The cross-linking structure and physical properties of epoxy resins cured with amine under off-stoichiometric ratio conditions were examined. As the excess amine increased, some of the amine not only remained as unreacted monomers or low-molecular-weight isolated chains within the cross-linking structure, but also formed dangling chain ends. As a result, the cross-linking density and mass density decreased, as did the glass transition temperature. On the other hand, Young’s modulus increased with the excess amount of amine due to the suppression of the widening distance between phenyl groups.
- Satoru Yamamoto
- Nguyen Thao Phan
- Keiji Tanaka
