Effect of glycerol, nanoclay and graphene oxide on physicochemical properties of biodegradable nanocellulose plastic sourced from banana pseudo-stem

Banana pseudo-stems, as agricultural waste, are a potential source of ecofriendly nanocellulose-based biodegradable plastic. In this research, effect of glycerol as a plasticiser and nanoclay (NC), and graphene oxide (GO) as nanofillers on the banana pseudo-stem nanocellulose film mechanical, morphological, chemical, thermal, and barrier properties were studied extensively. NC and GO were found to be able to improve the tensile strength of the films but not their elasticity. These nano-fillers also increased the contact angle of the films. On the other hand, glycerol, which acted as a plasticiser, increased the elasticity of the films, but reduced the thermal stability, tensile strength, and contact angle. Synergetic effects were observed when nanofillers and glycerol were combined; both tensile strength and elasticity were improved and the contact angle of the films was significantly higher than films that only contained nanofillers. Concentration of plasticiser had significant effect on the film barrier properties. The water vapor permeability was positively correlated to the glycerol concentration. In contrast, oxygen permeability decreased as increase in glycerol concentration. These results strongly indicate that the properties of the banana pseudo-stem nanocellulose film could be engineered by modifying the type and concentration of added additives. This finding also provides fundamental knowledge and strategy options to further improve nanocellulose based bioplastic.