Aromatic polymers obtained by precipitation polycondensation: 4. Synthesis of poly(ether ketone ketone)s☆
Abstract High molecular weight aromatic poly(ether ketone ketone)s were synthesized by the Friedel-Crafts polyacylation condensation of iso- and terephthaloyl chlorides with diphenyl ether, 1,4- and 1,3-bis(4-phenoxybenzoyl)benzenes. Depending on the monomers used for polycondensation, polyketones of regular structure with different iso-/tereisomer repeating unit ratio ( 100 0 , 50 50 , 0 100 ) in the main chain were obtained. Polymers of each repeating isomer unit were prepared in two different ways. All the polymer syntheses were performed as precipitation polycondensations and the resulting polymers were obtained in particle form. The influence of reaction conditions and preparation route on the polymer properties were examined. The monomer concentration and monomer stoichiometric ratio were found to affect the polymer viscosity. The size and shape of the polyketone particles obtained were also found to be governed by reaction conditions and preparation route.
A Novel Approach to the Synthesis of High Performance and Functional Polymers
A novel series of linear, high molecular weight high performance and functional polymers were synthesized by a one-pot, superacid-catalyzed polyhydroxylakylation reaction of carbonyl compounds containing electron-withdrawing substituents, adjacent or relatively close to a carbocation center with non-activated aromatic hydrocarbons. The reactions were performed at room temperature in the Brønsted superacid CF3SO3H (trifluoromethanesulfonic acid, TFSA) and in a mixture of TFSA with methylene chloride, which was used as both solvent and a medium for generation of electrophilic species from the carbonyl component. Polycondensations of 1,1,1-trifluoroacetone, 2,2,2-trifluoroacetohenone, 2,7-dinitrofluorenone, acenaphthenequinone and isatin with aromatic hydrocarbons proceed readily in the presence of superacid at room temperature. The polymers obtained were found to be soluble in the common organic solvents, and flexible transparent films could be cast from the solutions. 1H and 13C NMR analyses of the polymers synthesized revealed their linear, highly regular structure. The polymers also possess high thermostability.
Thermodynamics on the Carbochlorination of Titanium-bearing Ores
The equilibrium compositions of the multi-component, multi-phase and multi-reaction system of carbochlorination of titanium-bearing ores are calculated with HSC, a computational chemistry software. The thermodynamic equilibrium calculation of the reaction system shows that a complete conversion of titanium-bearing ores is feasible at a temperature near 200oC. At temperatures ranging from 800 to 1600oC, the products of the reaction system are all in gaseous phase. Thermodynamic analysis accords with the industrial practice. The simulated results provide reasonable scientific basis for improving suitable technological conditions of the carbochlorination reduction.