Properties of Lignin from Oil Palm Empty Fruit Bunch and Its Application for Plywood Adhesive

Abstract

Lignin from lignocellulosic biomass is a potential biopolymer for wood adhesive. The aims of this study were to characterize lignin isolated from the black liquor of oil palm empty fruit bunch fiber pretreated with steam explosion in alkaline conditions and to examine the bond quality of aqueous polymer isocyanate (API) adhesive prepared from lignin, natural rubber latex (NRL), and polyvinyl alcohol (PVA) as base polymers with isocyanate crosslinkers. Lignin was precipitated from the black liquor by adding hydrochloric acid; then the precipitate was separated by filtration, thoroughly washed with water up to pH 2 and pH 5, and dried. The isolated lignin was characterized by ultimate analysis, UV spectroscopy, FT-IR spectroscopy, and thermal analysis. Three-layer plywood samples were prepared, and the bond strengths of the plywood samples were determined in dry conditions and after cyclic boiling. The lignin isolates with different pH values did not have significantly different chemical and thermal properties. Both lignin isolates had similar C, H, and O contents, identical functional groups in the FTIR spectra, similar absorption in the UV spectra, and high decomposition temperatures. The base polymers composition that could produce API adhesive for exterior applications was NRL/PVA/lignin (4/4/2). The use of more lignin in the adhesive formulation decreased the bond strength of the plywood. AbstrakSifat lignin dari tandan kosong kelapa sawit dan aplikasinya sebagai perekat kayu lapis. Lignin dari biomassa lignoselulosa merupakan biopolimer potensial untuk perekat kayu. Tujuan penelitian ini adalah untuk mengenali sifat lignin yang diisolasi dari lindi hitam sisa pretreatment steam explosion alkalis serat tandan kosong kelapa sawit, dan untuk menguji daya rekat perekat aqueous polymer isocyanatae (API) yang dibuat dari lignin, lateks karet alam (LKA) dan polivinil alkohol (PVA) sebagai polimer dasar dengan senyawa isosianat sebagai crosslinker. Lignin diendapkan dari lindi hitam dengan menambahkan asam klorida, setelah itu endapan dipisahkan dari larutan dengan penyaringan, dicuci dengan air sampai pH 2 dan pH 5, dan dikeringkan. Isolat lignin dikarakterisasi dengan analisis ultimat, spektroskopi UV, spektroskopi FT-IR, dan analisis termal. Kayu lapis (tiga lapisan) dibuat dari vinir kayu meranti (depan dan belakang) dan sengon (tengah) dan keteguhan rekatnya diuji pada kondisi kering dan setelah melalui perebusan berulang. Isolat lignin dengan pH yang berbeda tidak memberikan pengaruh nyata terhadap sifat kimia dan sifat termalnya. Kedua isolat lignin mempunyai kadar C, H, dan O yang mirip, gugus fungsi yang identik pada spektra FTIR, serapan yang mirip pada spektra UV, dan suhu dekomposisi yang tinggi. Komposisi polimer dasar yang dapat menghasilkan perekat API untuk aplikasi eksterior adalah LKA/PVA/lignin (4/4/2). Penggunaan lignin yang lebih banyak menurunkan keteguhan rekat kayu lapis.

Repurposing Kraft black Liquor as Reductant for Enhanced Lithium‐Ion Battery Leaching

“…The FTIR spectra exposes some of the functional groups involved in NMC 111 leaching (Figure 4B, full spectra available in Figure S3). The close involvement of ketone and carbonyl groups in the leaching of NMC 111 is depicted by the decrease of the C=O band at 1714 cm −1 , [52] although the partial overlap of the water band at 1640 cm −1 complicates the analysis. The C=C aromatic band at 1519 cm −1 disappears upon contact with NMC 111 , regardless of the presence of H 2 SO 4 .…”

Antibacterial Synergy Detection of Lignin Extract from Oil Palm Empty Fruit Bunches (Opefb) Combined with Amoxicillin Against Staphylococcus Aureus Using The Azdast Method

“…The procedure for determining lignin content refers to the research of Risanto et al (2014), modified. The maximum wavelength of lignin in the 200 -400 nm range was determined.…”

Mystifications and misconceptions of lignin: revisiting understandings

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