Eco-Friendly Tannin-Based Non-Isocyanate Polyurethane Resins for the Modification of Ramie (<i>Boehmeria nivea</i> L.) Fibers
Manggar Arum Aristri,
Rita Kartika Sari,
Muhammad Adly Rahandi Lubis,
Raden Permana Budi Laksana,
Petar Antov,
Apri Heri Iswanto,
Efri Mardawati,
Seng Hua Lee,
Viktor Savov,
Lubos Kristak,
Antonios N. Papadopoulos
Affiliations
Manggar Arum Aristri
Department of Forest Products, Faculty of Forestry and Environment, IPB University, Bogor 16680, Indonesia
Rita Kartika Sari
Department of Forest Products, Faculty of Forestry and Environment, IPB University, Bogor 16680, Indonesia
Muhammad Adly Rahandi Lubis
Research Center for Biomass and Bioproducts, National Research and Innovation Agency, Cibinong 16911, Indonesia
Raden Permana Budi Laksana
Research Center for Biomass and Bioproducts, National Research and Innovation Agency, Cibinong 16911, Indonesia
Petar Antov
Faculty of Forest Industry, University of Forestry, 1797 Sofia, Bulgaria
Apri Heri Iswanto
Department of Forest Products Technology, Faculty of Forestry, Universitas Sumatera Utara, Kwala Bekala, Medan 20145, Indonesia
Efri Mardawati
Research Collaboration Center for Biomass and Biorefinery between BRIN and Universitas Padjajaran, National Research and Innovation Agency, Cibinong 16911, Indonesia
Seng Hua Lee
Department of Wood Industry, Faculty of Applied Sciences, Universiti Teknologi MARA (UiTM), Cawangan Pahang Kampus Jengka, Bandar Tun Razak 26400, Malaysia
Viktor Savov
Faculty of Forest Industry, University of Forestry, 1797 Sofia, Bulgaria
Lubos Kristak
Faculty of Wood Sciences and Technology, Technical University in Zvolen, 96001 Zvolen, Slovakia
Antonios N. Papadopoulos
Laboratory of Wood Chemistry and Technology, Department of Forestry and Natural Environment, International Hellenic University, 661 00 Drama, Greece
This study aimed to develop tannin-based non-isocyanate polyurethane (tannin-Bio-NIPU) and tannin-based polyurethane (tannin-Bio-PU) resins for the impregnation of ramie fibers (Boehmeria nivea L.) and investigate their mechanical and thermal properties. The reaction between the tannin extract, dimethyl carbonate, and hexamethylene diamine produced the tannin-Bio-NIPU resin, while the tannin-Bio-PU was made with polymeric diphenylmethane diisocyanate (pMDI). Two types of ramie fiber were used: natural ramie without pre-treatment (RN) and with pre-treatment (RH). They were impregnated in a vacuum chamber with tannin-based Bio-PU resins for 60 min at 25 °C under 50 kPa. The yield of the tannin extract produced was 26.43 ± 1.36%. Fourier-transform infrared (FTIR) spectroscopy showed that both resin types produced urethane (-NCO) groups. The viscosity and cohesion strength of tannin-Bio-NIPU (20.35 mPa·s and 5.08 Pa) were lower than those of tannin-Bio-PU (42.70 mPa·s and 10.67 Pa). The RN fiber type (18.9% residue) was more thermally stable than RH (7.3% residue). The impregnation process with both resins could improve the ramie fibers’ thermal stability and mechanical strength. The highest thermal stability was found in RN impregnated with the tannin-Bio-PU resin (30.5% residue). The highest tensile strength was determined in the tannin-Bio-NIPU RN of 451.3 MPa. The tannin-Bio-PU resin gave the highest MOE for both fiber types (RN of 13.5 GPa and RH of 11.7 GPa) compared to the tannin-Bio-NIPU resin.
