新闻纸配浆中DCS的表征及其稳定性

Characterization of the Dissolved and Colloidal Substances from Newsprint Furnish and Their Stability Against Metal Ions

对马尾松化机浆和#8美国废纸脱墨浆中的溶胶物质进行了表征,研究了金属离子对其稳定性的影响。结果发现,马尾松DCS中的脂肪酸和树脂酸(RFAs)主要为脱氢纵酸(DHA)、亚油酸、油酸、棕榈酸等;脱墨浆DCS中主要是亚油酸甲酯、棕榈酸甲酯、棕榈酸、脱氢纵酸等。过氧化氢漂后,树脂酸所占比例大幅上升。DCS中的糖单元主要是半乳糖、甘露糖、半乳糖醛酸、葡萄糖等糖单元。漂白后糖单元的浓度提高,酸性组分的比例升高。DCS稳定性研究发现,H2O2漂白过程中释放出更多的能与Ca2+反应生成絮聚物的酸性物质,稳定性降低;而钠离子对其稳定性几乎没有影响。

The dissolved and colloidal substances（DCS） released from Masson＇s pine CTMP and DIP, the newsprint furnish was character- ized by GC-MS technique and the stability of DCS against metal ions was studied. The results showed that the major resin and fatty acids （RFAs） released from unbleached CTMP were dehydroabietic acid, linoleic acid, oleic acid and palmitic acid, while methyl linolein, methyl palmitin, palmitic acid and dehydroabietic acid were the major part of RFAs from DIP. Alkaline peroxide bleaching favors the release of resin acids. The main sugar units of DCS are galactose, mannose, glucose and galacturonic acids. The concentration and proportion of acidic sugar units increase during peroxide bleaching. Study on the DCS stability against metal ions indicated that alkaline peroxide leads to the dissolution of neutral and acidic hemicellulosic materials into aqueous phase, among which the neural portion favors the DCS stabihty against calci- um and sodium-induced aggregation, while the acidic portion, especially the polygalacturonic acid, may react with calcium ions and accelerate the aggregation of DCS.