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Curing properties of high-Ortho phenol-formaldehyde resins with co-catalysis |
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| Authors: | Jiongjiong Li Wenjie Zhu Jizhi Zhang Shifeng Zhang Qiang Gao Jianzhang Li Wei Zhang |
| Affiliation: | 1. Key Laboratory of Wood Materials Science and Application (Beijing Forestry University), Ministry of Education (MOE), Beijing 100083, China;2. Key Laboratory of Wood Materials Science and Application (Beijing Forestry University), Ministry of Education (MOE), Beijing 100083, China
Beijing Key Laboratory of Wood Science and Engineering, Beijing Forestry University, Beijing 100083, China;3. Key Laboratory of Wood Materials Science and Application (Beijing Forestry University), Ministry of Education (MOE), Beijing 100083, China Beijing Key Laboratory of Wood Science and Engineering, Beijing Forestry University, Beijing 100083, China Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (MOE), School of Materials Science and Engineering, Shandong University, Jinan 250061, China |
| Abstract: | In this study, sodium carbonate (Na2CO3) was used as a catalyst to prepare high-ortho phenol-formaldehyde (HOPF) resin, and ester and carbonate curing accelerators were used to increase its curing rate. The physicochemical properties of the prepared resins and the mechanism of curing acceleration were investigated. The results showed that, with the addition of Na2CO3, the ortho/para ratio of methylol groups increased from 7.257 to 27.800. The gel time of the cure-accelerated HOPF resins decreased from 620 to 240 s as compared with PF resin. The bonding strength of plywood bonded with the cure-accelerated HOPF resins were all above 0.70 MPa. The curing acceleration was caused by the carbonate ions rather than the metal ions, and a temporary incorporation mechanism apparently occurred for the ester accelerators. The prepared phenolic resin had fast curing rate, low curing temperature, high thermal stability, and favorable mechanical performance, which has potential for industry applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47229. |
| Keywords: | adhesives catalysts crosslinking thermosets |