A facile method to fabricate sustainable bamboo ethanol lignin/carboxymethylcellulose films with efficient anti-ultraviolet and insulation properties

Given the environmental concerns related to the non-degradability of conventional petroleum-based polymer films, the synthesis of biodegradable films utilizing natural polymers derived from biomass has emerged as a promising alternative, garnering significant attention in recent research endeavors. This research introduced an environmentally friendly and efficient method, utilizing extract liquid from the green ethanol pulping process as the solvent to completely dissolve carboxymethylcellulose into the film-forming liquid, and employing the solution pouring technique to successfully fabricate bamboo ethanol lignin/carboxymethylcellulose films (LCF). The findings revealed that the lignin content significantly influenced the LCF, endowing them with tunable mechanical properties, effective UV-blocking, and thermal insulation capabilities. With a lignin addition of 3.75 %, LCF-3.75 exhibited enhanced mechanical properties, characterized by a tensile strength of 19.4 MPa, along with superior UV-blocking efficiency, blocking 100 % of UVB and 99.81 % of UVA rays. Furthermore, relative to LCF-0, LCF-3.75 had been shown to possess enhanced hydrophobicity and thermal stability, culminating in the development of the composite films that showcased exceptional thermal insulation properties and biodegradability. The films not only harbored extensive application prospects as an anti-ultraviolet and heat-insulating glass films but also represented a potential avenue for the efficient utilization of lignin, thereby contributing to sustainable development.