Destruction of Chitosan and Its Complexes with Cobalt(II) and Copper(II) Tetrasulphophthalocyanines

Abstract

Chitosan is a naturally occurring polysaccharide derived from chitin with a wide range of uses. Phthalocyanines are macroheterocyclic compounds that have a number of useful properties such as coloring and catalytic and antioxidant activity. Phthalocyanines are able to immobilize on chitosan, forming complexes with new useful properties. In this work, we evaluated the ability of phthalocyanines to increase the thermal stability of chitosan. Chitosan (CS) forms complexes with copper(II)-(CuPc) and cobalt(II)-(CoPc) tetrasulphophthalocyanines. The processes of destruction of chitosan (CS) and its complexes with sulphophthalocyanines CuPc and CoPc in oxidizing and inert atmospheres have been studied. It was established that, regardless of the atmosphere composition, the first chemical reactions taking place in the studied systems are elimination reactions. The latter ones in the case of chitosan and complex CS-CuPc lead to the formation of spatially crosslinked polymer structures, and it causes the release of CuPc from the polymer complex. It was found that in the case of CS-CoPc elimination reactions did not lead to the formation of crosslinked polymer structures but caused the destruction of the pyranose rings with a partial release of CoPc. Metallophthalocyanines showed antioxidant properties in the composition of complexes with chitosan, increasing the temperature of the beginning of glycosidic bond cleavage reaction by 30–35 °C in comparison with the similar characteristics for chitosan.

Donor–acceptor interactions of gold(iii) porphyrins with cobalt(ii) phthalocyanine: chemical structure of products, their spectral characterization and DFT study

“…It is known that porphyrins and phthalocyanines have high thermal stability. 61–64 Fig. S8a† shows the TGA curve of 1 and its first derivative (DTG), revealing high thermal stability with a mass loss of 4.47% between 25 and 443 °C, which is due to adsorbed solvent molecules rather than metallophthalocyanine degradation.…”

Review—Electrochemical Separation of Organic and Inorganic Contaminants in Wastewater

“…Indicatively, the chitosan (CS) can form complexes with copper(II)-tetrasulphophthalocyanines (CuPc) and cobalt (II)-tetrasulphophthalocyanines (CoPc), but the destruction temperature of CS-CuPc is 10°C-15°C higher than CS-CoPc. 86 For other fields, like the food and pharmaceutical industry, the use of ED is expected to increase along with new and more cost-effective ion exchange membranes development, which could overcome the principal limitations of the process such as membrane fouling, mass transfer problems, and potential drop.…”

Efecto de las membranas con Cu+2 sobre el proceso de filtración y capacidad de biocida contra Escherichia coli

“…Las curvas de flujo de calor se obtuvieron en un TGA/DSC. A pesar de la baja sensibilidad de este equipo para obtener la curva de flujo de calor en comparación con la señal de un equipo específico de DSC, se puede utilizar para identificar efectos térmicos en el proceso de descomposición térmica y termo oxidativa de las muestras (Lebedeva et al, 2021;Schindler et al, 2017). Es por ello, que solamente se empleó esta curva para determinar los puntos en los cuales se produjo una degradación en la muestra.…”