Mechanics of Advanced Composite Structures

Mechanics of Advanced Composite Structures

Enhancing the Performance of High-Loaded Coconut Shell Biocomposites with NaOH Treatment

Document Type : Research Article

Authors
Widianti Widianti 1
Adi Rahwanto 2
Ismail Ismail 2
1 Master's Program in Physics, Department of Physics, Faculty of Mathematics and Natural Science, Universitas Syiah Kuala, Banda Aceh 23111, Indonesia
2 Department of Physics, Faculty of Mathematics and Natural Science, Universitas Syiah Kuala, Banda Aceh 23111, Indonesia
10.22075/macs.2026.38342.1889
Abstract
The immense environmental concerns and the need for sustainable materials have driven extensive research into the development of biocomposites. This paper, therefore, investigates the effects of alkali (NaOH) concentration on coconut shell particles and how it influences the physical, mechanical, and thermal characteristics of the resulting biocomposites. Coconut shell particles were soaked in NaOH solutions at varying concentrations of 0%, 5%, 10%, 15%, and 20%, with soaking times of 4 and 8 hours. Coconut shell particles were analyzed using X-ray diffraction (XRD), X-ray fluorescence (XRF), and Fourier Transform Infrared Spectroscopy (FTIR), both before and after NaOH treatment. The biocomposite boards were fabricated using a press method, applying a load of 9 tons for 30 minutes. The coconut shell particles were mixed with epoxy resin at a ratio of 80 vol.% coconut shell particles (high-loaded biocomposite) and 20 vol.% epoxy resin. The physical, mechanical, and thermal properties of the biocomposite were evaluated. The universal testing machine, thermogravimetric analysis, and scanning electron microscope (SEM) were utilized to characterize the biocomposite samples. The results indicated a significant improvement in the performance of the biocomposites following the treatment of coconut shell particles with a 20% NaOH solution for 8 hours. The thickness-swelling and porosity decreased from 10.9% and 9.5% to 2.8% and 2.5%, respectively. The modulus of rupture and modulus of elasticity increased from 8.34 MPa and 764 MPa to 19.22 MPa and 4447 MPa, respectively. The biocomposite became more thermally stable. The above points imply that the biocomposite material underwent property modifications due to the alkaline treatment of the coconut shells, thereby improving the compatibility and interaction between the coconut shell particles and the epoxy resin.
Keywords
Coconut shell particles
Alkali treatment
Physical property
Mechanical property
Thermal property
Subjects
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Mechanics of Advanced Composite Structures
Volume 14, Issue 2 - Serial Number 30
In Progress
November 2027
Pages 423-438