Synthesis and Properties of Soluble Branched Polyimides

摘要

Aromatic polyimides generally possess excellent thermal and mechanical, electrical, and chemical properties. However, their applications have been limited in many fields because of normally insoluble in common organic solvents. In order to improve the solubility and processability of polyimides, a serie of branched polyimides were prepared from 4,4',4''-triaminotriph-enylmethane(TATEM), with bis(phthalic anhydride) (DBPDA), 1,2-dihydro-2-(4-am inophenyl)-4-[4-(4-am inophenoxy)phenyl] phthalazin-1-one (DHPZDAM) via solution polymerization. In this paper, firstly the precursor polyimides were synthesized by DBPDA, DHPZ-DAM to obtain the polymers with different molecular weight and distributing, and then the precursor polyimides obtained were synthesized with TATEM. The structures of the polyimides were confirmed by 1 H-NMR and FT IR. The degree of branching (DB) values were calculated that were in the range of 0.074 to 0.143. The molecular weight and distributing of the polyimides were tested by GPC. The thermal behavior data of the polyimides were obtained by differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA). The Tg values of polyimides were in the range of 242 to 253 ??, and the Td values with 10% weight loss ranged from 486 to 505 ??. All of the polyimides showed good solubility in some common organic solvents.Key Words ￡obranched; solubility; polyimides