Synthesis of Chitosan from Prawn Shells and Characterization of its Structural and Antimicrobial Properties

Abstract

Chitin was prepared from prawn shells waste by chemical treatments viz. demineralization, deproteinization and decolorization. Chitosan was prepared by deacetylation of chitin with 50% NaOH at 100 °C in the presence of nitrogen. Deacetylation was performed at different intervals of time to get a series of chitosans having different degrees of deacetylation. Prepared chitosans were characterized by molecular weight determination, degree of deacetylation, Fourier transform infrared (FTIR) spectroscopy and Scanning electron micrography (SEM). The degree of deacetylation of chitosans was calculated by acid base titration and potentiometric titration. The molecular weights of commercial and prepared chitosan (CS-4.0) samples were determined using the Mark- Houwink equation and were found to be 3.5 × 105 (g/mole) and 3.3 × 104 (g/mole), respectively. The degree of deacetylation was found to linearly increase with the increase of reaction time. FTIR spectra showed the characteristic peaks of chitin and chitosan. Antimicrobial screening results revealed that the prepared chitosan (CS-4.0) was equally or more biologically active than the commercial chitosan.

Synthesis and Characterization of Chitosan From Raw Shrimp Shell Waste

“…The crystal-I and crystal-II in the structure of chitosan are related to the peaks at 9.63° and 19.93°. Crystal-I corresponds to the hydrated crystalline structure, whereas crystal-II corresponds to the relatively crystalline lattice (110) of chitosan (Pokhrel et al, 2016). Both peaks in this investigation showed a significant level of crystallinity.…”

Microstructural analysis of biowaste‐derived hydroxyapatite‐chitosan nanocomposites

“…Then, chitin was isolated from shell powder by wet chemical processes via demineralization (1 M HCl), deproteinization (2.5 M NaOH), and decolourization (2% bleaching powder). Finally, CS powder was isolated from the chitin by deacetylation (12.5 M NaOH) [27].…”

“…The spectrum of synthesized CS assigned the peaks around 1023.13, 1149.57, and 1056.99 cm −1 corresponding to the C─O─C stretching, and strong C─O bond and the peak at 1381.03 cm −1 represents the alkane bending vibration of the C─H group. Similarly, the peak at 1566.19 cm −1 is assigned to the ─NH 2 group and the peak at 2870.08 cm −1 shows C─H stretching with strong intensity, whereas the peak at 3255.84 cm −1 indicates N─H stretching and at 3356.16 cm −1 shows symmetric stretching of vibration of O─H [27,[36][37][38][39].…”

Peanut Shells Cellulose Based Biodegradable Nanocomposites with Polyvinyl Pyrrolidone (PVP) and Polyvinyl Alcohol (PVA)

“…The intense peak around 2921 and 1019 cm −1 were associated to C─H stretching and vibration and C─O─C structure of D-glycosidic linkage of cellulose, which implies the presence of cellulose in both the spectra. [33,34] The peak at 1639 cm −1 is attributed to C=C groups which are the attraction of aromatic cycle in lignin structure present in normal cellulose but this moiety was decomposed in CNCs due to acidic hydrolysis. [35]…”