Open Access

ARTICLE

Chemical Surface Treatments of Luffa Fibers to Enhance the Interfacial Adhesion and Mechanical Properties of Unsaturated Polyester Composites

Ouided Dehas^1,2, Yasmina Biskri^1,2, Laidi Babouri^1,2, S. M. Anas^3,*, Osama Khan^4,*, Fouad Boukhelf^5,*, Aboulkacem Moutie Hamed⁶, Mohammed Benzerara^7,*
1 Higher Normal School of Technological Education of Skikda, Skikda, Algeria
2 Laboratory of Anticorrosion-Materials, Environmental and Structure LAMES, University of 20 août 1955-Skikda, Skikda, Algeria
3 Independent Researcher, New Delhi, India
4 Department of Mechanical Engineering, College of Engineering, King Faisal University, Al-Ahsa 31982, Saudi Arabia
5 Institut de Recherche de la Construction, ESTP-Grande Ecole d’ingénieurs de la Construction, 28 Avenue du Président Wilson, Cachan, France
6 The Laboratory of Eco-Materials, Chemical Processes, and Sustainable Development, University of Biskra, Biskra, Algeria
7 Materials Geomaterials and Environment Laboratory (LMGE), Department of Civil Engineering, Faculty of Technology, Badji Mokhtar-Annaba University, P.O. Box 12, Annaba 23000, Algeria
* Corresponding Author: S. M. Anas. Email: ; Osama Khan. Email: ; Fouad Boukhelf. Email: ; Mohammed Benzerara. Email:
(This article belongs to the Special Issue: Sustainable Development and Multifunctional Application of Cellulose Composites)

Journal of Polymer Materials https://doi.org/10.32604/jpm.2026.084491

Received 23 April 2026; Accepted 18 June 2026; Published online 28 July 2026

Abstract

This study focuses on the reinforcement of thermosetting matrices with lignocellulosic fibers and the limited interfacial compatibility that remains a major obstacle to the structural use of bio-based composites. The effect of chemical surface treatment on the interfacial behavior and macroscopic performance of unsaturated polyester resin (UPR) reinforced with Luffa fibers (LF) is studied in depth. LF was treated with two different chemical treatments: (i) alkaline treatment with sodium hydroxide (NaOH) and (ii) a combined NaOH/acetic acid (CH₃COOH) treatment. The structural and morphological characteristics of the LF treated were examined using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Composite specimens were fabricated through a contact molding technique. Mechanical performance was assessed via density, tensile strength, impact resistance, hardness test, and water absorption. Results demonstrate that composites containing 10 wt.% LF exhibits improvements in mechanical properties, with tensile strength, impact strength, and hardness increasing by 74%, 192%, and 16.2%, respectively. The chemical treatments further enhance performance by reducing water absorption and improving fiber–matrix interfacial densification. SEM observations indicate uniform fiber dispersion at low fiber contents, while higher loadings lead to fiber agglomeration. The results demonstrate that luffa fibers can serve as an eco-friendly strengthening material in unsaturated polyester resin composites.

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Keywords

Composites; vegetable fiber; luffa fiber; chemical treatment; unsaturated polyester resin; microstructure

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