Study on prawn shell waste into chitosan and its derivatives as value added products for cellulosic fibres

Abstract

Purpose The purpose of this paper is to synthesize chitosan, N-octyl chitosan (NOCh) and carboxymethyl chitosan (CMCh) derivative from prawn shell wastes and identify their applications as modifiers on cellulosic fibres, jute and cotton, to develop quality textile fibres. Design/methodology/approach Chitosan was obtained by deacetylation of chitin. NOCh was obtained by reductive amination of chitosan. Water-soluble CMCh was prepared by reacting chitosan with monochloroacetic acid in aqueous alkaline media at ambient conditions. Chitosan, NOCh and CMCh were applied on cellulosic fibres, and structure and physico-chemical characteristics of chitosan derivatives and modified fibres were investigated and analysed. Findings The molecular weight, degree of deacetylation and ash content of prepared chitosan were 1,39,958 Da, 85 and 2.33 per cent, respectively. The moisture content, water holding capacity and total nitrogen content were above 10, 450 and 6.5 per cent, respectively. Average degree of substitution of CMCh was 0.82 as determined by titrimetric analysis. Fourier transform infrared spectroscopy (FTIR) spectra showed characteristic peaks of carbonyl group at 1,659 cm−1, –NH2 at 1,600 cm−1, symmetric stretching of C-H in the methyl group at 1,520 cm−1 and carboxylic group at 1,737 cm−1. Thermograms showed moderate thermal stability in treated fibres compared to untreated fibres. Surface morphology of the modified fibres exhibited smoother surface due to the absorption of chitosan, NOCh and CMCh. Originality/value Modification of jute and cotton by sorption of NOCh and CMCh introduced new functional groups on the fibre surface with chemical bonding, which was confirmed by FTIR. Surface morphology of the fibres was carried out by scanning electron microscopy. As the modified fibres also showed good dyeability and colour fastness as well as other properties, the chitosan derivatives as a textile modifier would be helpful to avoid synthetic petroleum-based chemical modifiers as well as to manage the environmental pollution from prawn shell waste and other toxic chemicals.

Surface modification of polylactic acid and poly (D, L-lactide-co-glycolide) biodegradable materials via chitosan-coating treatment: A new approach for developing novel antibacterial acupoint catgut embedding materials

“…26 With its abundant reserve, chitosan is the second most important natural polymer globally (the first is cellulose) and has been widely extracted from marine arthropods (prawns, crabs, shellfish, etc). 27 As shown in our previous reports, chitosan-coating modification can be used to improve the surface roughness, mechanical properties, and biocompatibility of PLA-and PGA-embedding monofilaments. 28,29 Moreover, there are many applications of chitosan in the surface modification of textile materials for different purposes, including salt-free neutral dyeing of cotton, 30,31 antibacterial cotton and wool, 32 dyeing of wool, 33 and antibacterial wound dressings.…”