Difficulty: Hydrolytic methods of sulfonic acid, sulphonate and amido.
难点：磺酸及其盐类的水解、氨基的水解。
2
Synthesis of Water-soluble Hyperbranched Polymer with Alternating Amido, Tertiary Amino and Ester Units from Benzene-1,2,4-tricarboxylic Acid-1,2-anhydride and N-(2-Hydroxyethyl)piperazine.