紫外线照射对漂白桉木硫酸盐浆热稳定性的影响

Effect of ultraviolet irradiation on the thermal stability of bleached eucalyptus kraft pulp

研究了植物纤维在波长360nm的紫外线下分别照射24h和48h后的变化。所用浆样为经ECF漂白的桉木硫酸盐浆,漂白流程为O/OD(EP)DP。经紫外线照射后,分析植物纤维聚合度的变化,抽提物和聚戊糖的含量,纤维中水溶出物紫外和可见光谱的变化以及热学分析(热重分析/差热分析)。紫外处理对纤维素的聚合程度没有影响。紫外处理后,羰基和羧基组分的吸收信号逐渐增加,可见纤维的水抽出物中含有纤维素的氧化物,这些氧化物影响纤维的热稳定性。

The changes occurring on cellulosic fibers caused by ultraviolet irradiation at 360 nm for 24b and 4811 were investigated. A never-dried industrial Eucalyptus urograndis elemental chlorine free bleached kraft pulp sample [O/OD （EP）DP sequencel was used throughout the work. After irradiation, the cellulosic fibers were analyzed for polymerization degree changes, extractive and pentosan content, ultraviolet and visible spectrometric changes of water leachate from the fibers and thermal analysis （TGA/DTA）. The ultraviolet treatment had 11o effect on the degree of cellulose polymerization. The water extracted from ultraviolettreated fibers revealed cellulose oxidation, with increasing absorbance signals for carbonyl and carboxyl groups. Those oxidations influenced fiber thermal stability.