Aromatic/aliphatic polyamides were synthesized from a diamine monomer, 2,3-bis-p-aminophenylquinoxaline （IV）, based on quinoxaline and various dicarboxylic acids of aliphatic, aromatic and heterocyclic. The diamine ...Aromatic/aliphatic polyamides were synthesized from a diamine monomer, 2,3-bis-p-aminophenylquinoxaline （IV）, based on quinoxaline and various dicarboxylic acids of aliphatic, aromatic and heterocyclic. The diamine and polyamides were characterized by elemental analysis, FTIR and IH-NMR. The solubility of the polyamides was affected by the quinoxaline and heterocyclic groups in the polymer chain. They were all soluble in common organic solvents such as dimethylsulfoxide （DMSO）, N,N-dimethylformamide （DMF） and N-methylpyrolidone （NMP）. The polyamides showed inherent viscosity in the range of 0.25-0.3 dL/g in DMSO at 25℃ and good thermal stability with the char yields in the range of 65%-82% at 600℃ in nitrogen.展开更多
A series of new polycalixesters （PCES） were synthesized by polyesterification of calixarene dicarboxylic acid derivatives having tertiary butyl pendant groups at the upper rim using five different diols. All polyest...A series of new polycalixesters （PCES） were synthesized by polyesterification of calixarene dicarboxylic acid derivatives having tertiary butyl pendant groups at the upper rim using five different diols. All polyesters were readily soluble in polar solvents such as NMP （N-methylpyrrolidone）, DMF （dimethylformamide）, DMSO （dimethylsulfoxide）, pyridine, THF （tetrahydrofurane）, HMPA （hexamethylenephosphoramide） and DMAC （dimethylacetamide）. The PCES were also partially soluble in TCE （tetrachloroethane） and ethanol and they were unsoluble in aceton. The glass transition temperatures of polyesters were between 80-184 ℃, the crystallinity temperatures of polyesters were between 130-212 ℃ and the melting temperatures of polyesters were between 185-234 ℃, as determined by differential scanning calorimeter （DSC）. The inherent viscosities of polyesters were obtained from 0.55 dL/mg to 0.61 dL/mg. The temperatures at 10% weight loss of polyesters ranged from 182 ℃ to 237 ℃. The temperatures at 25% weight loss of polyesters ranged from 258 ℃ to 331 ℃. The half weight loss （50%） temperatures of polyesters were among 315 ℃ to 371 ℃ and the char yields at 600 ℃ were determined within 13% to 22.3% in N2 atmosphere, as determined by thermo gravimetric analysis （TGA）. The polyester, PES3, has the higher melting point （234 ℃） and higher inherent viscosity （molecular weight） than the other polyesters.展开更多
A series of new Schiff base polyamides（PAs） were synthesized by polycondensation of benzilbisthiosemicarbazone diamine（LH6） with different commercially available aliphatic and aromatic diacid chlorides. The monome...A series of new Schiff base polyamides（PAs） were synthesized by polycondensation of benzilbisthiosemicarbazone diamine（LH6） with different commercially available aliphatic and aromatic diacid chlorides. The monomer and all the PAs were characterized by FTIR,^1H-NMR,and elemental analysis.The prepared polyamides showed inherent viscosities in the range of 0.30-0.36 dL/g in DMF at 25℃,indicating their moderate molecular weight.The PAs were completely soluble in aprotic polar solvents such as dimethylformamide（DMF）,N-methylpyrolidone（NMP）, tetrachloroethane（TCE）,dimthylsulfoxide（DMSO） and also in H_2SO_4 and partially soluble in THF,acetone and chloroform at room temperature.Thermal analysis showed that these PAs were practically amorphous and exhibited 10%weight loss above 220℃.展开更多
文摘Aromatic/aliphatic polyamides were synthesized from a diamine monomer, 2,3-bis-p-aminophenylquinoxaline （IV）, based on quinoxaline and various dicarboxylic acids of aliphatic, aromatic and heterocyclic. The diamine and polyamides were characterized by elemental analysis, FTIR and IH-NMR. The solubility of the polyamides was affected by the quinoxaline and heterocyclic groups in the polymer chain. They were all soluble in common organic solvents such as dimethylsulfoxide （DMSO）, N,N-dimethylformamide （DMF） and N-methylpyrolidone （NMP）. The polyamides showed inherent viscosity in the range of 0.25-0.3 dL/g in DMSO at 25℃ and good thermal stability with the char yields in the range of 65%-82% at 600℃ in nitrogen.
文摘A series of new polycalixesters （PCES） were synthesized by polyesterification of calixarene dicarboxylic acid derivatives having tertiary butyl pendant groups at the upper rim using five different diols. All polyesters were readily soluble in polar solvents such as NMP （N-methylpyrrolidone）, DMF （dimethylformamide）, DMSO （dimethylsulfoxide）, pyridine, THF （tetrahydrofurane）, HMPA （hexamethylenephosphoramide） and DMAC （dimethylacetamide）. The PCES were also partially soluble in TCE （tetrachloroethane） and ethanol and they were unsoluble in aceton. The glass transition temperatures of polyesters were between 80-184 ℃, the crystallinity temperatures of polyesters were between 130-212 ℃ and the melting temperatures of polyesters were between 185-234 ℃, as determined by differential scanning calorimeter （DSC）. The inherent viscosities of polyesters were obtained from 0.55 dL/mg to 0.61 dL/mg. The temperatures at 10% weight loss of polyesters ranged from 182 ℃ to 237 ℃. The temperatures at 25% weight loss of polyesters ranged from 258 ℃ to 331 ℃. The half weight loss （50%） temperatures of polyesters were among 315 ℃ to 371 ℃ and the char yields at 600 ℃ were determined within 13% to 22.3% in N2 atmosphere, as determined by thermo gravimetric analysis （TGA）. The polyester, PES3, has the higher melting point （234 ℃） and higher inherent viscosity （molecular weight） than the other polyesters.
文摘A series of new Schiff base polyamides（PAs） were synthesized by polycondensation of benzilbisthiosemicarbazone diamine（LH6） with different commercially available aliphatic and aromatic diacid chlorides. The monomer and all the PAs were characterized by FTIR,^1H-NMR,and elemental analysis.The prepared polyamides showed inherent viscosities in the range of 0.30-0.36 dL/g in DMF at 25℃,indicating their moderate molecular weight.The PAs were completely soluble in aprotic polar solvents such as dimethylformamide（DMF）,N-methylpyrolidone（NMP）, tetrachloroethane（TCE）,dimthylsulfoxide（DMSO） and also in H_2SO_4 and partially soluble in THF,acetone and chloroform at room temperature.Thermal analysis showed that these PAs were practically amorphous and exhibited 10%weight loss above 220℃.
