| 초록 |
In this work, di-functional epoxy resin is cured using an electron beam (EB) irradiation. After the EB curing, the specimens are post-thermal cured using heat and then, the effect of post-thermal curing on the cure and dynamic mechanical behaviors is investigated using near infrared spectroscopy (NIR), nuclear magnetic resonance spectroscopy (NMR), and dynamic mechanical analysis (DMA). As experimental results, the absorption intensity of carbonyl groups in NIR spectra is remarkably decreased while that of the hydroxyl groups connected with the crosslinkage is increased with increasing post-thermal curing time. And the decreases of extant epoxides and secondary alcohol groups with the post-thermal curing are confirmed from 13C-solid-state NMR spectra. Also, the glass transition temperature (Tg) and the crosslinking density (δ) obtained from DMA are significantly increased with the post-thermal curing. These results can be explained by the fact that the crosslinking density is increased with the re-crosslinking, resulting from the post-thermal curing. |
