Trapping and identification of volatile photo-products of a photo-oxidised epoxy matrix

In previous papers [1-3] (Monney L, Dudois C, Chambaudet A, Polym Degrad Stab 1997;56;357-366; Monney L, Belali R, Vebrel J, Dubois C, Chambaudet A. Polym Degrad Stab 1995;62;353-359; Monney L, Rouge N, Dubois C, Chambaudet A. Polym Degrad Stab 1995;62;367-371.) the photo-oxidation of an epoxy resin (DGEBA) cross-linked with the hardener methyltetrahydrophthalic anhydride (MTHPA) was studied. The chemical evolution of the surface was analyzed by FT-IR spectrophotometry with attenuated total reflection (ATR) and by X-ray analysis [2,3], The analyses confirmed the presence of a thin photo-oxidation layer at the surface of the material, which was predicted from measurement of the organic matrix's ablation [1]. Ablation is due to the loss of volatile photo-oxidation products. A photo-oxidation chamber was designed to trap and analyze these products. The chamber was put into an artificial photo-aging cell and linked to a GC-MS instrument. Photo-oxidation mechanisms were constructed from the data obtained. These mechanisms led to the ablation of the epoxy matrix. (C) 1999 Elsevier Science Ltd. All rights reserved.