Mechanical performance of biobased polyurethane composites reinforced with treated sisal fibers

Bruno Targino de Oliveira; Renata Martins Parreira

doi:10.1590/0104-1428.20250057

Original Article

Mechanical performance of biobased polyurethane composites reinforced with treated sisal fibers

Bruno Targino de Oliveira; Renata Martins Parreira

http://dx.doi.org/10.1590/0104-1428.20250057 Polímeros: Ciência e Tecnologia, vol.36, n1, e20260004, 2026

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Abstract

This study investigates the mechanical behavior of biobased polyurethane (PU) composites reinforced with chemically treated sisal fibers. Two composites were fabricated: one reinforced with sisal fibers treated in a 10% NaOH solution and the other with fibers treated in a 10% Al(OH)₃ solution. The novelty of this work resides in comparing how each treatment affects tensile performance and fracture characteristics. Tensile tests were conducted following ASTM D3039, and fracture surfaces were analyzed by scanning electron microscopy (SEM). The composite reinforced with Al(OH)₃-treated fibers exhibited the highest tensile strength (15.14 MPa), followed by the NaOH-treated composite (14.09 MPa), both outperforming neat PU (6.46 MPa). SEM revealed mixed fracture modes, indicating improved fiber–matrix adhesion in treated systems. Results confirm that chemical treatment significantly enhances the mechanical properties of PU–sisal composites. Among the methods studied, Al(OH)₃ treatment yielded the most favorable performance, highlighting the potential of treated fibers for sustainable high-performance composites.

Keywords

biobased polyurethane, mechanical properties, natural fiber composite, sisal fiber, tensile strength

References

1 Mora-Murillo, L. D., Orozco-Gutiérrez, F., Vega-Baudrit, J., & González-Paz, R. J. (2017). Thermal-mechanical characterization of polyurethane rigid foams: effect of modifying bio-polyol content in isocyanate prepolymers. Journal of Renewable Materials, 5(3-4), 220-230. https://doi.org/10.7569/JRM.2017.634112.

2 Ionescu, M. (2005). Chemistry and technology of polyols for polyurethanes. Shawbury: Rapra Technology Limited.

3 Faruk, O., Bledzki, A. K., Fink, H.-P., & Sain, M. (2012). Biocomposites reinforced with natural fibers: 2000–2010. Progress in Polymer Science, 37(11), 1552-1596. https://doi.org/10.1016/j.progpolymsci.2012.04.003.

4 Yan, L., Chouw, N., & Jayaraman, K. (2014). Flax fibre and its composites – A review. Composites. Part B, Engineering, 56, 296-317. https://doi.org/10.1016/j.compositesb.2013.08.014.

5 Rev, T., Wisnom, M. R., Xu, X., & Czél, G. (2022). The effect of transverse compressive stresses on tensile failure of carbon fibre/epoxy composites. Composites. Part A, Applied Science and Manufacturing, 156, 106894. https://doi.org/10.1016/j.compositesa.2022.106894.

6 Monteiro, S. N., Lopes, F. P. D., Barbosa, A. P., Bevitori, A. B., Silva, I. L. A., & Costa, L. L. (2011). Natural lignocellulosic fibers as engineering materials: an overview. Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, 42(10), 2963-2974. https://doi.org/10.1007/s11661-011-0789-6.

7 Liao, Z., Hu, Y., Shen, Y., Chen, K., Qiu, C., Yang, J., & Yang, L. (2024). Investigation into the reinforcement modification of natural plant fibers and the sustainable development of thermoplastic natural plant fiber composites. Polymers, 16(24), 3568. https://doi.org/10.3390/polym16243568. PMid:39771421.

8 Fernandes, R. A. P., Silveira, P. H. P. M., Bastos, B. C., Pereira, P. S. C., Melo, V. A., Monteiro, S. N., Tapanes, N. L. C. O., & Bastos, D. C. (2022). Bio-based composites for light automotive parts: statistical analysis of mechanical properties; effect of matrix and alkali treatment in sisal fibers. Polymers, 14(17), 3566. https://doi.org/10.3390/polym14173566. PMid:36080641.

9 Campos, A., Teodoro, K. B. R., Marconcini, J. M., Mattoso, L. H. C., & Martins-Franchetti, S. M. (2011). Effect of fiber treatments on properties of thermoplastic starch/polycaprolactone/sisal biocomposites. Polímeros: Ciência e Tecnologia, 21(3), 217-222. https://doi.org/10.1590/S0104-14282011005000039.

