Identifying the structure-property relationships in recycled expanded polystyrene-coconut coir fiber biocomposites for acoustic applications

Authors

DOI:

https://doi.org/10.15587/1729-4061.2026.364889

Keywords:

expanded polystyrene waste, coconut coir fibers, polymer composites, sound absorption, flexural properties

Abstract

The object of this study is sustainable acoustic panel materials for building noise-control and sound-insulation applications. The large-scale generation of expanded polystyrene (EPS) waste presents a significant environmental challenge due to its inherent resistance to natural degradation. Recycled expanded polystyrene (EPS) reinforced with coconut coir fibers was investigated as a potential material for these applications. The EPS waste was first dissolved in commercial gasoline (Pertalite) via cold dissolution, subsequently blended with 5–60 vol% coconut coir fibers, and fabricated into composites using standard casting techniques. The acoustic and mechanical properties of the resulting materials were evaluated using an impedance tube (ASTM E1050-98) and flexural testing (ASTM D790-03), respectively. Experimental results demonstrated that the optimal solvent-to-EPS ratio was 3:1, yielding a highly homogeneous matrix ideal for composite fabrication. Acoustic analysis revealed that most specimens achieved a sound absorption coefficient exceeding 0.2; the sole exception was the composite containing a 5 vol% fiber fraction, which recorded a value of 0.1 at 500 Hz. Furthermore, the sound absorption capacity consistently improved with increasing frequency, highlighting the efficacy of the composites across the mid- to high-frequency spectrum. Regarding mechanical performance, evaluations indicated that the composite incorporating a 30 vol% fiber fraction achieved the maximum flexural strength and modulus. Overall, these findings establish that bio composites derived from EPS waste and coconut coir fibers possess substantial potential as sustainable acoustic materials, delivering both functional performance and tangible environmental benefits

Author Biographies

I Ketut Gede Sugita, Udayana University

Doctor of Materials

Department of Mechanical Engineering

Ngakan Putu Gede Suardana, Udayana University

Professor of Materials Engineering

Department of Mechanical Engineering

Jefri S. Bale, Universitas Nusa Cendana

Professor of Materials Engineering

Department of Mechanical Engineering

Cipk Kencanawati, Udayana University

Doctor of Materials

Department of Environmental Engineering

Putu Lokantara, Udayana University

Doctor of Materials (Composite)

Department of Mechanical Engineering

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Identifying the structure-property relationships in recycled expanded polystyrene-coconut coir fiber biocomposites for acoustic applications

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Published

2026-06-30

How to Cite

Sugita, I. K. G., Suardana, N. P. G., Bale, J. S., Kencanawati, C., & Lokantara, P. (2026). Identifying the structure-property relationships in recycled expanded polystyrene-coconut coir fiber biocomposites for acoustic applications. Eastern-European Journal of Enterprise Technologies, 3(12 (141), 6–17. https://doi.org/10.15587/1729-4061.2026.364889

Issue

Vol. 3 No. 12 (141) (2026): Materials Science

Section

Materials Science

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Copyright (c) 2026 I Ketut Gede Sugita, Ngakan Putu Gede Suardana, Jefri S. Bale, Cipk Kencanawati, Putu Lokantara

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