Papers by Author: Aîcha Sérier

Abstract: The aim of this work is the studyof the degradation mechanism of a glass fiber/unsaturated polyester (UP) composite immersed inacidic(H₂SO₄)and alkaline(NaOH)solutionslike establishing a relation between the chemical and the mechanical behaviors of this material. The gravimetric analyses showed a pseudo fickianbehavior for the samples immersed in H₂SO₄ and mass losses with a pseudo-stage of saturation as from 64 hours of immersion for the samples immersed in NaOH.The Fourier transform infrared analysis (FT-IR)of the UP resin revealed the presence of chemical degradation phenomenon (hydrolysis).Microscopic observations (SEM) confirmed the fibres/matrix interfacesdegradation. The effect of these degradations has been reflected one the mechanical properties of the materials.

Abstract: The aim of this work is the study of the long term behaviour of a laminated composite made in glass/polyester and aged in seawater at various temperatures. The results obtained show that the immersion in seawater causes ageing of the composite material. This was reflected first by a change in color of the material depending on the temperature of the immersion and the gel-coat loses its brightness. The infrared spectroscopy has confirmed activation of chemical degradation (hydrolysis of the resin and of the fibre/matrix interface, fibre degradation). This chemical degradation could be the cause of decrease in strength and ductility detected by analysing the behaviour of immersed testing specimens. It could also be the cause of the increase of absorption rate recorded for immersions exceeding 22 days.