Molecular Composites from the Phase Separation at Low Temperatures of Kevlar and Diaminophenylindane Polyimide in Sulfuric Acid

摘要

In a molecular composite, a ductile matrix is reinforced with a stiff, strong, rigid-rod polymer molecule. One of the approaches used to make a rigid-rod molecular composite involves the physical mixing by coprecipitation of single-phase solutions of a rigid-rod and a flexible-coil polymer in a common solvent. We and others have reported previously on the preparation of three-dimensional fibrous materials using the phase separation of polymer solutions at low temperature and sublimation or extraction of the solvent. It is conceivable that a molecular composite would give a superior 3D fibrous material by combining the strength of the rigid-rod macromolecules with the better processibility of the random-coil polymer. This preprint describes our attempts to test this hypothesis. Molecular composites from Kevlar and diaminophenylindane polyimide were fabricated by quenching sulfuric acid solutions. The structure and properties of the resulting three-dimensional fibrous structures were then determined. (aw)