A water-soluble polyimide precursor: Synthesis and characterization of poly(amic acid) salt

Abstract

We have synthesized a water-soluble polyimide precursor, poly(amic acid) amine salt (PAD), from pyromellitic dianhydride (PMDA),4, and N, and have investigated in detail its properties with respect to the degree of salt formation (D sf ). The maximum value of D sf we obtained upon precipitation of the precursor solution into acetone was 79%. We synthesized a PAD having a D sf of 100% (PAD100) by the solid state drying of an organic solution. The precursors showed different solubility depending on the D sf to make up to 4 wt% solutions in water containing a small amount of DMEA. PAD100 is completely soluble in pure water. We investigated the imidization behavior of PAD in aqueous solution using various spectroscopic methods, which revealed that PAD100 has faster imidization kinetics relative to that of the poly(amic acid)-type precursors. The resulting polyimide films prepared from an aqueous precursor solution possess almost similar physical and thermal properties as those prepared from N-methyl-2-pyrrolidone(NMP) solution. Therefore, we have demonstrated that PAD can be used as a water-based precursor of polyimide; this procedure avoids the use of toxic organic solvents, such as NMP.

Synthesis, characterization, and catalytic activity of fluorescent polyimide nanocomposites

“…Required amount of PTCDAH (0.50 g) and ODA (0.50 g) were taken in a 100 mL capacity round bottomed flask (RBF) filled with 25 mL NMP solvent and heated to 160 °C under nitrogen atmosphere with mild stirring . The stirring was continued for 5 h. At the end of the reaction excess amount of methanol was added in order to precipitate the polymer (Scheme‐1).…”

“…Generally, such a high performance polymer can be synthesized by treating a dianhydride with a diamine under suitable experimental conditions. In 2004, water soluble PI precursor was reported by Yang and Lee . Yin et al .…”

Microstructure and properties of fully aliphatic polyimide/mesoporous silica hybrid composites

“…After stirring half an hour, it became a homogeneous solution, indicating the formation of water soluble polyamic acids. 11,12 The solution was poured into acetone and the precipitated solid was filtered and dried in a vacuum. Scheme I represents the synthesis procedure.…”

Preparation of PMDA/ODA polyimide membrane for use as substrate in a thermally stable composite reverse osmosis membrane

“…On the other hand, the typical polyamic acid absorption bands at 1660 cm −1 (C O stretching, amide I) and 1550 cm −1 (C-N stretching, amide II) [36], and typical isoimide bands at 1800 cm −1 [37] are totally absent. Therefore, this membrane has identical infrared spectrum to the polyimide film cured by thermal process [35][36][37], indicating the polyamic acid was completely transformed to polyimide under these reaction conditions.…”