PAE-SA二元体系对混合废纸增强效果及机理探究

选用海藻酸钠(SA)作为废纸纤维增强助剂与聚酰胺多胺环氧氯丙烷(PAE)组成二元体系，研究PAE及PAE-SA二元体系对废纸的增强效果，发现PAE-SA二元体系对废纸增强效果显著，明显优于PAE，且可降低PAE的用量，起到环保作用。通过PAE、SA、PAE-SA二元体系的膜红外谱图分析，扫描电镜和原子力显微镜对废纸表面微观形态的观察，元素含量分析以及纸浆细小组分留着率的测定，探究PAE-SA二元体系的增强机理。结果表明:单独添加PAE时，0.8%PAE对废纸增强效果最佳，干强指数比空白增加17.11%，湿强指数比空白增加1 500.00%；添加0.8%PAE+0.4%SA时，干强指数、湿强指数相对于单加0.8%PAE依次增加26.65%、81.25%，且耐破度、撕裂度均有显著增强。通过机理探究发现:PAE与SA两者之间不发生反应，在协同作用过程中主要依靠静电吸附和膜包覆，通过增加纤维对PAE的吸附，增加PAE的自交联及与纤维的共交联，从而增加纤维对细小组分的吸附及纤维间的结合面积，进而增强废纸的性能。 

Strengthening effect and mechanism of PAE-SA binary system on mixed wastepaper

An eco-friendly polymeric additive, sodium alginate ( SA ) developed as functional additives with polyamideamine-epichlorohydrin ( PAE) was used to improve the mechanical properties of wastepaper. The effects of PAE and the binary system of SA-PAE on the regenerative wastepaper properties were investigated. It was found that the PAE-SA binary system had a significant effect on the regenerative wastepaper fiber, and it was obviously better than PAE, which could reduce the dosage of PAE and play a role in environmental protection. Therefore, through the infrared spectrum of PAE, SA, PAE-SA film, the micro morphology of SEM and AFM, the analysis of C and N contents and the determination on the retention rate of fines, the enhancement mechanism of the PAE-SA binary system was studied. The results showed that: when the addition of PAE was 0. 8%, the enhancement effect of wastepaper was best. The dry tensile index increased by 17. 11% and the wet tensile index increased by 1500. 00%compared with the blank. In the binary system of PAE-SA, when the addition of PAE was 0. 8% and the addition of SA was 0. 4%, the dry tensile index and wet tensile index increased by 26. 65% and 81. 25%, respectively. What is more, the burst index and tear index of the wastepaper were significantly enhanced. Through researching the mechanism, it was found that PAE and SA were not involved in the reaction. So the increase of mechanical performance of wastepaper was mainly depend on the electrostatic adsorption and film coating structure by the increase of PAE adsorption, the crosslinking of PAE and itself or fiber, the adsorption of fines between the fibers and the fiber bonding area.