Novel Heat Resistant Blend Produced by Compositional Quenching: A Thermoplastic Polyimide Impact Modified with a Fluoroelastomer.

摘要

The polymers used in this work are Ultem, a thermoplastic polyimide produced by General Electric, and Viton A, a fluoroelastomer made by Dupont. Both the polymer and rubber were chosen for this study because of their excellent thermal stability. Ultem is a heat and chemical resistant polymer that suffers from poor impact strength. The addition of a dispersed rubber phase to Ultem significantly reduces this problem. Compositional quenching is a process in which a single-phase solution consisting of two (or more) polymers dissolved in a common solvent is heated and then flashed in a vacuum chamber. Rapid devolatilization of the solvent results leaving behind a two-phase polymer blend in which the minor component is microdispersed within the major component through the action of spinodal decomposition. Through the process of compositional quenching, Ultem-Viton blends were produced that contained relatively uniform-sized, spherical Viton particles approximately one-half micron in diameter. (jes)