Thermal Properties Of Chitosan Research Articles

Synergistic effect of ZnO nanoparticles and hesperidin on the antibacterial properties of chitosan

In this study, hesperidin (HSP) biological agent, which has strong antioxidant properties, was successfully transferred to ZnO nanoparticles, which were first synthesized by the hydrothermal method. Then, chitosan (CS)/ZnO-HSP nanocomposites were produced by adding different ratios of the ZnO-HSPs to the biodegradable CS biopolymer by hydrothermal method. The resulting materials were characterized using various biophysical strategies, including X-ray diffraction (XRD), Fourier transform infrared spectrometry, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy. The mean particle size of ZnO was estimated to be 29 nm from the XRD calculations and SEM measurements. The effect of the ZnO-HSPs on the thermal properties of pure CS was investigated by thermogravimetric analysis and differential scanning calorimetry techniques, and improvements were noted in the thermal properties of CS. While the T g value of CS was 81 °C, this value increased by 13–94 °C with the addition of 6 wt% by weight of the ZnO-HSP. The antibacterial effect of materials was determined by the disc diffusion method. The ZnO-HSPs added to the CS caused the nanocomposites to have a remarkable effect against Escherichia coli and Staphylococcus aureus microorganisms. While the inhibition diameter of the CS against E. coli was 18.3, the same value increased to 22.3 for the composite containing 6 wt% the ZnO-HSP. The HSP increased the antioxidant capacity of both the ZnO-HSP particles and the CS/ZnO-HSP nanocomposites, reducing the toxic effects of ZnO nanoparticles. Thus, it was determined that the CS/ZnO-HSP nanocomposites did not have any cytotoxicity in healthy human cells. The fact that the produced nanocomposites exhibit antibacterial activity and do not harm human cells shows that they can be a safe product for health. From all these results, this triple hybrid system is hoped that it will be used in biomedical applications as a naturally-sourced, environmentally friendly, and cost-effective composite biomaterial by combining its antimicrobial and strong antioxidant properties.

A review on the properties and applications of chitosan, cellulose and deep eutectic solvent in green chemistry

The concept of green chemistry has attracted attention due to the green synthesis and ecofriendly nature of the compounds leading to the green and sustainable chemical industries and processes. Chitosan is an ecofriendly material, which is biodegradable, non-toxic, and biocompatible. It has the potential to be modified into biofilms for various applications such as biomedical, packaging, and pharmaceutical fields. Nevertheless, some poor properties of chitosan restrict its wide applications. The incorporation of nanocellulose fillers into chitosan matrix can enhance the mechanical and thermal properties of chitosan. Cellulose nanomaterials can be achieved through chemical and mechanical modifications. The common type of nanocellulose are cellulose nanofibers (CNFs), cellulose nano-whiskers (CNWs), tunicate CNCs (t-CNCs), algae cellulose particles (AC) and bacterial cellulose particles (BC). Nanocellulose are applied as the reinforcement fillers in various polymer matrices such as polysaccharides, proteins, lipids, polylactic acid etc. Deep eutectic solvents (DES) are relatively novel green solvents, which can be applied in various fields. DES are widely applied in metal processing, polymer processing and synthesis. Even though there are not much studies available on DES for synthesis of nanocomposite films; however they are used as eco-friendly solvents in manufacturing processes. This study reviews the discovery, structure, properties of chitosan and cellulose, their derivatives and applications. In addition, the paper also discusses the properties of DES and their applications.

Thermal properties of polyurethane-based composites modified with chitosan for biomedical applications

The thermal properties of chitosan and hydroxyapatite (HAp)-crosslinked polyurethanes (PU) prepared in a two-step bulk polymerization were investigated. Synthesis of PU was carried out using 1,6-hexamethylene diisocyanate, poly(ethylene glycol) 2000 and dibutyltin dilaurate as a catalyst. Various molar ratios of chitosan and 1,4-butanediol were applied, and the effects of incorporating different HAp amounts and the chitosan-to-BDO ratio were studied. It was found that the thermal properties of PU materials depend on polysaccharides and bioceramics load, which was confirmed by differential scanning calorimetry and thermogravimetry. The glass transition temperature increases with increasing chitosan fraction. Similarly, the onset temperature of degradation increased with chitosan addition. On the other hand, the presence of ceramics did not show a significant impact on the thermal properties of PU composites. Successful polymerization and chain extension of the isocyanate groups with hydroxyl moieties from chitosan and HAp were confirmed by Fourier transform infrared spectroscopy, and the morphology was examined using scanning electron microscopy.

