The use of Raman spectroscopy to study the reaction between an amine-terminated thermoplastic and epoxy resins

Reactive thermoplastics are increasingly used as toughening modifiers for e poxy resins. A way to understand the influence of the reactive end-groups o n the toughening and curing mechanisms is to observe in situ the reaction b etween the thermoplastic and the growing epoxy network. For this purpose, R aman spectroscopy has been used to follow the reaction of aromatic amines w ith epoxide monomers through the evolution of an amine-substituted aromatic vibration. A double shift of this peak was correlated with the formation o f secondary and tertiary amines. Band assignment was confirmed by the study of model compounds. Through this method, qualitative observation of the re action between an amine-ended copolyethersulphone thermoplastic and epoxide was performed. Unfortunately, in the studied blend containing the curing a gent, a band appearing upon curing overlapped with the band characterising the end-group reaction. (C) 2000 Elsevier Science Ltd. All rights reserved.