A conventional chemical method was applied for the extraction of chitosan (CH) from shrimp shell wastes (SSWs) in three stages: (1) Demineralization: SSWs were treated with HCl to remove minerals. (2) Deproteinization: NaOH was used to eliminate proteins from the demineralization shells. 3: Deacetylation: The chitin (CT) obtained from stage 2 was converted to chitosan in alkaline medium using NaOH. This study aims to demonstrate the impact of varying deacetylation times on chitosan surface morphology, elemental composition, thermal resistance, structural configuration, and deacetylation degree (DD). Variable techniques including UV-visible spectroscopy, Fourier Transformed Infra-Red (FTIR-ATR), Thermogravimetry (TG/DTG), Scanning Electron Microscopy (SEM), and Energy-dispersive X-ray spectroscopy (EDX) analyses were employed to analyze how increased deacetylation periods affect the characterization of the products. The FTIR spectra showed a notable similarity between all extracted chitosan processed with increasing deacetylation time and the commercial one. Moreover, the results revealed that all the extracted chitosan samples acquired DD values, based on FTIR-ATR analysis, are comparable to that of commercial ones i.e. 79.54%, 78.23%, 74.81%, and 76.56% for deacetylated times of 22 h, 30 h, 36 h, and 40 h, respectively are comparable to that of the commercial chitosan (76.1%). Furthermore, the EDX analysis confirms that the extracted chitosan is non-toxic product, making it suitable for various applications, including biological and medical uses. Graphical Abstract

A conventional chemical method was applied for the extraction of chitosan (CH) from shrimp shell wastes (SSWs) in three stages: 1. Demineralization: SSWs were treated with HCl to remove minerals. 2. Deproteinization: NaOH was used to eliminate proteins from the demineralization shells. 3: Deacetylation: The chitin (CT) obtained from stage 2 was converted to chitosan in alkaline medium using NaOH. This study aims to demonstrate the impact of varying deacetylation times on chitosan surface morphology, elemental composition, thermal resistance, structural configuration, and deacetylation degree (DD). Variable techniques including UV-visible spectroscopy, Fourier Transformed Infra-Red (FTIR-ATR), Thermogravimetry (TG/DTG), Scanning Electron Microscopy (SEM), and Energy-dispersive X-ray spectroscopy (EDX) analyses were employed to analyze how increased deacetylation periods affect the characterization of the products. The FTIR spectra showed a notable similarity between all extracted chitosan processed with increasing deacetylation time and the commercial one. Moreover, the results revealed that all the extracted chitosan samples acquired DD values, based on FTIR-ATR analysis, are comparable to that of commercial ones i.e. 79.54%, 78.23%, 74.81%, and 76.56% for deacetylated times of 22 hrs, 30 hrs, 36 hrs, and 40 hours, respectively are comparable to that of the commercial chitosan (76.1%). Furthermore, the EDX analysis confirms that the extracted chitosan is non-toxic product, making it suitable for various applications, including biological and medical uses.

To enhance and widely spread the bioactive sustainable applications of chitosan (CH), three newly developed solid chitosan derivatives were prepared and characterized. Chitosan was obtained from shrimp shell wastes through alkaline deacetylation of its precursor chitin. The obtained CH was reacted with bis-(hydroxyethyl) terephthalate (BHET), which was derived from the recycling of post-consumer PET waste, to create the first derivative, referred to as CBHET. This derivative was then transformed into a second chitosan derivative by grafting with acrylic acid (AA) denoted as CBHET–AAI. The third chitosan derivative was produced by simultaneously reacting CH with both BHET and AA, added at the same time, and this product was designated as CBHET–AAII. The structural characteristics of the three prepared chitosan derivatives were evaluated and confirmed by applying Fourier Transform Infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermal analyses (TGA, DTG and DSC), and scanning electron microscopy (SEM). Factors that could affect the properties of the final products were investigated, including treatment temperature, reaction time, and reactant concentrations. The three derivatives were found to be very hard, solid composites, insoluble in most common solvents, acids, bases, and even water. Based on TGA data, CBHET exhibited the highest mass loss at 63.4%, compared to 57.7% for CBHET–AAI and 41% for CBHET–AAII. The crystallinity index (ICR), average crystalline size (D) in ηm, and average interchain spacing in A° were also calculated. According to the data obtained, it can be concluded that these chitosan derivatives are ideal bioactive, sustainable, and newly developed biopolymers based on two waste ingredient materials: namely chitosan from shrimp shell wastes and BHET from glycolysis of post-consumer PET. These novel derivatives can be utilized efficiently and safely as a sustainable biosorbent in the handling of wastewater management, treatment of low- and medium-level radioactive waste effluents, and many other potential applications.

The objective of the submitted work was to assess the effect of hot air and/ or gamma irradiation following the application of a protein hair conditioner on the skin hygiene. Ninety six albino rats were employed. They were divided into eight groups; each included six males and six females. Rats in group 1 served as control . Rats of groups 2, 3 and 4were rubbed with conditioner for one, two and three times, respectively, every was separated by seven days. Following every treatment, the rats were exposed to hot air (95 ᵒC) for one minute. Rats in groups5,6 and 7 were treated in the same manner . After one week, they exposed to a single dose gamma irradiation (10 Gy). Rats in group 8 were treated once with conditioner and then directly exposed to the same dose. Post one week of irradiation, all rats were anesthetized and blood samples were collected for biochemical analyses, while shaven skin cuts from the centre protein applying area for histological examinations. Morphological observations revealed alopecia and skin ulcer. Whereas, the biochemical results indicated that serum collagen I contents decreased while heat shock protein concentrations increased as treatment repetitions. The level of vascular endothelial growth factor exhibited inconsistence trend. Histopathological observations confirmed the morphological findings. In conclusion, there is no protein hair conditioner products that can be considered completely safe. It is worth to state that, it’s time to give serious consideration for stopping these treatments to avoid the cumulative application risks.