Wood cellulose nanofibrils prepared by TEMPO electro-mediated oxidation
Wood cellulose nanofibrils prepared by TEMPO electro-mediated oxidation
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DOI：
10.1007/s10570-010-9484-9
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发表时间：
2011-04
期刊：
影响因子：
5.7
通讯作者：
T. Isogai;Tsuguyuki Saito;A. Isogai
中科院分区：
文献类型：
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作者：
T. Isogai;Tsuguyuki Saito;A. Isogai
采用无氯氧化剂的TEMPO或4-乙酰氨基-TEMPO对针叶木漂白硫酸盐浆（SBKP）进行了电催化氧化。氧化后的SBKPs水不溶性组分固回收率大于80%，氧化48 h后c6 -羧酸含量增加到约1 mmol g−1，氧化后的SBKPs中还形成了大量的c6 -醛基团（0.17-0.38 mmol g−1）。在pH值为10的TEMPO和pH值为6.8的4-乙酰氨基-TEMPO氧化48 h后，聚合度分别从2,200下降到520和1,400。氧化后SBKP保持了原有的纤维素I晶体结构和结晶度，说明所有c6氧化基团都选择性地在结晶纤维素微纤维表面形成。羧酸盐含量大于0.9 mmol g−1的氧化SBKPs在水中分解转化为单个纤维素纳米原纤维，产率超过80%。
A softwood bleached kraft pulp (SBKP) was subjected to electro-mediated oxidation in water with TEMPO or 4-acetamido-TEMPO without any chlorine-containing oxidant. Solid recovery ratios of water-insoluble fractions of the oxidized SBKPs were more than 80%, and C6-carboxylate contents increased up to approximately 1 mmol g−1after oxidation for 48 h. Significant amounts of C6-aldehyde groups (0.17–0.38 mmol g−1) were also formed in the oxidized SBKPs. The degree of polymerization decreased from 2,200 to 520 and 1,400 by the oxidation for 48 h with TEMPO at pH 10 and 4-acetamido-TEMPO at pH 6.8, respectively. The original cellulose I crystal structure and crystallinity of SBKP were maintained after the oxidation, indicating that all C6-oxidized groups were selectively formed on crystalline cellulose microfibril surfaces. The oxidized SBKPs with carboxylate contents of more than 0.9 mmol g−1were convertible to individual cellulose nanofibrils in yields of more than 80% by disintegration in water.