The miscibility and the thermal behaviour of chitosan acetate (ChA) with poly(vinyl alcohol) (PVA) have been investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) ...and dynamic mechanical analysis (DMA). Chitosan is blended with poly(vinyl alcohol) in acetic acid solution and this solution is cast to prepare the blend film. From thermal curves the thermal transitions:
T
g,
T
m and characteristic temperatures of decomposition:
T
di,
T
max have been determined and compared. The influence of the degree of PVA hydrolysis on the thermal properties of blend systems has been discussed.
Based upon the observation on the DSC analysis, the melting point of PVA is decreased when the amount of ChA in the blend film is increased. Though some broadening of the transition curves could be noticed (DSC, TGA and DMA), the obtained results suggest that in the solid ChA/PVA blends the components are poorly miscible. Only PVA sample with relatively low DH
=
88% and hence low degree of crystallinity shows partial miscibility with ChA of relatively low molecular weight.
In this study, blends based on hyaluronic acid (HA) and poly(vinyl alcohol) (PVA) were characterized by the viscometric method, steady shear rheological tests and FTIR spectroscopy (Fourier Transform ...Infrared Spectroscopy). Viscometric studies showed the miscibility of HA and PVA in distilled water: 0.1 mol dm−3 NaCl and 0.1 mol dm−3 HCl. The method proposed by Garcia et al. was applied to assess the miscibility of polymers, while Δη and Δb were introduced to determine of miscibility from the Huggins plots. The viscometric data showed that the attractive forces of HA and PVA were dominant when dissolved in 0.1 mol dm−3 NaCl and 0.1 mol dm−3 HCl, while, in distilled water, repulsive forces played the leading role. All polymer solutions were well characterized using a power law model, and exhibited non-Newtonian behavior with pseudoplasticity increasing with the increasing weight fraction of HA in 0.1 mol dm−3 NaCl and 0.1 mol dm−3 HCl. FTIR studies exhibited the formation of new intermolecular interactions between HA and PVA via hydrogen bonding.
In the times of dynamically developing regenerative medicine, more and more attention is focused on the use of natural polymers. This is due to their high biocompatibility and biodegradability ...without the production of toxic compounds, which means that they do not hurt humans and the natural environment. Chitosan and its derivatives are polymers made most often from the shells of crustaceans and are biodegradable and biocompatible. Some of them have antibacterial or metal-chelating properties. This review article presents the development of biomaterials based on chitosan and its derivatives used in regenerative medicine, such as a dressing or graft of soft tissues or bones. Various examples of preparations based on chitosan and its derivatives in the form of gels, films, and 3D structures and crosslinking products with another polymer are discussed herein. This article summarizes the latest advances in medicine with the use of biomaterials based on chitosan and its derivatives and provides perspectives on future research activities.
Chitosan (Chit) and its composite films are widely used in biomedical, cosmetic, and packaging applications. In addition, their properties can be improved and modified using various techniques. In ...this study, the effect of the type of clay in Chit composites on the structure, morphology, and physical properties of Chit solution and films was tested. The liquid flow properties of Chit solution with and without clay were carried out using the steady shear test. Chit films containing clay were obtained using the solution-casting method. The morphology, structure, and physical properties of the films were characterized by scanning electron microscopy, atomic force microscopy, infrared spectroscopy, swelling behavior, and tensile tests. The results reveal that for the Chit solution with clay (C1) containing 35 wt.% dimethyl dialkyl (C14–C18) amine, the apparent viscosity is the highest, whereas Chit solutions with other clays show reduced apparent viscosity. Rheological parameters of Chit composites were determined by the power law and Cross models, indicating shear-thinning behavior. Analytical data were compared, and show that the addition of clay is favorable to the formation of intermolecular interactions between Chit and clay, which improves in the properties of the studied composites.
In the context of the growing interest in biopolymer-based materials for various applications, this study aimed to enhance the properties of chitosan (CS, a derivative of chitin) films by ...incorporating caffeic acid, a polyphenol compound known for its multiple health benefits. The objective was to improve the mechanical parameters of the resulting films, including surface roughness and elasticity. CS was combined with caffeic acid and then underwent a neutralization process. The modified films exhibited potential for use in soft tissue engineering, where increased elasticity and surface roughness are desirable characteristics. The main methods employed to evaluate the structure and properties of the films included mechanical analysis, infrared spectroscopy, scanning electron microscopy, atomic force microscopy, thermogravimetric analysis, contact angle measurement, and swelling behavior. The study's main findings revealed significant alterations in the mechanical properties and surface morphology of the films. The main conclusions drawn from the study suggest that interactions between caffeic acid and CS hold promise for the development of advanced biomaterials in medicine, tissue engineering, and cosmetic formulations. However, a deeper understanding of these interactions is necessary to optimize the material properties and unlock their full potential.
