Synergistic influence of eco-friendly treatment and fly ash on water absorption morphology and hardness of grewia optiva / basalt fiber hybrid polyester composites
Restricted accessResearch articleFirst published online 2026
Synergistic influence of eco-friendly treatment and fly ash on water absorption morphology and hardness of grewia optiva / basalt fiber hybrid polyester composites
The present study investigates composites reinforced with treated Grewia optiva (GO), basalt (BA) fibers both chopped into 3 mm length and fly ash (FA) fillers in an unsaturated polyester resin (UPR) matrix. GO fibers were treated with a 5 wt.% mild alkaline sodium bicarbonate (NaHCO3) solution. BA and FA are set from 5 to 10 wt.%, and treated-GO fiber loading is varied between 5 and 15 wt.%. Experimental (1.20-1.36 g/cm3) and theoretical (1.22-1.41 g/cm3) density of composites have substantial degree of agreement with minimum (1.63%) voids fraction for C15/5-5 hybrid composite, remarking adequate association and enhance interface bonding. Diffusion pattern occurs in three phases of water absorption equilibrium between the ranges from 1.23 to 2.23%. Higher swelling and micro-porosity are observed as the concentration of treated-GO fiber increase in the composite. The maximum shore D hardness (39.2 HD) was achieved in C15/5-5 hybrid composite due to higher stiffness. The diffusion coefficient (2.003×10−6-2.335×10−6 mm2/s) has enhanced with the increment of fibers and FA, professed for better barrier characteristics. Comprehensive the present study revealed that the treated natural fiber, and inorganics filler reinforcement developed long-lasting, weight suitability, eco-friendly, and resistant against water absorption hybrid composite for constructive engineering in the Uttarakhand landslide-prone level areas.
MohantyAKMisraMDrzalLT. Sustainable bio-composites from renewable resources: opportunities and challenges in the green materials world. J Polym Environ2000; 10(1): 19–26. https://doi.org/10.1023/a:1021013921916
2.
MehdikhaniMGorbatikhLVerpoestI, et al.Voids in fiber-reinforced polymer composites: a review on their formation, characteristics, and effects on mechanical performance. J Compos Mater2019; 53(12): 1579–1669. https://doi.org/10.1177/0021998318772152
AlshahraniHSebaeyTAAwd AllahMM, et al.Jute-basalt reinforced epoxy hybrid composites for lightweight structural automotive applications. J Compos Mater2023; 57(7): 1315–1330. https://doi.org/10.1177/00219983231155013
5.
DeebanBKomaliKIllangoE, et al.Mechanical, moisture absorption, and morphological analysis of epoxy composites reinforced with natural fibres. Iran Polym J2025; 34(1): 1–25. https://doi.org/10.1007/s13726-025-01580-1
6.
Al FaruqueMASalauddinMRaihanMM, et al.Bast fiber reinforced green polymer composites: a review on their classification, properties, and applications. J Nat Fibers2022; 19(12): 8006–8021. https://doi.org/10.1080/15440478.2021.1958431
7.
BalakrishnanTSSultanMTHShaharFS, et al.Hybridization of woven kenaf and unidirectional glass fibre roving for unsaturated polyester composite. Iran Polym J2024; 33(10): 1231–1244. https://doi.org/10.1007/s13726-024-01319-4
8.
VadivelEVenkateshR. Effect of amino processed fiber and nanoceramic actions on water absorption and functional characteristics of polypropylene composites. Iran Polym J2025; 34(2): 1–11. https://doi.org/10.1007/s13726-025-01585-w
9.
KaliaSKaithBSKaurI. Pretreatments of natural fibers and their application as reinforcing material in polymer composites—a review. Polym Eng Sci2009; 49(7): 1253–1272. https://doi.org/10.1002/pen.21328
10.
HosseiniSBGaffMLiH, et al.Effect of fiber treatment on physical and mechanical properties of natural fiber-reinforced composites: a review. Rev Adv Mater Sci2023; 62(1): 20230131. https://doi.org/10.1515/rams-2023-0131
IlyasRAAisyahHANordinAH, et al.Natural-fiber-reinforced chitosan, chitosan blends and their nanocomposites for various advanced applications. Polymers2022; 14(5): 874. https://doi.org/10.3390/polym14050874
13.
PokhriyalMPrasadLRaturiHP. An experimental investigation on mechanical and tribological properties of Himalayan nettle fiber composite. J Nat Fibers2018; 15(6): 752–761. https://doi.org/10.1080/15440478.2017.1364202
14.
KumarSPrasadLBijlwanPP, et al.Thermogravimetric analysis of lignocellulosic leaf-based fiber-reinforced thermosets polymer composites: an overview. Biomass Convers Biorefinery2024; 14(5): 12673–12698. https://doi.org/10.1007/s13399-022-03332-0
15.
MaGYanLShenW, et al.Effects of water, alkali solution and temperature ageing on water absorption, morphology and mechanical properties of natural FRP composites: plant-based jute vs. mineral-based basalt. Compos Part B2018; 153: 398–412. https://doi.org/10.1016/j.compositesb.2018.09.015
16.
