Synthesis and characterization of novel polyimides. In: V Mittal (ed) High performance polymers and engineering plastics

Abstract: A new diamine, 1,1-bis[4-(4-aminophenoxy)phenyl]-1-(4-hydroxyphenyl)ethane, was synthe-sized in three steps starting from 1,1,1-tris(4-hydroxyphenyl)ethane. New aromatic polyimides having hydroxy side groups were prepared from this diamine and various tetracarboxylic dianhydrides by the conventional two-step procedure that included ring-opening polymerization in N-methyl-2-pyrrolidone (NMP) and subsequent thermal cyclic dehydration. The polyimides were characterized by X-ray diffrac-tion, differential scanning calorimetry (DSC), thermogravimetry (TG), and dynamic mechanical analysis (DMA). All the polyimides were amorphous, and had glass transition temperature (Tg) in the range of 232–304 C. The properties of polyimides were compared with those of polyimides prepared from 1,1-bis[4-(4-aminophenoxy)phenyl]-1-phenylethane, which had no hydroxy side groups. The effects of the hydroxy side groups were observed in the thermal properties, thermal mechanical properties and solubility of polyimides. Key Words: 1,1-bis[4-(4-aminophenoxy)phenyl]-1-(4-hydroxyphenyl)ethane, 1,1-bis[4-(4-aminophenoxy)phe-nyl]-1-phenylethane, hydroxy side groups, thermal mechanical properties, thermal properties, solubility, water absorption 1