Dynamic Mechanical Characterization of Advanced Composite Epoxy Matrix Resins of Altered Composition

Abstract

The compositions of several advanced composite epoxy matrix resins were intentionally altered to assess acceptable limits of compositional variability. The objective of the work reported herein was to determine if these compositional variations could be related to the material's dynamic mechanical (DM) response. DM characterization of epoxy resins has been shown (1,2) to be useful in elucidating structure-property relationships. In this work the DM behavior of these altered samples was studied in shear as a function of frequency, temperature and absorbed moisture. Absorbed moisture has been shown (3) to dramatically affect an epoxy resin's mechanical response. Experimental The epoxy resins investigated are representative of current high performance composite epoxy matrix resin systems. They contain multifunctional epoxy resins, an aromatic diamine curing agent (diaminodiphenylsulfone, DDS), and, in certain formulations, an organometallic catalyst (boron trifluoride complex). Compositional variations investigated are shown in Tables I, II, and III. Samples were prepared by casting