| 摘要 |
PURPOSE:To obtain a high-MW polyglycolide inexpensively, by polycondensing glycolic acid in the presence of a catalyst and adding liquid paraffin to the reaction system after reaching a specified MW. CONSTITUTION:Glycolic acid is polycondensed at 150-250 deg.C in the presence of 0.01-1.0wt%, based on the acid, catalyst (e.g., stannous chloride). When the MW of the condensate reaches 2,000-6,000 after about 2-10hr from the start of the reaction, 5-30wt%, based on the acid, liquid paraffin is added to the reaction system and the reaction is further continued for about 1-20hr. This process is useful also for the production of a polylactide from lactic acid. |
