Thermal Properties of Ethanol Organosolv Lignin Depending on Its Structure

Abstract In general, lignin exhibits unpredictable and nonuniform thermal properties due to the structural variations caused by the extraction processes. Therefore, a systematic understanding of the correlation between the extraction conditions, structural characteristics, and properties is indispensable for the commercial utilization of lignin. In this study, the effect of extraction conditions on the structural characteristics of ethanol organosolv lignin (EOL) was investigated by response surface methodology. The structural characteristics of EOL (molecular weight, hydroxyl content, and intramolecular coupling structure) were significantly affected by the extraction conditions (temperature, sulfuric acid concentration, and ethanol concentration). In addition, the correlation between the structural characteristics and thermal properties of the extracted EOLs was estimated. The relevant…