Structure, thermal stability, electrochemical behaviors, and mechanical properties of organosoluble polyimide with pyrimidine ring in the main chain

Abstract

A novel organosoluble polyimide (PI) with pyrimidine ring in the main chain was synthesized by chemical and thermal imidization, respectively, from 3,3 0 ,4,4 0 -benzophenone tetracarboxylic dianhydride and 2,4-diamino-6-chloropyrimidine as raw materials and its molecular structure, solubility, UV-visible absorption characteristic, crystallinity, thermal stability, electrochemical behaviors, and mechanical properties were also studied. It was found that the introduction of pyrimidine ring in the main chain could increase the solubility of PI in polar aprotic solvents at room temperature and 60 8C, respectively, because of its molecular main chain with asymmetric structure and two polar N atoms in pyrimidine ring. Furthermore, PI had strong optical absorption peak intensity, excellent thermal stability, good redox reversibility, especially outstanding mechanical properties, which were conductive to its potential applications in adhesives, polyelectrolyte, separation membrane, and so on. V C 2016 Wiley Periodicals, Inc. J.Appl. Polym. Sci. 2016, 133, 43680.

Highly Compressible and Robust Polyimide/Carbon Nanotube Composite Aerogel for High-Performance Wearable Pressure Sensor

“…Finally, thermal stability of PI and PI/CNT aerogel was determined with TGA. Generally, their decomposition process can be divided into three stages from the TGA curves in Figure E: (I) the evaporation of adsorbed water and residual solvents (<100 °C), leading to a slight decrease in weight; (II) the release of residual TEA molecules absorbed on the PI molecular chain (100 °C < T < 480 °C) due to the fact that no characteristic peak of PAA is observed for PI; and (III) the thermal decomposition of PI (>480 °C), causing a significant decrease of weight. − Furthermore, two obvious decomposition peaks also appear in the derivative thermogravimetry curves in Figure F. Obviously, the PI/CNT composite aerogel possesses lower onset decomposition temperature (the temperatures at 5% weight loss, T 5% ) and maximum decomposition rate temperatures ( T max ) than those of the pure PI aerogel.…”

Fabrication and characterization of soluble, high thermal, and hydrophobic polyimides based on 4‐(3,5‐dimethoxyphenyl)‐2,6‐bis(4‐aminophenyl)pyridine

“…However, PIs also exhibited some shortcomings, including poor solubility in common solvents, intractability, infusibility, and deep color, which further restricted their development and utility. Furthermore, with the rapid development of science and technology, the high performance requirements for polymer materials become more important in some high‐end areas, especially the problem of solubility, the balance of processability and thermal properties, and strong color . Hence, many efforts have been devoted to improve the solubility and maintain thermal stability of PIs by incorporation of flexible linkages, rigid moieties, bulky pendent groups, non‐coplanar and hyperbranched structure into the polymer backbones …”