Optimizing chemical treatments for enhanced bamboo fibre properties for sustainable industrial applications

Abstract

Natural fibres (NF) are becoming increasingly appealing to investigate due to their numerous applications, susceptibility, biodegradability, and ability to offer sustainable products that promote technical invention and a range of industrial applications. In this investigation, NF obtained from Bamboo fibres (BmF) was chemically modified. First, the NF was pre-treated with ethanol (C₂H₆O), followed by Potassium permanganate (KMnO₄) in acetone solution at different circumstances concerning the treatment duration and chemical concentration. Utilizing both treated and untreated fibres, X-ray diffraction (XRD), Fourier transform infrared (FTIR), Thermo Gravimetric analysis (TGA), scanning electron microscopy (SEM), and mechanical characterization were utilized to determine the impact of this alteration on the crystallographic, thermal, macromolecular, morphological, and mechanical properties of the BmF. The XRD scrutiny unveiled significant modifications in the fibre’s crystalline characteristics. The partial elimination of wax, hemicellulose, and lignin was verified by FTIR examination. TGA analysis results demonstrated that the treated fibres were suitable for processing with low-temperature polymers. At optimal conditions, the tensile strength of treated single fibres exhibited 52.17% improved strength over pristine BmF, and surface roughness was attained according to SEM morphology. This study has demonstrated that at optimal treatment conditions, the treated BmF has the potential for usage as reinforcement in a variety of bio-composites for distinct industrial and advanced applications.

Keywords

bamboo fibres ethanol industrial applications modification natural fibres treatment

Introduction

NF has been a vital component of human society for generations, providing materials for textiles, construction, and other applications.^1–5 Owing to their prospective uses in sustainable sectors and their environmental friendliness, these NF have lately attracted renewed study.^6,7 With a diverse spectrum of characteristics, these NF are obtained from plants, minerals, and animals.

The biodegradability breathability, and comfort of plant-based fibres including jute, cotton, hemp, and flax are well-known attributes.^7–9 NF offers various advantages over synthetic counterparts. They are biodegradable and renewable, reducing the environmental impact associated with disposal. NF is also less energy-intensive during production, contributing to lower carbon emissions. These fibres find applications in textiles, packaging, composites, construction, high-performance composites, and even medical fields.^10–13 The processing of NF involves several stages, including harvesting, retting (for plant fibres), cleaning, and spinning.^14,15 Mechanical, chemical, and enzymatic retting methods are employed to extract fibres from plant sources. Mechanical methods involve physically breaking down the plant tissues, whereas chemical techniques depend on dissolving the binding components with chemicals. One of the primary rationales for the resurgence of interest in NF is their eco-friendliness.^14,16,17 Synthetic fibres, such as Polyester, Rayon, Nylon, Acrylic and Aramid, are derived from petrochemicals and contribute to microplastic pollution. NF, on the other hand, decomposes naturally without releasing harmful substances. The cultivation of NF can also positively affect soil quality and carbon sequestration, further enhancing their environmental credentials. NF treatments can improve surface roughness, minimize moisture absorption mechanisms, remove or minimize surface contaminants, and modify the surface chemically. Additionally, the amount of independent hydroxyl groups in cellulose is reduced, which lessens the contrariness of the molecules in the cellulose and improves their conformity with the matrices.^18–20

To enhance NF properties and performance, researchers have explored different pre-treatment methods. Ethanol pre-treatment is one such technique that offers advantages in improving fibre characteristics and compatibility with matrices. The process aims to remove impurities, waxes, and lignin present on the fibre surface, enhancing fiber-matrix adhesion and mechanical properties.^21,22 Ethanol is chosen for its propensity to dissolve both non-polar and polar compounds, effectively cleaning and modifying fibre surfaces.^23–25

In comparison to other well-known natural fibers like jute, coir, sisal, straw, and banana, BmF offer higher specific strength and stiffness in plastic materials, which is why their anatomical characteristics, ultrastructure, and plant breakage process are generating increasing interest in them.¹¹ Permanganate treatment of BmF holds promise for enhancing its properties and expanding its range of applications. The treatment affects the surface roughness, wettability, mechanical and properties with implications in absorbent, textiles, and composites materials.^26–28 Permanganate treatment significantly modifies the characteristics of NF, impacting colour, surface properties, and chemical composition. The permanganate treatment can be employed to modify a range of NF, including banana, cotton, bamboo, jute, linen, plantain, and hemp.^27,29–31 BmF has emerged as a remarkable and sustainable alternative to traditional textile materials, offering a range of unique properties and environmental benefits. BmF has garnered considerable attention as an eco-friendly and sustainable alternative to traditional textile materials owing to their advancement and minimal environmental effect.^32–35 BmF finds applications in various products such as clothing, packaging, architecture, and construction.^25–34

