Acetylated lignin from oil palm empty fruit bunches and its electrospun nanofibres with PVA: Potential carbon fibre precursor

Mahyuni Harahap; Yurika Almanda Perangin-Angin; Vivi Purwandari; Ronn Goei; Alfred Ling Yoong Tok; Saharman Gea

doi:10.1016/j.heliyon.2023.e14556

Acetylated lignin from oil palm empty fruit bunches and its electrospun nanofibres with PVA: Potential carbon fibre precursor

Heliyon. 2023 Mar 13;9(3):e14556. doi: 10.1016/j.heliyon.2023.e14556. eCollection 2023 Mar.

Authors

Mahyuni Harahap^{1

2}, Yurika Almanda Perangin-Angin^{2

3}, Vivi Purwandari^{1

2}, Ronn Goei⁴, Alfred Ling Yoong Tok⁴, Saharman Gea^{2

3}

Affiliations

¹ Department of Chemistry, Universitas Sari Mutiara Indonesia, Jalan Kapten Muslim No. 79, Medan, 20124, Indonesia.
² Cellulosic and Functional Materials Research Centre, Universitas Sumatera Utara, Jalan Bioteknologi No. 1, Medan, 20155, Indonesia.
³ Departement of Chemistry, Universitas Sumatera Utara, Jalan Bioteknologi No. 1, Padang Bulan, Medan, 20155, Indonesia.
⁴ School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Block N4.1, 637335, Singapore.

Abstract

The electrospinning of acetylated lignin/polyvinyl alcohol (PVA) nanofibres was carried out to expand the application of lignin materials obtained from oil palm empty fruit bunches (OPEFB). Lignin was isolated by the steam explosion method and subsequently precipitated using H₂SO₄. Acetylated lignin was produced by mixing acetic anhydride and pyridine at a 2:1 v/v ratio. Following the acetylation process, FTIR analysis showed the absorption of the C=O carbonyl group at wavenumber 1714.6 cm^-1. The chemical structures of isolated and acetylated lignin were established using ¹H NMR spectral analysis, and XRD examination demonstrated their amorphous character. The electrospinning process of acetylated lignin and PVA solution was then carried out at 15 kV voltage, 0.8 mL/h flow rate, and 12 cm distance between the needle and collector. The sample exhibited electrical conductivity of 443 μS/cm and viscosity of 2.8 × 10^-3 Pa s. The morphology analysis showed that there were more beads on the surface of lignin/PVA nanofibres than acetylated lignin/PVA nanofibres. In addition, acetylated lignin/PVA nanofibre was more stable than lignin/PVA. The G-band of carbonized material increased with the presence of lignin. The works presented suggest the potential of using waste materials such as OPEFB as a suitable precursor for the preparation of carbon fibre.

Keywords: Acetylation; Carbon fibre; Electrospinning; Lignin; Oil palm empty fruit bunches.