Issue 78

N. Nayak et alii, Fracture and Structural Integrity, 78 (2026) 378-392; DOI: 10.3221/IGF-ESIS.78.22

 The dielectric response was governed mainly by fibre loading, frequency and microstructural uniformity. Improved fibre dispersion and reduced interfacial defects supported stable insulating behaviour in treated composites.  The RSM models showed good agreement between experimental and predicted responses, confirming their suitability for identifying an optimum processing region within the investigated design space.  SEM analysis supported the experimental trends by showing better fibre embedding, fewer interfacial gaps and reduced pull-out in treated composites. Overall, the study confirms that alkali treatment combined with statistical optimization is an effective approach for developing sustainable, lightweight sisal fibre/polypropylene composites with balanced mechanical and dielectric properties. [1] Islam, S., Jalil, M.A., Kodric, M., Erakovic, Z. and Hasan, M. B. (2026). A systematic review of sisal fiber-reinforced polymer composites: Sustainable innovations, industrial applications, and future prospects, Journal of Polymer Materials, online first. DOI: http://dx.doi.org/10.32604/jpm.2026.075107. [2] Nagaraja, S., Anand, P. B., Kumar, K. M. and Ammarullah, M. I. (2024). Synergistic advances in natural fibre composites: A comprehensive review of eco-friendly bio-composite development, characterization and diverse applications, RSC Advances, 14, pp. 17594–17611. DOI: http://dx.doi.org/10.1039/D4RA00149D. [3] Miniappan, P., Marimuthu, S., Kumar, S. D., Gokilakrishnan, G., Sharma, S., Li, C., Dwivedi, S. P. and Abbas, M. (2023). Mechanical, fracture-deformation, and tribology behavior of fillers-reinforced sisal fiber composites for lightweight automotive applications, Reviews on Advanced Materials Science, 62(1), 20230342. DOI: http://dx.doi.org/10.1515/rams-2023-0342. [4] Tao, H., Yan, M., Zhang, L., Zou, Z., Han, H., Dong, H., Zhu, B. and Li, X. (2024). Progress in preparation, processing, and application of high dielectric polypropylene matrix composite materials, Polymer Composites, 45(6), pp. 4819–4838. DOI: http://dx.doi.org/10.1002/pc.28111. [5] Mylsamy, B., Shanmugam, S.K.M., Aruchamy, K., Palanisamy, S., Nagarajan, R. and Ayrilmis, N. (2024). A review on natural fiber composites: Polymer matrices, fiber surface treatments, fabrication methods, properties, and applications, Polymer Engineering & Science, 64(6), pp. 2345–2373. DOI: http://dx.doi.org/10.1002/pen.26713. [6] Seshweni, N. (2025). Mechanical and thermal characterizations of polypropylene composite reinforced with alkali [7] Joseph, P.V., Joseph, K. and Thomas, S. (2003). Effect of surface treatments on the mechanical properties and interfacial adhesion of sisal fiber-reinforced polypropylene composites, Composites Science and Technology, 63(3), pp. 355–364. DOI: http://dx.doi.org/10.1016/S0266-3538(02)00268-2. [8] Bledzki, A.K. and Gassan, J. (1999). Composites reinforced with cellulose-based fibres, Progress in Polymer Science, 24(2), pp. 221–274. DOI: http://dx.doi.org/10.1016/S0079-6700(98)00018-5. [9] Ochi, S. (2012). Mechanical properties of kenaf fiber reinforced biodegradable composites using response surface methodology, Industrial Crops and Products, 36(1), pp. 420–425. DOI: http://dx.doi.org/10.1016/j.indcrop.2011.10.016. [10] Li, Y., Mai, Y.W. and Ye, L. (2000). Sisal fibre and its composites: A review of recent developments, Composites Science and Technology, 60(11), pp. 2037–2055. DOI: http://dx.doi.org/10.1016/S0266-3538(00)00101-9. [11] Kuruvilla, J., Sabu, T. and Koshy, P. (1999). Effect of fiber length and fiber loading on the mechanical properties of short sisal fiber-reinforced polypropylene composites, Composites Science and Technology, 59(16), pp. 2311–2319. DOI: http://dx.doi.org/10.1016/S0266-3538(99)00083-0. [12] Jacob, M., Varughese, K.T. and Thomas, S. (2006). Dielectric characteristics of sisal fiber reinforced natural rubber composites, Journal of Materials Science, 41(17), pp. 5538–5547. DOI: http://dx.doi.org/10.1007/s10853-006-0309-x. [13] Ma, J., He, L., Wu, Z. and Hou, J. (2024). Optimization and modelling of the physical and mechanical properties of grass fiber reinforced with slag-based composites using response surface methodology, Materials, 17(15), article 3703. DOI: http://dx.doi.org/10.3390/ma17153703. [14] Mittal, M. and Phutela, K. (2023). Modeling and parameters optimization of biocomposite using Box-Behnken response surface methodology, Journal of Applied Research and Technology, 21(6), pp. 991–1018. treated sisal fiber, Recent Patents on Mechanical Engineering, 18(1). DOI: http://dx.doi.org/10.2174/0122127976319507240723102247. R EFERENCES

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