Bioinspired multilayer multiscale architectures into PDMS for simultaneously enhancing the thermal conductivity and flame retardancy

Combing high thermal conductivity and excellent flame retardancy is crucial for the development of thermal management composites. Herein, we report a bioinspired multilayer multiscale architecture comprising nanoscale MXene as the protective layer 1, atomic Cu2+ coordination molecular scale dendritic PEI as the protective layer 2 and encapsulated flammable PDMS as a matrix. Upon exposure to flame, the two layers can hinder polymer combustion, wherein MXene nanosheets and PEI-Cu serve as a barrier and thermally conductive layers, as well as catalytic and adsorption layers, respectively. As a result, the as-prepared PDMS composites exhibit a high out-of-plane thermal conductivity of ∼0.60 W m−1k−1, a reduced heat release rate and extremely low smoke (CO and CO2) generation at low filler loadings, suggesting excellent smoke suppression and toxicity reduction. This study provides a new strategy for the development of polymer composites with high thermal management capabilities and excellent flame retardancy.