Several eucalyptus pulps (85% of cellulose) with different lignin and HexA content (unbleached, TCF and ECF) as well as cotton linters (97% of cellulose) were treated with ozone (at different pH and ozone doses) in order to modify its fibre-components. Special interest was given in the introduction of functional groups in carbohydrates. The presence of these groups was mainly identified by the chain scissions due to carbonyl groups (CS_C=O) produced in cellulose during viscosity measurement. At a dose of 0.5% odp of ozone, the greatest amount of CS_C=O (0.5) was created at acidic pH and with the ECF pulp, followed by the TCF (0.3) and by the unbleached (0.2). The same CS_C=O (0.2) was obtained in cotton pulp. In this pulp, the ozone concentration had to be increased for the treatment to be effective. A further increase in the accessibility in both pulps was achieved by applying a washing stage between two ozone stages at 0.5% (0.5 + 0.5). With this treatment, the CS_C=O was increased to 5.3 in the ECF, to 0.8 in the TCF and only to 0.3 in cotton. Brightness reversion and the amount of DNPH consumed were also used to verify the presence of functional groups. At 0.5 + 0.5, brightness reversion was increased from 16 to 55% in ECF, from 27 to 46% in TCF and from 7 to 31% in cotton. Therefore, it is shown that functional groups can be introduced by ozone in carbohydrates, but this effect strongly depends on the lignin, HexA and hemicellulose content.

Graphical abstract

中文翻译：

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评估臭氧在纤维素上产生官能团的潜力

用臭氧（在不同的 pH 值和臭氧剂量）处理几种具有不同木质素和 HexA 含量（未漂白、TCF 和 ECF）的桉树浆（85% 的纤维素）以及棉绒（97% 的纤维素）以改变其纤维成分。特别感兴趣的是在碳水化合物中引入官能团。这些基团的存在主要通过在粘度测量过程中纤维素中产生的羰基 (CS _C=O )引起的断链来确定。在 0.5% odp 的臭氧剂量下，在酸性 pH 值和 ECF 纸浆中产生最大量的 CS _C=O (0.5)，其次是 TCF (0.3) 和未漂白纸 (0.2)。相同的 CS _C=O(0.2) 在棉浆中获得。在这种纸浆中，必须增加臭氧浓度才能使处理有效。通过在两个臭氧阶段之间应用 0.5% (0.5 + 0.5) 的洗涤阶段，进一步提高了两种纸浆的可及性。通过这种处理，ECF 中的 CS _C=O增加到 5.3，TCF 中增加到 0.8，棉花中仅增加到 0.3。亮度回复和消耗的 DNPH 量也用于验证官能团的存在。在 0.5 + 0.5 时，ECF 的亮度回复从 16% 增加到 55%，TCF 从 27% 增加到 46%，棉花从 7% 增加到 31%。因此，表明可以通过臭氧在碳水化合物中引入官能团，但这种效果很大程度上取决于木质素、HexA 和半纤维素的含量。

图形概要