Enhancing mechanical properties of polyvinyl alcohol films through cellulose nanocrystals derived from corncob

Abstract

The present study aimed to investigate the influence of incorporating cellulose nanocrystals in a polyvinyl alcohol (PVA) matrix to achieve the enhanced mechanical properties. Cellulose nanocrystals (CNC) were extracted from waste corncob through sulfuric acid hydrolysis. The maximized yield of CNC (41.8%) was observed at the parameters, 65 mass %, 45 ℃, and 60 min for sulfuric acid concentration, reaction temperature, and hydrolysis time, respectively. FTIR showed that CNC had evidence with various functional groups. SEM morphology showed that the prepared CNC had needle-shaped and an average length of 170.3 nm. The crystallinity index characterized by XRD for CNCs (79.3%) was found to be higher than the extracted cellulose (76.4%). In addition, the thermal stability using TGA analysis showed that the degradation temperature of the CNC reached around 327 ℃, which was higher than that of the raw corncob and extracted corncob cellulose. Further, an investigation was performed on PVA/CNC nanocomposite films that were prepared by solution casting technique using different loadings of resultant CNC (2, 4, and 6 mass%) as nanofillers. By doing so, the tensile strength, elongation, and elastic modulus of polyvinyl alcohol films incorporated with CNC nanofillers were found to be improved significantly.