In this study, ethanol pre-treated permanganate BmF was prepared at different permanganate concentrations and duration. The primary objectives of these actions are to isolate the technical fibres by removal of non-structural debris from the BmF bundles and evaluate the impact of these changes on the fibre’s crystallographic, thermal, macromolecular, morphological, and characteristics. The mechanical properties via tensile strength were also evaluated. KMnO₄ and ethanol were selected as treatments for this study due to their effective surface modification properties. KMnO₄ is a potent oxidizing agent that introduces hydroxyl and carboxyl functional groups onto the fibres surface, improving interfacial adhesion with the polymer matrix. Ethanol acts as a solvent to remove surface impurities, waxes, and residual contaminants, ensuring better chemical interaction. Alternative treatments such as NaOH³⁶ can enhance surface roughness but may weaken the fibres at high concentrations, while silane coupling agents improve compatibility by forming siloxane linkages. Acid treatments (e.g., HCl, H₂SO₄) can remove amorphous components but risk excessive degradation, whereas enzyme-based therapies offer an eco-friendlier approach with controlled surface modification. Considering these factors, KMnO₄ and ethanol were chosen for their balance between effectiveness and minimal fibres damage.

Materials and methods

Bamboo fibres were supplied by Go Green Products, Valasaravakkam, Chennai. Tamil Nadu, India (Figure 1). KMnO₄, ACS reagent, ≥99.0%, Acetone ACS reagent, ≥99.9%, and absolute ethanol were purchased from Sigma-Aldrich (Merck).

Figure 1.

Bamboo fibres (a) Pristine BmF (b) Treated BmF samples.

Sample preparation and permanganate treatment

The supplied BmF were of irregular length of between 30 and 100 cm and a diameter of 15 ± 2 μm. Initially, the BmF was chopped into tiny pieces measuring 10 mm ± 2 mm. The BmF were immersed in absolute C₂H₆O, for 30 min, and stirred slowly at every 5 min intervals. Thereafter the C₂H₆O solution was poured out, and the Bmf oven dried for 1 h at 65 ± 5°C.³⁶ KMnO₄ - acetone ((CH₃)₂CO) solution of 0.01 %, 0.05 %, and 0.10 % was prepared by dissolving the KMnO₄ crystals in [(CH₃)₂CO] solution to obtain a purple solution. At different intervals of 1 min, 2 min, and 3 min, the pre-treated BmF were submerged in the prepared solution.^10,12,31 Following the specified amount of time, the resulting solution was strained, and the BmF was washed several times with excess acetone to eliminate any excess KMnO₄ solution. The treated BmF was transferred to an air circulation oven and dried at 60 ± 5°C for 6 h.^10,12,31 The BmF were placed in a desiccator after weighing to allow them to cool. Thereafter, it was placed back in the oven at the same temperature for another 1 h and re-weighted. This procedure was followed up till a steady weight was achieved. The fibres were assigned the names indicated in Table 1. The prefix “P” indicates the KMnO₄ solution’s concentration, while the suffix “P” represents the fibre’s immersion duration, expressed in minutes. “RF” refers to the designation of untreated fibres.

Table 1.

Treatment parameters for BmF.

Samples	KMnO₄ Concentration (%)	KMnO₄ Treatment time (Mins)
RF	0	0
0.01P1	0.01	1
0.01P2	0.01	2
0.01P3	0.01	3
0.05P1	0.05	1
0.05P2	0.05	2
0.05P3	0.05	3
0.10P1	0.10	1
0.10P2	0.10	2
0.10P3	0.10	3

Characterization

The consequence of the chemical modification on the crystallographic structures of the BmF was investigated via XRD, engaging a Empyrean X-Ray diffractometer. The angle of diffraction was scanned from 5 ° to 90 °. There are several methods available to determine crystallinity index (CI).^37–41 Some of these methods include the Segal method,⁴² Ruland –Vonk method,⁴³ and Rietveld refinement method.⁴⁴ del Cerro, et al., (2020), reported CI is calculated by deconvolution (pseudo-Voigt fitting) of the 1D X-ray diffractograms.⁴⁵ In the XRD analysis, X-ray spectra were fitted using Origin software. Equation (1) is utilized to calculate the crystallinity index (CI), which was suggested by Segal et al., (1959). After subtracting the background signal, the height ratio between the crystalline peak’s intensity and the overall intensity was used to compute the CI as previously describe.⁴⁰ The Debye-Scherrer equation was utilized to calculate the crystallite size from equation (2).^46,47

C I = \frac{I_{200} - I_{A M}}{I_{200}}

(1)

C_{x r d} = \frac{k λ}{β \cos θ}

(2)

The variables λ, CuKα = 1.5418 Å, β is the full width at half maximum (rad) of the X-ray diffraction peaks, θ is the Bragg angle of the XRD peak, and K is a constant, usually equal to 0.89.^46,47

Chemical compositions were identified by FTIR spectroscopy (PerkinElmer Spectrum version 10.03.02). density was determined using a pycnometer. TGA investigation was performed using a thermal analyser (NETZSCH STA 449F4) at a range of 20°C/20.0(K/min)/500°C. A SEM microscope (TESCAN VEGA3 XMU) was exploited to study the surface morphology of the BmF. An MTS tensile testing apparatus was employed to do single fibres tensile testing.

