Cellulose microfibril threads reinforced with cationic starch and polyvinyl alcohol
Name: JAIR ROGERIO COLARES NETO
Publication date: 19/08/2024
Examining board:
Name |
Role |
|---|---|
| DANILLO WISKY SILVA | Examinador Externo |
| JORDAO CABRAL MOULIN | Presidente |
| MARESSA CARVALHO MENDONCA | Examinador Externo |
| MICHEL PICANCO OLIVEIRA | Examinador Interno |
Summary: The production of renewable-based polymers to replace fossil-derived ones and reduce environmental impacts is gaining prominence. Cellulose is the most abundant renewable polymer on Earth, and cellulose microfibrils (MFC) exhibit mechanical and physical properties that enable the production of filaments. This study explores the fabrication of MFC-reinforced yarns, combining cationic starch (AC) and polyvinyl alcohol (PVA) as reinforcements, using sodium alginate as the matrix. Both bleached and unbleached MFC (4.5% w/w) were used, with AC (3% w/w) and PVA (2% w/w) in a sodium alginate matrix (2% w/w) as the binding agent, using the wet spinning process with calcium chloride as the solvent. Analyses included microstructure, water absorption, thermogravimetry, infrared spectroscopy, X-ray diffraction, and mechanical strength tests. The results indicate that the addition of AC and PVA improves the properties of the yarns. Tensile strength increased from 30 MPa to 60 MPa (AC) and to 50 MPa (PVA). The elastic modulus increased from 2 GPa to 4 GPa (AC) and to 3.5 GPa (PVA). Unbleached MFC yarns showed higher water absorption (5.52 g/g) compared to bleached MFC yarns (4.08 g/g). Regarding filament size, PVA yarns had a larger diameter, being 16% larger than the cationic starch yarns. It is concluded that the combination of MFC with AC and PVA improves the properties of the filaments.
Keywords: Filament, nanocellulose, chemical reinforcements.
