Synthesis And Characterization Of Hyperbranched Polyimide

Polyimides (PI) have been used in many advanced technologies and novel applications, such as aerospace, aeronautical, optical, electrical and microelectronics industry, because of their excellent thermal stability, high mechanical performance, and outstanding electrical properties. Hyperbranched polyimide(HBPIs) with high branching and imide structure, which makes its has overall performance, not only has good hyperbranched polymer solubility, low melt viscosity, other characteristics, but also with heat resistance and excellent dielectric properties, etc. processing performance have been greatly improved, widely used in aviation, aerospace, electrical and microelectronic industries.A triamine monomer, 1, 3, 5-tris (4-aminophenyl) benzene (TAPB) was synthesized in this paper. A novel hyperbranched polyimide with highly solubility was prepared through chemical imidization and thermal imidization with this triamine monomer 1, 3, 5-tris (4-aminophenyl) benzene(TAPB)and3, 3' 4, 4'-benzophenone dianhydride (BTDA), 1, 2, 4, 5-Benzenetetracarboxylicanhydride, 4, 4'-(Hexafluoroisopropylidene) diphthalicanhydride. The structure of the product was characterized with infrared spectrum (FT-IR) and nuclear magnetic resonance (NMR). Structure and properties of polymer was characterized, specifically including the following aspects:1. The synthesis of three amine monomer 1, 3, 5 - (aminophenyl) benzene (TAPB)The 1, 3, 5- (aminophenyl) benzene (TAPB) has been synthesized by nitroacetophenone. Three catalytic systems were used: SOCl2/EtOH catalyst system, silicontetrachloride (TCS)/ethanol catalytic system, CF3SO3H/C7H8 catalyst system, and their catalytic conditions and catalytic effects were compared and analyzed. The choice of the reduction system were also selected: FeCl3 ? 6H2O and activated carbon catalyst system, reducing agent hydrazine hydrate reduction system; pd/c as catalyst, the reduction of hydrazine hydrate as the reducing agent system; pd/c and HCOONH4, methanol restore the system, and reducing conditions and effects are analyzed and compared.The structure of the product was characterized with infrared spectrum (FT-IR) and nuclear magnetic resonance (NMR), structure and properties of polymer were characterized, the results show that the solubility of the polymer is further improved.2. The synthesis of hyperbranched polyimide A triamine monomer, 1, 3, 5-tris (4-aminophenyl) benzene (TAPB) was synthesized in this paper. A novel hyperbranched polyimide with highly solubility was prepared through chemical imidization and thermal imidization with this triamine monomer 1, 3, 5-tris (4-aminophenyl) benzene(TAPB)and3, 3' 4, 4'-benzophenone dianhydride(BTDA), 1, 2, 4, 5-Benzenetetracarboxylic anhydride, 4, 4'-(Hexafluoroisopropylidene)diphthalicanhydride. On this basis, BTDA-ODA-TAPB, PMDA-ODA-TAPB, 6FDA-ODA-TAPB hyperbranched copolymer polyimide were synthesized, the structure has been confirmed by FTIR, 1HNMR, and thermal analysis, XRD, viscosity and solubility tests were carried out, the analysis of the structureshows that the solubility of hyperbranched polyimide significantly better than linearpolyimide which synthesized under the same conditions, XRD data show that thehyperbranched polyamide was not as linear crystal polyimide as good, sometimes maybe amorphous state. Viscosity tests show that more linear hyperbranched polyimide lower viscosity; these features make the hyperbranched polyimide has a broad prospect in industrial production and in applications.