Results and discussion

XRD analysis

Figure 2 exhibits the XRD spectra of treated and untreated BmF. The diffraction peaks with Miller indices were located at the 2θ of 14.91°, (1-10), 16.31°, (110), 22. 35° (200) and 34.65° (004). These are diffraction peak regions for cellulose I.^45,48 However, peaks 14.91° and 16.31° are so broad and close that they overlap.⁴⁹ The crystallinity index, crystallite size, and density are shown in Table 2. It was revealed that the concentration and treatment time of KMnO₄ affect the CI. Similar studies have reported that this might be owing to the elimination of the native wax, surface impurities and amorphous part of the BmF, which improves the proportion of the crystalline portion.^50,51

Figure 2.

Xrd spectral of treated and untreated BmF.

Table 2.

Physical and crystallographic parameters of treated and untreated BmF.

Samples	Crystallinity index (%)	Crystallite size (Å)	Density (g/cm³)
UT	59.93	16.18	1.6161
0.01P1	61.84	20.49	1.4172
0.01P2	62.13	15.10	1.5324
0.01P3	61.15	15.15	1.5050
0.05P1	63.44	15.93	1.4491
0.05P2	71.16	14.94	1.3512
0.05P3	61.81	16.24	1.4032
0.10P1	68.13	15.24	1.5009
0.10P2	62.77	19.37	1.4466
0.10P3	58.48	15.32	1.3799

However, the highest value for crystallinity index, crystallite size, and bulk density for 0.01 % concentration was observed at 2 min treatment, while at 0.05 % concentration, 1 min treatment gave the highest, and for 0.10 % concentration, 1 min of treatment gave the highest values. This can be ascribed to the partial removal of cellulosic constituents alongside lignin at different concentrations and times.^50–52

FTIR analysis

FTIR data of treated and untreated BmF are revealed in Figure 3. The broadband exhibited at 3321 cm^-1 and 1637 cm^-1, is assigned to the intricate vibrational stretching of hydrogen-bonded hydroxyl groups (O-H), linked to free, intermolecular, and intramolecular bound hydroxyl groups.⁵³ The peak at approximately 2900 cm^-1 is attributed to the C-H Stretching vibration of the alkane group in carbohydrates and lignin existing in cellulosic BmF.^54–56 Robust adsorption caused by nitrile (C-N) stretching was observed between 2200 cm^-1 to 2335 cm^-1.^56,57 Significant changes in this absorption band after treatment can be observed. The Carbonyl C = O Stretching characteristic bands of hemicellulose in NF are noticed at around 1739 cm^-1. Peak 1625 cm^-1 – 1637 cm^-1 represents the C = O bonds on hemicellulose. The increase of this peak intensity after treatment suggests the introduction of an ester group in the fibers after treatment.⁵⁸ The peak between 1500 cm^-1 -1400 cm^-1 is attributed as the characteristic peak of lignin in NF. This peak was observed to reduce after treatments. This is an indication of effective modification of the lignin presence in the fibres.^59–61 The band located between 1430 cm⁻¹ and 1490 cm⁻¹ signified the presence of OH groups and the OH stretching caused by moisture present in BmF. The intensity of these peaks was observed to reduce after treatment, indicating the treatment was effective in reducing the moisture content thus improving the hydrophobicity of the BmF.^60–63 The C-O Stretching C-vibration of the acetyl group in lignin was observed at 1242 cm^-1 to reduce in treated BmF, indicating the partial elimination of lignin from the BmF surface. The most prominent peak in all BmF was observed at 1033 cm^-1, this peak is ascribed to the aromatic ring’s C-H and C-O groups’ bending vibration in the polysaccharides found in NF. The increases in this peak intensity after treatment are an indication of the chemical reaction between the fibres and permanganate compound.¹² The absorption band at 896 cm^-1 and 649 cm^-1 is attributed to C-OH bending. It showed a decrease in the alcohol groups’ major C–O stretching and deformation in cellulose and the aromatic hydrogen groups’ significant C–OH out-of-plane bending in lignin.^64,65 The variations in these peaks’ intensities show that the treatment was successful in modulating the BmF. The variations in these peaks’ intensities suggest that this procedure has effectively modulated the BmF.

Figure 3.

Ftir spectral of treated and untreated BmF.

