Waterborne Polyimides and Poly(imide-Siloxane)s

摘要

The optimum design for composite fiber matrix interfaces has not been established. Our working hypothesis is that the interfacial material should be: ductile, applicable from water, and either miscible with, or reactive with the matrix. Our focus has been to prepare water soluble Ultem poly(amic acid) salts for use as sizing and interface toughening materials for composite manufacturing. Stable water soluble Ultem type poly(amic acid) salts were prepared from methanolic tripropylamine. Rapid imidization (10 min at 260°C) of the poly(amic acid)s and poly(amic acid) salts allows for on-line processing. Epoxy/polyimide networks prepared from amine terminated Ultem polyimides and DER 331 epoxy resin showed microphase separation (100-300 nm inclusions) using transmission electron microscopy and atomic force microscopy. Diffusion of the reactive interface material was seen in the AFM of the polyimide/epoxy bilayer film, whereas no diffusion was evident in the poly(imide-siloxane) bilayer films.