Determination of molar-mass parameters of TEMPO-oxidized pulps by SEC/MALLS/RI

IF 4.8 2区工程技术 Q1 MATERIALS SCIENCE, PAPER & WOOD

Cellulose Pub Date : 2025-07-05 DOI:10.1007/s10570-025-06636-2

Gaoyuan Hou, Korawit Chitbanyong, Miyuki Takeuchi, Izumi Shibata, Akira Isogai

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引用次数: 0

Abstract

Molar-mass (MM) and MM distributions of TEMPO-oxidized pulps (TEMPO: 2,2,6,6-tetramethylpiperidine-1-oxyl radical) measured under the same conditions as those of the original pulps are important for understanding the changes of MM parameters of cellulose molecules in pulps during TEMPO-catalyzed oxidation. The carboxy groups in TEMPO-oxidized pulps prepared from softwood and hardwood bleached kraft pulps were esterified in high yield by trimethylsilyl diazomethane using a newly established protocol, which enabled complete dissolution in 8% (w/w) lithium chloride/N,N-dimethylacetamide (LiCl/DMAc). A linear relationship was obtained between the carboxy contents (0.05–2.68 mmol/g) of TEMPO-oxidized pulps and the signal area ratio of methyl/C1 carbon atoms in solid-state ¹³C NMR spectra of the esterified products. Next, 1% (w/v) LiCl/DMAc solutions of the original pulps and TEMPO-oxidized and then esterified products were subjected to size-exclusion chromatography with refractive index and multi-angle static laser light scattering detection. Chromatographic elution patterns, MM plots, conformation plots, and related MM parameters of the pulps and esterified products were obtained with good reproducibility. The results showed that the changes of the degree of polymerization and its distribution for TEMPO-oxidized pulps can be investigated in terms of carboxy content, mass recovery ratio, and TEMPO-catalyzed oxidation conditions.

Graphical abstract

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用SEC/MALLS/RI测定tempo氧化纸浆的摩尔质量参数

TEMPO氧化纸浆（TEMPO: 2,2,6,6-四甲基哌啶-1-氧基）在相同条件下的摩尔质量（MM）和MM分布对于了解TEMPO催化氧化过程中纤维素分子MM参数的变化具有重要意义。用三甲基硅基重氮甲烷在8% （w/w）氯化锂/N，N-二甲基乙酰胺（LiCl/DMAc）溶液中高效酯化了软、硬木漂白硫酸盐纸浆中的羧基。结果表明，tempo氧化纸浆的羧基含量（0.05 ~ 2.68 mmol/g）与酯化产物的固体13C NMR中甲基/C1碳原子的信号面积比呈线性关系。然后，用1% (w/v) LiCl/DMAc溶液对原浆和tempo氧化后酯化产物进行排粒径层析，并进行折射率和多角度静态激光散射检测。获得了纸浆和酯化产物的色谱洗脱图、MM图、构象图及相关MM参数，重现性好。结果表明，可以从羧基含量、质量回收率和tempo催化氧化条件三个方面考察tempo氧化纸浆聚合程度及其分布的变化。图形抽象

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来源期刊

Cellulose 工程技术-材料科学：纺织

CiteScore

10.10

自引率

10.50%

发文量

580

审稿时长

3-8 weeks

期刊介绍： Cellulose is an international journal devoted to the dissemination of research and scientific and technological progress in the field of cellulose and related naturally occurring polymers. The journal is concerned with the pure and applied science of cellulose and related materials, and also with the development of relevant new technologies. This includes the chemistry, biochemistry, physics and materials science of cellulose and its sources, including wood and other biomass resources, and their derivatives. Coverage extends to the conversion of these polymers and resources into manufactured goods, such as pulp, paper, textiles, and manufactured as well natural fibers, and to the chemistry of materials used in their processing. Cellulose publishes review articles, research papers, and technical notes.