Poly(limonene): A novel renewable oligomeric antioxidant and UV-light blocking additive for chitosan-based films

Limonene is a well-known bioactive additive for biopolymer-based films. However, its high volatility considerably limits such applications. Herein, we propose the use of a low molecular weight poly(limonene) (PLM) as an alternative high-performance additive for chitosan-based (CH) films. Effects of different concentrations (0.15-0.45 % w/w) of PLM on the properties of CH films were systematically evaluated. Overall, films with impressive antioxidant activity and UV light barrier were easily obtained, even at reduced PLM loads. Among the concentrations explored, there was a reduction in the film's tensile strength from 23.73 to 12.08 MPa, when the maximum concentration of PLM (0.45 %) was used. However, the elongation at break did not change significantly for any sample. Additionally, the water vapor transmission rate decreased from approximately 547 to 412 g m(-2) day(-1). Therefore, PLM demonstrates the potential to appear as a novel high-stability additive for active bio-based film development serving food packaging.