Synthesis and characterization of organo‐soluble polyimides derived from a new spirobifluorene diamine

Abstract

Polyimides exhibit outstanding thermal and thermo‐oxidative stability, excellent solvent resistance, good mechanical and electrical properties and superior chemical resistance. However, their practical applications are frequently limited by their infusible and insoluble nature. Structural modifications of the polymer backbone have been utilized to modify polyimide properties, either by reducing the interaction or by reducing the stiffness of the polymer backbone. Novel organo‐soluble polyimides containing spirobifluorene units were synthesized by the polycondensation of 2,7‐bis‐amino‐2′,7′‐di‐t‐butyl‐9,9′‐spirobifluorene with three aromatic dianhydrides. The one‐step polymerization procedure was conducted at 200 °C in m‐cresol, and the structures of the resulting polyimides were confirmed using infrared and NMR spectroscopy. The weight‐average molecular weights and polydispersities of the resulting polymers were in the ranges 20 600–341 000 and 1.02–1.30, respectively. The glass transition temperatures of the polyimides were in the range 289–322 °C, and the 10% weight loss in nitrogen appeared at a temperature higher than 435 °C and the residual weight at 800 °C was above 58%. The spiro segment has been introduced into polyimides, resulting in amorphous polyimides, conferring on them an enhanced solubility and leading to a significant increase in both glass transition temperature and thermal stability. These types of materials have potential for many applications. Copyright © 2010 Society of Chemical Industry

Organosoluble, low‐dielectric‐constant fluorinated polyimides based on 9,9‐bis[4‐(4‐amino‐2‐trifluoromethyl‐ phenoxy)phenyl]xanthene

“…However, their applications have been limited in some fields because of their poor solubility and high processing temperature, which are caused by the rigid polymer backbones and the strong interchain interactions. To overcome these limitations, considerable efforts have been devoted to the development of melt‐processable or soluble polyimides without deterioration of their inherent excellent properties by introducing flexible linkages,3–5 bulky groups6–9 and molecular asymmetry or non‐coplanarity10–14 into the polymer backbone. In addition, it is generally recognized that the incorporation of pendant loop groups (cyclic side‐groups) along the polymer backbone imparts greater solubility and enhanced rigidity as well as better mechanical and thermal properties 15.…”

Effect of cyano dipolar groups on the performance of lithium-ion battery electrospun polyimide gel electrolyte membranes

“…Polyimides have rigid molecular chains, resulting in poor solubility in common organic solvents which affects their synthesis, processing and application [2]. Therefore, significant efforts have been performed to chemically modify the structure in order to improve their processability without affecting other relevant properties, such as thermal stability or mechanical properties.…”

Synthesis of 2,2′-diamino-7-tert-butyl-9,9′-spirobifluorene starting from 4,4′-di-tert-butylbiphenyl

“…Further purification and drying by standard methods were employed, and they were distilled prior to use when necessary. Compound 1 was prepared starting from biphenyl according to the method described in the literature [23].…”