| 초록 |
Novel latent thermal initiators for cationic polymerization of epoxy resins, i.e., triphenylphosphinium hexafluoro-antimonate (TBPH) and methyldiphenylphosphinium hexafluoroantimonate (MDPH) are synthesized and characterized. And, the latent, thermal, and mechanical properties of difunctional epoxy resins cured by 1 phr of either TBPH or MDPH initiator are investigated. As experimental results, multiple peaks are observed at the DSC curve profile in both DGEBA/TBPH and DGEBA/MDPH. Also, the cure reaction of DGEBA/TBPH and DGEBA/MDPH do not proceed below 180℃ but rapidly proceed above 200℃. And, the second exotherms of TDGEBA/TBPH and DGEBA/MDPH show broad curves at 320℃ and 270℃, respectively. This can be interpreted in terms of slow thermal diffusion rate and bulk structure of four phenyl groups in TBPH. However, in case of the thermal and mechanical properties, DGEBA/MDPH system is higher than DGEBA/TBPH system. This result is probably due to the fact that DGEBA/MDPH has more dense structure in intra- and inter- molecular because of low steric hindrance. |
