Green engineering of polylactic acid/polymyrcene/cellulose nanocrystals films with tunable mechanical and UV-shielding properties for food packaging applications.

In the modern era, polymyrcene, a sustainable polymer made from renewable resources, offers a potential path towards the advancement of green products. Here, we successfully created and characterized the first-ever all-bio-based composite films using cellulose nanocrystals (CNCs) made from agricultural waste, polylactic acid (PLA), and polymyrcene. Environmentally acceptable substitutes for traditional polymer composites have been made possible by incorporating CNCs into the PLA-Polymyrcene matrix, which produced materials with improved structural and functional qualities. The successful integration of CNCs into the polymyrcene matrix was validated by ATR-IR spectroscopy, demonstrating the components' compatibility. The inclusion of CNCs considerably raised the films' crystallinity, demonstrating better packing density and structural order according to X-ray diffraction patterns. At 3 % CNC loading, the tensile strength improved by 3.6 times, from 2.5 MPa for PLA-Polymyrcene films to 9 MPa. The swelling study shows 6 times increment from 3 % to 18 %, and solubility has not been more than 6 %. The films showed excellent UV blocking up to the 300 nm region with good opacity. With the said properties, composite films retain their mechanical strength, shape, and barrier properties over time, leading to an enhanced structural integrity, which is crucial for food packaging, biomedical implants, and agro-film applications.