Thermo Gravimetric analysis

To explore the thermal stability of treated and untreated BmF at different concentrations and times, TGA was utilized. The TGA and derivatives curves (DTG) for untreated and treated BmF are demonstrated in Figures 4(a)–6(a). Three decomposition stages were noticed in the TGA spectral, the first stage (26°C −70°C) was owing to primary changes occasioned by moisture evaporation on the BmF surfaces. The second decomposition stage (220°C – 350°C) showed a significant weight loss. The degradation of hemicellulose and cellulosic portions occasioned this. Hemicellulose has been reported to begin breaking down at 220°C and kept going till 300°C.^66–68 The onset of the second decomposition stage differs for each group of treatments. As observed in Figure 4, second-stage degradation started at 230°C, while in Figure 5 started at 220°C, and in Figure 6 onset was observed at 222°C. The dissimilarities in hemicellulose, cellulose, and lignin’s chemical structures after chemical modification, cause them to break down at varying temperatures. Comparable outcomes have been documented.^66,69 The final stage degradation (350°C −500°C) resulted from cellulose and lignin decomposition. As attested by previous studies, thermal analysis of cellulose degradation began at 310°C and continued until 500°C.⁷⁰ When the temperature rose above 380°C, almost all the cellulose decomposed, and there were few solid leftovers.

Figure 4.

Analysis of 0.01 % KMnO₄ BmF at different treatment times (a) TGA (b) DTG.

Figure 5.

Analysis of 0.05 % KMnO₄ BmF at different treatment times (a) TGA (b) DTG.

Figure 6.

Dtg analysis of 0.10 % KMnO₄ BmF at different treatment times (a) TGA (b).

The DTG decomposition rate of untreated and treated BmF began around 220°C to 375°C in the DTG curve as exhibited in Figures 4(b)–6(b). The maximum degradation temperature of the treated and untreated samples is shown in Table 3. As observed, the maximum degradation of untreated BmF was obtained as 333.59°C. The degradation temperature for treated BmF was observed to be reduced with samples 0.01K2, 0.05K1, and 0.10K1, which have the maximum degradation temperature at 0.01 %, 0.05 %, and 0.10 % treatment concentration. This was because of the degradation of α-cellulose and hemicellulose respectively after chemical modification of the fibres.^71,72 A higher hemicellulose proportion is directly correlated with increased thermal stability. This also collaborates with the XRD analysis. Previous studies have suggested that when NF undergo chemical changes, their thermal stability will be reduced.^66,73 However, due to its lesser thermal stability, these treated BmF can be a good choice for compounding with polymers in fibres-reinforced composites suitable at lower processing temperatures.⁷⁴

Table 3.

DTG analysis of treated and untreated BmF.

Samples	DTG peak (^oC)
RF	333.59
0.01P1	332.58
0.01P2	332.97
0.01P3	327.60
0.05P1	332.43
0.05P2	312.59
0.05P3	331.80
0.10P1	331.65
0.10P2	329.63
0.10P3	330.64

Tensile strength of BmF

The ultimate tensile strength (UTS) of single filament BmF was performed in triplicate, and the average data for each sample are displayed in Figure 7. The UTS of treated BmF showed improvement from untreated ones as the concentration and treatment time increased. This is attributed to removing natural and artificial impurities and effective oxidation of the fibres surface after treatments. As observed, when treatment time increased from 1 to 3 min, there were corresponding increases in UTS at 0.01 to 0.05% treatment concentration. However, as the treatment concentration increased to 0.1%, degradation in UTS was observed. This was consistent with results obtained from previous studies, which were attributed to delignification caused by excessive treatment of the fibres at high concentrations or prolonged treatment time of KMnO₄.^10,75–78 Maximum tensile strength at 0.01 % concentration was obtained after 2 min of treatment time, maximum UTS at 0.05 % concentration was obtained after 1 min of treatment, and at 0.10 % concentration, maximum UTS was obtained after 1 min of treatment. This was attributed to the effective improvement of the strength-bearing cellulose after treatment.^75,76 These findings collaborate also with observations in XRD and thermal analysis in this study. However, higher concentrations and prolonged treatment of the fibres with KMnO₄ cause excess delignification of the fibres structure and degrade its strengths.^10,77,78

Figure 7.

Ultimate tensile strength of treated and untreated BmF at different treatment times.

SEM analysis

Ethanol pre-treated permanganate BmF with improved thermal, micromolecular, and crystallographic structures from this study was selected for SEM morphology. The SEM morphological structure of selected BmF is exhibited in Figure 8. As observed, the smooth surface of the untreated BmF has presumably been encrusted with waxes and other contaminants. Displayed in Figures 8–11 is the optimal surface roughness achieved for each treatment concentration level. It was observed that BmF’s surface roughness amplified at different concentrations and times. This can be ascribed to the partial removal of lignin, hemicellulose, and other surface contaminants after permanganate treatment, as reported in previous studies.^10,79,80 The BmF treated with 0.05 % concentration for 2 min exhibited the highest level of surface roughness (Figure 10), which could be attributed to the significant elimination of contaminants and partial extirpation of hemicellulose from the BmF, resulting in noticeable fibrous area. High fibres surface roughness has been reported as a potential for usage as reinforcement in a variety of bio-composites.^29,75,77,79

Figure 8.

