Properties and behavior under environmental factors of isosorbide-plasticized starch reinforced with microcrystalline cellulose biocomposites

Isosorbide, a versatile green chemical: Elucidating its ADME properties for safe use

Isosorbide, an environmentally friendly and renewable substance, finds extensive application in diverse fields, such as a bisphenol A substitute, polymers, functional materials, organic solvents, fuels, and pharmaceuticals. Despite its increasing interest and widespread usage, there remains a notable absence of available reports regarding its absorption, distribution, metabolism, and excretion (ADME) properties. This study endeavors to investigate the ADME characteristics of isosorbide in rats. Isosorbide levels in biological samples were quantified based on the analytical method using gas chromatography-mass spectrometry (GC-MS). Following administration, isosorbide exhibited rapid absorption and elimination, with a bioavailability of 96.1%. The metabolic stability assay indicated that isosorbide remained stable during metabolism. The majority of absorbed isosorbide was promptly excreted, with urinary excretion as the primary route. This study furnishes valuable insights into the ADME of isosorbide, contributing to its safety assessment and fostering its continued application across various domains.

Green composites based on thermoplastic starch reinforced with micro- and nano-cellulose by melt blending - A review

Starch is a biodegradable biopolymer, a sustainable material that can replace conventional petrochemical-based plastics. However, starch has some limitations, as it must be processed by heating and treated mechanically with a plasticizer to become thermoplastic starch (TPS). Different variables such as mixing speeds, amount, and kind of plasticizers play a vital role in preparing TPS by melting. Despite this, the properties of the TPS are not comparable with those of traditional plastics. To overcome this limitation, microcellulose or nanocellulose is added to TPS by melt mixing, including the extrusion and internal mixing process, which enables large-scale production. This review aims to compile several studies that evaluate the effect of plasticizers, as well as the relevance of incorporating different cellulosic fillers of different dimensions on the properties of TPS obtained by melt mixing. Potential applications of these materials in food packaging, biomedical applications, and other opportunities are also described.

Isosorbide plasticized corn starch filled with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) microparticles: Properties and behavior under environmental factors

In this work, new green and fully biodegradable composites, based on corn starch, plasticized with two different amounts of isosorbide and filled by poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) microparticles, were obtained by melt processing. The analysis of their morphologies, crystallinity, structural interactions and dynamomechanical properties as well as the evaluation of their moisture resistance and biodegradability in soil, were performed in function of the plasticizer and/or microparticle amount. The analysis of morphology, crystallinity and structural interactions showed that the plasticization process was completed under the melting processing conditions used. The microparticles were homogeneously dispersed in the thermoplastic starch matrix without suffering any deformation or breaking during the processing. Biocomposites with adequate storage modulus values were obtained, especially the TPS plasticized with 35% of isosorbide and filled with 5 wt% of PHBV microparticles. The incorporation of PHBV microparticles leads to biocomposites with higher moisture resistance. All the biocomposites were completely biodegraded in soil in a short period of time. The performed study demonstrated that these biocomposites could be used for applications in the packaging industry.

Thermoplastic starch blown films functionalized by plasticized nitrite blended with PBAT for superior oxygen barrier and active biodegradable meat packaging

Functional bioplastic packaging was produced from thermoplastic starch (TPS) with nitrite (1-5%) and polybutylene adipate terephthalate (PBAT) (PBAT/TPS at 30/70 and 40/60) via blown-film extrusion. TPS-nitrite interaction increased thermal destabilization and decreased α-relaxation temperature of TPS phase, indicating improved plasticization and disruption of starch granules. Nitrite modified C=O bonding of PBAT and improved compatibility with TPS networks, resulting in compact microstructures that reduced oxygen and water vapor permeability. Films containing nitrite showed up to 39.7% decrease (p≤0.05) in mechanical properties while effectively improving and stabilizing redness of vacuum-packaged pork during storage for 12 days. Nitrite release led to up to 0.66 ppm residual nitrite, which corresponded to formation of nitrosyl myoglobin (3.4-9.6 ppm), and effectively reduced total viable count, lactic acid bacteria and yeast and molds (p≤0.05). Stabilized lipid components also increased with increasing nitrite. Novel nitrite-containing biodegradable film enhanced functional properties and retained quality of packaged meat.

Developments of biobased plasticizers for compostable polymers in the green packaging applications: A review

The demand for biobased materials for various end-uses in the bioplastic industry is substantially growing due to increasing awareness of health and environmental concerns, along with the toxicity of synthetic plasticizers such as phthalates. This fact has stimulated new regulations requiring the replacement of synthetic conventional plasticizers, particularly for packaging applications. Biobased plasticizers have recently been considered as essential additives, which may be used during the processing of compostable polymers to enormously boost biobased packaging applications. The development and utilization of biobased plasticizers derived from epoxidized soybean oil, castor oil, cardanol, citrate, and isosorbide have been broadly investigated. The synthesis of biobased plasticizers derived from renewable feedstocks and their impact on packaging material performance have been emphasized. Moreover, the effect of biobased plasticizer concentration, interaction, and compatibility on the polymer properties has been examined. Recent developments have resulted in the replacement of synthetic plasticizers by biobased counterparts. Particularly, this has been the case for some biodegradable thermoplastics-based packaging applications.

Thermoplastic starch blown films with improved mechanical and barrier properties

The development and production of thermoplastic starch (TPS) films based on blown film extrusion have been spurred by increasing interest in renewable resources and an alternative solution to meet industrial-scale demand. The chemical structure of the plasticizer and its proportion have a significant effect on the mechanical and barrier properties of TPS films. Therefore, this research aims to evaluate the influence of plasticizer type and content on the performance of TPS blown films. TPS films were prepared by mixing cassava starch with three types of plasticizer, i.e. glycerol, glycerol/xylitol, and glycerol/sorbitol with a weight ratio of 1:1. The quantity of plasticizer varied among 38, 40, and 42 parts per hundred parts of starch. Although TPS films plasticized with the small-sized plasticizer glycerol were easily processed and extensible, the surface stickiness leading to single-wall films, low tensile strength, and poor water vapor barrier properties would limit their use. By replacing glycerol with larger-sized plasticizers such as xylitol or sorbitol, the films exhibited reduced stickiness and separable double walls and showed improved tensile strength, stiffness, and water vapor and oxygen barrier properties. The obtained TPS blown films offer potential applications as edible films for food and pharmaceutical products.