Eco-friendly and facile preparation of chitosan-based biofilms of novel acetoacetylated lignin for antioxidant and UV-shielding properties

The development of eco-friendly, sustainable, biodegradable, and biocompatible green biopolymer composites is becoming increasingly important. In this study, acetoacetylated lignin (ATL) was obtained via an eco-friendly, facile one-step synthesis reaction, and chitosan (CS)-containing ATL films (CSL) were prepared. The chemical structural analysis of ATL confirmed that the acetoacetyl groups were successfully grafted onto kraft lignin (KL). ATL with adequate acetoacetyl groups exhibited enhanced molecular weight and antioxidant and ultraviolet (UV)-shielding properties. In particular, ATL, with a half maximal inhibitory concentration (IC50) of 23.8 mu g center dot mL-1, exhibited superior antioxidant activity than butylated hydroxytoluene (38.3 mu g center dot mL-1) and KL (50.0 mu g center dot mL-1). When ATL was incorporated into the CS solution to prepare biofilms, the antioxidant activity, UV-shielding property, water resistance, and thermal stability of the CSL greatly improved. Notably, the UV-A and UV-B shielding properties of the 2 % CSL were 130 % and 78 % higher than those of the pure CS film, respectively. Therefore, ATL designed with lignin-derived multifunctional properties has potential applications as an antioxidant and UV-shielding bio-additive and shows significant prospects in food packaging and biomedical applications.

Automated summary

The development of eco-friendly, sustainable, biodegradable, and biocompatible green biopolymer composites is of increasing importance. In this study, acetoacetylated lignin (ATL) was successfully synthesized and used to prepare chitosan (CS)-containing films. The ATL showed enhanced antioxidant and UV-shielding properties, and when incorporated into CS, the resulting films exhibited improved properties, including antioxidation, UV shielding, water resistance, and thermal stability.