目的 针对传统湿强剂在使用过程中所造成的环境污染问题，研究利用高碘酸钠选择性氧化纤维提高纸张湿强度的新方法。方法 以未漂硫酸盐针叶木浆为原料，采用高碘酸钠对纤维进行选择性氧化，通过纤维形态分析仪对氧化后的纤维进行形态分析，并用红外光谱对纤维进行表征，对成纸的物理特性及纸张表面形态进行分析和观察。结果 经高碘酸钠氧化后，纤维的长度和宽度变化不大，但纤维的粗度明显降低，纤维表面产生了大量醛基，在纸张成型过程中，纤维表面的醛基能够与纤维上的羟基发生缩合反应，形成半缩醛结构，提高了纤维间的结合强度，从而提高了纸张的湿强度。结论 高碘酸钠选择性氧化未漂硫酸盐浆可以提高纸张的湿强度。

The work aims to study a new method to increase the wet strength of paper by selective oxidized fiber with sodium periodate with regard to the environmental pollution caused by the use of traditional wet strength agent. With the unbleached softwood kraft pulp as raw material, the fiber was selectively oxidized with sodium periodate. Fiber morphology analyzer and infrared spectroscopy were applied to analyze the fiber morphology and characterize the fiber, respectively. The physical characteristics of the finished paper and the paper surface morphology were analyzed and observed. After the oxidation with sodium periodate, the fiber length and width had a little change, but the fiber roughness decreased significantly. Besides, there was a large number of aldehyde groups on the fiber surface. The aldehyde groups on the fiber surface could have the condensation reaction with the hydroxy on the fiber in the process of paper formation, thus forming the hemiacetal structure. The hemiacetal structure improved the bonding strength between the fibers, thus improving the wet strength of the paper. The wet strength of paper can be improved by selective oxidized unbleached kraft pulp with sodium periodate.