South African Journal of Chemical Engineering (Jan 2024)
Environmentally friendly strength bio-composite preparation by grafting of HEMA onto shrimp chitosan without destroying original microstructure to enrich their physicochemical, thermomechanical, and morphological properties
Abstract
Shrimp shell is the most significant chitin source among bio-based materials since a huge quantity of crustacean wastes has been expelled out as a waste material from various shrimp processing industries/zones. The carapaces were treated by 2 M HCl for demineralization (DM), 2 N NaOH for deproteinization (DP), and 50 % NaOH for deacetylation (DA) to extract chitosan, without destroying the inherent microstructure of native shells. Then grafting was carried out by 2‑hydroxy ethyl methacrylate (HEMA) by using a redox initiator K2S2O8/FeSO4 to produce environmentally friendly strength bio-composite. Meanwhile, maximum yield was found when the concentration of monomer and initiator were 2.55 × 10−1 mol/L, 8.48 × 10−3 mol/L, at 70°C whereas the value has been recorded around 73.33±0.03 %. Besides the honeycomb microstructure of chitosan could enhance the overall properties of the fabricated biocomposites by using mechanical interlocking mechanism during compounding. The samples were characterized by fourier transform infrared (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), solid-state 13C cross-polarization magic-angle-spinning nuclear magnetic resonance (CPMAS-NMR) and tensile strength (TS) techniques. The microstructure and thermo-mechanical profile exhibited noteworthy changes on the bulk property of the CS-g-HEMA composites. Result suggested that the shrimp waste shell would be an attractive source of strength bio-composites that retains outstanding physicochemical, thermomechanical, morphological properties. Thus the grafted products would be significantly utilized in various engineering, and bulk scale industrial applications as a suitable replacement of fossil based synthetic ones for the sustainable environmental protection.
