| Abstract: | Various amino acid esters and dicarboxylic acid esters having a β-thioether group have been synthesized and their polycondensation with diamine was found to occur at room temperature to form polyamide thioether. The effect of solvents or chelating agents on their polycondensation reaction was investigated. Metal acetylacetonates or inorganic salts had a great influence on the rate of the polycondensation reaction, and the catalytic activity of metal acetylacetonates M(AcAc)n or inorganic salts decreased in the following order: Mg(AcAc)2?Th(AcAc)4>Cu(AcAc)2>Li(AcAc)>None>Zr(AcAc)4, MgCl2·6H2O>CuCl2·.2H2O>ZnCl2>MgCl2>None. It was also found that the amount of polyamide thioether was dependent on solvents or the presence of chelating agents because the polycondensation rate and the apparent equilibrium between ring and chain structures were both greatly influenced by solvents or chelating agents. These effects of solvents or chelating agent on the polycondensation may be attributable to formation of a complex with the thioether group which enhances the reactivity of ester. |
