Effects of Catalyst Isoquinoline in Polymerization Process on the Aggregation Structures of Polyimide in Solution

Summary: A thermoreversible gel or a dendritic crystal has been obtained in a novel polyimide solution at low temperature, depending on the approach taken to add the isoquinoline catalyst during the polymerization process. By adding the isoquinoline at the beginning of polymerization, two kinds of layer structures in the gel are developed. However, by adding the isoquinoline after the polymerization has been carried out for one hour, a perfect dendritic crystalline structure is gradually developed in the polymerization solution. PLM photographs of the obtained polyimide crystals. magnified image PLM photographs of the obtained polyimide crystals.