Study On Synthesis And Properties Of New Aromatic Multi-ketonic Tetracarboxylic Dianhydride And Poly (Aryl Ether Sulfone Ether Ketone Ketone)s Having Pendant Dicarboxyl Groups.

With the rapid development of high-technology, high-performance polymers are eagerly being demanded, especially for the integrative and high thermo-stability materials. Polyimides(PIs) and Poly(aryl ether ketone)s(PEKs) are high-performance materials, which have heat, impact, creep, wear and chemical resistance, good mechanical properties, electrical properties and radiation-proof, fire retardant, etc. They are suitable for insulation and structural materials especially high-performance resin matrix composite materials. And they are widely applied in aviation, aerospace, electronic information, energy and other high-tech fields. In this dissertation, a novel multi-ketonnic tetracarboxylic dianhydride was designed and obtained. And then polymers having carboxyl acid groups were synthesized. The structure and properties of the resulting polymers has been investigated. The dissertation has three sections as followed:1. 1, 4-Di (3', 4'-methylbenzoyl) benzene was synthesized from terephthaloyl chloride (TPC) and o-xylene by the Friedel-Crafts electrophilic substitution reaction. And 1,3-di(3',4'-formylcarboxyl benzoyl)benzene was prepared from 1,3-di(3',4'-methyl benzoyl)benzene, for potassium permanganate and pyridine as the oxidation system. 1, 4-di (3, 4-diformic anhydride benzoyl) benzene (p-DKDA) obtained through the reaction carboxylic anhydride in the presence of thionyl chloride. And 1, 3-di (3, 4-diformic anhydride benzoyl) benzene (i-DKDA) synthesized from isophthaloyl chloride (IPC) and ortho-xylene. The resulting products were characterized by FT-IR and 1H-NMR. It was proved that has high purified and productive. A series of high-performance polymers such as poly (aryl ether ketone) (PEK), polyarylates (PAR) and aryl polyamide can be obtained for the titled compound as monomers.2. 4,4'-Bis(phenoxy)diphenyl sulfone(DPODPS) and 4,4'-bis(2,6-dimethyl) phenoxy diphenyl(Me2-DPODPS) were synthesized by nucleophilic substitution in one pot. Its chemical structure was characterized by FT-IR, 1H NMR, etc. The results show that the synthesis process of DPODPS/ Me2-DPODPS is suitable for industrial production, the average crude yield above 90.0% and total yield above 80.0%.3. Poly(aryl ether sulfone ether ketone ketone)s having two pendant carboxyl groups(PESEKK) were synthesized by binary copolymerization of pyromellitic dianhydride (PMDA)/1,4-di(3,4-diformic anhydride benzoyl)benzene(p-DKDA) with 4,4'-diphenoxy diphenyl sulfone(DPODPS)/ 4,4'-bis(2,6-dimethyl)phenoxydiphenyl (Me2-DPODPS) separately. The polymerization was low temperature solution polycondensation, using aluminum trichloride (AlCl3) as catalyst, 1, 2-dichloro ethane (DCE) as solvent, N, N-dimethyl formamide (DMF) as a cosolvent. Then, poly (aryl ether sulfone ether ketone ketone)s (E1-4) containing pendant aryl ester groups were synthesized by P1-4 and phenols, for thionyl chloride as acylating reagent in the present of 1,1,2,2-tetrachloroethane. The polyers were characterized by FT-IR, TGA and DSC. As amount of carboxyl in the polymer chain is increased, the thermalstability is decreased and the polymers (E1-4) have higher thermal stability and better solubility than the corresponding ones'.4. A series of poly (aryl ether sulfone ether ketone ketone) s (PESEKK-A) containing two carboxyl groups were synthesized by ternary polymerization of PMDA, IPC with DPODPS, over a wide molar ratio of PMDA/IPC. Then, poly (aryl ether sulfone ether ketone ketone) s (PESEKK-COO-Ar) containing pendant aryl ester groups were synthesized by (PESEKK-A) s and phenols, for thionyl chloride as acylating reagent in the present of 1, 1, 2, 2-tetrachloroethane. The copolymers were characterized by FT-IR, TGA and DSC. The results show the polymers have lower melting temperatures(Tm), better solubilities and good thermal stabilities.