Bio-nanocomposite foams of starch reinforced with bacterial nanocellulose fibers
Sunan Tacha, Kedmanee Somord, Phattharasaya Rattanawongkun, Uraiwan Intatha, Nattaya Tawichai, Nattakan Soykeabkaew
Abstract
In this study, the bio-nanocomposite foams of cassava starch incorporated with nanocellulose fibers (NCF) produced by bacteria were prepared by microwave processing. The effect of NCF adding content of 0.25–2.0 wt% on the morphology, structure, mechanical properties as well as water resistant properties of the starch/NCF nanocomposite foams was examined. The cellular structure of starch-based foams essentially changed by the addition of NCF, owing to its nucleating effect. The number of cells in the foam structures was found to increase dramatically with the cell size decreased (but more uniform) and the cell wall thickness increased (as confirmed by SEM). From the flexural tests, the strength and modulus of these nanocomposite foams were markedly improved (2 to 3-fold increase). At the optimum NCF loading content of 1.0 wt%, the flexural strength and modulus of this nanocomposite foam were raised to 7.71 MPa and 448 MPa, respectively. The water resistance of the current starch/NCF nanocomposite foams were also noticeably improved. The results in this study demonstrate another promising greener technology to produce a sustainable foam material for our planet with enhanced performance.