Abstract
Synopsis: Properties as thermally latent initiators of highly dissociative salts made of 4-hydroxyphenylbenzylmethylsulfon ium (4-HPBS) or 4-acetoxyphenylbenzylmethylsulfonium (4-APBS) as a cation and bis(trifluoromethanesulfonyl)imide (TFSI), tricyanomethanide (TCM), tetrakis(pentafluorophenyl)borate (TFPB), or hexafluoroantimonate (SbF6) as an anion were examined for cationic polymerization of various epoxides. The polymerization activity of the anion was in the order of TFPB > SbF6 > TFSI > TCM. The polymerization activity of the highly active salts using 4-HPBS as a cation, 4-HPBS・TFPB and 4-HPBS・SbF6, were compared with the salts having 4-APBS as a cation, 4-APBS・TFPB and 4-APBS・SbF6. Although the polymerization activity of the salts with 4-APBS as a cation was higher than that of those with 4-HPBS as a cation, the room temperature storage stability was much lower. Based on these results, 4-HPBS・TFPB is considered to be the most promising salt as a novel thermally latent polymerization initiator.
