Publications by authors named "Jaan Kers"

Fiber-reinforced plywood is a composite material that combines the natural strength and rigidity of plywood with the added durability and resilience provided by reinforcing fibers. This type of plywood is designed to offer improved characteristics over standard plywood, including enhanced strength, stiffness, resistance to impact and moisture, and environmental degradation. By integrating reinforcing fibers, such as glass, carbon, or natural fibers (like flax, bamboo, or hemp) into or onto plywood, manufacturers can create a material that is better suited for applications where traditional plywood might fall short or when a decrease in product weight or savings in wood raw material are necessary.

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Article Synopsis
  • The study presents a new method for transesterifying cellulose with vinyl esters using an environmentally friendly ionic liquid, [mTBNH][OAC], allowing for improved homogeneous reactions and recyclability.
  • Various long-chain cellulose esters were synthesized, achieving a degree of substitution (DS) up to 1.8, with optimized reaction parameters such as temperature and reactant ratios.
  • Structural and thermal analyses indicate successful incorporation of alkyl chains into cellulose, enhancing material properties and suggesting these esters could replace traditional cellulose derivatives.
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This article investigates the effects of combining a novel protic ionic liquid-based fire retardant (FR) with alkalized hemp fiber. A pivotal importance of this study refers to the hydrophilic properties and limits regarding poor thermal resistance of green composites where standard guidelines for fire risks are crucial. Although it is well-studied that alkalization is essential for green composite's moisture and mechanical durability, research on the flammability of such a combined treatment for natural fiber-reinforced biopolymer composites is lacking.

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Thermoplastic cellulose esters are promising materials for bioplastic packaging. For that usage, it is important to understand their mechanical and surface wettability properties. In this study, a series of cellulose esters are prepared, such as laurate, myristate, palmitate, and stearate.

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This research investigates an effective alkali (NaOH) treatment and fire-retardant coating to produce biocomposites from frost-retted hemp fiber and PLA. The fiber surface treatment with various NaOH concentrations was investigated throughout a range of soaking times. The results show that the extracted non-cellulosic fiber content increases with treatment duration and NaOH concentration, while the fraction of targeted components removed remains nearly unchanged after soaking for 1, 2, and 4 h with a 5 wt.

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The effects of surface pretreatment (water and alkali) and modification with silane on moisture sorption, water resistance, and reaction to fire of hemp fiber reinforced polylactic acid (PLA) composites at two fiber loading contents (30 and 50 wt.%) are investigated in this work. Moisture adsorption was evaluated at 30, 50, 75 and 95% relative humidity, and water resistance was determined after a 28-day immersion period.

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This study investigated the effect of hemp fiber pretreatments (water and sodium hydroxide) combined with silane treatment, first on the fiber properties (microscale) and then on polylactide (PLA) composite properties (macroscale). At the microscale, Fourier transform infrared, thermogravimetric analysis, and scanning electron microscopy investigations highlighted structural alterations in the fibers, with the removal of targeted components and rearrangement in the cell wall. These structural changes influenced unitary fiber properties.

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