Synthesis And Properties Of Metallophthalocyanine-containing Polyimides

Polyimides possessing the cyclic imide and aromatic groups in the main chains, have been one of the most promising polymer materials, because of their excellent heat resistance, good mechanical performance etc. overall performance. They have been widely applied in many areas. With the development of science and technology, the research on polyimides and their applications continue to broaden. In recent years, more attention was paid to their functionalization. It's effective method to bring some functional compounds into PI by chemical modification or by physical method to introducing functional groups into PI. Chemical methods like grafting, copolymerization, etc., physical methods such as blending, doping and so on.Metal phthalocyanine is a class of multi-functional, multi-purpose complex, which has excellent comprehensive performance. It is an important class of functional materials.Because of its low prices, low toxicity, thermal stability, chemical stability, good spectral response in the visible area, and good catalytic properties, it has been applied in many areas. In addition to being traditional blue-green dye, it can also be used for nonlinear optics, photoconductivity, electrochromic and electroluminescent displays, photovoltaic cells, chemical sensors, optical data storage, LB (Langmuir Blodgett) film, liquid crystal, solar energy conversion, catalysis and photodynamic cancer therapy and many other high-tech fields. It's an interesting and challenging work to combine its outstanding properties and the excellent nature of polymer materials to develop new materials.Therefore, in this paper we introduced the metal phthalocyanine into the polyimide system. We synthesized metal phthalocyanine-terminated hyperbranched polyimide and poly(metal phthalocyanine)imide, two types of metallophthalocyanine-containing hyperbranched polyimides.In the first part, an anhydride-terminated hyperbranched polyimide (AD-HBPI) was synthesized by using a triamine monomer, 1,3,5-tris(2-trifluoromethyl-4-aminophenoxy) benzene (TFAPOB), and a flexible dianhydride monomer, 4,4'-oxydiphthalic anhydride (ODPA). And then reacted with 4-aminophthalonitrile, we successfully synthesized cyano-terminated hyperbranched polyimide. Finally, under the conditions of different metal salts, a series of novel hyperbranched polyimides end-capped with metallophthalocyanines were prepared by the reactions of cyano-terminated hyperbranched polyimide with excessive amounts of phthalonitrile. These resulting polymers show high glass transition temperatures (216-225℃) and high thermal stability (Td(5%)≥440℃). They show good solubility in common solvents like DMSO, DMAc, NMP, DMSO, they can even solve in THF and CHCl3. And they show strong optical absorption in the visible region.In the second part, poly(metal phthalocyanine)imide copolymers [P(MPc)I] were prepared with 4,4',4",4'"-phthalocyanine teraamines(4NH2-MPc),4,4'-diamino diphenyl ether (4,4'-ODA), and 4,4'-oxydiphthalic anhydride (ODPA). These resulting P(MPc)Is can't dissolve in any solvent, so we took UV-vis test when they were P(MPc)AA. And compared with teraamine monomers (4NH2-MPc), they show obvious blue-shift. This can prove that the existence of phthalocyanine ring in the polymer. The polymer films show high thermal stability (Td(5%)≥545℃). Their morphology was observed by scanning electron microscope.We studied the dielectric properties of the two kinds of films, found that in low frequency, the dielectric constants of P(CuPc)I and P(ZnPc)I are 5.7 and 5, respectively, which are more than 1.5 times of the dielectric constant of pure PI. In high frequency(1MHz), both of the dielectric constants of the two kinds of polymer are 3.9, which are greater than the dielectric constant of pure PI. And they have a relatively low dielectric loss.We also prepared carbon nanotubes/poly(copper phthalocyanine)imide [MWNTs/P(CuPc)I] compound materials with different contents of carbon nanotubes by solution composite, using P(CuPc)I as matrix. We studied the dielectric properties and the morphologies of MWNTs/P(CuPc)I compound materials.