Synthesis and properties of highly organosoluble aromatic polyimides containing N-(4-(di(1H-indole-3-yl)methyl)phenyl) moieties

Abstract

A new diamine monomer containing indole unit, 3,5-diamino- N-(4-(di(1H-indol-3-yl)methyl)phenyl)benzamide, was successfully synthesized and applied in the preparation of a series of polyimides (PIs) via a conventional two-step polymerization procedure with three aromatic tetracarboxylic dianhydrides. The prepared polymers showed excellent solubility in organic solvents such as N-methyl-2-pyrrolidinone (NMP), N, N-dimethylacetamide, and N, N-dimethylformamide. Flexible and strong films of PIs were obtained via casting from their solutions. The glass transition temperature of these polymers was in the range of 223–264°C. They were fairly stable up to a temperature around 300°C and lost 10% weight at 372°C in nitrogen atmosphere. All of the polymers revealed absorption maxima around 323 nm with a fluorescence emission maxima around 378–406 nm in NMP. The cyclic voltammetry of the PIs exhibited an oxidation wave with a peak at 1.07 V. The resulting polymer films had tensile strengths from 83 MPa to 107 MPa, elongates at break of 7–10%, and tensile moduli of 2.2–2.3 GPa.

Preparation and properties of polyimide-based nanocomposites containing functionalized Fe3O4 nanoparticles

“…Aromatic polyimides (PIs) have been accepted as high-performance materials for extensive applications in various industrial fields, including electronic and aerospace industries, because of their high thermal stability, along with excellent mechanical and superior chemical resistance. 36 –40 However, the technological applications of these polymers are limited by processing difficulties due to high melting or softening temperatures and low solubility in organic solvents. To overcome such difficulties, the polymer chemical structure modification becomes essential.…”