The Synthesis Of The Alicyclic Diamine Based On Nadic Anhydride And Research On Performance Of The Novel Polyimide

Polyimides are an important class of functional material with excellent thermal stability, mechanical properties, chemical resistance and dielectric properties, which used in such applications as electrical, aircraft, coating material, microelectronics industry and so on. However, due to the rigid polyimide inter-molecular chain interaction, many of these aromatic polyimides are insoluable, infusible, darker and higher dielectric constant, which has limited the widespread use of the polymers. With the rapid development of modern industrial, the specific properties of a polyimide material is particularly important.In the last half century, lots of approaches have been launched to modify the polyimide material from the level of the molecular structure, which greatly enriched the application of such materials. The incorporation of noncoplanar (kink, spiro, and cardo structures), cyclic aliphatic, bulky, silicified, fluorinated structures into polymer back bone has been a hot research. And incorporating alicyclic groups was a unique approach to synthesis soluble polyimides. This is mainly because of alicyclic dianhydride or diamine monomer into polyimide structure would diminish intra-molecular and inter molecular charge transfer. Meanwhile, the absorption in the visible wavelength range is reduced, so that it greatly improved the transmittance. Thus, these polyimides exhibit optical transparency, as well as good thermal stability.So we use the nadic anhydride as a raw material to synthesis a novel alicyclic diamine monomer (BAHA)2,3-bis (4-aminophenoxymethylene) bicyclo [2.2.1] heptane. In this paper, polyimides with main chains containing cycloaliphatic units were synthesized by conventional two step polycondensation BAHA with BTDA or ODPA. The differences in properties among these polyimides, including solubility, thermal and mechanical properties as well as electrical and optical properties were systematically investigated. In the third part of this paper, we synthesized the alicyclic diamine (BABHA)2,3-bis (4-aminobenzoyloxymethylene) bicyclo [2.2.1] heptane. The products were structurally characterized by FT-IR.