Open Access

SHORT COMMUNICATION

Comparative Study of PLA/Kenaf Core and PLA/Kenaf Bast Flexural Properties

Siti Norasmah Surip¹, Wan Nor Raihan Wan Jaafar^1,*, Jaka Fajar Fatriansyah², Ing Kong³

1 Faculty of Applied Sciences, Universiti Teknologi MARA, 40450, Shah Alam, Selangor, Malaysia
2 Department of Metallurgy and Materials Engineering, Faculty of Engineering, Universitas Indonesia, Depok, 16424, West Java
3 Department of Engineering, La Trobe University, Bendigo, VIC 3552, Australia

* Corresponding Author: Wan Nor Raihan Wan Jaafar. Email:

(This article belongs to the Special Issue: Biomass-based Thermoset and Thermoplastic Polymers for Biomass-based Composites)

Journal of Renewable Materials 2026, 14(7), 4 https://doi.org/10.32604/jrm.2025.02025-0182

Received 30 September 2024; Accepted 01 December 2025; Issue published 28 July 2026

Abstract

Most studies on kenaf fibre composites focus on the bast due to its higher fibre yield and strength, while the core is often neglected. In this work, Polylactic Acid (PLA) matrix was reinforced with both kenaf bast and core fibres at a 49:1 wt% ratio. The fibres were chemically treated and cryo-crushed to improve bonding and dispersion. Mechanical testing revealed that treated Kenaf Core Composites (KCC) exhibited comparable flexural and impact properties to Kenaf Bast Composites (KBC), with flexural strengths of 46.19 and 46.52 MPa, respectively, and impact strengths of 5.8 and 4.4 J/m. Meanwhile, thermal analysis reported increased glass transition temperature (Tg) and crystallinity for both composites compared to neat PLA, indicating restricted polymer chain mobility and enhanced interfacial bonding. Moreover, Scanning Electron Microscopy (SEM) confirmed strong fibre-matrix adhesion and good dispersion of both fibre types. This indicates that kenaf core can perform as well as bast in composites, supporting full-plant utilization. Overall, using both bast and core can reduce waste, improve sustainability, and enhance the economic value of kenaf in bio-composite applications.

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Keywords

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