聚乙烯亚胺对阴离子干扰物的化学控制及对纸料湿部性能的影响

The chemical control of anionic trash with PEI and its effects on wet-end properties

造纸湿部系统中溶解与胶体物质(Dissolved and Colloidal Substances,简称DCS)以及无机电解质积累所引起的黏性干扰物问题对造纸生产具有严重影响。选用低分子质量、高阳电荷密度的聚乙烯亚胺(Polyethylenimine,简称PEI)固着剂控制纸料中的DCS,探究不同Ca^(2+)浓度及PEI用量条件下DCS的固着效果,并探讨其对纸料湿部性能的影响。结果表明:随着PEI用量提高,DCS的固着效果提高,纸料的Zeta电位绝对值和网下滤液阳离子需求量降低,纸料滤水速度略有提升;当纸料中存在Ca^(2+)时,Ca^(2+)会屏蔽纤维及DCS模拟物表面负电荷,影响PEI对DCS的固着效果,但可提升纸料的滤水性能。

The accumulation of dissolved and colloidal substances in papermaking wet-end system were easily gathered together and formed non-ionic DCS interferent （pitch deposits and depositions） with electrolytes, which adversely affect papermaking. By choosing polyethyleneimine fixing agent with low molecular weight and high cationic charge density, the DCS in slurry was controlled. The fixation efficiency of DCS simulacra and the wet-end properties were explored under varying Ca^2＋ condition with addition of PEI. The results showed that the fixation and retention efficiency of DCS simulacra were improved, the Zeta potential of pulp and drainage rate of pulp increased, and the cationic demand of pulp filtrate decreased as increasing PEI dosage; Ca^2＋ could shied the negatively charged in the surface of fibers and DCS simulacra, and influencing the fixation efficiency of PEI to DCS sirnulacra, but it can improve the drainage rate of pulp.