Creating Sustainable Composite Boards with Common Reed and Seaweed Binder
Rajakari, Patrick (2026)
2026
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-202603265040
https://urn.fi/URN:NBN:fi:amk-202603265040
Tiivistelmä
This thesis investigates the possibility of producing fully bio-based composite boards using common reed (Phragmites australis) reinforced with a natural adhesive extracted from the green alga Ulva intestinalis. Three extraction methods for obtaining polysaccharide-rich adhesive solutions were examined: conventional alkaline extraction, microwave-assisted extraction (MAE), and ultrasound-assisted extraction (UAE). The aim was to evaluate both the practical viability of each method and how the resulting adhesive performed in reed-based composites.
MAE showed promising extraction efficiency, but the microwave equipment used led to uncontrolled pressure buildup, making the method unsuitable without laboratory sys-tems specifically designed for pressurized operations. UAE produced small quantities of extract with limited viscosity and bonding ability, likely due to insufficient temperature and suboptimal extraction conditions. In contrast, the conventional alkaline method yielded the highest amount of adhesive and demonstrated strong bonding performance when used in hot-pressed composite boards.
The resulting composites were lightweight, cohesive, and visually uniform, suggesting suitability for non-structural applications such as interior panels, packaging materials or insulation-related components. The findings highlight the importance of extraction yield, polysaccharide viscosity, crosslinking chemistry, and processing parameters in determining composite quality.
The study demonstrates the potential of locally sourced Baltic biomass as an alternative to synthetic adhesives and wood-based composites. Future work should focus on opti-mizing UAE conditions, chemical characterization of the adhesives, refinement of pressing parameters, and mechanical testing to evaluate industrial feasibility.
MAE showed promising extraction efficiency, but the microwave equipment used led to uncontrolled pressure buildup, making the method unsuitable without laboratory sys-tems specifically designed for pressurized operations. UAE produced small quantities of extract with limited viscosity and bonding ability, likely due to insufficient temperature and suboptimal extraction conditions. In contrast, the conventional alkaline method yielded the highest amount of adhesive and demonstrated strong bonding performance when used in hot-pressed composite boards.
The resulting composites were lightweight, cohesive, and visually uniform, suggesting suitability for non-structural applications such as interior panels, packaging materials or insulation-related components. The findings highlight the importance of extraction yield, polysaccharide viscosity, crosslinking chemistry, and processing parameters in determining composite quality.
The study demonstrates the potential of locally sourced Baltic biomass as an alternative to synthetic adhesives and wood-based composites. Future work should focus on opti-mizing UAE conditions, chemical characterization of the adhesives, refinement of pressing parameters, and mechanical testing to evaluate industrial feasibility.