Innovative Hemp Shive-Based Bio-Composites: Part I: Modification of Potato Starch Binder by Sodium Meta-Silicate and Glycerol

Abstract

The growing demand for sustainable building materials has boosted research on plant-based composite materials, including hemp shives bound with biodegradable binders. This study investigates the enhancement of potato-starch-based binders with sodium metasilicate and glycerol to produce eco-friendly bio-composites incorporating hemp shives. Potato starch, while renewable, often results in suboptimal mechanical properties and durability in its unmodified form. The addition of sodium metasilicate is known to improve the mechanical strength and thermal stability of starch-based materials, while glycerol acts as a plasticizer, potentially enhancing flexibility and workability. Bio-composites were produced with varying concentrations of sodium metasilicate (0–107% by mass of starch) and glycerol (0–133% by mass of starch), and their properties were evaluated through thermal analysis, density measurements, water absorption tests, compressive strength assessments, and thermal conductivity evaluations. The results demonstrate that sodium metasilicate significantly increases the bulk density, water resistance, and compressive strength of the bio-composites, with enhancements up to 19.3% in density and up to 2.3 times in compressive strength. Glycerol further improves flexibility and workability, though excessive amounts can reduce compressive strength. The combination of sodium metasilicate and glycerol provides optimal performance, achieving the best results with an 80% sodium metasilicate and 33% glycerol mixture by weight of starch. These modified bio-composites offer promising alternatives t2 o conventional building materials with improved mechanical properties and environmental benefits, making them suitable for sustainable construction applications.