Review of synthetic polymer-based thermal insulation materials in construction and building

Thermal insulation materials (TIMs) play a crucial role in reducing heat transfer, improving energy efficiency, and reducing carbon emissions. Among the various types of TIMs, synthetic polymer-based thermal insulation materials (SP-TIMs), such as polyethylene, polyimide, polyvinyl chloride, polystyrene, etc., have been extensively used in construction and building because of their extraordinary advantages including low thermal conductivity, high lightness, high flexibility, and high hydrophobicity. Herein, a timely and comprehensive overview of SP-TIMs for thermal insulation is presented. The thermal transport mechanisms in synthetic polymer-based thermal insulation materials are first summarized. Then the three major types of SP-TIMs: thermoplastic polymers, thermosetting polymers, and synthetic rubber, are reviewed systematically. For each type of SP-TIMs, the thermal insulation performance of the selected synthetic polymers is summarized with a focus on the relationship of preparation, assembly method, microstructures, and thermal insulation ability. A resuming table reporting the thermal insulation performance of typical synthetic polymer-based thermal insulation materials is also included in this review. Finally, the future challenges and perspectives including the upcycling of the SP-TIMs are critically discussed. We believe this work can greatly promote the development of synthetic polymerbased thermal-efficient materials.