ONE DIMENSIONAL RESIN TRANSFER MOLDING PROCESS MODELING

Dan Shantz, Dr. Rick Davis, and Slade Gardner
National Science Foundation and Technology Center:
High Performance Polymeric Adhesive and Composites, and
Department of Chemical Engineering
Virginia Polytechnic Institute and State University
Blacksburg, Virginia

ABSTRACT

Polyamic acid (PAA) solubility in water was studied with four tetraalkyl ammonium hydroxide bases with varying cation sizes. The minimum amount of each base needed to dissolve Ultem polyamic acid in a 0.42 wt% polyamic acid/water solution was found. An additional dilute solution of 0.6 wt% Ultem polyamic acid with a stochiometric amount of tetramethyl ammonium hydroxide was made to study the polyamic acid degradation kinetics. Dissolution studies were performed with 15 wt% LaRC TPI polyamic acid using 25% excess base to explore the possibility of using the solutions as a matrix material for aqueous solution prepregging. Maximum loading tests were then performed using 50% excess tetraethyl ammonium hydroxide. The dilute solution tests show improved solubility with increasing counterion size, consistent with polyelectrolyte theory. The dilute solution viscosity results suggest rapid polyamic acid degradation kinetics. The concentrated solutions showed potential processibility windows for aqueous solution prepregging.