Non-woven Membranes of ODPA-ODA Polyimide Prepared by Electrospinning

In the present study, a new process for making non-woven membranes of polyimide (PI) using as insulation materials was described. The ODPA-ODA PI fibers are prepared by electrospinning a poly (amic acid) (PAA) solution, a precursor of polyimide, synthesized from 4,4'-oxydianiline (ODA) and 4,4'-oxydiphthalic anhydride (ODPA), followed by thermal imidization. The chemical structure, surface morphology, thermal stability of ODPA-ODA PI and PAA were characterized by Fourier transform infrared spectroscope (FT-IR), scanning electron microscope (SEM) and thermogravimetry analysis (TGA) respectively. The fibers of PAA with average diameters less than 1mum appeared to be densely packed on the surface. The fibers of ODPA-ODA PI with the diameters less than 500nm obtained after imidization at 300degC exhibited shrinkable, twisted and ribbon-shaped cross section. The ODPA-ODA PI non-woven membranes with decomposition temperature of above 500degC possess excellent heat-resistance.