Preparation and Characterization of Cellulose Acetate Butyrate/Organoclay Nanocomposites Produced by Extrusion

Abstract

Nanocomposite films based on cellulose acetate butyrate, modified montmorillonite (Cloisite ® 30B), plasticizer (triethyl citrate) and antimicrobial compounds (carvacrol and cinnamaldehyde) were prepared by extrusion. The effects of the Cloisite ® 30B content and antimicrobial compound types on the morphology of the nanocomposite films were investigated by X-ray diffraction and transmission electron microscopy. The thermal characteristics of films were analysed by thermogravimetry and differential scanning calorimetry; oxygen and water vapour permeability and tensile strength were determined. The film's antimicrobial behaviour against Listeria innocua, Staphylococcus aureus, Escherichia coli O157:O7 and Saccharomyces cerevisiae was investigated and determined using a viable cell count method. Nanocomposites with a Cloisite ® 30B content of 3 wt% showed better dispersion than nanocomposites with a 5 wt% content. For films with antimicrobial compounds, tensile strength and Young's modulus decreased and water vapour permeability increased (150%) because of the plasticization effect of the antimicrobial compounds (essential oils). The nanocomposites with carvacrol and cinnamaldehyde were effective against the tested Gram-positive bacteria (reduction of at least 3.0 log CFU/ml) and yeast (reduction of at least 4.0 log CFU/ml). This study demonstrates that antimicrobial cinnamaldehyde and carvacrol can be successfully incorporated into cellulose acetate butyrate nanocomposites and that they have an inhibitory effect against microbial growth in solid medium. It shows the potential use of cellulose acetate butyrate for food packaging applications.

Cellulose acetate/AgNPs-organoclay and/or thymol nano-biocomposite films with combined antimicrobial/antioxidant properties for active food packaging use

“…The melting parameters (T m , ΔH m ) and crystallinity grade were also depressed, indicating that Th hindered the CA crystallization. Similar results have been stated for CA and butyrate CAB or other polymer containing Th or other EOs [32,55,56,60,61].…”

“…Indeed, an efficient dispersion of the clay platelets into the polymer matrix may form a tortuous pathway for gas molecules to permeate through the film. Comparable results were observed in nanocomposites of CAB/C30B [55,56] and CA/Cu 2+ -MMt [65] with various clay loadings.…”

“…In agreement with DSC analysis deductions, the addition of Th induced a plasticizing effect that altered the balance of interaction forces in the CA matrix, with a subsequent loss of film cohesion that facilitated chain mobility during film stretching, causing an increase in ductile properties. These common results, attesting that the addition of EOs to polymer films reduced the intermolecular chains interactions and produced materials with lower tensile strength, were broadly discussed in nanocomposites of cellulosic derivatives [32,55,56] and other polysaccharides [22,23,63].…”

“…Overall, both clay and Th additives caused an obvious decrease in the relative intensity of the first hump, indicating an alteration in the intermolecular distance between the CA and TEC. This result may be due to the occurrence of interactions, mostly hydrogen bonds, between the polar groups of pC and those of AgM as well as the hydroxyl groups of Th, which is expected to display the characteristic EOs plasticizing effect [26,27,32,55,56].…”

Organic-Inorganic Hybrid Materials: Layered Double Hydroxides and Cellulose Acetate Films as Phosphate Recovery

“…Cellulose acetate (CA) polymers are thermoplastic materials produced by esterification of cellulose materials such as recycled paper, cotton and wooden cellulose, among others. These materials are used as matrices to obtain a variety of products such as optical film, laminates, textile fibers and coatings for medications and foods [17]. There is a current line of research that evaluates the synthesis and characterization of products (for example, montmorillonite) based on CA and clay minerals [17][18][19][20].…”