氧脱木素过程中松木浆的木聚糖自组装改性

Modification of pine pulp during oxygen delignification by xylan self-assembly

自组装是包括大分子在内的不同种目标分子之间相互作用的一种制备功能材料的技术。本文使用的阔叶木木聚糖,分别采用加压热水抽提(HWX)和碱抽提(CAX)从桦木木片和桦木漂白硫酸盐浆中获得。抽提出来的木聚糖使用气相色谱法(GC)、体积排阻色谱法(SEC)和傅立叶变换红外光谱(FTIR)来定性,随后将其加入到松木硫酸盐浆进行氧脱木素的反应器中。木聚糖-纸浆纤维的组装,使用先进的飞行时间次级离子质谱法(To F-SIMS)和成像技术来表征。木聚糖-松木浆的组装产物在全无氯漂白和低浓打浆过程中并没有明显的脱除。相对比参照纸浆,改性纤维具有非常好的机械性能。本技术易于应用到制浆造纸工业中,并且为充分利用生物纤维新材料提供了新的可能。

Self-assembly is a technique of preparing functional materials based on targeted intermolecular inter-actions involving different macromolecules. In this work, hardwood xylan was disassembled from wood and birch bleached kraft pulp using pressurized hot water extraction （HWX） and cold alkali extraction （CAX）, respectively. The extracted biopolymers were characterized using gas chromatography （GC）, size exclusion chromatography （SEC） and fourier transform infrared spectroscopy （FTIR）, and subsequently added into an oxygen deligniifcation reactor containing pine kraft pulp. The assembly of xylan-pulp ifber was characterized using advanced time-of-lfight secondary ion mass spectrometry （ToF-SIMS） and imaging. The xylan-pine pulp assembly was not signiifcantly removed during the whole elemental chlorine free bleaching sequence or during low consistency reifning. Modiifed ifbers had superior mechanical properties compared to the reference pulp. Our concept can be easily applied in the pulp and paper industry, and it opens new possibilities for the utilization of fully bio-based ifbers in new materials.