Characterization​ and ​analysis of ​m​otion ​m​echanism​ of electroactive​ chitosan-based actuator

Ugucioni

Borges

2020

J Food Process Preserv

Chitosan is a biodegradable polymer and could be applied as packaging. To make chitosan more competitive, plasticizers and cross‐linking agents are added in films. The aim of this paper was to obtain and characterize films of chitosan without or with glutaraldehyde (0; 0.99 mg/150 ml) in different concentrations of glycerol (0, 10, 20, and 30%w/w), for improving the properties like tensile resistance and the water vapor permeability. The films were homogeneous, without phase separation, and with a similar chemical structure. The glutaraldehyde makes the chitosan partly hydrophobic, leading to glycerol saturation in samples with glutaraldehyde and 20 or 30% of glycerol. The Principal Component Analysis for the film with glutaraldehyde and 10% of glycerol presented 3.60 g.mm/kPa.day.m2 of water vapor permeability and 36.96 MPa of tensile resistance. The use of plasticizer and cross‐linking in combination is promising to make chitosan film more competitive on the market of packaging. Practical Applications The addition of glutaraldehyde and glycerol was efficient to improve film properties like water vapor permeability and mechanical properties. The chitosan films with glycerol and glutaraldehyde exhibited similar physical and chemical properties to non‐biodegradable polymers from the petrochemical origin and non‐renewable sources. Furthermore, chitosan films with these additives can be applied as packaging, improving the competitiveness of this biopolymer to the market. The technology described in the paper is important for application as secondary or tertiary packaging in the food industry.

Section: Resultsmentioning

confidence: 99%

“…CGlut samples also showed two stages of thermal degradation. The first step is about 55°C, which corresponds to water evaporation (Altınkaya et al., 2018; Hai & Sugimoto, 2018; Zohuriaan & Shokrolahi, 2004). The second step is about 288°C for chitosan degradation.…”

Section: Resultsmentioning

confidence: 99%

Effect of glutaraldehyde/glycerol ratios on the properties of chitosan films

Ugucioni

Borges

2020

J Food Process Preserv

“…19,36,41 Furthermore, the TGA and DTG results of Cs films also presented three degradation steps (Figure 3b): The first at 96 C, the second at around 290 C, and the third at 537 C, which could be attributed to the evaporation of water and hydroxyl groups of chitosan; degradation of chitosan by deacetylation and depolymerization; and the carbonization of chitosan, respectively. 19,42,43 Regarding the analysis of thermal decomposition of pure glycerol (Figure 3c), the mass loss curve of this material was completely monophasic with a maximum degradation temperature at 230 C. 44,45 F I G U R E 1 Electrical conductivity (σ) of chitosan, polyaniline (PANI), glutaraldehyde, and glycerol films showed in Table 1. * mass of PANI per volume of chitosan (Cs)/Gly or Cs/Gly/Glut solution The thermal results of Cs.PANI100.Gly30 and Cs.…”

Section: Thermogravimetric Analysismentioning

confidence: 99%

Effect of glycerol on electrical conducting of chitosan/polyaniline blends

J of Applied Polymer Sci

Santos

Ugucioni

et al. 2021

Chitosan (Cs) and polyaniline (PANI) were studied in this article for possible application as conductive and flexible films. Cs is a biodegradable polymer, that presents interesting properties as film applications. Otherwise, PANI is a semiconductor polymer with a wide range of applications. The films were produced by casting adding 30% glycerol and glutaraldehyde. The morphology, thermally, chemical structure, and electrical properties of films were obtained.Results showed the casting technique becomes possible to obtain self-standing films, with a chemical structure identical to precursor materials. Glutaraldehyde reacted to amine groups of terminal PANI chains, acting in the increase of electric conductivity and decrease of sheet resistance. The plasticizing effect of glycerol increased the spacing between Cs chains and facilitated the PANI dispersion. Therefore, glycerol and glutaraldehyde proved to be extremely efficient in increasing the electrical conductivity of blends.

“…The second stage (peak at about 260°C) was associated with the mass loss due to the chitosan degradation mainly through dehydration, deacetylation, and depolymerization. Finally, the third stage (at temperatures above 400°C) was related to degradation events corresponding to the final polymer residues (Altınkaya et al, 2018;Hai & Sugimoto, 2018;de Oliveira et al, 2019de Oliveira et al, , 2021.…”

Section: Thermogravimetric Analysis (Tga)mentioning

confidence: 99%

Properties of chitosan–papain biopolymers reinforced with cellulose nanofibers

Santos

J. Food Process. Preserv.

Lago

et al. 2021

The growing demand for environmentally friendly packaging has led to studies on the development of biodegradable packaging made from biopolymers. Among the natural polymers used for the development of biodegradable packaging, chitosan stands out due to its excellent film-forming capacity and good barrier properties (de Castro e Silva et al., 2020;de Moraes Crizel et al., 2018;de Oliveira et al., 2019). Chitosan is produced industrially by deacetylation of chitin, which is the second most abundant polysaccharide in nature nontoxic, biodegradable, biocompatible, commercially available, with wide application in the production of biodegradable films for food packaging (de