Crosslinking of Hardwood Lignin with Citric Acid for Sustainable Wood Adhesives
DOI:
https://doi.org/10.6000/1929-5995.2025.14.07Keywords:
Crosslinking, Hardwood lignin, Citric acid, Wood adhesivesAbstract
The toxicity of petroleum-based crosslinkers raises health and environmental concerns, prompting interest in bio-based alternatives. This study reports the facile crosslinking of hardwood lignin (HWL) with citric acid (CA) as a bio-crosslinker for application as a lignin-based wood adhesive. HWL is characterized by GPC and DSC to determine its molecular weight and glass transition temperature, respectively. The successful crosslinking and esterification reactions of the HWL-CA-based resin are confirmed by the exothermic peaks observed in the DSC thermogram and by FT-IR analysis. The HWL-based adhesives with various proportions of CA meet the Korean standard shear strength requirement of 0.60 MPa, with 12% CA (HWL-CA12) giving the maximum value of 1.07 MPa. The successful surface modification of the veneer pre-treatment with CA is also confirmed by FT-IR analysis. Although the adhesive strength of the HWL-CA12 is decreased on the pre-treated veneer relative to the untreated veneer, it remains above the standard requirement on the veneers that were treated with 10% and 15% of CA. These findings demonstrate the potential of CA-crosslinked lignin as a sustainable alternative to petroleum-based wood adhesives.
References
Ejaz U, Sohail M. Lignin: A Renewable Chemical Feedstock. Handbook of Smart Materials, Technologies, and Devices: Applications of Industry 4.0: Volume 1-3, vol. 2, Springer International Publishing; 2022, p. 1529-44. DOI: https://doi.org/10.1007/978-3-030-84205-5_55
Mili M, Hashmi SAR, Ather M, Hada V, Markandeya N, Kamble S, et al. Novel lignin as natural-biodegradable binder for various sectors—A review. J Appl Polym Sci 2022; 139. DOI: https://doi.org/10.1002/app.51951
Czaikoski A, Gomes A, Kaufmann KC, Liszbinski RB, de Jesus MB, Cunha RL da. Lignin derivatives stabilizing oil-in-water emulsions: Technological aspects, interfacial rheology and cytotoxicity. Ind Crops Prod 2020; 154. DOI: https://doi.org/10.1016/j.indcrop.2020.112762
Fazeli M, Mukherjee S, Baniasadi H, Abidnejad R, Mujtaba M, Lipponen J, et al. Lignin beyond the status quo: recent and emerging composite applications. Green Chemistry 2024; 26: 593-630. DOI: https://doi.org/10.1039/D3GC03154C
Sen S, Patil S, Argyropoulos DS. Thermal properties of lignin in copolymers, blends, and composites: a review. Green Chemistry 2015; 17: 4862-87. DOI: https://doi.org/10.1039/C5GC01066G
Liu R, Smeds A, Willför S, Xu C. Structural properties of softwood lignin fractions: Revealed by NMR and Py-GC/MS. Ind Crops Prod 2024; 209. DOI: https://doi.org/10.1016/j.indcrop.2024.118055
Lee J, Park BD, Wu Q. Adhesion of Technical Lignin-Based Non-Isocyanate Polyurethane Adhesives for Wood Bonding. J Renew Mater 2024; 12: 1187-205. DOI: https://doi.org/10.32604/jrm.2024.049948
Zerpa A, Pakzad L, Fatehi P. Hardwood Kraft Lignin-Based Hydrogels: Production and Performance. ACS Omega 2018; 3: 8233-42. DOI: https://doi.org/10.1021/acsomega.8b01176
