Evaluation of physicochemical, thermomechanical, and structural properties of chickpea flour composite films reinforced with crystalline nanocellulose

Abstract

ABSTRACTChickpea flour–crystalline nano‐cellulose (CNC) composite films were prepared using chickpea flour as the film forming material, glycerol as the plasticizer and 2.5 to 10% CNC as reinforcement supplement. Mechanical properties of the composite films increased with an increase in the CNC content up to 5%. By inclusion of CNC up to 10%, the storage modulus of chickpea flour matrix increased by an order of magnitude from 7.3 to 86.4 MPa. The storage modulus of all samples, on the other hand, decreased as temperature increased. The Tg values measured by dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) were shifted toward higher temperatures by the addition of CNC. The creep resistance of chickpea flour films increased again up to 5% added CNC, and strain sweep tests confirmed the extension of linear viscoelastic region. X‐ ray diffraction (XRD) confirmed a positive correlation between the degree of crystallinity of chickpea flour composties and CNC content. FTIR spectroscopy confirmed the molecular interaction between chickpea flour, glycerol and CNC. SEM results revealed agglomeration in the structure of the film with the addition of CNC beyond 5% and diminishing of surface homogeneity, while decreasing the pore size of chickpea flour matrix. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48389.