SEM image of RF BmF.

Figure 9.

SEM image of 0.01P1 Treated BmF.

Figure 10.

SEM image of 0.05P2 Treated BmF.

Figure 11.

SEM image of 0.10P1 Treated BmF.

Conclusion

An investigation has been conducted to evaluate the suitability of pre-treating BmF with ethanol before applying KMnO₄ treatment at varied concentrations and treatment durations. The chemical alteration impacted the BmF’s parameters, crystallographic structures, and macromolecular characteristics. Following treatment at ideal conditions of 0.05P2, improvements in bulk density, degree of crystallinity, crystallite size, and improved tensile strength were noted. The surface of the BmF altered following treatment, as evidenced by SEM micrographs, becoming rougher. FTIR spectra verified the treatment’s reduction of the hemicellulose and lignin groups existing in the BmF. Less thermal stability of these treated bamboo fibres suggests the treated fibres as a good choice for compounding with polymers as a fibre-reinforced composite that can be processed at a lower temperature. Therefore, these results demonstrate the potential of the analysed treated fibres for use as reinforcement in various bio-composites for industrial and advanced applications.

Footnotes

Acknowledgment

The authors would like to appreciate the support from the National Research Foundation (NRF) of South Africa and also the University of Johannesburg.

ORCID iD

Mamookho Elizabeth Makhatha

Consent for publication

All authors consent to the publication of this manuscript.

Author contributions

Conceptualization: Mamookho Elizabeth Makhatha Methodology: Mamookho Elizabeth Makhatha Patrick Ehi Imoisili. Formal analysis and investigation: Mamookho Elizabeth Makhatha Patrick Ehi Imoisili; Writing - original draft preparation: Patrick Ehi Imoisili; Writing - review and editing: Mamookho Elizabeth Makhatha and Tien-Chien Jen, Funding acquisition: Mamookho Elizabeth Makhatha; Resources: Mamookho Elizabeth Makhatha Patrick Ehi Imoisili, Tien-Chien Jen. Supervision: Mamookho Elizabeth Makhatha and Tien-Chien Jen.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

Declaration of conflicting interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Data Availability Statement

The corresponding author will provide raw data upon request. Data will be made available on request.*

References

Mohanasundaram

Nagabhooshanam

Sharma

, et al. Electromagnetic interference shielding and mechanical and hydrophobic properties of papaya peel biocarbon and banana fiber–reinforced epoxy composite: synthesize and characterization. Biomass Convers Biorefin. 2024; 15(8): 12689–12698.

Khan

Hossain

Hasan

, et al. Advances of natural fibers composites in diverse engineering applications–A review. Appl Eng Sci 2024; 2024: 100184.

Taib

MNAM

Yee

Trache

. et al. Modification on nanocellulose extracted from kenaf (Hibiscus cannabinus) with 3-aminopropyltriethoxysilane for thermal stability in poly (vinyl alcohol) thin film composites. Cellulose 2024; 31(2): 997–1015.

Raj

MKA

Muthusamy

Panchal

, et al. Investigation of mechanical properties of dual-fiber reinforcement in polymer composite. J Mater Res Technol 2022; 18: 3908–3915.

Kumar

Rakesh

Sreehari

. Investigation on physico-chemical, mechanical and thermal properties of extracted novel Pinus roxburghii fiber. J Nat Fibers 2023; 20(1): 2157924.

Kamarudin

Mohd Basri

Rayung

, et al. A review on natural fiber reinforced polymer composites (NFRPC) for sustainable industrial applications. Polymers 2022; 14(17): 3698.

Punia Bangar

Ilyas

Chaudhary

, et al. Plant-based natural fibers for food packaging: a green approach to the reinforcement of biopolymers. J Polym Environ 2023; 31(12): 5029–5049.

Pokhriyal

Rakesh

. Processing and characterization of novel Himalayacalamus falconeri fiber reinforced biodegradable composites. Biomass Convers Biorefin 2024; 14(17): 21245–21260.

Akhil

Radhika

Saleh

, et al. A comprehensive review on plant‐based natural fiber reinforced polymer composites: fabrication, properties, and applications. Polym Compos 2023; 44(5): 2598–2633.

10.

Imoisili

Jen

. Modelling and optimization of the impact strength of plantain (Musa paradisiacal) fibre/MWCNT hybrid nanocomposite using response surface methodology. J Mater Res Technol 2021; 13: 1946–1954.

11.

Widiastuti

Solikhun

Cahyo

, et al. Treatment of bamboo fibres in improving mechanical performance of polymer composites–A review. AIP Conf Proc. 2018; 1977(1): 1–7.

12.

Imoisili

Jen

. Mechanical and water absorption behaviour of potassium permanganate (KMnO4) treated plantain (Musa Paradisiacal) fibre/epoxy bio-composites. J Mater Res Technol 2020; 9(4): 8705–8713.

