High-efficiency flame-retardant microcapsules: A review

Flame-retardant microcapsule technology serves as a key pathway to overcome the application limitations of traditional flame-retardants, enhance material safety performance, and advance fire safety across multiple sectors. This paper systematically reviews the research progress of flame-retardant microcapsules, covering their design principles, structure-performance regulation mechanisms, preparation methods, and application fields. Aiming at the limitations of traditional flame-retardant technologies in terms of compatibility, stability, and efficiency, it focuses on expounding the advantages of the microencapsulation strategy in improving compatibility, enhancing stability, and increasing flame-retardant efficiency, and analyzes and discusses the design principles of core materials and shell materials, the influence of microstructure on performance, as well as the characteristics and applicable scenarios of mainstream preparation methods. Meanwhile, it summarizes the application achievements of this technology in multiple fields, discusses the current challenges, such as the balance between high load and mechanical properties, environmental stability, and industrialization cost, and points out the core bottlenecks, including insufficient material compatibility, single function, and immature green preparation process. And looks forward to the key development directions in the future, including more accurate design of microcapsule structure and performance, integrated integration of multiple functions, and green preparation paths of bio-based shell materials and halogen-free flame-retardant core materials. Through systematic discussion from design principles to industrial application of flame-retardant microcapsules, this paper provides a theoretical basis and technical reference for structural optimization, performance improvement, and industrialization advancement of high-performance flame-retardant microcapsules.