Improvement of the Degradation of Tensile and Impact Strength of Water-aged Sisal Fiber-reinforced Polyester Composites: A Comparative Study on the Effects of Hybridizations, Hybrid Layering Sequences, and Chemical Treatments

ABSTRACT

This research aims to reduce the degradation of sisal fiber-reinforced polyester composites due to water absorption through chemical treatments and hybridizations. Sisal fibers were treated using sodium hydroxide (NaOH) and baking soda (NaHCO3). Unidirectional glass and carbon fibers were chosen as hybrid fibers. Thirteen laminates of pure sisal fibers, hybridized with glass or carbon fibers at different stacking sequences and volume fractions, were prepared using the hand layup technique. The laminates were examined for tensile and impact strength at dry and wet conditions. The effects of baking soda and sodium hydroxide treatments, glass and carbon fibers hybridization, and the sequence and volume of the hybrid fibers on the tensile strength, impact strength, water absorption, and degradation of the laminates were studied and compared. Chemical treatments and hybridizations have enhanced the tensile and impact strength of the composites. Significant reduction in the water uptake rate and degradation of the laminates were observed. Almost 166% and 87%, respectively, improvements were obtained in the tensile and impact strength of the dry samples. Moreover, more than 74% reduction in water uptake, and 84.7% and 91.7%, respectively, improvements in the degradation of the tensile and impact strengths were discovered.

摘要

本研究旨在通过化学处理和杂交, 减少剑麻纤维增强聚酯复合材料因吸水而产生的降解. 用氢氧化钠 (NaOH) 和小苏打 (NaHCO3) 处理剑麻纤维. 选择单向玻璃纤维和碳纤维作为混杂纤维. 采用手工叠层技术, 制备了13块不同叠层顺序和体积分数的纯剑麻纤维与玻璃纤维或碳纤维混杂层压板. 在干燥和潮湿条件下, 对层压板的拉伸和冲击强度进行了检查. 研究并比较了小苏打和氢氧化钠处理, 玻璃纤维和碳纤维杂化以及杂化纤维的顺序和体积对层压板拉伸强度, 冲击强度, 吸水率和降解的影响. 化学处理和杂交提高了复合材料的拉伸和冲击强度. 观察到层压板的吸水率和降解显著降低. 干燥样品的拉伸强度和冲击强度分别提高了166%和87%. 此外, 发现吸水率降低了74%以上, 拉伸强度和冲击强度的降低分别提高了84.7%和91.7%.

KEYWORDS:

• Sisal fiber
• alkali treatment
• hybridization
• stacking sequence
• water absorption
• mechanical properties

Acknowledgments

The authors are glad to appreciate the School of Mechanical and Industrial Engineering and School of Civil Engineering at Ethiopian Institute of Technology Mekelle (EIT-M), Mekelle University for helping us by providing materials, laboratory service, and research funding.

Disclosure statement

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