Development Of Polyimide-based Carbon Nano-fiber Membrane

Polyimide(PI), as a kind of high-performance engineering material, possesses excellent physical and chemical properties. It has been widely used in microelectronics packaging, high temperature adhesive and composite, etc. High voltage electrospinning technology having advantages of simple technology and convenient operation.The diameters of fiber with continuitie ranged from several decade nanometer to hundreds nanometers. Polyimide-based carbonnano-fiber was prepared by high voltage electrospinning technology is of great potential value in application.This article based on structure and properties of polyimide, using pyromellitic dianhydride(PMDA) and bis(4-aminophenyl)ether(ODA) as monomer to prepare polyamide acid in N,N′-dimethylacetamide, and utilize high voltage electrospinning technology to prepare polyamic acid nano-fiber membrane which was further imidized into polyimidenano-fiber membrane, then use polyimidenano-fiber membrane as precursor to prepare polyimide-based carbonnano-fiber membrane through high-temperature carbonization process. Fiber diameter and non-woven pore size distribution were controlled by eletrospinning technological conditions. Scanning electronmicroscopy(SEM) and transmission electron microscopy (TEM) were utilized to investigate the surface morphology characteristics, Thermogravimetric analysis(TG), X-ray Diffraction (XRD) and infrared analysis(IR) were used to analysis and forecast structure.The results showed that polyimide-based carbonnano-fiber membrane possesses excellent thermal stability. SEM analysis shows that with the carbonation temperature increased, fiber diameter decreases gradually, distribution change narrowlly, mainly located between 100～200nm; when carbonization temperature reached 1000℃, Filamentous carbon content in polyimide-based carbon nano-fiber membrane is 96.16%. Fiber film start deoxy when temperature reached 600℃, and the structure of a graphite like formed temperature reached 700℃, after 700℃the combination of the heterocyclic may be produced to remove sulfur nitrogen oxide, then form continuous aromatic heterocyclic compounds, with temperature continue increased to 900℃fused ring aromatization happen, hexagonal carbon layer with graphite-like structure gradually increased.