Slaked Lime Solution as a Viable Eco-friendly Treatment to Improve the Tensile Strength of Maize Stem Fibers

ABSTRACT

In this study, the effect of the environmentally friendly slaked lime solution on the tensile strength of maize stem fibers was investigated and compared with the tensile strength obtained with a 3% wt NaOH and 10% wt NaHCO₃ solutions. Maize fibers from dried stems were manually extracted, cleaned, and treated with the respective three solutions at different soaking periods. The results showed that a maximum increase in tensile strength of 165.1% was obtained with the NaOH treatment (at 24 hours) followed by an increase of 107.1% (at 21 hours) for the Ca(OH)_2, and a 46.6% (at 18 hours) increase for the NaHCO₃ treatment. Analysis of the FTIR spectra revealed that the significant improvement in the tensile strength for the NaOH treatment is attributed to the partial transformation of cellulose I to cellulose II. However, the increase in the strength of the Ca(OH)₂-treated fibers has been attributed first, to the significant reduction in the fiber cross-sectional area, second, to the removal of specific amorphous constituents such as hemicellulose, and to the formation of a stable calcium pectinate layer, which improves the fiber’s resistance to fracture.

摘要

在本研究中, 研究了环境友好的熟石灰溶液对玉米茎纤维拉伸强度的影响, 并与3%wt NaOH和10%wt NaHCO3溶液获得的拉伸强度进行了比较. 从干茎中提取玉米纤维, 在不同的浸泡期分别用三种溶液清洗和处理. 结果表明, NaOH处理 (24小时时) 的拉伸强度最大增加165.1%, Ca(OH)2处理 (21小时时) 增加107.1%, NaHCO3处理 (18小时时) 增加46.6%. FTIR光谱分析表明, NaOH处理的拉伸强度显著提高归因于纤维素I向纤维素II的部分转化. 另一方面, 经Ca (OH)2处理的纤维强度的增加首先归因于纤维横截面积的显著减小, 其次归因于去除了特定的无定形成分, 如半纤维素, 形成稳定的果胶酸钙层, 提高纤维的抗断裂性.

KEYWORDS:

• Maize stem fibers
• tensile strength
• sodium hydroxide
• sodium bicarbonate
• calcium pectinate
• slaked lime solution

Authors bibliography

H. Ramasawmy is an Associate Professor in the Mechanical & Production Engineering Department, University of Mauritius, with more than 25 years of working experience in academia. His current main field of research is green functional products development based on natural fibres and composites.

Jaykumar Chummun joined the Faculty of Engineering of the University of Mauritius more than 25 years ago and is currently a Senior Lecturer in the Mechanical & Production Engineering Department. His main area of interest is Sustainable Manufacture with emphasis in the use of locally available natural fibres.

Ms. P. D. Emrith is current a full time research scholar at the Faculty of Engineering, University of Mauritius, working in the field of natural fibres.

Acknowledgments

The authors wish to thank the Higher Education Commission (HEC), Republic of Mauritius for the financial support for the project work entitled ‘Investigation in the use of banana and maize agro-wastes as a source of natural fibres for Engineering, Textile and Handicraft Applications’ (under the Inter-disciplinary/Inter-institutional Team based Research Scheme).

The authors would also wish to thank Ms R. Nowbuth and Mrs V. Oogarah of the FAREI, Mauritius for their kind collaboration and support.

Disclosure statement

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

Additional information

Funding

This work was supported by the Higher Education Commission, Mauritius. [project work entitled ‘Investigation in the use of banana and maize agro-wastes as a source of natural fibres for engineering, textile and handicraft applications'].