About this Journal Submit a Manuscript Table of Contents
Advances in Materials Science and Engineering
Volume 2013 (2013), Article ID 869075, 10 pages
http://dx.doi.org/10.1155/2013/869075
Research Article

Degradation in Seawater of Structural Adhesives for Hybrid Fibre-Metal Laminated Materials

1Center for Durability and Structural Integrity of Materials (CISDEM-UPM/CSIC), Universidad Politécnica de Madrid, C/Ronda Valencia, 3-28015 Madrid, Spain
2Research Group on Degradation and Corrosion of Materials, Universidad de Cantabria, c/Gamazo, 1-39004 Santander, Spain

Received 16 November 2012; Revised 15 January 2013; Accepted 22 January 2013

Academic Editor: Luigi Nicolais

Copyright © 2013 Cristina Alia et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The adhesives used for applications in marine environments are subject to particular chemical conditions, which are mainly characterised by an elevated chlorine ion content and intermittent wetting/drying cycles, among others. These conditions can limit the use of adhesives due to the degradation processes that they experience. In this work, the chemical degradation of two different polymers, polyurethane and vinylester, was studied in natural seawater under immersion for different periods of time. The diffusion coefficients and concentration profiles of water throughout the thickness of the adhesives were obtained. Microstructural changes in the polymer due to the action of water were observed by SEM, and the chemical degradation of the polymer was monitored with the Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The degradation of the mechanical properties of the adhesive was determined by creep tests with Mixed Cantilever Beam (MCB) specimens at different temperatures. After 180 days of immersion of the specimens, it was concluded that the J-integral value (depending on the strain) implies a loss of stiffness of 51% and a decrease in the failure load of 59% for the adhesive tested.