MFC负载铁离子催化对纸浆纤维的芬顿表面氧化作用研究

Study on Surface Oxidation of Pulp Fiber by MFC Loaded Iron Ion Catalysis based on Fenton Reaction

中文关键词:  漂白硫酸盐针叶木浆  微纤化纤维素  表面氧化  芬顿反应

Key Words:softwood bleached kraft pulp （SWBK）  micro-fibrillated cellulose  surface oxidation  Fenton reaction

中文摘要:

      将富含铁离子的微纤化纤维素（MFC-铁离子）吸附于漂白硫酸盐针叶木浆纤维表面，然后对纸浆纤维表面进行芬顿氧化；通过激光扫描共聚焦显微镜（LSCM）间接检测纤维上芬顿反应产生的羟基自由基（·OH），使用扫描电子显微镜（SEM）和能谱仪（EDS）检测纤维上铁元素的分布；评价了在相同打浆转数下，芬顿表面氧化处理对纤维素平均聚合度（DP）、纤维形态及成纸抗张指数和撕裂指数的影响。结果表明，芬顿表面氧化预处理产生的·OH主要分布在纸浆纤维表面，并且基本保留了纤维平均长度；与原浆相比，芬顿表面氧化浆的纤维素平均DP仅下降约4.9%，打浆转数8000转时，成纸抗张指数和撕裂指数较原浆成纸分别提高了20.9%和25.7%。

Abstract:

      Iron ions were loaded on micro-fibrillated cellulose as a catalyst to perform Fenton oxidation pretreatment on the surface of softwood bleached kraft pulp （SWBK）. The distribution of hydroxyl radicals generated by Fenton reaction on the fibers was detected by laser scanning confocal microscopy （LSCM）. The adsorption of iron ion on the fibers was determined by scanning electron microscopy （SEM） and energy dispersive spectroscopy （EDS）. The influence of Fenton oxidation pretreatment on fiber surface was evaluated through the average degree of polymerization （DP）， fiber morphology， the tensile index and tearing index of handsheets under the same PFI beating revolution. The results showed that the hydroxyl radicals generated by the decomposition of hydrogen peroxide during the oxidation pretreatment process were mainly occurred on the surface of the pulp fibers， which made them possible to oxidize the surface of the fibers. Compared with the pulp without Fenton pretreatment， the DP of Fenton surface-oxidated pulp only decreased by 4.9%. When the PFI beating revolution was about 8000 r， the tensile index and the tearing index of the sheet made with surface oxidation pretreated fibers were increased by about 20.9% and 25.7% respectively compared with the handsheet prepared with the original pulp.