| Popis: |
The feasibility of using two step procedures with thermal imidization of polyamic acid (PAA) for synthesizing hydroxyl group polyimide (PI), based on 2,2-Bis(3-amino-4-hydroxyphenyl)hexafluoropropane (Bis-AP-AF), was studied. It was found that a high molecular weight PAA could be successfully synthesized from Bis-AP-AF with 3,3',4,4'-Benzophenone tetracarboxylic dianhydride (BTDA). The optimum polycondensation reaction time on synthesizing molecular weight of the PAA was 4 hours. The PI films could be successfully prepared by thermal imidization of the PAA. The higher the inherent viscosity of the PAA is, the more beneficial for the tensile properties of the PI films. All the results indicate that two step procedures with thermal imidization of the PAA under appropriate conditions represented a promising way for preparation PI films, with a reasonable level of mechanical properties. |