Liu LY, Chiang WS, Chang HM, Yeh TF. Phenolation to Improve Hardwood Kraft Lignin for Wood Adhesive Application. Polymers (Basel) 2024; 16. DOI: https://doi.org/10.3390/polym16131923
Zhao D, Li Z, Zhang Y, Fu P. The role of lignin in adhesives for lignin-based formaldehyde-based resins: a review. Biomass Convers Biorefin 2025. DOI: https://doi.org/10.1007/s13399-024-06397-1
Tao Y, Zhou S, Luo Q, Song F, Gong X, Wang Z, et al. Replacing Phenol and Formaldehyde for Green Adhesive Synthesis by Lignin and Furfural. ACS Appl Polym Mater 2024; 6: 6897-905. DOI: https://doi.org/10.1021/acsapm.3c03087
Zhang J, Wang W, Zhou X, Liang J, Du G, Wu Z. Lignin-based adhesive crosslinked by furfuryl alcohol-glyoxal and epoxy resins. Nord Pulp Paper Res J 2019; 34: 228-38. DOI: https://doi.org/10.1515/npprj-2018-0042
Watumlawar EC, Park BD. Synthesis of acetone-fractionated hardwood kraft lignin-based adhesive crosslinked with epichlorohydrin. J Adhes Sci Technol 2024; 38: 442-57. DOI: https://doi.org/10.1080/01694243.2023.2236400
Zhang Q, Xu G, Pizzi A, Lei H, Xi X, Du G. A Green Resin Wood Adhesive from Synthetic Polyamide Crosslinking with Glyoxal. Polymers (Basel) 2022; 14. DOI: https://doi.org/10.3390/polym14142819
Zhao L, Li W, Cheng Y, Zhao J, Tian D, Huang M, et al. Preparation and evaluation of lignin-phenol-formaldehyde resin as wood adhesive using unmodified lignin. Ind Crops Prod 2024; 211. DOI: https://doi.org/10.1016/j.indcrop.2024.118168
Hu S, Chen X, Ni S, Wang Z, Fu Y, Qin M, et al. Formaldehyde-Free, High-Bonding Performance, Fully Lignin-Based Adhesive Cross-Linked by Glutaraldehyde. ACS Appl Polym Mater 2025; 7: 859-67. DOI: https://doi.org/10.1021/acsapm.4c03378
Ji X, Guo M. Preparation and properties of a chitosan-lignin wood adhesive. Int J Adhes Adhes 2018; 82: 8-13. DOI: https://doi.org/10.1016/j.ijadhadh.2017.12.005
Sutiawan J, Hermawan D, Massijaya MY, Kusumah SS, Lubis MAR, Marlina R, et al. Influence of different hot-pressing conditions on the performance of eco-friendly jabon plywood bonded with citric acid adhesive. Wood Mater Sci Eng 2022; 17: 400-9. DOI: https://doi.org/10.1080/17480272.2021.1884898
Li C, Lei H, Wu Z, Xi X, Du G, Pizzi A. Fully Biobased Adhesive from Glucose and Citric Acid for Plywood with High Performance. ACS Appl Mater Interfaces 2022; 14: 23859-67. DOI: https://doi.org/10.1021/acsami.2c02859
Xu D, Li C, Pizzi A, Xi X, Wang Z, Du G, et al. Self-Neutralizing Citric Acid-Corn Starch Wood Adhesives. ACS Sustain Chem Eng 2024; 12: 13382-91. DOI: https://doi.org/10.1021/acssuschemeng.4c05590
Tolbert A, Akinosho H, Khunsupat R, Naskar AK, Ragauskas AJ. Characterization and analysis of the molecular weight of lignin for biorefining studies. Biofuels, Bioproducts and Biorefining 2014; 8: 836-56. DOI: https://doi.org/10.1002/bbb.1500
Gao S, Tian G, Fu Y, Wang Z. Production of Cellulose Pulp and Lignin from High-Density Apple Wood Waste by Preimpregnation-Assisted Soda Cooking. Polymers (Basel) 2023; 15. DOI: https://doi.org/10.3390/polym15071693
Watumlawar EC, Park B-D. Effects of Precipitation pH of Black Liquor on Characteristics of Precipitated and Acetone-Fractionated Kraft Lignin. Journal of the Korean Wood Science and Technology 2023; 51. DOI: https://doi.org/10.5658/WOOD.2023.51.1.38
