Dissolution Study of Lignin from Coconut Fiber as Lignocellulosic Biomass Using Eutectic Based Ionic Liquids Ahmad Mudzakir*1, Asep Bayu Dani Nandiyanto1, Eddy Heraldy2, Jon Efendi3, Karina Mulya Rizky1, Mia Widyaningsih1 and Lewi Stefanus Anggiat1
1. Universitas Pendidikan Indonesia, Jl. Dr. Setiabudi 229 Bandung, 40154, West Java, Indonesia
2. Universitas Sebelas Maret, Jalan Ir. Sutami 36 Kentingan, Jebres, Surakarta, 57126, Middle Java, Indonesia
3. Universitas Negeri Padang, Jln. Prof. Dr. Hamka, Air Tawar, Padang, West Sumatera, Indonesia
*Corresponding email: mudzakir.kimia[at]upi.edu
Abstract
Lignin is one of the main components in lignocellulose, the second most abundant after cellulose in the biosphere. Many applications are the potential use of lignin as a substitute for petroleum-based materials and energy. However, the structure and complexity of lignin limits its use and conversion as a value-added chemical. The purpose of this study was to study the chemical process of lignin dissolution and delignification of lignocellulose-containing biomass waste such as coconut fibers while also studying antifungal activity using eutectic based ionic liquids (EILs) based on choline chloride. EILs in this study were synthesized by simple heating method on two of its constituent components, oxalic acid and ZnCl2. EILs that were successfully synthesized were subjected to an FTIR-NMR study and their density was measured. The synthesized EILs were used in the dissolution and delignification of lignin from coconut fiber and bamboo coatings in fungal resistance tests. The results of the EILs synthesis showed that ionic liquids were successfully synthesized from their form which is a colorless homogeneous liquid with a density of 1.2864 g/cm3 and 1.7526 g/cm3 for EILs CO and CZ, respectively. FTIR studies on EILs confirmed that EILs were successfully synthesized. The maximum solubility study of the synthesized EILs on lignin- cellulose was 42.03%- 5.44% and 32.51%- 7.73% for CO and CZ EILs, respectively. The maximum solubility study of the synthesized EILs on lignin- cellulose was 42.03%- 5.44% and 32.51%- 7.73% for CO and CZ EILs, respectively. FTIR studies confirmed delignified lignin which was shown to be at a peak intensity in the 1700-1400 cm-1 region as a characteristic peak of lignin. The characteristics of coconut fiber after delignification showed an increase in intensity for the functional groups present in cellulose, as shown by the FTIR results. The results of the fungal resistance test showed that for 18 days after inoculation (dai), the growth of fungi on bamboo coated with EILs could be inhibited better by CZ. EILs inhibition ability CZ > CO in inhibiting all three fungi present in this study.
