| Abstract: | High molecular weight poly(ethylene oxalate) with fiber-forming properties was obtained from oxalic acid and ethylene glycol. The process was carried out on two stages in the melt. A new method was used for aliphatic oligoester synthesis in the melt, because the decomposition of oxalic acid takes place in the presence of glycol. The process was carried out at low temperatures with azeotropic water removal. Investigations of the polycondensation of oxalic acid and ethylene glycol with a compound forming a heteroazeotrope with water showed that the process is subject to the general laws of the polycondensation in melt: it depends on the ratio of initial components, presence of accelerating compounds, etc. However, the reaction time of polycondensation was dependent on the stirring intensity. High molecular weight poly(ethylene oxalate) was obtained by oligomer polycondensation in the melt. Thorium carbonate and tin dichloride were used as catalysts. |
