LOW-TEMPERATURE POLYCONDENSATION OF CARBOXYLIC-ACIDS AND CARBINOLS INHETEROGENEOUS MEDIA

Aliphatic diols and dicarboxylic acids condense in hydrophobic solvent s to form polyesters at 27-75 degrees C when the solutions interface w ith an acidic hydrophilic phase. Certain aliphatic omega-hydroxy acids behave similarly. Rigorous removal of the by-produced water by distil lation is unnecessary and examples are cited where polyesters are isol ated in 85-90% yields having number-average molecular weights between 10,000-35,000. Polydispersity indices tend in many cases to be lower t han expected for statistical step-growth polymerizations. Many of the side reactions encountered in high temperature polyesterifications, de pending on the nature of the acidic phase, are absent or suppressed. W hile there are some limitations on the type of monomer, the mild condi tions offer the possibility of forming polyesters with temperature sen sitive structures directly from the corresponding carboxylic acids and carbinols. (C) 1998 John Wiley & Sons, Inc.