Synthesis And Characterization Of Novel Polyimides Containing Phosphine Oxide And Fluorine Moieties

Polyimides (PI) are well known as materials of high performance for their excellent thermal stabilities, radiation resistance, chemical and physical stabilities, mechanical and electrical properties. They are widely used in the aerospace, microelectronics, automobile, petroleum and other high technological industries.Phosphorus monomer, bis(3-aminophenyl)phenyl phosphine oxide (BAPPO) and fluorine-containing monomer,3,5-diaminobenzotrifluoride were synthesized and then characterized by FT-IR,1H-NMR. MS and DSC. The synthesis and purification routes and the influences of reaction conditions such as reaction temperature, reaction time on yield and so on were also studied.Series of novel polyimides containing phosphine oxide and fluorine moieties were synthesized by different ratio of BAPPO,3,5-diaminobenzotrifluoride and4,4’-diamin-odiphenyl ether (ODA) which reacted with pyromellitic dianhydride (PMDA) or2,2-bis [4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (BAPDA) through two-step method reaction of solution polycondensation. The influences of reaction conditions such as solid content, reaction temperature, reaction time and the effort of monomers’ratio were also studied. The structure of these series of polymers were characterized by FT-IR,’H-NMR, and the properties were characterized by DSC, TGA and solubility test, which indicates that introducting phosphine oxide and fluorine moieties can maintain high glass transition temperature of polyimides, high thermal stability and improve solubility. The properties of the polyimide films containing phosphine oxide and fluorine moieties were tested, which indicates they possess excellent mechanic properties. Contact angle test indicates that copolymerization polymer can enhance the ability to resist moisture, which is conducive to maintaining the mechanical properties and the stability of polymers in practical application. The water-intake rate of polyimide films containing phosphine oxide and fluorine moieties indicates that they have low water-intake rate.