The viscosity behaviour and physical properties of blends containing hyaluronic acid (HA) and poly(N-vinylpyrrolidone) (PVP) were studied by the viscometric technique, steady shear tests, tensile ...tests and infrared spectroscopy. Viscometric and rheological measurements were carried out using blends of HA/PVP with different HA weight fractions (0, 0.2, 0.5, 0.8 and 1). The polymer films and HA/PVP blend films were prepared using the solution casting method. The study of HA blends by viscometry showed that HA/PVP was miscible with the exception of the blend with high HA content. HA and its blends showed a shear-thinning flow behaviour. The non-Newtonian indices (n) of HA/PVP blends were calculated by the Ostwald–de Waele equation, indicating a shear-thinning effect in which pseudoplasticity increased with increasing HA contents. Mechanical properties, such as tensile strength and elongation at the break, were higher for HA/PVP films with wHA = 0.5 compared to those with higher HA contents. The elongation at the break of HA/PVP blend films displayed a pronounced increase compared to HA films. Moreover, infrared analysis confirmed the existence of interactions between HA and PVP. The blending of HA with PVP generated films with elasticity and better properties than homopolymer films.
Collagen films are widely used as adhesives in medicine and cosmetology. However, its properties require modification. In this work, the influence of salicin on the properties of collagen solution ...and films was studied. Collagen was extracted from silver carp skin. The rheological properties of collagen solutions with and without salicin were characterized by steady shear tests. Thin collagen films were prepared by solvent evaporation. The structure of films was researched using infrared spectroscopy. The surface properties of films were investigated using Atomic Force Microscopy (AFM). Mechanical properties were measured as well. It was found that the addition of salicin modified the roughness of collagen films and their mechanical and rheological properties. The above-mentioned parameters are very important in potential applications of collagen films containing salicin.
Acid soluble collagen (ASC) was extracted from Silver Carp fish skin. Collagen was dissolved in acetic acid at varying concentrations and its rheological properties were studied. Steady shear flow ...properties of collagen solutions at concentrations of 5 and 10 mg/mL were characterized using rheometry at 20 °C. Collagen solutions were irradiated with UV light (wavelength 254 nm) for up to 2 h and rheological properties were measured. All the collagen solutions showed a shear-thinning flow behavior. A constant viscosity region was observed after 1 h of UV irradiation, which showed that collagen molecules were fully denatured. A short treatment with collagen solution by UV (ultraviolet) light led to an increase in viscosity; however, the denaturation temperature of UV-irradiated collagen decreased. Depending on the time of UV treatment, collagen extracted from Silver Carp fish skin may undergo physical crosslinking or photodegradation. Physically crosslinked collagen may find applications in functional food, cosmetic, biomedical, and pharmaceutical industries.
Chitosan (CS) has gained considerable attention due to its distinctive properties and its broad spectrum of potential applications, spanning cosmetics, pharmaceuticals, and biomedical uses. In this ...study, we characterized thin films comprising chitosan mixtures containing salicin (SAL) and glycerin (GLY), both with and without hyaluronic acid (HA) as active ingredients. Characterization was achieved through release studies of SAL, infrared spectroscopy, microscopy techniques (AFM and SEM), and thermogravimetric analysis (TGA). CS/GLY/SAL and CS/GLY/SAL/HA mixture films were fabricated using the solvent evaporation technique. We probed interactions between the components in the chitosan mixtures via infrared analysis. The concentration of released salicin was monitored at various time intervals in a phosphate buffer (PBS) at pH 5.5 using HPLC. The linear regression analysis for the calibration graph showed a good linear relationship (R
= 0.9996) in the working concentration range of 5-205 mg/dm
. Notably, the release of SAL reached its peak after 20 min. Furthermore, the introduction of HA caused changes in the films' morphology, but their roughness remained largely unchanged. The results obtained were compared, indicating that the release of SAL in the CS mixture films is sufficient for diverse applications, including wound-healing materials and cosmetic beauty masks.
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