Abstract
Cardanol/phenol-based foaming resol resins were prepared successfully by reacting formaldehyde with cardanol/phenol. Phenolic foams were fabricated with the above foaming resol resin and certain foaming agents. Two kinds of resol resins were characterized with Fourier transform infrared spectroscopy, rheological analysis and Scanning electron microscope. Meanwhile, the nonisothermal curing reactions of these resol resins were studied in detail using a dynamic Differential scanning calorimetry technique at a series of heating rates. The global activation energies of the reactions were determined with the Ozawa methods. The results indicated that the peak temperatures of the exothermic reactions and global activation energies of cardanol-based foaming resol resin were higher than those of phenol-based foaming resol resin, which indicated that the more complex molecular structure of cardanol-based foaming resol resin has a negative effect on the curing speed of resin.
Acknowledgements and declarations
The authors are thankful to the Reviewers and the Editor for their valuable comments and insightful suggestions in improving this paper.
Author Contributions
Conceptualization, Wenzheng Zhang; methodology, Wenzheng Zhang and Zan Wang; validation, Tingting Zhang and Li Huang; formal analysis, Wenzheng Zhang and Cangkui Cui; investigation, Wenzheng Zhang and Zan Wang; data curation, Li Huang and Zan Wang; writing—original draft preparation, Tingting Zhang; writing—review and editing, Wenzheng Zhang; project administration, Wenzheng Zhang. All authors have read and agreed to the published version of the manuscript.
Disclosure statement
No potential conflict of interest was reported by the author(s).