Agus Wedi Pratama, Melbi Mahardika, Sena Maulana, Ahmad Nurfaizi, Asep Hidayat, Holilah, Bambang Piluharto, Asranudin, Nurul Widiastuti, Ach. Fauzan Mas'udi, R.A. Ilyas, Victor Feizal Knight, Mohd Nor Faiz Norrrahim, Mohd Shahrieel Mohd Aras, M.K. Mohamad Haafiz
The valorization of agricultural waste is critical for developing a sustainable bioeconomy. Agarwood ( Aquilaria spp. ) bark, a significant byproduct of the agarwood industry, represents an underutilized source of high-quality cellulose microfibrils (CMFs). This study examines the effect of a sequential chemical treatment, with a specific focus on the re-bleaching step, on the properties of CMFs derived from this waste material. The extraction process involved alkaline treatment, initial bleaching, and final re-bleaching. The results demonstrate that the re-bleaching treatment is a crucial step for significantly enhancing CMFs properties. The cellulose content increased progressively from 49.89 % in the raw fibers to 85.86 % in the re-bleached CMFs, while the lignin content was reduced to 3.11 %. Fourier-transform infrared (FTIR) spectroscopy confirmed the systematic removal of non-cellulosic components, including hemicellulose and lignin. Morphological analysis by scanning electron microscopy (SEM) revealed a transformation from rough, bundled raw fibers (average diameter 10.01 ± 3.37 μm) to smooth, uniform CMFs (average diameter 5.30 ± 0.84 μm). Furthermore, X-ray diffraction (XRD) analysis showed a significant increase in the crystallinity index from 46.69 % to 60.38 % after re-bleaching. Thermogravimetric analysis (TGA) confirmed a substantial improvement in thermal stability, with the onset decomposition temperature rising from 229.16 °C for raw fibers to 345.35 °C for the final CMFs. These findings highlight the significance of the re-bleaching process in producing high-purity, highly crystalline, and thermally stable CMFs from agarwood bark waste, indicating their potential use as reinforcing agents in advanced biocomposite materials. © 2025 The Authors.
Department of Agrotechnology, Faculty of Agriculture, University of Jember, Jember, Indonesia; Research Center for Biomass and Bioproducts, National Research and Innovation Agency of Indonesia (BRIN), Serpong, South Tangerang 15314, Banten, Indonesia; Division of Bioresource Technology, School of Industrial Technology, Universiti Sains Malaysia, Pulau Pinang, Gelugor, 11800, Malaysia; Research Collaboration Center for Nanocellulose, BRIN-Andalas University, West Sumatera, Padang, 25163, Indonesia; Department of Forestry Engineering, Institut Teknologi Sumatera, Lampung, Indonesia; Research Center for Ecology, National Research and Innovation Agency (BRIN), Jl. Raya Jakarta-Bogor KM. 46, KST Soekarno, Cibinong, Indonesia; Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember, Jember, Indonesia; Research Center for Applied Microbiology, National Research and Innovation Agency (BRIN), JI Jakarta-Bogor KM 46, KST Soekarno, Cibinong, Indonesia; Department of Chemistry, Faculty of Science and Data Analytics, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia; Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Malaysia; Centre for Advanced Composite Materials (CACM), Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor, Malaysia; Research Center for Chemical Defence, Defence Research Institute, Universiti Pertahanan Nasional Malaysia, Kem Sungai Besi, Kuala Lumpur, 57000, Malaysia; Faculty of Electrical Technology & Engineering, Universiti Teknikal Malaysia Melaka, 76100 Durian Tunggal, Melaka, Malaysia; Green Biopolymer, Coatings & Packaging Cluster, School of Industrial Technology, Universiti Sains Malaysia, Penang, 11800, Malaysia