Effects of Alcell Lignin Methylolation and Lignin Adding Stage on Lignin-Based Phenolic Adhesives
To investigate the effects of lignin methylolation and lignin adding stage on the resulted lignin-based phenolic adhesives, Alcell lignin activated with NaOH (AL) or methylolation (ML) was integrated into the phenolic adhesives system by replacing phenol at various adhesive synthesis stages or direc...
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-11-01
|
| Series: | Molecules |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1420-3049/26/22/6762 |
| _version_ | 1797509244426125312 |
|---|---|
| author | Xianbin Ai Shanghuan Feng Tao Shui Himant Kakkar Chunbao Charles Xu |
| author_facet | Xianbin Ai Shanghuan Feng Tao Shui Himant Kakkar Chunbao Charles Xu |
| author_sort | Xianbin Ai |
| collection | DOAJ |
| description | To investigate the effects of lignin methylolation and lignin adding stage on the resulted lignin-based phenolic adhesives, Alcell lignin activated with NaOH (AL) or methylolation (ML) was integrated into the phenolic adhesives system by replacing phenol at various adhesive synthesis stages or directly co-polymerizing with phenolic adhesives. Lignin integration into phenolic adhesives greatly increased the viscosity of the resultant adhesives, regardless of lignin methylolation or adding stage. ML introduction at the second stage of adhesive synthesis led to much bigger viscosity than ML or AL introduction into phenolic adhesives at any other stages. Lignin methylolation and lignin adding stage did not affect the thermal stability of lignin based phenolic adhesives, even though lignin-based adhesives were less thermally stable than NPF. Typical three-stage degradation characteristics were also observed on all the lignin-based phenolic adhesives. Three-ply plywoods can be successfully laminated with lignin based adhesives, and it was interesting that after 3 h of cooking in boiling water, the plywoods specimens bonded with lignin-based phenolic adhesives displayed higher bonding strength than the corresponding dry strength obtained after direct conditioning at 20 °C and 65% RH. Compared with NPF, lignin introduction significantly reduced the bonding strength of lignin based phenolic adhesives when applied for plywood lamination. However, no significant variation of bonding strength was detected among the lignin based phenolic adhesives, regardless of lignin methylolation or adding stages. |
| first_indexed | 2024-03-10T05:14:56Z |
| format | Article |
| id | doaj.art-995da34084e442c0a9cfc2b823135447 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-10T05:14:56Z |
| publishDate | 2021-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-995da34084e442c0a9cfc2b8231354472023-11-23T00:33:22ZengMDPI AGMolecules1420-30492021-11-012622676210.3390/molecules26226762Effects of Alcell Lignin Methylolation and Lignin Adding Stage on Lignin-Based Phenolic AdhesivesXianbin Ai0Shanghuan Feng1Tao Shui2Himant Kakkar3Chunbao Charles Xu4Institute of Energy Research, Jiangxi Academy of Science, Nanchang 330096, ChinaDepartment of Chemical and Biochemical Engineering, Western University, London, ON N6A 5B9, CanadaDepartment of Chemical and Biochemical Engineering, Western University, London, ON N6A 5B9, CanadaDepartment of Chemical and Biochemical Engineering, Western University, London, ON N6A 5B9, CanadaDepartment of Chemical and Biochemical Engineering, Western University, London, ON N6A 5B9, CanadaTo investigate the effects of lignin methylolation and lignin adding stage on the resulted lignin-based phenolic adhesives, Alcell lignin activated with NaOH (AL) or methylolation (ML) was integrated into the phenolic adhesives system by replacing phenol at various adhesive synthesis stages or directly co-polymerizing with phenolic adhesives. Lignin integration into phenolic adhesives greatly increased the viscosity of the resultant adhesives, regardless of lignin methylolation or adding stage. ML introduction at the second stage of adhesive synthesis led to much bigger viscosity than ML or AL introduction into phenolic adhesives at any other stages. Lignin methylolation and lignin adding stage did not affect the thermal stability of lignin based phenolic adhesives, even though lignin-based adhesives were less thermally stable than NPF. Typical three-stage degradation characteristics were also observed on all the lignin-based phenolic adhesives. Three-ply plywoods can be successfully laminated with lignin based adhesives, and it was interesting that after 3 h of cooking in boiling water, the plywoods specimens bonded with lignin-based phenolic adhesives displayed higher bonding strength than the corresponding dry strength obtained after direct conditioning at 20 °C and 65% RH. Compared with NPF, lignin introduction significantly reduced the bonding strength of lignin based phenolic adhesives when applied for plywood lamination. However, no significant variation of bonding strength was detected among the lignin based phenolic adhesives, regardless of lignin methylolation or adding stages.https://www.mdpi.com/1420-3049/26/22/6762Alcell ligninlignin methylolationphenolic adhesiveslignin based phenolic adhesives |
| spellingShingle | Xianbin Ai Shanghuan Feng Tao Shui Himant Kakkar Chunbao Charles Xu Effects of Alcell Lignin Methylolation and Lignin Adding Stage on Lignin-Based Phenolic Adhesives Molecules Alcell lignin lignin methylolation phenolic adhesives lignin based phenolic adhesives |
| title | Effects of Alcell Lignin Methylolation and Lignin Adding Stage on Lignin-Based Phenolic Adhesives |
| title_full | Effects of Alcell Lignin Methylolation and Lignin Adding Stage on Lignin-Based Phenolic Adhesives |
| title_fullStr | Effects of Alcell Lignin Methylolation and Lignin Adding Stage on Lignin-Based Phenolic Adhesives |
| title_full_unstemmed | Effects of Alcell Lignin Methylolation and Lignin Adding Stage on Lignin-Based Phenolic Adhesives |
| title_short | Effects of Alcell Lignin Methylolation and Lignin Adding Stage on Lignin-Based Phenolic Adhesives |
| title_sort | effects of alcell lignin methylolation and lignin adding stage on lignin based phenolic adhesives |
| topic | Alcell lignin lignin methylolation phenolic adhesives lignin based phenolic adhesives |
| url | https://www.mdpi.com/1420-3049/26/22/6762 |
| work_keys_str_mv | AT xianbinai effectsofalcellligninmethylolationandligninaddingstageonligninbasedphenolicadhesives AT shanghuanfeng effectsofalcellligninmethylolationandligninaddingstageonligninbasedphenolicadhesives AT taoshui effectsofalcellligninmethylolationandligninaddingstageonligninbasedphenolicadhesives AT himantkakkar effectsofalcellligninmethylolationandligninaddingstageonligninbasedphenolicadhesives AT chunbaocharlesxu effectsofalcellligninmethylolationandligninaddingstageonligninbasedphenolicadhesives |