The adhesion behaviour or lack thereof, of polyimides is well known. T
he inherent brittleness of epoxy resins has also led to a search for a
dditives to improve the physical properties of epoxy. In order to impr
ove both of these properties, we utilized a unique strategy to cue a d
iepoxy (diglycidyl ether of bisphenol A) with a polyamic acid derived
from oxydianiline and pyromellitic dianhydride. The polyamic acid synt
hesis was conducted in a low boiling point solvent consisting of tetra
hydrofuran and methanol (80/20) and nor traditional high boiling point
aprotic solvents such as dimethylacetamide. This resulted in a materi
al that had adhesion superior to both the pure epoxy and the pure poly
imide. The state of cure was also seen to have an effect of the adhesi
on strengths. (C) 1997 Elsevier Science Ltd.