• • Hyperbranched polyimides with tailored dianhydride monomers and branching degrees achieve tunable dielectric constants, directly correlating with chain packing density of polar groups, enabling precise molecular-level design for energy storage applications.
• • Molecular simulation reveals that increased packing density of polar functionalities enhances dielectric constant by optimizing dipole alignment, providing a predictive tool for material design without extensive trial-and-error synthesis.
• • The study addresses limitations of filler-based composites by achieving property enhancement through intrinsic molecular structure, avoiding batch-to-batch inconsistency and mechanical/thermal deterioration, thus improving reliability for high-temperature film capacitors.
• • Experimental results show a significant correlation between monomer electrical distribution and packing density, offering a quantitative framework to guide synthesis of hyperbranched polyimides with targeted dielectric performance.