Abstract

The effects of exposure to different humid environments in a commercial cold-cured epoxy adhesive were investigated. Samples were exposed up to one month to 55%, 75% and 100% relative humidity (RH) or immersed in liquid water, at a constant temperature (23 °C). Weight changes, thermal and mechanical properties before and at different stages of the aging, were discussed.In the examined aging conditions, absorbed water remained below 1% and saturation level was not achieved. Plasticization, reactivation of curing reactions and erasure of physical aging were observed in the specimens subjected to the different humidity regimes, all affecting both the thermal and the mechanical properties of the aged samples: while the Tg was influenced by plasticization mainly at shorter times of exposure and by post-curing at longer treatment times, the mechanical characteristics were less affected by these phenomena. These effects were found more pronounced at humidity levels higher than 75% RH. Doubly hydrogen-bonded water molecules linked to the network also influenced the Tg of the system, while they did not affect noticeably their flexural properties. Finally, the effects of water exposure can be regarded as equivalent to those of a thermal treatment at temperature around the Tg, i.e. both leading to an erasure of the physical aging.

Autore Pugliese

• Lettieri Mariateresa

Tutti gli autori

• M. Lettieri; M. Frigione

Titolo volume/Rivista

Construction & building materials

Anno di pubblicazione

2012

ISSN

0950-0618

ISBN

Non Disponibile

Numero di citazioni Wos

Nessuna citazione

Ultimo Aggiornamento Citazioni

Non Disponibile

Numero di citazioni Scopus

Non Disponibile

Ultimo Aggiornamento Citazioni

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Settori ERC

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Codici ASJC

Non Disponibile