| 摘要 |
Polyesters are made by reacting dicarboxylic anhydrides with alkylene oxides containing 2-4 carbon atoms in the presence of a catalyst which is a zinc compound, e.g. the oxide, carbonate, chloride, acetate or maleate or a complex of formula [Zn(NH3)6]Cl2. A small amount of water is advantageously added to the reaction mixture. Specified anhydrides are succinic, adipic, glutaric, maleic, tetrahydrophthalic and phthalic anhydrides. In an example, phthalic anhydride, maleic anhydride and propylene oxide are reacted. |
