Synthesis of a New Hyperbranched Polyaminoester and Its Use as a Reactive Modifier in Anionic Curing of DGEBA Thermosets

The synthesis and characterization of a new hyperbranched PAE with a flexible structure and terminal hydroxyl groups is reported. The influence of PAE in the anionic curing of DGEBA with 1-methylimidazole was studied. The curing reaction was investigated by DSC and FT-IR. The covalent incorporation of the modifier in the matrix was proven. The addition of PAE to the formulation reduced the contraction on curing. The modified materials were more thermally degradable than neat DGEBA thermosets, which is advantageous from the point of view of their reworkability. Their T(g)s were reduced by the flexibility introduced by the aliphatic structure of PAE. SEM microscopy on the fractured surface of cured samples revealed a homogeneous morphology and a possible effect of PAE as a toughness enhancer.