阳离子聚合物对二次胶粘物稳定性及沉积性能的影响

Effect of Cationic Polymers on the Stability and the Depositing Characteristics of Secondary Stickies

以丙烯酸酯压敏胶作为废纸回用中二次胶粘物的模型物,研究了阳离子聚合物对二次胶粘物稳定性及其在浆水体系中沉积性能的影响。结果表明,高分子质量、低电荷密度的阳离子聚丙烯酰胺和阳离子淀粉主要通过桥联机理造成二次胶粘物的失稳,而低分子质量、高电荷密度的聚乙烯亚胺则通过电荷补丁机理导致其失稳。低用量的阳离子聚合物可以引起二次胶粘物沉积,大量的聚乙烯亚胺和阳离子聚丙烯酰胺通过将二次胶粘物粒子固着到纤维上减少沉积,而大量的阳离子淀粉除了将部分二次胶粘物粒子固着到纤维上减少沉积外,还能通过吸附到二次胶粘物粒子上降低其粘性而减少树脂沉积。

Acrylate pressure-sensitive adhesive was chosen as the model substance of the secondary stickles in waste paper recycling to study the effect of cationic polymers on its stability and deposition. The results showed that Polyacrylamide （CPAM） and cationic starch with high molecular weight and low charge density destabilize the secondary, stickes particles by mechanism of interparticle bridging, but polyethyleneimine （PEI） with high charge density and low molecular destabilize the secondary stickes by patch flocculation.The deposit was induced at low addition level of cationic polymers in pulp suspension, but the deposit reduced at higher cationic polymers amount. High dosage PEI and CPAM could fix the stickies particles to the fibers and reduce the stickies deposits. On the other hand, high dosage cationic starch not only fixed a part of the secondary stickies particles onto the fiber, therefore could reduce the deposit, but also was adsorbed to the stickles particles to reduce its stickiness and decrease its deposit. When the cationic polymers was added to the pulp suspension containing secondary stickies, PEI was adsorbed to the secondary stickes particles prior to the fibers, but CPAM and cationic starch were adsorbed to the fibers and the secondary stickles simultaneously.