Abstract
SynopsisTo further improve the characteristics of phenolic resins and the moldings, it is necessary to design the cross-linking structure. Currently, analysis of the structure and properties of the cured phenolic resin is not progressing much, because they are insoluble in solvents and not melt. In this study, we investigated cross-linking structure of cured phenolic resins by 13C-MAS method of solid-state NMR and evaluated mechanical properties of them. As a result, intermediate structure was increased with increasing hardener and was converted into methylene bridge by the post-cure. In addition, Tg of cured phenolic resin was increased with increasing the amount of intermediate structure and methylene bridge.
