Polyetherimide nanocomposite with enhanced mechanical, thermal and dielectric properties by incorporating synergistically exfoliated‐chemical functionalization induced hexagonal boron nitride nanosheets

Abstract The present study aims to improve the mechanical, thermal and dielectric properties of polyetherimide (PEI) nanocomposite via simplified method, involving the creation of a nanocomposite using PEI incorporated with exfoliated‐chemical functionalization induced hexagonal boron nitride nanosheets (BNNS). XRD, FTIR and Raman elucidated the chemical structure of functionalized BNNS and indicated the success preparation of functionalized BNNS. Functionalization effectively improved the compatibility of nanocomposites and contributed to the property improvements. Morphological analysis unveiled a compact and dense microstructure within the nanocomposites in correlation with functionalized BNNS. Broad band dielectric spectroscopy revealed excellent dielectric properties of produced PEI nanocomposite. DMA testing verified a noteworthy enhancement in both T g and storage modulus upon incorporating of BNNS. In summary, this comprehensive investigation highlights the impact of functionalized BNNS on mechanical, thermal and dielectric properties of developed PEI dielectric nanocomposite and is expected to expand the application of PEI in the field of high‐temperature energy storage. Highlights Polyetherimide (PEI) was used as polymer matrix and boron nitride derivatives as dielectric fillers to prepare PEI dielectric nanocomposite. Due to the influences of dielectric properties by interface polarization effect and the local distribution of electric field of the fillers in PEI matrix, the dielectric constant, breakdown strength and energy storage density of PEI nanocomposites were obviously improved compared with pure PEI. The effects of interfacial interactions between PBNNS and PEI contributes to the uniform dispersion and comprehensive property improvements of PEI dielectric nanocomposites. This work presents a systematic investigation into the fabrication of PEI/BNNS nanocomposite using a one‐step solution blending method, inspiring the research and development of PEI in the energy storage applications areas in the future.