Studies on the Effect of Structure on Cure and Mechanical Properties in Tetrafunctional Epoxy Resins

Interpretation of the mechanism of 3,3′-dichloro-4,4′-diamino diphenylmethane synthesis over HY zeolites

“…Comprehensive investigation on MOCA synthesis over HY (11) The heterogeneous synthesis of MOCA over HY (11) was further investigated in a xed bed continuous ow reactor.…”

“…Identication of reaction intermediates M and N. Heterogeneous synthesis of MOCA over HY (11) might involve several active intermediates, and their identication would provide some insights into the mechanism of reaction and catalyst deactivation. Aer great effort, however, only two intermediates M and N were successfully isolated by preparative chromatography, puried and then characterized by LC-MS and 1 H NMR, respectively.…”

“…6b could be assigned to 2-chloro-4-(o-chloroanilino-methyl)-phenyl amine. In consequence, the identication of the two intermediates would help us to have an insight into the mechanism and pathways of MOCA synthesis over HY (11).…”

“…For example, 4,4 0 -diaminodiphenyl methane (MDA) is an important additive in the preparation of polyurethane and thermosets, 1-5 3,3 0dimethyl-4,4 0 -diamino diphenylmethane (MDT) is used as a good curing agent in the preparation of electric cables and wires with excellent properties of insulation, heat endurance and chemical resistance, [6][7][8][9][10] and also 3,3 0 -dichloro-4,4 0 -diaminodiphenylmethane (MOCA) plays a vital role in preparing high quality polyurethane and epoxy resin. [11][12][13][14] The condensation of unsubstituted and methyl-or chlorinesubstituted aromatic amine with formaldehyde (HCHO) has provided a convenient route to prepare MDA, 15,16 MDT 17 and MOCA. 18 Such condensation reactions, however, normally requires acid catalysis.…”

“…Secondly, the catalytic performances of the promising HY with Si/Al ratios of 5, 7 and 11 were comparatively investigated. Thirdly, the effects of reaction temperature and time on the activity and selectivity of HY (11) as the best catalyst were further examined. Finally, the synthetic mechanism of MOCA involving key reaction intermediates was interpreted in detail, and also the deactivation and regeneration of catalyst was preliminarily discussed.…”