13.

Sakoshev

Blaznov

Bychin

, et al. Morphological and physicomechanical characterization of synthetic and natural fibers. J Polym Res 2024; 31(3): 86.

14.

Elfaleh

Abbassi

Habibi

, et al. A comprehensive review of natural fibers and their composites: an eco-friendly alternative to conventional materials. Results Eng 2023; 2023: 101271.

15.

Akhil

Radhika

Saleh

, et al. A comprehensive review on plant‐based natural fiber reinforced polymer composites: fabrication, properties, and applications. Polym Compos 2023; 44(5): 2598–2633.

16.

Karimah

Ridho

Munawar

, et al. A review on natural fibers for development of eco-friendly bio-composite: characteristics, and utilizations. J Mater Res Technol 2021; 13: 2442–2458.

17.

Sahu

Gupta

. A review on the properties of natural fibres and its bio-composites: effect of alkali treatment. Proceedings of the Institution of Mechanical Engineers, Part L. J Mater: 2020; 234(1): 198–217.

18.

Mohammed

Rahman

Mohammed

, et al. Surface treatment to improve water repellence and compatibility of natural fiber with polymer matrix: recent advancement. Polym Test 2022; 115: 107707.

19.

Gudayu

Steuernagel

Meiners

, et al. Effect of surface treatment on moisture absorption, thermal, and mechanical properties of sisal fiber. J Ind Textil 2022; 51(2_suppl): 2853S–2873S.

20.

Yeh

Rizkiana

, et al. Effect of fiber size, cyclic moisture absorption and fungal decay on the durability of natural fiber composites. Constr Build Mater 2021; 286: 122819.

21.

Alsubari

Zuhri

Sapuan

, et al. Potential of natural fiber reinforced polymer composites in sandwich structures: a review on its mechanical properties. Polymers 2021; 13(3): 423.

22.

Zaghloul

. Developments in polyester composite materials–An in-depth review on natural fibres and nano fillers. Compos Struct 2021; 278: 114698.

23.

Abbass

Paiva

Oliveira

, et al. Insight into the effects of solvent treatment of natural fibers prior to structural composite casting: chemical, physical and mechanical evaluation. Fibers 2021; 9(9): 54.

24.

Bitencourt

Corrêa

JLG

Carvalho

, et al. Valorization of pineapple pomace for food or feed: effects of pre-treatment with ethanol on convective drying and quality properties. Waste Biomass Valorization 2022; 13(4): 2253–2266. DOI: 10.1007/s12649-021-01659-9.

25.

El Moussi

Otazaghine

Caro-Bretelle

, et al. Controlling interfacial interactions in LDPE/flax fibre biocomposites by a combined chemical and radiation-induced grafting approach. Cellulose 2020; 27: 6333–6351.

26.

Ezeamaku

Eze

Obibuenyi

, et al. Examination of the effects of potassium permanganate chemical modification on bamboo fiber reinforced with natural honey bio resin and paw-paw leaves extract. Mediterr J Chem 2022; 12(2): 210–217.

27.

Chen

Dauletbek

, et al. Properties and applications of bamboo fiber-A current-state-of-the art. J Renew Mater 2022; 10(3): 605–624.

28.

Imoisili

Jen

. Mechanical and acoustic performance of plantain (Musa paradisiacal) fibre reinforced epoxy bio-composite. J Nat Fibers 2022; 19(15): 11658–11665.

29.

Ezeamaku

Onukwuli

Ezeh

, et al. Experimental investigation on influence of selected chemical treatment on banana fibre. Ind Crop Prod 2022; 185: 115135.

30.

Sugiman

Setyawan

Anshari

. Effects of alkali treatment of bamboo fibre under various conditions on the tensile and flexural properties of bamboo fibre/polystyrene-modified unsaturated polyester composites. J Eng Sci Technol 2019; 14(1): 27–47.

31.

Makhatha

Imoisili

Jen

. Crystallographic, macromolecular, thermal, and mechanical properties of Bambusa balcooa fibers: effect of two-step chemical modification. Polym Bull. 2025; 82: 1297–1313.

32.

Sánchez

Patino

Cardenas

. Physical-mechanical properties of bamboo fibers-reinforced biocomposites: influence of surface treatment of fibers. J Build Eng 2020; 28: 101058.

33.

Nurazzi

Norrrahim

Sabaruddin

, et al. Mechanical performance evaluation of bamboo fibre reinforced polymer composites and its applications: a review. Funct Compos Struct 2022; 4(1): 015009.

34.

Rasheed

Jawaid

Parveez

, et al. Morphological, chemical and thermal analysis of cellulose nanocrystals extracted from bamboo fibre. Int J Biol Macromol 2020; 160: 183–191.

35.

