类木质素母体小分子对甲酸蒸煮纸浆性能的影响

Effect of Lignin-like Precursor Small Molecules on Pulp Properties in Formic Acid Cooking

关键词:  甲酸  木质素  类木质素母体小分子  纸浆

Key Words:formic acid  lignin-like  lignin precursor small molecules  pulp

摘要:本研究构建了类木质素母体小分子协同甲酸的蒸煮体系，在蒸煮过程中，利用类木质素母体小分子与木质素碳正离子的亲核反应，抑制木质素分子间的缩合，从而提高木质素去除率，探究类木质素母体小分子对纸浆白度和纸张强度性能的影响。结果表明，甲酸分别与对羟基苯甲醛、对羟基苯甲酸、香草醛、愈创木酚、紫丁香醇、水杨酸和苯甲醛组成蒸煮体系对杨木和松木进行组分分离，所得杨木浆白度（70.2%）高于松木浆（57.6%）。相比单一甲酸蒸煮体系，添加愈创木酚和紫丁香醇后获得的杨木浆白度由41.5%分别提升至70.2%和69.4%；同时，杨木浆中纤维素含量高于90%，木质素含量低于2%，制备纸张的撕裂、耐破和抗张指数显著提升，分别达3.16 mN·m²/g、1.03 kPa·m²/g和31.5 N·m/g。

Abstract:In this study， a formic acid cooking system with cooperation with lignin-like precursor small molecules was constructed. In the cooking process， the nucleophilic reaction between lignin-like precursor small molecules and lignin carbocations was used to inhibit the condensation between lignin molecules， thereby improving the lignin removal rate. The effects of lignin-like precursor small molecules on the whiteness of pulp and the strength of paper were investigated. The results showed that when the formic acid was used to separate the components of poplar and pine in a cooking system with p-hydroxybenzaldehyde， p-hydroxybenzoic acid， vanillin， guaiacol， syringol， salicylic acid， and benzaldehyde， respectively， whiteness of poplar pulp（70.2%）was higher than that of pine pulp（57.6%）. Compared with the pure formic acid cooking system， the whiteness of poplar pulp obtained by the formic acid synergistic cooking system with guaiacol or syringol increased from 41.5% to 70.2% and 69.4%， respectively. Meanwhile， the cellulose content in the obtained poplar pulp reached higher than 90% with the lignin content lower than 2%， the tear index， burst index， and tensile index of prepared paper reached 3.16 mN·m²/g， 1.03 kPa·m²/g， and 31.5 N·m²/g， respectively.