Effects of Physical and Mechanical Properties of Coir Fiber and Reinforced Epoxy Composites Treated with Acetic Anhydride and Alkali

ABSTRACT

Modified coir fiber improves compatibility between fiber and matrix. To explore a better fiber treatment approach and enhance the mechanical properties of composites, this study conducted alkali treatment and acetic anhydride treatment on long and short coir fibers. The effects of different treatments on the properties of coir fibers were characterized using TGA, FTIR, SEM, and stereomicroscopy, and the mechanical properties of the composites were tested. Results showed that the tensile strength of alkali-treated coir fibers (ACF) and acetic anhydride-treated coir fibers (AACF) were remarkably improved. Notably, ACF exhibited a significant 69% increase in tensile strength. The tensile strength of composites with alkali-treated long coir fibers (ALC) and composites with alkali-treated short coir fibers (ASC) reached 34.51 and 21.14 MPa, respectively. The highest flexural strength was found for the acetic anhydride-treated coir fibers, and the flexural strength of composites with acetic anhydride-treated long coir fibers (AALC) and composites with acetic anhydride-treated short coir fibers (AASC) reached 54.38 and 53.46 MPa, respectively. This study presents an improved methodology for enhancing the interfacial bonding ability between coir fibers and the matrix, consequently improving the properties of composites. It offers reference for the investigation of natural fiber composites.

摘要

椰壳纤维增强复合材料具有显著的适用性，但由于椰壳纤维与聚合物基体之间的粘附性较弱，需要进行改性. 为了探索更好的纤维处理方法，提高复合材料的力学性能，本研究对长纤维进行了碱处理，对短纤维进行了醋酸酐处理. 利用热重分析、红外光谱、扫描电镜和立体显微镜表征了不同处理对椰壳纤维性能的影响，并测试了复合材料的力学性能. 结果表明，碱处理的椰壳纤维（ACF）和醋酸酐处理的椰皮纤维（AACF）的抗拉强度均有明显提高. 值得注意的是，ACF的抗拉强度显著提高了69%. 碱处理的椰壳纤维与环氧树脂的界面结合能力最好. 碱处理长椰壳纤维（ALC）复合材料和碱处理短椰壳纤维复合材料的拉伸强度分别达到34.51和21.14MPa. 醋酸酐处理的椰壳纤维的弯曲强度最高，醋酸酐处理长椰壳纤维复合材料（AALC）和醋酸酐处理短椰壳纤维（AASC）复合材料的弯曲强度分别达到54.38和53.46MPa. 本研究提出了一种改进的方法来提高椰壳纤维与基体之间的界面结合能力，从而改善复合材料的性能. 为天然纤维复合材料的研究提供了参考.

KEYWORDS:

• Coir fiber
• acetic anhydride
• NaOH
• composite
• surface morphology
• mechanical properties

关键词:

• 椰子壳粗纤维
• 乙酸酐
• 混合成的
• 表面形态
• 机械性能

Highlights

• The characteristics of coir fibers treated by different methods are compared and studied.

• The principle of the method to improve the interfacial properties between coir fiber and epoxy resin is studied.

• The mechanical properties of composites are studied by tensile strength test and flexural strength test.

• The moisture resistance of composites is studied by hygroscopicity test.

Acknowledgments

The authors acknowledge the Hainan Provincial Natural Science Foundation of China for supporting this study.

Disclosure statement

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

Additional information

Funding

This work was supported by Hainan Provincial Natural Science Foundation of China, 521RC494, 521QN0869, and 520RC536.