Publications by authors named "I Krasnou"
In this study, we explored the selectivity of softwood lignin toward esterification through chloromethylation. Organosolv pine lignin chloromethylated by a novel greener protocol was subjected to esterification with decanoic acid (C10), tetradecanoic acid (C14), and stearic acid (C18). The success of lignin esterification was confirmed by using FTIR and NMR spectroscopy.
View Article and Find Full Text PDFInvited for this issue's cover are researchers from Tallinn University of Technology (TalTech). The image depicts the lignin chemical evolution route from raw biomass through a greener chloromethylation procedure developed by the research team. It showcases the transformation into lignin-supported metal nanoparticles, serving as a catalyst for various chemical reactions in both batch and continuous flow conditions.
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- Researchers synthesized cellulose palmitates (CPs) using a catalyst-free method in a superbase ionic liquid environment, focusing on varying degrees of substitution (DS) influenced by temperature, time, and vinyl palmitate ratios.
- * The study detailed the effects of reaction conditions on CPs' structural composition, revealing the importance of specific hydroxy groups in the transesterification process and identifying optimal conditions that result in a DS between 0.5 to 2.3.
- * Various spectroscopic methods verified the CPs' chemical structure and stability, while comparisons of untreated and regenerated cellulose highlighted changes in their properties due to the ion liquid system used.
We present a novel, greener chloromethylation procedure for organosolv aspen lignin under mild reaction conditions without Lewis acid as a catalyst and in acetic acid as a solvent. This synthetic protocol provides a reliable approach to chloromethylated lignin (CML) and means to obtain valuable lignin derivatives. The resulted CML was subsequently transformed into 1-methylimidazolium lignin (ImL), which effectively serves as a stabilizing agent for Pd/CuO nanoparticles (Pd/CuO-NPs).
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- 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.