| Título: | SYNTHESIS AND CHARACTERIZATION OF KRAFT LIGNIN-BASED EPOXY RESINS |
| Autores: |
El Mansouri, Nour Eddine Yuan, Qiaolong Huang, Farong |
| Fecha: | 2011-04-29 |
| Publicador: | Bioresources |
| Fuente: |
 |
| Tipo: |
info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion |
| Tema: | Lignin; Hydroxymethylation; Glyoxalation; Epoxidization; Epoxy resin |
| Descripción: | 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. |
| Idioma: | Inglés |