Wood is a natural growth material that possesses excellent mechanical properties, including high strength, good durability, high moisture content, and high specific gravity. Wood can be classified in two types of wood, softwood and hardwood. While each type is different—e.g., the longitudinal cells in softwood are shorter in length when compared to hardwood—both types have a similar hierarchical structure, meaning the orientation of the cells is identical in the wood. This unique anisotropic structure, the properties with distinctive values when measured in several directions, allows it to pump ions and water for photosynthesis in the wood. Similarly, in transparent wood composites, removing the lignin and maintaining the cellulose fiber tubes it allows it to become a clear wood that can get soaked in a glue-like epoxy that makes it a robust and transparent material. An excellent raw material with high transmittance and enhanced mechanical properties.
Researchers have successfully tested an eco-friendly alternative: limonene acrylate, a monomer made from limonene, into an acrylate. Limonene is a common cyclic terpene that can be extracted from industrial waste, via isomerization of α‐pinene (from wood) or from citrus peel oil. The bio-based polymers can offer advantages compared to conventional non‐renewable polymers from fossil resources, and still retain a high mechanical performance and it is lightweight, stemming from its porous and anisotropic cellulosic structure; and is of great interest for large-scale sustainable nanotechnologies. Succinylation of the delignified wood substrate using succinic anhydride results in a nanostructured and mechanically strong biocomposite. The polymer matrix usually accounts for ≈70 vol%, results in nanostructured biocomposites combining an excellent optical transmittance of 90% at 1.2 mm thickness and a remarkably low haze of 30%, with a high mechanical performance (strength 174 MPa, Young's modulus 17 GPa).