Supian

Jawaid

Rashid

, et al. Mechanical and physical performance of date palm/bamboo fibre reinforced epoxy hybrid composites. J Mater Res Technol 2021; 15: 1330–1341.

36.

Zhou

Liu

, et al. Hydrophobic surface modification of ramie fibers with ethanol pretreatment and atmospheric pressure plasma treatment. Surf Coating Technol 2011; 205(17-18): 4205–4210.

37.

Kumar

Rakesh

Sreehari

, et al. Experimental investigations on material properties of alkali retted Pinus Roxburghii Fiber. Biomass Convers Biorefin 2024; 14(17): 21345–21361.

38.

Isogai

Atalla

. Amorphous celluloses stable in aqueous media: regeneration from SO2–amine solvent systems. J Polym Sci Polym Chem 1991; 29(1): 113–119.

39.

Bowden

Brown

, et al. An improved X-ray diffraction method for cellulose crystallinity measurement. Carbohydr Polym 2015; 123: 476–481.

40.

Park

Baker

Himmel

, et al. Cellulose crystallinity index: measurement techniques and their impact on interpreting cellulase performance. Biotechnol Biofuels 2010; 3: 1.

41.

Yao

Weng

Catchmark

. Improved cellulose X-ray diffraction analysis using Fourier series modeling. Cellulose 2020; 27: 5563–5579.

42.

Segal

Creely

Martin

JAE

, et al. An empirical method for estimating the degree of crystallinity of native cellulose using the X-ray diffractometer. Textil Res J 1959; 29(10): 786–794.

43.

Thygesen

Oddershede

Lilholt

, et al. On the determination of crystallinity and cellulose content in plant fibres. Cellulose 2005; 12: 563–576.

44.

Imoisili

Jen

. Effect of mercerization on the crystallographic, macromolecular, and thermal properties of plantain fibers for fiber reinforced composite. Mater Sci Forum 2024; 1115: 63–70.

45.

del Cerro

Koso

Kakko

, et al. Crystallinity reduction and enhancement in the chemical reactivity of cellulose by non-dissolving pre-treatment with tetrabutylphosphonium acetate. Cellulose 2020; 27: 5545–5562.

46.

Yue

Liu

. Preparation of nanocrystalline cellulose via ultrasound and its reinforcement capability for poly (vinyl alcohol) composites. Ultrason Sonochem 2012; 19(3): 479–485.

47.

Low

Samsudin

Yusoff

, et al. Hydrolytic cleavage of glycosidic bonds for cellulose nanoparticles (CNPs) production by BmimHSO4 ionic liquid catalyst. Thermochim Acta 2020; 684: 178484.

48.

Patra

Bisoyi

. Investigation of the electrical and mechanical properties of short sisal fiber-reinforced epoxy composite in correlation with structural parameters of the reinforced fiber. J Mater Sci 2011; 46: 7206–7213.

49.

French

. How crystalline is my cellulose specimen? Probing the limits of X-ray diffraction. Bioresources 2022; 17(4): 5557.

50.

Kabir

Wang

Lau

, et al. Chemical treatments on plant-based natural fibre reinforced polymer composites: an overview. Compos B Eng 2012; 43(7): 2883–2892.

51.

Maepa

Jayaramudu

Okonkwo

, et al. Extraction and characterization of natural cellulose fibers from maize tassel. Int J Polym Anal Char 2015; 20(2): 99–109.

52.

Klemm

Heublein

Fink

, et al. Cellulose: fascinating biopolymer and sustainable raw material. Angew Chem Int Ed 2005; 44(22): 3358–3393.

53.

Singh

Gaikwad

Park

, et al. Microwave-assisted step reduced extraction of seaweed (Gelidiella aceroso) cellulose nanocrystals. Int J Biol Macromol 2017; 99: 506–510.

54.

Wen

Cheng

, et al. Preparation of cellulose nano-crystals through a sequential process of cellulase pretreatment and acid hydrolysis. Cellulose 2016; 23: 2409–2420.

55.

Gurukarthik Babu

Prince Winston

SenthamaraiKannan

, et al. Study on characterization and physicochemical properties of new natural fiber from Phaseolus vulgaris. J Nat Fibers 2019; 16(7): 1035–1042.

56.

Phanthong

Guan

, et al. Effect of ball milling on the production of nanocellulose using mild acid hydrolysis method. J Taiwan Inst Chem Eng 2016; 60: 617–622.

57.

Rong

Zhang

Liu

, et al. The effect of fiber treatment on the mechanical properties of unidirectional sisal-reinforced epoxy composites. Compos Sci Technol 2001; 61(10): 1437–1447.

58.

Oladimeji

Dominic

Echeng

, et al. Influence of chemical surface modifications on mechanical properties of Combretum dolichopetalum fibre-high density polyethylene (HDPE) composites. Pak J Sci Ind Res Ser A Phys Sci 2018; 61(1): 28–34.

59.

