Cellulose nanofiber-protein composite

Abstract

Cellulose and protein are the two most abundant naturally occurring polymers. Both polymers are renewable and biodegradable. The exploration of various applications of these two polymers is vital to sustaining development of our society as far as the environment and resource are concerned. Due to the strong mechanical strength and modulus and high aspect ratio, nanocellulose in the form of a nanowhisker and nanofiber has been extensively studied as reinforcing fibers. The nanocellulose/protein composite has been attracted much research attention to make fully biodegradable materials. The good chemical structure compatibility of the cellulose fiber and the protein matrix imparts strong inter-facial interaction and hence resulting in great improvement of mechanical properties. Another unique property of the protein composite films reinforced with nanocellulose of <500 nm in diameter is the high optical transparency even though the fiber content is as much as 30 wt%. Because of the superhigh length- to-diameter ratio of nanocellulose, cellulose nanofibers or whiskers and protein matrix readily form an interpenetrating network (IPN) alike composite material. Such a structure enhances the thermal stability and barrier properties and reduces the moisture absorption and water swelling ratio of the nanocellulose/protein composite materials.