Development and characterization of nanosoy‐reinforced dextran nanocomposite membranes

Crosslinked nanocomposite membranes were developed by in situ reaction of dextran and soy protein isolate nanoparticles (nanosoy). The formation of a covalent bond between the reducing end of dextran and the amine groups of nanosoy (NS) leads to the in situ crosslinking. The NS particles employed for this study were 5–15 nm in size, as observed in the high‐resolution transmission electron microscopy micrograph. Glycerol addition assisted in the plasticization of the membranes, thus improving their flexibility and handling features. The effect of polymer composition on the extent of crosslinking, morphology, and flexibility of the films was investigated. Field emission scanning electron microscopy and atomic force microscopy revealed that single‐phase, homogeneous membranes are obtained within a specific composition of dextran/NS/glycerol (D/NS/G). The degree of crosslinking was evaluated by Raman spectroscopy and gel content measurements. The crystallinity of the D/NS/G membranes was found to increase monotonically as the NS content in the blend increased. An increase in tensile strength and decrease in Young's modulus was observed with an increase in NS content up to 28%, due to the reinforcing effect of NS and the plasticizing effect of glycerol playing roles simultaneously in the system. The reinforcing effect of the NS assisted in the formation of high‐strength nanocomposite membranes. Furthermore, they were characterized to analyze their thermal behavior. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44655.