| 초록 |
The aromatic hyperbranched polyimides were prepared by condensation polymerization of a series of commercially available A2 type dianhydride monomers such as 4,4-biphthalic anhydride (BPAD), pyromellitic dianhydride (PMDA), and 3,3’,4,4’-diphenylsulfontetracarboxylic dianhydride (DSDA) with a BB’2 type triamine monomer, 2,4,6-triaminopyrimidine (TAP). There were two steps in the synthesis: the formation of hyperbranched polyamic acid precursors and the imidization. In this work, polyimides with two different terminated groups were obtained by different molar ratios of TAP and dianhydrides. FT-IR and 1H NMR were used to verify the molecular structures of the obtained hyperbranched polyimides. The glass transition temperatures of the polyimides were obtained by differential scanning calorimetry. The excellent thermal stabilities of the hyperbranched polyimides studied were discussed in themogravimetric analysis. |