10 Ichim, M., Muresan, E. I., & Codau, E. (2024). Natural-fiber-reinforced polymer composites for furniture applications: technical, ecological and economic demands. Polymers, 16(22), 3113. https://doi.org/10.3390/polym16223113. PMid:39599204.

11 Thimmegowda, D. Y., Hindi, J., Markunti, G. B., & Kakunje, M. (2025). Enhancement of mechanical properties of natural fiber reinforced polymer composites using different approaches: a review. Journal of Composites Science, 9(5), 220. https://doi.org/10.3390/jcs9050220.

12 Thepruttana, S., Patthanavarit, J., Hankoy, M., Kitiwan, M., Keawprak, N., & Tunthawiroon, P. (2024). Enhancement of flexural strength in fiber–cement composites through modification of sisal fiber with natural rubber latex and expanded perlite. Buildings (Basel, Switzerland), 14(4), 1067. https://doi.org/10.3390/buildings14041067.

13 Merlini, C., Soldi, V., & Barra, G. M. O. (2011). Influence of fiber surface treatment and length on physico-chemical properties of short random banana fiber-reinforced castor oil polyurethane composites. Polymer Testing, 30(8), 833-840. https://doi.org/10.1016/j.polymertesting.2011.08.008.

14 Olanrewaju, O., Oladele, I. O., & Adelani, S. O. (2025). Recent advances in natural fiber reinforced metal/ceramic/polymer composites: an overview of the structure-property relationship for engineering applications. Hybrid Advances, 8, 100378. https://doi.org/10.1016/j.hybadv.2025.100378.

15 Islam, S., Hasan, B., Kodrić, M., Motaleb, K. Z. M. A., Karim, F.-E., & Islam, R. (2025). Mechanical properties of hemp fiber-reinforced thermoset and thermoplastic polymer composites: a comprehensive review. SPE Polymers, 6(1), e10173. https://doi.org/10.1002/pls2.10173.

16 Kılınç, A. C., Atagür, M., Özdemir, O., Şen, I., Küçükdoğan, N., Sever, K., Seydibeyoğlu, O., Sarikanat, M., & Seki, Y. (2016). Manufacturing and characterization of vine stem reinforced high density polyethylene composites. Composites. Part B, Engineering, 91, 267-274. https://doi.org/10.1016/j.compositesb.2016.01.033.

17 Liu, Y., Zhang, X., Liu, J., Xing, D., Shen, H., Chen, D., & Sun, J. (2015). Superelasticity in polycrystalline Ni-Mn-Ga-Fe microwires fabricated by melt-extraction. Materials Research, 18(Suppl. 1), 61-65. https://doi.org/10.1590/1516-1439.325914.

18 Angrizani, C. C., Amico, S. C., Cioffi, M. O. H., & Zattera, A. J. (2014). Influência da espessura nas propriedades mecânicas de compósitos híbridos interlaminares de curauá/vidro/poliéster. Polímeros, 24(2), 184-189. https://doi.org/10.4322/polimeros.2014.063.

19 American Society for Testing and Materials - ASTM. (2017). ASTM D3039/D3039M-17: Standard test method for tensile properties of polymer matrix composite materials. West Conshohocken: ASTM. Retrieved in 2025, July 15, from https://www.astm.org/d3039_d3039m-17.html

20 Kehl Indústria e Comércio Ltda – ME. (2022). FISPQ – Ficha de Informações de Segurança de Produto Químico: Sistema Poliol + Isocianato PU Vegetal. Retrieved in 2025, July 15, from https://www.kehl.ind.br

21 Sencadas, V., Correia, D. M., Ribeiro, C., Moreira, S., Botelho, G., Gómez Ribelles, J. L., & Lanceros-Méndez, S. (2012). Physical–chemical properties of cross-linked chitosan electrospun fiber mats. Polymer Testing, 31(8), 1062-1069. https://doi.org/10.1016/j.polymertesting.2012.07.010.

Mechanical performance of biobased polyurethane composites reinforced with treated sisal fibers

Bruno Targino de Oliveira; Renata Martins Parreira

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Polímeros: Ciência e Tecnologia