Tran

Bénézet

Bergeret

. Rice and Einkorn wheat husks reinforced poly (lactic acid)(PLA) biocomposites: effects of alkaline and silane surface treatments of husks. Ind Crop Prod 2014; 58: 111–124.

60.

Migneault

Koubaa

Perré

, et al. Effects of wood fiber surface chemistry on strength of wood–plastic composites. Appl Surf Sci 2015; 343: 11–18.

61.

Indran

Raj

Sreenivasan

. Characterization of new natural cellulosic fiber from Cissus quadrangularis root. Carbohydr Polym 2014; 110: 423–429.

62.

Sanjay

Madhu

Jawaid

, et al. Characterization and properties of natural fiber polymer composites: a comprehensive review. J Clean Prod 2018; 172: 566–581.

63.

Kusuktham

. Mechanical properties and morphologies of high density polyethylene reinforced with calcium carbonate and sawdust compatibilized with vinyltriethoxysilane. Silicon 2019; 11: 1997–2013.

64.

Jayamani

Loong

Bakri

. Comparative study of Fourier transform infrared spectroscopy (FTIR) analysis of natural fibres treated with chemical, physical and biological methods. Polym Bull 2020; 77(4): 1605–1629.

65.

Cha

. Preparation and characterization of thermal/pH-sensitive hydrogel from carboxylated nanocrystalline cellulose. Carbohydr Polym 2012; 88(2): 713–718.

66.

Thomason

Rudeiros-Fernández

. Thermal degradation behaviour of natural fibres at thermoplastic composite processing temperatures. Polym Degrad Stabil 2021; 188: 109594.

67.

Rachini

Le Troedec

Peyratout

, et al. Comparison of the thermal degradation of natural, alkali-treated and silane-treated hemp fibers under air and an inert atmosphere. J Appl Polym Sci 2009; 112(1): 226–234.

68.

Tajvidi

Takemura

. Thermal degradation of natural fiber-reinforced polypropylene composites. J Thermoplast Compos Mater 2010; 23(3): 281–298.

69.

Domenek

Berzin

Ducruet

, et al. Extrusion and injection moulding induced degradation of date palm fibre-polypropylene composites. Polym Degrad Stabil 2021; 190: 109641.

70.

Dev

Rahman

Repon

, et al. Recent progress in thermal and acoustic properties of natural fiber reinforced polymer composites: preparation, characterization, and data analysis. Polym Compos 2023; 44(11): 7235–7297.

71.

Seta

Liu

, et al. Preparation and characterization of high yield cellulose nanocrystals (CNC) derived from ball mill pretreatment and maleic acid hydrolysis. Carbohydr Polym 2020; 234: 115942.

72.

Senthil Muthu Kumar

Chandrasekar

Senthilkumar

, et al. Utilization of bamboo fibres and their influence on the mechanical and thermal properties of polymer composites. Bamboo Fiber Composites: Processing, Properties and Applications 2021. Springer, pp. 81–96. DOI: 10.1007/978-981-15-8489-3_5.

73.

De Souza

d'Almeida

. Tensile, thermal, morphological and structural characteristics of abaca (Musa textiles) fibers. Polym Renew Resour 2014; 5(2): 47–60.

74.

Chaves

da Silveira

Neuba

, et al. Evaluation of the density, mechanical, thermal and chemical properties of babassu fibers (Attalea speciosa.) for potential composite reinforcement. J Mater Res Technol 2023; 23: 2089–2100.

75.

Alshahrani

Prakash

. Mechanical, fatigue and DMA behaviour of high content cellulosic corn husk fibre and orange peel biochar epoxy biocomposite: a greener material for cleaner production. J Clean Prod 2022; 374: 133931.

76.

Muralidaran

Natrayan

Kaliappan

, et al. Grape stalk cellulose toughened plain weaved bamboo fiber-reinforced epoxy composite: load bearing and time-dependent behavior. Biomass Convers Biorefin 2024; 14(13): 14317–14324.

77.

Birniwa

Abdullahi

Yakasai

, et al. Studies on physico-mechanical behaviour of kenaf/glass fiber reinforced epoxy hybrid composites. Bull Chem Soc Ethiop 2021; 35(1): 171–184.

78.

Cosse

Voet

Folkersma

, et al. The effect of size and delignification on the mechanical properties of polylactic acid (PLA) biocomposites reinforced with wood fibres via extrusion. RSC Sustain 2023; 1(4): 876–885.

79.

Osório

Amrani

Delahaye

, et al. Hollow-core fibers with reduced surface roughness and ultralow loss in the short-wavelength range. Nat Commun 2023; 14(1): 1146.

80.

Imoisili

Adeleke

Makhatha

, et al. Response surface methodology (RSM)-artificial neural networks (ANN) aided prediction of the impact strength of natural fibre/carbon nanotubes hybrid reinforced polymer nanocomposite. Eng Sci 2023; 23: 852.