An investigation of the effect of relative humidity on viscoelastic properties of flax fiber reinforced polymer by fractional-order viscoelastic model

The lignocellulosic fiber has distinct capacities and properties from diverse perspectives. As there is a crucial need for the development of green products, many industries are racing to identify potential fibers for their products. This work focuses first on the property enhancement using chemical modification techniques for Cymbopogon flexuosus stem fiber (CFS), which is extracted from the waste residue of an oil industry. The chemically treated fibers resulted in higher cellulose (77.35%) and lower hemicellulose‐lignin contents (8.36% and 14.5%), which favors composite manufacturing. Morphological analysis on the fiber surface through scanning electron microscope (SEM) and atomic force microscope (AFM) evidenced the surface was rough, and a single fiber tensile test reveals an average tensile strength of 635 ± 4.5 MPa. Further x‐ray diffraction examination verified the existence of semi‐crystalline cellulose with a size of 14.32 nm and a higher crystallinity index of 55.17%. Secondly, to explore fiber prospective qualities against the commercially available bio‐composite, epoxy resin‐based composites were prepared by varying the weight and length of fiber reinforced. The surface‐modified CFS epoxy composite has the highest tensile strength (77.71 MPa), tensile modulus (5.26 Gpa), flexural strength (87.4 MPa), flexural modulus (1.85 GPa), hardness (64 HRRW), and impact strength (9.31 J/cm2). The thermogravimetric analyses were evaluated to assess their weight loss under heat influence. Tensile fractography was also investigated to establish the structure–property relationship between the composite and fiber. Thus, unique fiber was identified as an ecologically benign and economically viable raw material to build lightweight green materials for industrial applications.Highlights Studies explores the potential of CFSF, which is typically an industrial waste. Chemical modification reveals the enhancement of properties. Identifies optimum parameters that enhance composite properties. This aligns with the broader trend of sustainable and green manufacturing.

Section: Fabrication and Characterization Of The Compositementioning

confidence: 99%

Section: Fabrication and Characterization Of The Compositementioning

confidence: 99%

Enhancing properties and sustainability: Surface modified Cymbopogon flexuosus stem fiber for green composite materials

Somasundaram,

Ananchaperumal

et al. 2023

“…In addition to inducing creep, the hierarchical and porous structure of the natural plant fiber also results in moisture‐sensitive properties of the PFRP 15,23,24 . Previous research has pointed out that the mechanical properties of PFRP can be significantly affected by the humidity level of the environment 25 . Pupure et al 26 reported an obvious structural change in flax fiber due to the moisture absorbed by cellulose, which seriously impacts the mechanical properties of flax polymer reinforced by flax fiber.…”

Section: Introductionmentioning

confidence: 99%

“…15,23,24 Previous research has pointed out that the mechanical properties of PFRP can be significantly affected by the humidity level of the environment. 25 Pupure et al 26 reported an obvious structural change in flax fiber due to the moisture absorbed by cellulose, which seriously impacts the mechanical properties of flax polymer reinforced by flax fiber. By monotonic mechanical tests, Thuault et al 27 claimed that flax fiber's tensile strength significantly decreases while working in a high-humidity environment.…”

Section: Introductionmentioning

confidence: 99%

Effect of environmental humidity on the creep behavior of flax fiber‐reinforced polymer composites

Hurk

Lugger

et al. 2023

Self Cite

Flax fiber‐reinforced polymer (FFRP) composites are emerging popular environmental‐friendly construction materials. However, their significant creep properties have been a major concern for using FFRP in load‐bearing structures. This article presents an investigation of the effect of environmental humidity on the creep behavior of the FFRP. Samples with flax fiber in 0°, 90°, and ± 45° were manufactured, respectively, by the vacuum infusion method. Accelerated creep tests were conducted on samples in different relative humidities (RH), and the results were analyzed by the time–temperature superposition principle (TTSP). It is found the creep development of samples with 0° and 90° fiber increases with the RH, and their 30‐year total strain in 97% RH is about 10 times higher than that in 11% RH. The samples with ±45° fiber are found not obviously sensitive to the humidity change. The scanning electron microscope (SEM) check indicates the change in the fiber–matrix interface and cracks between microfibrils in a fiber bundle is the main reason for the change of creep behavior in high humidity. This study may benefit the design of structures made of natural fiber‐reinforced polymer composites, especially for load‐bearing structures working in high‐humidity environments.

“…7 PFRP durability concerns include weathering caused by moisture, alkaline exposure, temperature/humidity cycles, UV irradiation, and stress effects such as fatigue and creep. 8,9 Unlike glass fiber or carbon fiber, natural plant fiber consists of pectin and cellulose in heterogeneous characteristics, making its mechanical performance dependent on environmental factors such as humidity and temperature. 10 Several studies have investigated the long-term performance of PFRP.…”

Section: Introductionmentioning

confidence: 99%

Effect of UV‐water weathering on the mechanical properties of flax‐fiber‐reinforced polymer composites

Xu,

van den Hurk,

Liu

et al. 2023

Self Cite

This study examines the influence of weathering aging on the mechanical properties and durability of flax fiber‐reinforced polymer composites (FFRP) intended for outdoor applications. Employing an accelerated weathering environment replicating natural outdoor conditions, encompassing UV radiation, condensation, and water spray, the FFRP samples with 2 and 4 mm thicknesses underwent exposure durations of 0, 500, 1000, and 1500 h. Mechanical tests characterized tensile, flexural, and inner‐plane shear properties, while a custom‐made apparatus measured the long‐term tensile creep behavior. Additionally, scanning electron microscopy allowed for the observation of microscopic changes in fiber and matrix. The findings illustrate a consistent decline in tensile and flexural properties with increased weathering exposure, resulting in reductions of 17% and 38% in the tensile strength and modulus, and 24% and 52% in the flexural strength and modulus after 1500 h. Intriguingly, inner‐plane shear strength exhibited a slight increase after 500 h before a subsequent decrease. Furthermore, samples with the same thickness demonstrated an increased creep development with longer weathering durations. Despite this, the mechanical degradation rate induced by weathering was comparatively slower for thicker samples. Overall, the diminished mechanical properties of FFRP post‐weathering can be attributed not only to the polymer but also to the substantial role played by flax fibers in this process.Highlights UV weathering degrades the mechanical properties of flax/polyester composites. Both the instantaneous elastic properties and the long‐term creep behavior are affected by weathering. Thickness influences the mechanical degradation of the composites caused by UV weathering. SEM confirmed UV‐water weathering resulted in the degradation of both natural fiber and polymer matrices.