Research progress on properties and applications of bio-based polybenzoxazine materials

Under the background of increasing awareness of global environmental protection, traditional petrochemical products have received extensive attention due to non-renewable raw materials and environmental pollution. Especially in the field of thermosetting resins, petroleum-based polybenzoxazine (PBz) has excellent properties but is limited by the non-renewable nature of its raw materials, which brings a heavy burden to the ecological environment. In recent years, bio-based PBz has come into being. As a cutting-edge technology, it not only inherits the excellent performance of traditional petroleum-based similar products but also has significant advantages in raw material sources and green sustainability. In addition, the flexibility of its molecular structure design enables it to play an excellent role in many fields. PBz, as a high-performance thermosetting resin, has an excellent performance in low dielectric properties due to its inherent high crosslinking density and large volume rigid ring structure. In particular, the introduction of organophosphorus compounds and oxygen-containing heterocyclic structures such as furan rings in the molecule can effectively improve the flame retardancy of the material and broaden its application in the field of fire safety. The synthetic raw materials of PBz mainly include phenols and amines. Among them, the phenolic source can be derived from abundant natural resources, such as vanillin, vanillic acid, guaiacol and cardanol; the amine source covers a variety of options such as furfurylamine, stearic amine, octadecylamine and even chitosan. This paper focused on the research progress of bio-based PBz in flame retardant materials, epoxy resin reinforced materials and low dielectric materials in the past five years. The shortcomings of the existing PBz materials were analyzed and the improved methods were proposed. The future research direction of bio-based PBz was prospected.