Mechanical and Thermal Properties of Chitosan Filled Poly Lactic Acid/Basalt Fiber Hybrid Composites

Mechanical and Thermal Properties of Chitosan Filled Poly Lactic Acid/Basalt Fiber Hybrid Composites

Greatly improved mechanical and thermal properties of chitosan by carboxyl-functionalized MoS2 nanosheets

In this work, molybdenum disulfide (MoS2) nanosheets were employed to enhance the mechanical and thermal properties of chitosan (CS), which was one of the most promising biomaterials. In order to promote a homogeneous dispersion of MoS2 and improved interface interactions between CS and fillers, carboxyl functionalization was subjected to the exfoliated MoS2 nanosheets by chemical conjugation with thioglycolic acid before compositing with CS. Afterward, the CS/MoS2–g–COOH composite films were prepared by a simple solution blending method. Micromorphology characterizations showed that MoS2–g–COOH nanosheets dispersed much better than unmodified MoS2 nanosheets, which was considered to be quite beneficial for the enhanced properties of CS nanocomposites. DMA results indicated that the mechanical properties of CS were improved by incorporating with MoS2–g–COOH nanosheets compared with neat CS and unmodified MoS2-filled CS. The thermal stability of CS/MoS2–g–COOH was also improved. This work demonstrated a promising route to prepare MoS2-based polymer nanocomposites with excellent performances.

Characterization of Physicochemical and Thermal Properties of Chitosan And Sodium Alginate after Biofield Treatment

Characterization of Physicochemical and Thermal Properties of Chitosan And Sodium Alginate after Biofield Treatment

P-Amino phenol immobilized on multi-walled carbon nanotubes for the preparation of chitosan nanocomposites

Novel nanocomposites of chitosan and p-amino phenol functionalized multi-walled carbon nanotubes (chitosan/multi-walled carbon nanotube– p-amino phenol nanocomposites) were synthesized by solution casting method. The resulting chitosan/multi-walled carbon nanotube– p-amino phenol nanocomposites were characterized with Fourier transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and thermogravimetric analysis. The effects of multi-walled carbon nanotubes– p-amino phenol content on the structure, morphology, and thermal properties, as well as the mechanical properties of the nanocomposite films, were studied. The presence of the p-amino phenol functional moieties helped to improve the dispersion and compatibility of the multi-walled carbon nanotubes in the chitosan matrix. The results showed that the low multi-walled carbon nanotubes– p-amino phenol content leads to increasing in the mechanical and thermal properties of chitosan.

Characterization of Physicochemical and Thermal Properties of Chitosan and Sodium Alginate after Biofield Treatment

Chitosan (CS) and sodium alginate (SA) are two widely popular biopolymers which are used for biomedical and pharmaceutical applications from many years. The objective of present study was to study the effect of biofield treatment on physical, chemical and thermal properties of CS and SA. The study was performed in two groups (control and treated). The control group remained as untreated, and biofield treatment was given to treated group. The control and treated polymers were characterized by Fourier transform infrared (FT-IR) spectroscopy, CHNSO analysis, X-ray diffraction (XRD), particle size analysis, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). FT-IR of treated chitosan showed increase in frequency of –CH stretching (2925→2979 cm- 1) vibrations with respect to control. However, the treated SA showed increase in frequency of –OH stretching (3182→3284 cm-1) which may be correlated to increase in force constant or bond strength with respect to control. CHNSO results showed significant increase in percentage of oxygen and hydrogen of treated polymers (CS and SA) with respect to control. XRD studies revealed that crystallinity was improved in treated CS as compared to control. The percentage crystallite size was increased significantly by 69.59% in treated CS with respect to control. However, treated SA showed decrease in crystallite size by 41.04% as compared to control sample. The treated SA showed significant reduction in particle size (d50 and d99) with respect to control SA. DSC study showed changes in decomposition temperature in treated CS with respect to control. A significant change in enthalpy was observed in treated polymers (CS and CA) with respect to control. TGA results of treated CS showed decrease in Tmax with respect to control. Likewise, the treated SA also showed decrease in Tmax which could be correlated to reduction in thermal stability after biofield treatment. Overall, the results showed that biofield treatment has significantly changed the physical, chemical and thermal properties of CS and SA.

