Advancements in limonene derived polymers: from monomer synthesis to sustainable applications

The increasing demand for green polymers has resulted in a growing search for sustainable raw materials to substitute fossil-based monomers. Among the key biomolecules, (R) (+) limonene is a monoterpene that is widely available and extracted from citrus processing byproducts and has received much attention due to its abundance, low cost, and diverse chemical reactivity. This review sheds light on the latest breakthroughs in the preparation of this terpene and its structural characteristics, selectivity, and polymerization for the production of green polymeric materials. This review focuses on the relationship between molecular structure and chemical reactivity, with emphasis on how the two chemically distinct carbon double bonds enable the preparation of intermediate polymerizable materials via reactions such as epoxidation, acylation, carbonylation, and thiol-ene click reactions. These advances have enabled the preparation of a wide range of bio-based polymers, including polycarbonates, polyurethanes, epoxy resins, photocurable coatings, flexible plastics, and other advanced functional materials. The review also addresses industrial challengesassociated with industrial application, including the availability of raw materials, purification costs, catalyst selectivity, and polymerization control. Finally, it discusses emerging strategies, including eco-friendly extraction methods, chemical catalysis, the use of carbon dioxide, and chemical recyclability, as promising approaches to improving the sustainability and commercial viability of bio-based platform molecule-derived polymers in the context of the circular bioeconomy.In addition to compiling the latest published research, this review provides a critical synthesis that directly links region-selective reactivity and the spatial orientation of the two chemically distinct double bonds in limonene, and the design choices for monomers and initiators to produce expandable polymers of industrial quality.