Synthesis and properties of polyimides, polyamides and poly(amide-imide)s from ether diamine having the spirobichroman structure

Abstract

A novel spirobichroman unit containing dietheramine, 6,6′‐bis(4‐aminophenoxy)‐4,4,4′,4′,7,7′‐hexamethyl‐2,2′‐spirobichroman (3), was prepared by the nucleophilic substitution of 6,6′‐dihydroxy‐4,4,4′,4′,7,7′‐hexamethyl‐2,2′‐spirobichroman with p‐chloronitrobenzene in the presence of K2CO3 followed by hydrazine catalytic reduction of the intermediate dinitro compound. A series of polyimides were synthesized from diamine 3 and various aromatic dianhydrides by a conventional two‐stage procedure through the formation of poly(amic‐acid)s followed by thermal imidization. The intermediate poly(amic‐acid)s had inherent viscosities of 1.00–2.78 dL/g. All the poly‐(amic‐acid)s could be thermally cyclodehydrated into flexible and tough polyimide films, and some polyimides were soluble in polar solvents such as N‐methyl‐2‐pyrrolidone (NMP), N,N‐dimethylacetamide (DMAc), and N,N‐dimethylformamide (DMF). These polyimides had glass transition temperatures (Tg) in the range of 236–256°C, and 10% weight loss occurred up to 450°C. Furthermore, a series of polyamides and poly(amide‐imide)s with inherent viscosities of 0.71–2.29 dL/g were prepared by direct polycondensation of the diamine 3 with various aromatic dicarboxylic acids and imide ring‐containing dicarboxylic acids by means of triphenyl phosphite and pyridine. All the polyamides and poly(amide‐imide)s were readily soluble in polar solvents such as DMAc, and tough and flexible films could be cast from their DMAc solutions. These polymers had glass transition temperatures in the range of 137–228°C and 10% weight loss temperatures in the range of 419–443°C in air and 404–436°C in nitrogen, respectively. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1487–1497, 1997

Synthesis and characterization of soluble polyimides based on a new fluorinated diamine: 4-Phenyl-2,6-bis[3-(4′-amino-2′-trifluoromethyl-phenoxy) phenyl] pyridine

“…Solubilization of the polyimides has been targeted by several methods, such as introduction of flexible linkage [9,10], bulky units in the polymer backbone [11,12], bulky pendent substituents [13,14], or noncoplanar moieties [15,16]. Among these approaches, introduction of bulky pendent substituents and heteroaromatic rings into polyimide chains has been considered to be efficient, which can provide not only enhanced solubility but also good thermostability and processability.…”

Synthesis and properties of new pyridine-bridged poly(ether-imide)s based on 4-(4-trifluoromethylphenyl)-2,6-bis[4-(4-aminophenoxy)phenyl]pyridine

“…However, despite the excellent combined properties, their widespread applications are often limited by their poor processability, limited solubility in common organic solvents and high melting point, which make it impossible for most polyimides to be directly processed in their imidized forms. In order to overcome these limitations, soluble polyimides have been targeted by many efforts, including introduction of flexible linkages [4][5][6], bulky units [7,8], bulky pendent substituents [9][10][11], or non-coplanar moieties [12,13], in the polymer backbone. Recently, considerable attention has been devoted to the fluorinated aromatic poly(ether-imide)s, especially trifluoromethyl-containing poly(ether-imide)s, with excellent solubility and low refractive indices, water uptake, and dielectric constant [14][15][16][17].…”

Novel Semi‐Fluorinated Poly(ether imide)s Derived From 4‐(p‐Aminophenoxy)‐3‐trifluoromethyl‐4′‐aminobiphenyl

“…[1] To utilize the thermal stability of poly(imide)s for further applications, and also to take advantage of other properties of these classes of polymers, such as high chain rigidity, packing density, and polar chain interactions for different applications, it is desirable to synthesize soluble and/or melt-processable variations. Solubilization of the polyimides has been targeted by several means, such as introduction of flexible linkages, [3] bulky substituents [4] or bulky units in the polymer backbone, [5] or noncoplanar [6] or alicyclic [7] monomers. The main concept behind all these Full Paper: An unsymmetrical diamine monomer 4-(paminophenoxy)-3-trifluoromethyl-4 0 -aminobiphenyl has been synthesized successfully.…”