SYNTHESIS OF PHOTOREACTIVE IMIDAZOLE DERIVATIVES AND THERMAL CURING REACTION OF EPOXY-RESINS CATALYZED BY PHOTO-GENERATED IMIDAZOLE

Photoreactive blocked imidazoles such as N-(2-nitrobenzyloxycarbonyl)i midazole (2-NBCI), N-(3-nitrobenzyioxycarbonyl)imidazole (3-NBCI), N-( 4-nitrobenzyloxycarbonyl)imidazole (4-NBCI), N-(4-chloro-2-nitrobenzyl oxycarbonyl)imidazole (CNBCI). N-(5-methyl-2-nitrobenzyloxycarbonyl)im idazole (MNBCI), and -(4,5-dimethoxy-2-nitrobenzyloxycarbonyl)imidazol e (DNBCI) were synthesized in good yields by reactions of N,N'-carbony ldiimidazole (CD I) with corresponding benzyl alcohols. The prepared 2 -NBCI decomposed smoothly to produce imidazole by UV-irradiation in te trahydrofuran (THF) solution or poly(methyl methacrylate) (PMMA) film. Rates of photolysis of DNDCI, MNBCI and CNBCI were higher than that o f 2-NBCI in PMMA film, although the rates of 3-NBCI and CNBCI were slo wer than that of 2-NBCI in PMMA film under the same conditions. Therma l curing reactions of epoxy resins and poly(glycidyl methacrylate-co-m ethyl methacrylate) CP(GMA(55)-MMA(45))] using photo-generated imidazo le were examined at 100-160 degrees C. The ring opening reaction of ep oxide groups, confirmed by IR spectra, in epoxy resins and P(GMA(55)-M MA(45)) proceeded smoothly by catalysis of the photo-generated imidazo le.