Ageing of the DGEBA/TETA epoxy system with off-stoichiometric compositions

An investigation was carried out on the room temperature ageing of off-stoichiometric DGEBA/TETA epoxy formulations. The results obtained show that the epoxy rich mixtures have their inherent brittleness increased by the ageing treatment due to recrystalization of the unreacted epoxy monomers, altho...

Full description

Saved in:
Bibliographic Details
Published in:Materials research (São Carlos, São Paulo, Brazil) São Paulo, Brazil), 2003-06, Vol.6 (3), p.415-420
Main Authors: d'Almeida, José Roberto Moraes, Menezes, Gustavo Wagner de, Monteiro, Sérgio Neves
Format: Article
Language:English
Subjects:
ageing
ENGINEERING, CHEMICAL
epoxy resins
MATERIALS SCIENCE, MULTIDISCIPLINARY
mechanical properties
METALLURGY & METALLURGICAL ENGINEERING
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:An investigation was carried out on the room temperature ageing of off-stoichiometric DGEBA/TETA epoxy formulations. The results obtained show that the epoxy rich mixtures have their inherent brittleness increased by the ageing treatment due to recrystalization of the unreacted epoxy monomers, although homopolymerization could also play a minor role. The initial reaction steps dominated by the amine addition reactions control the macromolecular structure and the mechanical performance of the stoichiometric and near stoichiometric formulation with excess of epoxy monomer. Plasticization due to absorbed -OH results on a significant increase of the deformability of these formulations. The amine rich mixtures have the more stable structures, although plasticization due to moisture absorption from the surrounding environment also produces an increase on the deformability of all, but one, of the formulations investigated.
ISSN:1516-1439
1980-5373
1516-1439
DOI:10.1590/S1516-14392003000300017