Physical and Thermal Properties of Chitosan

This work aims at characterizing the thermal and physical properties of chitosan. The samples were evaluated for potentiality to use as raw material for biodegradable films raw material. Their thermal and physical properties have been also discussed in detail which Fourier Transform Infrared Spectroscopy (FTIR), Thermo-Gravimetric Analysis (TGA), Energy Dispersive X-Ray Fluorescence (EDXRF) and X-Ray Diffraction (XRD), respectively. The result of the XRD pattern indicated the sample has amorphous-crystalline structure and FTIR results confirmed the formation of intermolecular hydrogen bonding between the amino and hydroxyl groups of the sample. In good agreement between the EDXRF and TGA results, noticed that the removal of moisture and volatile material.

The Effect of Pimelic Acid Interaction on the Mechanical and Thermal Properties of Chitosan and Collagen

An attempt was made on to evaluate the feasibility on interaction of pimelic acid with natural polymers, namely chitosan and collagen, and further assess the functional, mechanical, thermal and biocompatible properties. Pimelic acid cross-linked 3D-scaffold biopolymer of chitosan and collagen displayed appreciable mechanical strength, thermal stability, and biocompatibility. The chemistry of interaction suggested noncovalent interactions play a major role in deciding the property of the said materials and its suitability for biomedical applications.

Zeolite molecular sieve 5A acts as a reinforcing filler, altering the morphological, mechanical, and thermal properties of chitosan

Chitosan-like bio-derived polymers possess a number of useful biological properties, but their mechanical and thermal durability needs to be improved to produce performance-driven materials. Inorganic particles are commonly used as fillers to provide reinforcement in polymer matrix. Zeolites are commercially important inorganic materials that are used extensively as adsorbents, ionic exchangers, and catalysts. One form of zeolite, known as molecular sieve 5A, is a Na+ and Ca2+ exchanged zeolite type A with a 1:1 Si:Al ratio. In this study, the role of zeolite as a reinforcing filler in a chitosan/malonic acid composite was investigated. The thermal stability, mechanical properties, and morphology of the chitosan matrix and chemical interactions within the composites were evaluated. It was observed that zeolite significantly improved the tensile strength, modulus, and thermal stability of chitosan and created a fibrous network-like morphology in the chitosan matrix. This study revealed that the inclusion of zeolite molecular sieve 5A improves the performance of chitosan-based biomaterials.

Studies on the Interfacial Interaction in Natural Rubber Latex/Chitosan Blends

Chitosan (CS) has been blended with natural rubber (NR) latex by solution casting method followed by compression molding at 140°C. The blend is found to be incompatible from DSC, morphology and FTIR studies. The water absorbability of blends increases with increasing percentage of chitosan in the blend. Blending has improved the thermal properties of chitosan. The blended samples show enhanced mechanical properties. From the study of mechanical properties, it is found that there is good adhesion between the two phases. The interfacial adhesion is attributed to the presence of proteins and lipids at the surface of the rubber particles in the latex acting as a compatibiliser between chitosan, a polar polymer and rubber a nonpolar polymer. The interfacial adhesion may be due to interfacial interaction between the carboxyl groups of protein present in the latex and the amino groups of chitosan and also due to thermal cross-linking of NR during compression at 140°C. The presence of bound rubber and reacted chitosan in the blend supports the interfacial interaction between the phases in the blend and also thermal cross-linking.The compatibilising effect of maleic anhydride (MA) on NR/CS blends shows that there is better interfacial interaction between NR and CS in the presence of maleic anhydride. The overall improvement in properties of compatibilised blends suggests that MA can be used as an effective reactive compatibiliser for NR/CS blends. © Koninklijke Brill NV, Leiden, 2012

Influence of electric fields on the structure of chitosan edible coatings

The aim of this work was to evaluate the effect of electric fields applied at different field strength values on mechanical and thermal properties of chitosan films/coatings (obtained from lobster of the Cuban coasts). XRD analyses indicated that electrically treated chitosan films exhibited a more ordered structure and a clearly higher crystallinity when compared with non-treated films, thus displaying significant effects on the value of the crystallinity index ( CI). SEM micrographs evidenced that the surface morphology of chitosan films was influenced by the electric field. In fact, the electric field treatment led to a structure with more regular layers as can be seen in the cross-sections of the films observed under SEM. The application of the electric field to chitosan film-forming solutions resulted in an increase of the tensile strength (c.a. 9%) and elongation-at-break (c.a. 18%) of the corresponding chitosan films. The reported results demonstrate that the application of an electric field to film-forming solutions of chitosan is an interesting instrument to taylor relevant properties of the films or coatings produced from them.