ThakurVKSinghaAS. Mechanical and water absorption properties of natural fibers/polymer biocomposites. Polym Plast Technol Eng2010; 49(7): 694–700. https://doi.org/10.1080/03602551003682067
17.
PavlovicAValzaniaLMinakG. Effects of moisture absorption on the mechanical and fatigue properties of natural fiber composites: a review. Polymers2025; 17(8): 1996. https://doi.org/10.3390/polym17141996
18.
WangQChenTWangX, et al.Recent progress on moisture absorption aging of plant fiber reinforced polymer composites. Polymers2023; 15(19): 4121. https://doi.org/10.3390/polym15204121
JahanFSoniM. Effects of chemical treatment on mechanical properties of various natural fiber reinforced composite: a review. Mater Today Proc2021; 46(15): 6708–6711. https://doi.org/10.1016/j.matpr.2021.04.175
21.
Valadez-GonzalezACervantes-UcJMOlayoR, et al.Effect of fiber surface treatment on the fiber–matrix bond strength of natural fiber reinforced composites. Compos Part B1999; 30(3): 309–320. https://doi.org/10.1016/s1359-8368(98)00054-7
22.
NarayanaVLRaoLB. A brief review on the effect of alkali treatment on mechanical properties of various natural fiber reinforced polymer composites. Mater Today Proc2021; 44(4): 1988–1994.
23.
BhuvaneshwaranMSampathPSSagadevanS. Influence of fiber length, fiber content and alkali treatment on mechanical properties of natural fiber-reinforced epoxy composites. Polimery2019; 64(2): 93–99. https://doi.org/10.14314/polimery.2019.2.2
24.
SoodMDwivediG. Effect of fiber treatment on flexural properties of natural fiber reinforced composites: a review. Egypt J Pet2018; 27(4): 775–783. https://doi.org/10.1016/j.ejpe.2017.11.005
BoopalanMNiranjanaaMUmapathyMJ. Study on the mechanical and thermal properties of jute and banana fiber reinforced epoxy hybrid composites. Compos Part B2013; 51: 54–57. https://doi.org/10.1016/j.compositesb.2013.02.033
AlsubariSZuhriMYMSapuanSM, et al.Potential of natural fiber reinforced polymer composites in sandwich structures: a review. Polymers2021; 13(3): 423. https://doi.org/10.3390/polym13030423
29.
KumarSPrasadLMishraNK, et al.Thermogravimetric investigation and FEA study on mechanical properties of Grewia optiva/basalt fiber reinforced hybrid polyester composites. J Indian Chem Soc2025; 102(1): 102002. https://doi.org/10.1016/j.jics.2025.102002
30.
BijlwanPPPrasadLSharmaA, et al.Taguchi optimized sliding wear behavior and hardness of novel Grewia optiva/basalt fiber reinforced hybrid polyester composites. J Appl Polym Sci2023; 140(22): e54106. https://doi.org/10.1002/app.54106
31.
ChaudharyVBajpaiPKMaheshwariS. Effect of moisture absorption on the mechanical performance of natural fiber reinforced woven hybrid bio-composites. J Nat Fibers2020; 17(1): 84–100. https://doi.org/10.1080/15440478.2018.1469451
32.
RajamuruganGKrishnasamyPMuralidharanB, et al.Contribution of hybrid particles (BaSO4/fly ash) on the drilling and wear performance of flax/aloevera fiber composite. Part Sci Technol2022; 40(5): 638–650. https://doi.org/10.1080/02726351.2021.1985024
33.
NagarajaSAnandPBAmmarullahMI, et al.Influence of fly ash filler on the mechanical properties and water absorption behaviour of epoxy polymer composites reinforced with pineapple leaf fibre for biomedical applications. RSC Adv2024; 14(21): 14680–14696. https://doi.org/10.1039/d4ra00529e
34.
KumarSPrasadLKumarS, et al.Physicomechanical and Taguchi optimized abrasive wear behaviour of KOH/KMnO4/NaHCO3 treated Himalayan agave fiber reinforced polyester composite. Mater Res Express2020; 6(12): 125353. https://doi.org/10.1088/2053-1591/ab6387
35.
British Standards Institution. Plastics—determination of water absorption (ISO 62). BS EN ISO 62 1999.
36.
YuHXingP. Moisture absorption characterization of carbon fiber‐reinforced polymer using Fickian and non‐fickian models. Polym Compos2022; 43(12): 8935–8946. https://doi.org/10.1002/pc.27074
37.
BachchanAADasPPChaudharyV. Effect of moisture absorption on the properties of natural fiber reinforced polymer composites: a review. Mater Today Proc2022; 49(6): 3403–3408. https://doi.org/10.1016/j.matpr.2021.02.812
38.
ApeagyeiAKGrenfellJRAireyGD. Application of Fickian and non-Fickian diffusion models to study moisture diffusion in asphalt mastics. Mater Struct2015; 48(5): 1461–1474. https://doi.org/10.1617/s11527-014-0246-2
