Structure Damage on Cotton Fiber via Coupling Effect of Moisture Regains and Low Temperature

ABSTRACT

The most crucial variables that influence the characteristics and quality of cotton fibers during the cotton growth and ginning processes are temperature and moisture regains. Here the cotton fiber samples were generated with pre-treatment using a synergistic strategy of moisture regains and low temperatures, the morphology and structure of the fibers with different pre-treatments were analyzed by using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray Photoelectron Spectrometer (XPS), X-ray diffraction (XRD), and Carbon-13 Nuclear Magnetic Resonance Spectrometry (13C NMR). Further, the mechanical properties of the cotton fibers were evaluated using LLY-06E tensile. The results shown that, with 3 days of freezing in -18℃, the linear density variation of the cotton fiber samples reached maximum, and the surface of the fibers showed noticeable fractures, local holes, and folded damage. Moreover, the low temperature and high moisture regain caused the internal water molecules of the cotton fibers interact in complex ways, altering the intermolecular forces but without changing the chemical composition. This research expands the temperature field of cotton fibers, particularly in the ginning process, by investigating the damage to the mechanical characteristics of cotton fibers caused by the combined effect of low temperature and moisture regain.

摘要

在棉花生长和轧棉过程中，影响棉纤维特性和质量的最关键变量是温度和回潮率。在这里，使用回潮和低温的协同策略对棉纤维样品进行了预处理，并使用扫描电子显微镜（SEM）、傅立叶变换红外光谱（FTIR）、X 射线光电子能谱仪（XPS）、X 射线衍射（XRD）和碳 13 核磁共振谱（13CNMR）分析了经过不同预处理的纤维的形态和结构。此外，还使用 LLY-06E 拉伸法评估了棉纤维的机械性能。结果表明，在-18℃下冷冻 3 天后，棉纤维样品的线性密度变化达到最大值，纤维表面出现明显的断裂、局部孔洞和折叠损伤。此外，低温和高回潮导致棉纤维内部水分子发生复杂的相互作用，改变了分子间的作用力，但没有改变化学成分。这项研究通过研究低温和回潮共同作用对棉纤维机械特性造成的破坏，拓展了棉纤维的温度领域。

KEYWORDS:

• Moisture regains
• low-temperature
• mechanical damage
• cotton
• fibrils
• characterization
• freezing process

关键词:

• 水分恢复
• 低温
• 机械损伤
• 棉
• 原纤维
• 刻画
• 冷冻过程

Highlights

• A new pretreatment strategy, i.e., moisture regains and low-temperature, was designed for study the property changes of cotton fibers. The different types of cotton fiber samples were obtained by the treatment of moisture conditioning-low temperature-rewarming. Comparing the control sample and the pretreatment fiber that had more obvious cracks, local holes and folded damage with increase of low-temperature freezing days.

• Synergistic effects of high moisture regain and low-temperature on the fibrils structure and crystallinity, and bonding energy of cotton fibers. The apparent structure, mechanical properties and macromolecular structure of the cotton fiber test samples were characterized and analyzed using IR, XRD, XPS and 13C NMR, etc. It was further verified that the internal molecules may have been changed or reorganized during the treatment of moisture conditioning- low-temperature- rewarming, and the stability of the internal aggregated state structure of the fibers decreases, exhibiting a decrease in the mechanical properties of the fibers.

• Ice-crystal damage to the fibrils causes mechanical property reduction. The results of mechanical indicated that, the mechanical properties of cotton fibers decreased rapidly when subjected to low-temperature freezing treatment, with a minimum value of 388.71 MPa and 7.7%, respectively, when the treatment days were 3 and 8.

Acknowledgments

We gratefully acknowledgements the financial support of the National Natural Science Foundation of China, the authors also thank College of Textile and Fashion, and the Ginning Company providing cotton sample, field investigation, and fiber testing.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author’s contributions

Jiqiang Cao: Methodology, Software, Testing, Data curation, Writing-Original draft preparation. Xiang Liu: Software, Supervision, Validation, Writing- Reviewing. Ruolian Mo: Visualization, Investigation Testing. Hongling Liu: Thesis structure construction, Data handling, sample analysis. Hong Xu: Conceptualization, Writing- Reviewing and Editing, Funding acquisition.

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I confirm that any participants (or their guardians if unable to give informed consent, or next of kin, if deceased) who may be identifiable through the manuscript (such as a case report), have been given an opportunity to review the final manuscript and have provided written consent to publish.

Ethical approval

I confirm that all the research meets ethical guidelines and adheres to the legal requirements of the study country.

Additional information

Funding

Funding was provided by National Natural Science Foundation of China [grant 51963020].