Flame-Retardant and Degradable Cellulose Micro/Nanofiber Films for Packaging Materials

Abstract

Cellulose, as the main structural component of plant cell walls, has gained widespread applications in many highend fields due to its outstanding physicochemical properties, such as renewability and biodegradability. To reduce reliance on virgin petro-based materials and construct sustainable, high-performance biobased structural materials, biodegradable cellulose materials have emerged as a crucial Frontier in research. However, its poor fire-resistant property strongly limits the practical application of cellulosics in many fields. Here, we design a biodegradable biobased composite film with a three-dimensional network structure by introducing alginate and calcium ions into cellulose micro-and nanofibers. Specially, sodium alginate is introduced into the network of the composite film and subsequently by crosslinking with calcium ions to enhance the flame retardancy of cellulose fibers film and improve the structural integrity of the film. As a result, the limiting oxygen index of NCF/SA-Ca reached 38%, with a reduction of 72.3% in the peak heat release rate. The limiting oxygen index of BCF/SA-Ca reached 35%, with a reduction of 66.6% in peak heat release rate. Furthermore, both materials exhibited a higher residual char in thermogravimetric analysis, indicating excellent flame-retardant properties. Therefore, this flame-retardant and biodegradable cellulose composite film can replace traditional membrane materials and gain wider applications in practical life, such as flame-retardant packaging materials.