Porous polyimide films with low dielectric constant prepared by integrated strategy containing construction of pore structure and crosslinking network engineering

Porous polyimide films have garnered significant attention for low-dielectric applications. However, most existing porous polyimide films exhibit poor mechanical properties and high water adsorption. In this study, we propose an integrated approach that combines pore structure design with crosslinking network engineering to fabricate crosslinked porous polyimide films (CL-PFPIs). The cross-linked network structure effectively reduces the dielectric constant while simultaneously improving mechanical strength and water resistance. The performance and porosity of the CL-PFPIs can be finely tuned. Notably, the CL-PFPI-30 variant demonstrates outstanding overall performance, including a low dielectric constant of 2.08, a low dielectric loss of 0.0067, a low water adsorption of 1.03%, and a high tensile strength of 79.1 MPa, making it a promising fcandidate or low-dielectric applications. • Porous crosslinked polyimide (CL-PFPI) films were prepared by an integrated strategy. • CL-PFPI films have tunable porosity and dielectric properties. • CL-PFPI films show low dielectric constant and good mechanical properties.