Creation of a new material stream from Japanese cedar resources to cellulose nanofibrils

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• 作者：Zhuqun Shi ; Quanling Yang ; Yuko Ono ; Ryunosuke Funahashi ; Tsuguyuki Saito ; Akira Isogai ; ^{aisogai@mail.ecc.u-tokyo.ac.jp" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Japanese cedar ; Cellulose nanofibril ; TEMPO-mediated oxidation ; Nanofibrillation ; Sugar composition
• 刊名：Reactive and Functional Polymers
• 出版年：2015
• 出版时间：October 2015
• 年：2015
• 卷：95
• 期：Complete
• 页码：19-24
• 全文大小：1040 K

文摘

Japanese cedar is one of the most abundant plantation softwoods in Japan, although it is not effectively utilized as a wood resource. Japanese cedar cellulose was isolated and subjected to one-pot catalytic oxidation and reduction with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and NaBH₄, respectively. The TEMPO-oxidized and NaBH₄-reduced Japanese cedar celluloses (TOCs-NaBH₄) had carboxylate content of up to 1.4 mmol/g and viscosity-average degrees of polymerization from 2000 to 3000. The X-ray diffraction patterns of the TOCs-NaBH₄ showed that the crystal widths were ~ 3 nm, indicating that the C6-OH groups present on the crystalline cellulose microfibril surfaces were selectively oxidized to C6-carboxylate groups. When the TOCs-NaBH₄ with carboxylate content of 0.9–1.4 mmol/g were mechanically disintegrated in water, transparent TEMPO-oxidized cellulose nanofibril (TOCN) dispersions were obtained. The lengths of the TOCNs, determined from their atomic force microscopy images, varied from 800 to 1500 nm, depending on the oxidation conditions. The TOCNs prepared from Japanese cedar cellulose have an average of high aspect ratios (> 300), which is greater than that (~ 150) prepared from wood pulp and thus advantageous.