Curing of new trimellitimide glycidyl ester derivatives with aromatic diamines

The cure behaviour of new epoxy resins containing a preformed imide ring with m‐phenylenediamine (mPDA) and diaminodiphenylmethane (DDM) was investigated. The progress of polymerization was followed by recording IR and 13C‐NMR spectra at time intervals. The curing proceeded mainly by chain extension at low temperatures, the reaction being not very fast, whereas crosslinking occurred as the gel point was reached (about 15 h at 60°C) by reaction of secondary amino groups with epoxides. Impurities influence, playing the part of catalysts, could be determined from the reaction rate of glycidyl and amino groups. So a kinetic study was made. The thermal behaviour of these cured epoxy resins was also studied.