Lignin, an abundant and complex aromatic biopolymer, holds significant potential for producing value-added chemicals and materials. However, its utilization is limited by its solubility in common organic solvents. In this study, we investigated the solubility of softwood Kraft lignin in benzyl alcohol and compared it to other traditionally studied solvents. Methanol achieved a lignin solubility yield of 59%, while ethanol (18%) and acetone (34%), due to their longer alkyl chains and lower polarity, were less effective in solubilizing larger lignin fragments. Benzyl alcohol, on the other hand, exhibited a complete dissolution of lignin, thereby exceeding by far the capability of the standard solvents. Furthermore, benzyl alcohol resulted in a moderate molecular weight of 3621 g/mol for the lignin fragments and a narrow polydispersity index of 1.54. The complete solubility of lignin in benzyl alcohol suggests significant potential for high yield lignin fractionation and subsequent chemical modifications, which are essential for valorization. Despite the high boiling point of benzyl alcohol, the enhanced solubility could facilitate the production of homogeneous lignin fractions with increased reactive sites, thereby broadening the scope of lignin applications in coatings and industrial materials.

中文翻译：

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使用苯甲醇作为牛皮纸木质素的溶剂


木质素是一种丰富而复杂的芳香族生物聚合物，在生产增值化学品和材料方面具有巨大潜力。然而，它的利用受到其在常见有机溶剂中的溶解度的限制。在这项研究中，我们调查了软木牛皮纸木质素在苯甲醇中的溶解度，并将其与其他传统研究的溶剂进行了比较。甲醇的木质素溶解度收率为 59%，而乙醇 （18%） 和丙酮 （34%） 由于烷基链较长且极性较低，在溶解较大的木质素片段方面效果较差。另一方面，苯甲醇表现出木质素的完全溶解，因此远远超过了标准溶剂的能力。此外，苯甲醇导致木质素片段的中等分子量为 3621 g/mol，多分散指数为 1.54。木质素在苯甲醇中的完全溶解度表明，高产率木质素分馏和随后的化学修饰具有巨大潜力，这对于增值至关重要。尽管苯甲醇的沸点很高，但增强的溶解度可以促进产生具有更高反应位点的均匀木质素组分，从而拓宽木质素在涂料和工业材料中的应用范围。