2026-04-17T15:57:14Zhttps://recercat.cat/oai/request

oai:recercat.cat:10256/76852024-06-14T09:24:45Zcom_2072_452955com_2072_2054col_2072_453062

Synthesis and characterization of kraft lignin-based epoxy resins El Mansouri, Nour-Eddine Yuan, Qiaolong Huang, Farong Lignina Lignin Resines epoxídiques Epoxy resins Epoxidization is an interesting way to develop a new application of lignin and therefore to improve its application potential. In this work, kraft lignin-based epoxy resins were obtained by the epoxidization reaction, using the kraft lignin recovered directly from pulping liquor and modified by a methylolation reaction. The methylolated lignins were obtained by the reaction of original kraft lignin with formaldehyde and glyoxal, which is a less volatile and less toxic aldehyde. 1H-NMR spectroscopy showed that methylolated kraft lignin has more hydroxymethyl groups than glyoxalated kraft lignin. For the epoxidization reaction we studied the influence of the lignin:NaOH (w/w) ratio, temperature, and time of the reaction on the properties of the prepared epoxidized lignins. The structures of lignin-based epoxy resins were followed by epoxy index test and FTIR spectroscopy. Optimal conditions were obtained for lignin-based epoxy resin produced at lignin/NaOH = 1/3 at 70 ºC for 3h. Thermogravimetry analysis (TGA) revealed that the epoxidization enhances the thermal stability of lignins and may allow a wider temperature range for applications with lignin epoxy-PF blends 2011 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://hdl.handle.net/10256/7685 http://hdl.handle.net/10256/7685 eng info:eu-repo/semantics/altIdentifier/issn/1930-2126 Tots els drets reservats info:eu-repo/semantics/openAccess application/pdf North Carolina State University © BioResources, 2011, vol. 6, núm. 3, p. 2492-2503 Articles publicats (D-EQATA)