Synthesis Methods and Properties of Polyazoles

Synthesis and characterization of thermally stable polymers (polybenzimidazoles)

“…[1][2][3][4][5][6][7][8][9][10] In this study, an aromatic hydroxamoyl chloride [terephthalohydroximoyl chloride, 4,4 0 -bis(phenylhydroxamoyl chloride)ether, 4,4 0 -bis(phenylhydroxamoyl chloride)disulfide, or 4,4 0 -bis(phenylhydroxamoyl chloride)] produced a heteroaromatic closing reaction with 3,3 0diaminbenzidine or 1,2,4,5-tetraaminobenzene. These polymers, whose molecular structures were identified by inherent viscosity measurements, FTIR, LC mass spectrometry, DTG-TGA, and elemental analysis, were prepared readily by direct polycondensa-tion.…”

“…Although the reaction period was long in past studies, the inherent viscosity values of the synthesized PBIs ranged from 0.5 to 8 dL/g (in concentrated sulfuric acid or methane sulfonic acid). [1][2][3][4][5][6][7][8] In this study, because some of the synthesized PBIs (PBI-1, PBI-3, PBI-5, PBI-7, and PBI-8) did not dissolve in a concentrated H 2 SO 4 solution, their inherent viscosity values could not be determined; despite this, the lowest value was determined to be 3.6 dL/g (Table I). Therefore, it can be stated that the molecular weights of these polymers were larger than those of PBIs synthesized with conventional methods.…”

“…The raw product was isolated by column chromatography using chloroform. The data of the melting point, elemental analysis, FTIR, and 1 Synthesis of 4,4 0 -diformylbiphenyl 4,4 0 -Diformylbiphenyl was synthesized according to the methods reported in the literature. 14 Zinc (131 g, 2.00 mol), 15 g (0.146 mol) of NaBr, 131 g (0.50 mol) of TTP, and 6.56 g (0.050 mol) of NiCl 2 were placed in a four-necked flask (with a dripping funnel, a mechanical mixer, a thermometer, and reverse cooler mechanisms) with a circular still of 2 L. DMF (600 mL) was added to the mixture in a nitrogen gas environment.…”

“…Yield: 83%. 1 General synthesis of dihydroximoyl chloride compounds Terephthalohydroxamoyl chloride, 4,4 0 -bis(phenylhydroxamoyl chloride)ether, 4,4 0 -bis(phenyl hydroxamoyl chloride)disulfide, and 4,4 0 -bis(phenylhydroxa-moyl chloride) were synthesized by the passage of chloride gas (dried and then passed under safe conditions) through a dioxime solution of terephthaldoxime and CCl 4 solutions of bis(4-formaldoximephenyl)ether, bis(4-formaldoximephenyl)disulfide, and 4,4 0 -biphenyldialdoxime through stirring for 2 h. 15,16 The synthesis reactions of the dihydroxamoyl chloride compounds are shown in Figure 2. Terephthalohydroxamoyl chloride.…”

“…There have been many studies performed in the past concerning the synthesis of PBIs [1][2][3][4][5][6][7][8][9][10][11] in which hydroxamoyl chloride was not used as the starting material. However, in this study, PBIs were obtained through the reaction of dihydroxamoyl chlorides and 3,3 0 -diaminbenzidine or 1,2,4,5-tetraaminobenzene.…”