Water Absorption Behavior and Its Effect on Static Mechanical and Dynamic Mechanical Properties of Flax Fabric Reinforced Epoxy Composites

ABSTRACT

In this work, four different grades of the Alkali cum Silane-treated plain-derived (irregular type) basket woven Flax fabric reinforced Epoxy (ASFE) composites were fabricated by varying their fiber weight fractions (0, 25, 35, and 45 wt.%) using compression molding technique. ASFE samples were subjected to salt water immersion test for 18 days and studied its effect on the their static and dynamic mechanical properties in accordance with ASTM standards. Also, interfacial shear strength between single flax fiber and epoxy material was determined using micro-droplet bonding test. Experimental Investigations revealed that salt water absorbed (SWA) flax/epoxy composites showed maximum drop of 23.23%, 29%, 35.43%, and 18.53% in tensile, flexural, impact and interlaminar shear strength, respectively. DMA study revealed that glass transition temperatures (T_g) of the ASFE composites were sensitive to the moisture absorption, and hence, SWA composites exhibited lower T_g value than dry composites. Furthermore, scanning electron microscopy clearly exposed fiber splitting, micro-cracks, and poor interfacial bonding of the ASFE composites.

摘要

在这项工作中, 通过使用模压技术改变其纤维重量分数 (0, 25, 35和45 wt.%), 制备了四种不同等级的碱-硅烷处理的普通衍生 (不规则型) 篮式编织亚麻织物增强环氧树脂 (ASFE) 复合材料. ASFE样品经过18天的盐水浸泡试验, 并根据ASTM标准研究了其对复合材料静态和动态力学性能的影响. 此外, 还通过微滴粘接试验测定了亚麻纤维与环氧材料之间的界面剪切强度 (IFSS). 实验研究表明, 盐水吸收亚麻/环氧复合材料的拉伸, 弯曲, 冲击和层间剪切强度 (ILSS) 分别下降了23.23%, 29%, 35.43%和18.53%. DMA研究表明, ASFE复合材料的玻璃化转变温度 (Tg) 对吸湿性敏感, 因此SWA复合材料的Tg值低于干燥复合材料. 此外, 扫描电子显微镜 (SEM) 揭示了ASFE复合材料的纤维分裂, 微裂纹和界面结合不良.

KEYWORDS:

• Flax/epoxy composites
• DMA
• moisture absorption
• silane treatment
• NFRPC

关键词:

• 亚麻/环氧复合材料
• 吸湿
• 硅烷处理

Research highlights

Overview of this research paper is as follows:

• Flax reinforced polymer composites have drawn attention of the industries and researchers due to its exceptional properties such as, high strength to weight ratio, abundant resource, bio-degradable, low cost and less abrasiveness. However, to achieve the superior properties in the flax/epoxy composites or in any natural fiber reinforced polymer composites, surface modified woven fabric reinforcement is preferable because fiber–matrix interaction would be higher.

• Most of the studies on flax woven fabric reinforced polymer composites showed greater mechanical properties when fabric reinforcements are in the form of plain, twill, satin, and basket structure. However, studies related to their derivatives are not discussed and has a lot of scope to explore in this domain.

• Plain-derived irregular basket woven flax reinforced epoxy composites on mechanical, dynamic mechanical, and sound acoustic properties have been delineated in our previous report. Moreover, their static mechanical and dynamic mechanical properties when exposed to different environment is highly required hence it has been explored in this current investigation.

Disclosure statement

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