(Photo : Wikimedia Commons) Researchers at KTH's Wallenberg Wood Science Centre used fossil-based polymers in earlier models of the composite. The researchers have now successfully tested an environmentally safe alternative: limonene acrylate, a limonene-derived monomer. They published their findings in the journal Advanced Science. "The current limonene acrylate is made from organic citruses, such as peel waste from the orange juice industry," says Céline Montanari, lead author and Ph.D. student. The polymer that restores the strength of delignified wood while allowing light to pass through is made from an extract from orange juice processing. According to the researchers, the modern composite has a 90 percent optical transmittance at 1.2 mm thickness and a 30 percent haze. Unlike other translucent wood composites produced in the last five years, the material manufactured at KTH is intended for structural use. With a power of 174 MPa (25.2 ksi) and an elasticity of 17 GPa, it demonstrates heavy-duty mechanical efficiency (or about 2.5 Mpsi).