Synthesis and characterization of isophorondiamine-based oligoamides: catalytic effect of amides during the curing of epoxy resins

The aminolysis products of PET could be applied in several fields. The purpose of this study was to explore their use as a dual-purpose component as cross-linkers and catalysts in epoxy curing. PET aminolysis was carried out with 1:1.5 and 1:2 PET/amine ratios to produce amides with different molecular weights. The reaction products were characterized with functional group analysis, NMR, FTIR, MALDI-TOF, and solution viscosimetry. The terephthalamides were dissolved in isophorondiamine and used as cross-linkers. Reaction kinetics studies with DSC, viscosimetry, and quantum chemical computational methods were used to characterize their accelerative effects. Our studies have shown that terephthalamides are active catalyst and their efficiency can be tuned with their molecular weight. The quantum chemical simulations suggested that the terephthalamides are in the same order of magnitude in effectiveness as phenolic accelerators. Consequently, terephthalamides are valued materials that can serve as double-purpose components in epoxy curing.