[1] Zhao Li, Li Shujin, Song Yang, et al. Analysis on degradation behaviors of sisal fibersat various pH conditions [J]. Journal of Southeast University (English Edition), 2022, 38 (3): 278-283. [doi:10.3969/j.issn.1003-7985.2022.03.009]

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Analysis on degradation behaviors of sisal fibersat various pH conditions()

剑麻纤维在不同pH值条件下的退化行为分析

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Journal of Southeast University (English Edition)[ISSN:1003-7985/CN:32-1325/N]

Volumn:

38

Issue:

2022 3

Page:

278-283

Research Field:

Materials Sciences and Engineering

Publishing date:

2022-09-20

Info

Title:

Analysis on degradation behaviors of sisal fibersat various pH conditions

剑麻纤维在不同pH值条件下的退化行为分析

Author(s):

Zhao Li¹;  2;  Li Shujin²;  Song Yang²;  Zhang Yamei¹

¹ School of Materials Science and Engineering, Southeast University, Nanjing 211189, China
² School of Civil Engineering and Architecture, Changzhou Institute of Technology, Changzhou 213032, China

赵丽¹;  2;  李书进²;  宋杨²;  张亚梅¹

¹ 东南大学材料科学与工程学院, 南京 211189; ² 常州工学院土木建筑与工程学院, 常州 213032

Keywords:

sisal fibers;  cement composites;  alkaline degradation;  microstructure;  tensile strength

剑麻纤维;  水泥基复合材料;  性能退化;  微观结构;  抗拉强度

PACS:

TU528.58

DOI:

10.3969/j.issn.1003-7985.2022.03.009

Abstract:

The degradation behaviors(mass loss, tensile strength, crystallinity index, and microstructure)of sisal fibers immersed in sodium hydroxide solution with pH of 13.6, 12.9, and 11.9 were investigated via X-ray diffraction and scanning electron microscopy. A three-stage degradation process of natural fibers in an alkaline environment was proposed. The results showed that the sisal fibers exhibited a sharp mass loss over the first 7 d of degradation under all pH conditions, attributable to the rapid hydrolysis of lignin and hemicellulose at the fiber surface. The sisal fibers degraded at pH 12.9 and 13.6 over 1 month exhibited significantly lower tensile strengths(181 and 195 MPa, respectively)than the original fibers(234 MPa)because of the loosely bound structure of the component microfibrils caused by the hydrolysis of the linking lignin and hemicellulose. After 6-month degradation, stripped microfibrils occurred in the fibers, resulting in substantial degradation in tensile strength. The sisal fibers degraded at pH 11.9 largely maintained their integrity and tensile strength, even after 6 months, indicating that reducing the environment pH can effectively mitigate the degradation.

采用X射线衍射和扫描电子显微镜, 从质量损失、抗拉强度、结晶度和微观形貌等方面研究了剑麻纤维在pH=13.6, 12.9, 11.9的NaOH溶液中的退化行为, 并提出了植物纤维在碱性环境中退化的三阶段模型.结果表明, 在所有pH值下退化的剑麻纤维, 前7 d均经历迅速的质量损失, 这是表面木质素和半纤维素迅速溶解导致的.剑麻纤维在pH=13.6, 12.9的NaOH溶液中退化1个月后, 夹层中的木质素和半纤维素水解, 导致微细纤维松散, 抗拉强度由234 MPa分别下降至181和195 MPa;退化6个月后, 微细纤维剥离, 抗拉强度大幅降低.剑麻纤维在pH=11.9的NaOH溶液中退化6个月后, 结构完整性与抗拉强度仍被保留, 表明降低pH可有效延缓退化进程.

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Memo

Memo:

Biography: Zhao Li(1987—), female, doctor, associate professor, xianrenqiu_xph1209@163.com.
Foundation items: The Natural Science Foundation of China(No. 52108191), the China Postdoctoral Science Foundation(No. 2021M690622), the Changzhou Sci&Tech Program(No. CJ20210153, CE20205050), the Qing Lan Project of Jiangsu, the Young Sci-tech Talents Promoting Project of Changzhou.
Citation: Zhao Li, Li Shujin, Song Yang, et al. Analysis on degradation behaviors of sisal fibers at various pH conditions[J].Journal of Southeast University(English Edition), 2022, 38(3):278-283.DOI:10.3969/j.issn.1003-7985.2022.03.009.

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