Starch-Polyvinyl Alcohol-Based Films Reinforced with Chitosan Nanoparticles: Physical, Mechanical, Structural, Thermal and Antimicrobial Properties

Abstract

The main purpose of the current study was to propose innovative composite films based on a corn starch/polyvinyl alcohol (PVA) blend (starch:PVA 40:60) and loaded with 3 different levels of chitosan nanoparticles (CNPs) (1, 3, and 5% w/v) to strengthen its physical, mechanical, structural, thermal and antimicrobial attributes. The synthesized CNPs were spherical with a particle size of ca. 100 nm as demonstrated by scanning electron microscopy (SEM) micrographs and dynamic light scattering tests. The results showed that the CNPs incorporation within the starch-PVA 40:60 films promoted a uniform surface without any considerable pores. These films were characterized by a homogeneous CNP distribution within the polymer matrix, causing a significant decrease in water vapor permeability (WVP) (e.g., from 0.41 for the control film to 0.28 g.mm/kPa.h·m2 for the composite film loaded with 5% CNPs). The film solubility, transparency, glass transition and melting temperatures, and elongation at break were also reduced by increasing the CNP content from 1% to 5%, while total color and tensile strength parameters increased. The antibacterial effects of CNPs were more effective against Gram-positive bacteria (Staphylococcus aureus) than Gram-negative bacteria (Escherichia coli and Salmonella typhimurium). It can be concluded that the addition of CNPs to the starch-PVA matrix could improve its functional and technological attributes for food packaging applications.

Tuning the Physicochemical, Structural, and Antimicrobial Attributes of Whey-Based Poly (L-Lactic Acid) (PLLA) Films by Chitosan Nanoparticles

“…Therefore, the faults in mechanical properties of 5% w/w CNPs loaded PLA films can be explained by the non-homogenous structure of these films. Moreover, the reduction in some physical and mechanical properties of 5% CNPs loaded PLLA films contained could be ascribed to its lower crystallinity compared to 1 and 3% CNPs loaded samples ( 23 ), as testified by the lower crystallinity degree calculated from DSC data ( Table 4 ).…”

“…Different color parameters (lightness ( L * ), red-green ( a * ) and yellow-blue ( b * )) were also obtained using a Hunter lab colorimeter (Minolta CR 300 Series, Osaka, Japan) ( 23 ).…”

Research Progress of Polyvinyl Alcohol Water-Resistant Film Materials

“…Garavand et al [ 65 ] proposed innovative composite films based on corn starch/PVA blends (starch:PVA 40:60) and loaded with three different levels of chitosan nanoparticles (CNPs) (1,3 and 5% w / v ). Water vapor transmission test results showed that the WVP values of the starch-PVA nanocomposite films were significantly decreased by adding CNPs into the film matrix.…”

Green synthesis of nanomaterials for smart biopolymer packaging: challenges and outlooks

“…The availability, biodegradability, and low cost of starchbased materials have made them increasingly popular in food packaging. However, starch has some drawbacks, including poor mechanical features and moisture barrier (strong hydrophilic behaviour) to traditional non-recyclable plastic films commonly used in food packaging [83,139]. Nanocomposite concepts have recently emerged as a viable approach for improving packaging films' mechanical and barrier properties (Table 3).…”