Obtaining Microcellulose from Solid Agro-Waste by Ball Mill Assisted by Light Acid Hydrolysis Process

Area of Science:

• Materials Science
• Biotechnology
• Sustainable Chemistry

Background:

• Cellulose is a globally abundant, biodegradable biopolymer with diverse applications.
• Valorizing plant waste is crucial for sustainable production of cellulose-based materials.
• Extraction methods significantly influence microcellulose properties and performance.

Purpose of the Study:

• To evaluate cowpea pod skin (Vigna unguiculata) as a novel source for microcellulose (CPMC) extraction.
• To compare the efficiency of a chemical-mechanical extraction process using cowpea pod skin, corn straw, and pineapple peel.
• To characterize the physicochemical properties of the extracted microcelluloses.

Main Methods:

• A chemical-mechanical process involving ball milling and acid hydrolysis was employed for microcellulose extraction.
• Fourier Transform Infrared Spectroscopy (FTIR) analyzed chemical composition.
• Thermogravimetric Analysis (TGA), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM) characterized thermal stability, crystallinity, morphology, and nanostructure.

Main Results:

• Characteristic cellulose absorption bands were confirmed via FTIR.
• All microcellulose samples exhibited three stages of mass loss in TGA, with CPMC showing the highest thermal stability.
• Crystallinity indices ranged from 69.23-75%, and AFM revealed distinct lamellar nanostructures (20-280 nm) for each microcellulose type.

Conclusions:

• The chemical-mechanical extraction method is effective for obtaining microcellulose from various plant biomass sources.
• Cowpea pod skin microcellulose (CPMC) and corn straw microcellulose (CSMC) demonstrated superior performance and efficiency.
• CPMC and CSMC are promising candidates for diverse industrial material applications.