Chitosan/clay films' properties as affected by biopolymer and clay micro/nanoparticles' concentrations

Abstract

Blends of chitosan (from Cuban lobster) and clay micro/nanoparticles were prepared by dispersion of the clay particles in the film matrix and the films obtained were characterized in terms of water solubility, water vapor, oxygen and carbon dioxide permeability, optical, mechanical and thermal properties using an Instron universal testing machine, differential scanning calorimetry, thermogravimetric analyses and scanning electron microscopy (SEM). The water vapor barrier properties of the films were significantly improved by incorporation of clay in their composition, while the water solubility decreased as the clay concentration increased (for a constant chitosan concentration). The tensile strength of chitosan/clay films increased significantly with increasing chitosan and clay concentrations, while the values of elongation decreased slightly for high values of chitosan concentration. T m increased with the increase of chitosan concentration, but the changes in T m with the addition of clay were not significant. Polynomial models were fitted to the experimental data in order to facilitate future design of chitosan/ clay film systems.

Preparation and characterization of bionanocomposite films reinforced with nano kaolin

“…Such phenomena of reduction in WVP with the incorporation of nanoclays have frequently been observed with different biopolymers, such as chitosan (Casariego et al 2009;Rhim et al 2006). (CMC)/starch (ST) (El Miri et al 2015).…”

“…The same effect has been reported by other authors (Rhim 2011;Almasi et al 2010) with nanoclay added to films composed of agar, chitosan, and cotton-carboxymethylcellulose. This effect is mainly due to the formation of strong interaction through hydrogen bonds between the hydroxyl groups of the biopolymer matrix and nanoclays with high surface area, thereby improving the cohesiveness of the biopolymer matrix and decreasing the water sensitivity (Casariego et al 2009). …”

Facile Preparation of Biocomposite from Prawn Shell Derived Chitosan and Kaolinite-Rich Locally Available Clay

“…The DSC thermogram of composites within the temperature range of 50 to 400 ∘ C at a heating rate of 10 ∘ C/min is shown in Figure 7. A very slight endothermic peak at temperature 40-45 ∘ C indicated the solvent evaporation that was present in very small quantity [29,33]. The sharp exothermic peak was observed at 302-307 ∘ C for different composite as shown in Table 3.…”

“…Figure 8 indicates that the clay particles were dispersed throughout the chitosan matrix. However, the micrographs revealed that the SB-1 possessed a more uniform and smooth surface than SB-5 [33]. From visual analysis of SEM images, it can be seen that with the increase in the amount of clay in the composite the surface becomes very rough.…”

“…As the SB-5 consisted of the highest amount of clay, its surface became rougher compared to SB-1. Nevertheless, it is necessary to continue working in this aspect, by means of applying other techniques such as AFM (Atomic Force Microscopy), which could allow the complete identification of intercalation or exfoliation of clay as well as determination of the degree of interaction between the particles of clay and chitosan [33].…”