Cardanol Benzoxazines: A Versatile Monomer with Advancing Applications

Abstract

Polybenzoxazines are evolving as a new class of phenolic resins with a tremendous amount of applications. The ease of structural designing, synthetic procedure, and polymerization reactions are attractive to affect their properties ensuing as an effective substitute for many existing polymers. The nonrenewable origin, toxicity, and increasing cost of petro‐based raw materials are alarming issues. Therefore, the emergence of sustainable benzoxazines, especially based on naturally abundant, agro‐waste origin cardanol is encouraging as it allows both solventless synthesis of monomers and processing to form highly thermally stable thermoset resins. The inherent functionalities in cardanol benzoxazine provide a platform for further structural modifications to advance their applications as adhesives, composites, and energy storage devices.

A cardanol-based polybenzoxazine vitrimer: recycling, reshaping and reversible adhesion

“…6 In addition, the versatility of their chemical design is a great platform for the use of renewable feedstock. 14,15 Cardanol, [16][17][18] vanillin, 19,20 and many other bio-phenols 21,22 have been used with success to create bio-based polybenzoxazines. However, like other thermosets, polybenzoxazines lack both recyclability and (re) processability.…”

Development of Prosopis juliflora carbon-reinforced PET bottle waste-based epoxy-blended bio-phenolic benzoxazine composites for advanced applications

“…9 Benzoxazine materials are known for their high temperature applications; they can be easily synthesized through ring-opening of cyclic benzoxazine monomers by a heat treatment process in the absence of any catalysts. 10 Polybenzoxazines nd a wide range of applications, viz., composite materials, 11 construction, 12 aerospace, 13 printed circuit boards, 14 brake pad adhesives, 15 packaging in the microelectronics industry, 16 co-curing agents, 17 and re retardants. 18 Further, the synthesized phenolic resins are resistant to solvents, moisture, heat and electrical conductance; they also have a variety of properties with a wide range of applications.…”

Low melting point, high thermal stable branched benzoxazines resin derived from mixed-substituted phosphazene core

“…Water was also used as a processing aid for benzoxazine composite preparation, but before curing, water still need to be removed from the system [33]. Another approach to lower the melting point of benzoxazine resin is introducing flexible chain [36][37][38] or functional group [39] into benzoxazine structure, but the improvement of processability is obtained at the sacrifice of the mechanical and thermal properties to some extent. Hence design and preparation of benzoxazine monomer with a low melting point but without decreasing its properties is a current challenge.…”