. This research provides valuable insights for developing the comprehensive PU insulating materials by utilizing eco-friendly cork as substitutes, and offers a reference for highly efficient utilization of biomass resources.