Poletto M. Assessment of the thermal behavior of lignins from softwood and hardwood species. Maderas: Ciencia y Tecnologia 2017; 19: 63-74. DOI: https://doi.org/10.4067/S0718-221X2017005000006
Li C, Wang Z, Hou M, Cao X, Jia W, Huang L, et al. Comparative study on the physicochemical characteristics of lignin via sequential solvent fractionation of ethanol and Kraft lignin derived from poplar and their applications. Ind Crops Prod 2025; 223. DOI: https://doi.org/10.1016/j.indcrop.2024.120071
Dorieh A, Ayrilmis N, Farajollah Pour M, Ghafari Movahed S, Valizadeh Kiamahalleh M, Shahavi MH, et al. Phenol formaldehyde resin modified by cellulose and lignin nanomaterials: Review and recent progress. Int J Biol Macromol 2022; 222: 1888-907. DOI: https://doi.org/10.1016/j.ijbiomac.2022.09.279
Galdino DS, Kondo MY, De Araujo VA, Ferrufino GLAA, Faustino E, Santos HF dos, et al. Thermal and Gluing Properties of Phenol-Based Resin with Lignin for Potential Application in Structural Composites. Polymers (Basel) 2023; 15. DOI: https://doi.org/10.3390/polym15020357
Ghahri S, Park B-D. Ether Bond Formation in Waste Biomass-Derived, Value-Added Technical Hardwood Kraft Lignin Using Glycolic Acid 2023; 12. DOI: https://doi.org/10.6000/1929-5995.2023.12.14
Cai L, Chen Y, Lu Z, Wei M, Zhao X, Xie Y, et al. Citric acid/chitosan adhesive with viscosity-controlled for wood bonding through supramolecular self-assembly. Carbohydr Polym 2024; 329. DOI: https://doi.org/10.1016/j.carbpol.2023.121765
Traoré M, Kaal J, Martínez Cortizas A. Differentiation between pine woods according to species and growing location using FTIR-ATR. Wood Sci Technol 2018; 52: 487-504. DOI: https://doi.org/10.1007/s00226-017-0967-9
Horikawa Y, Hirano S, Mihashi A, Kobayashi Y, Zhai S, Sugiyama J. Prediction of Lignin Contents from Infrared Spectroscopy: Chemical Digestion and Lignin/Biomass Ratios of Cryptomeria japonica. Appl Biochem Biotechnol 2019; 188: 1066-76. DOI: https://doi.org/10.1007/s12010-019-02965-8
Sun S, Zhao Z, Umemura K. Further exploration of sucrose-citric acid adhesive: Synthesis and application on plywood. Polymers (Basel) 2019; 11. DOI: https://doi.org/10.3390/polym11111875
Zhao Z, Sakai S, Wu D, Chen Z, Zhu N, Huang C, et al. Further exploration of sucrose-citric acid adhesive: Investigation of optimal hot-pressing conditions for plywood and curing behavior. Polymers (Basel) 2019; 11. DOI: https://doi.org/10.3390/polym11121996
Li J, Lei H, Xi X, Li C, Hou D, Song J, et al. A sustainable tannin-citric acid wood adhesive with favorable bonding properties and water resistance. Ind Crops Prod 2023; 201. DOI: https://doi.org/10.1016/j.indcrop.2023.116933
Downloads
Published
How to Cite
Issue
Section
License
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
Policy for Journals/Articles with Open Access
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are permitted and encouraged to post links to their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work
Policy for Journals / Manuscript with Paid Access
Authors who publish with this journal agree to the following terms:
- Publisher retain copyright .
- Authors are permitted and encouraged to post links to their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work .
