Abstract The influence of metal ions, Ca 2 + {\mathrm{Ca}^{2+}} and Mg 2 + {\mathrm{Mg}^{2+}}, on wood pitch retention at pH 8 was studied by investigating the pitch content of TMP-papers using both short- and long-column gas chromatography (GC). The effects of two different drying methods, air-drying and freeze-drying, on pitch retention were also compared in this work. The pitch emulsion was prepared with fatty acids, resin acids, and triglycerides at a certain ratio to simulate the pitch composition in closed water system in paper mill. At increasing pH, some of the resin and fatty acids will dissolve into the water phase as metal soaps. In this work, the retention of colloidal pitch in TMP-papers by metal ions at pH 8 was determined. The amount of 5 mM metal ions was found to retain more pitch. The tensile index decreased by the addition of metal ions, and the decrease became more pronounced as the increase of the metal ions concentration. Besides, the hydrophobicity of handsheets was found being changed only a little, which might because the morphology and pitch retained on the surface both affected the hydrophobicity.

中文翻译：

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金属离子和木沥青对TMP的保留和物理性能的影响

摘要 通过研究金属离子 Ca 2 + {\mathrm{Ca}^{2+}} 和 Mg 2 + {\mathrm{Mg}^{2+}} 在 pH 8 时对木沥青保持力的影响使用短柱和长柱气相色谱 (GC) 测定 TMP 纸的沥青含量。在这项工作中还比较了两种不同的干燥方法，风干和冷冻干燥对沥青保留率的影响。以一定比例的脂肪酸、树脂酸和甘油三酯制备沥青乳液，以模拟造纸厂闭水系统中的沥青组成。随着 pH 值的增加，一些树脂和脂肪酸会以金属皂的形式溶解到水相中。在这项工作中，测定了金属离子在 pH 8 下对 TMP 纸中胶体沥青的保留。发现 5 mM 金属离子的量保留了更多的间距。拉伸指数随着金属离子的加入而降低，并且随着金属离子浓度的增加，降低变得更加明显。此外，发现手抄纸的疏水性变化很小，这可能是因为表面保留的形态和沥青都影响了疏水性。