Synthesis and Characterization of Dendritic Poly(ether imide)s

Abstract

New dendritic poly(ether imide)s were synthesized by the convergent growth approach, using 1-(4-aminophenyl)-1,1-bis(4-hydroxyphenyl)ethane, as the building block. The aromatic nucleophilic substitution of the building block with 3-nitro-N-phenylphthalimide led to the first-generation dendron with aminophenyl group at the focal point, which was subsequently reacted with 3-nitrophthalic anhydride to yield the dendritic wedge containing an activated nitro group. The resulting nitro functionality was allowed to react with the building block to give the second-generation dendron, which was then condensed with 3-nitrophthalic anhydride, followed by ring closure to re-form the phthalimide ring and restore a reactive nitro group. Through an aromatic nucleophilic substitution, the dendritic wedges with an activated nitro group were coupled to the polyfunctional core to form the dendritic macromolecules. Structures of the ether−imide dendrimers were fully characterized by use of a combination of techniques including 1H NMR, 13C NMR, IR, and mass spectrometry. The glass transition temperature of the dendrimers increased with molecular weight, and the variation was consistent with theoretical calculations. These dendritic poly(ether imide)s are soluble in various organic solvents and had a thermal stability comparable to linear poly(aryl ether imide)s.

Facile and efficient preparation of phosphinate‐functionalized aromatic diamines and their high‐Tg polyimides

“…Generally, bisphenols29–33 and diamines33–36 could be prepared by acid‐catalyzed condensation of ketone or aldehyde compounds with excess phenol or aniline. Ketone/aldehyde compounds with35, 36 or without29, 32–34 the electron‐donating phenolic‐OH or amino groups can carry out the reaction.…”

“…These results seem conflict with our speculation, but actually they are not. Supporting Information Scheme S1 shows the possible mechanism of stabilization of carbocation in the work of Shu and coworkers30 and Li et al31 As in Supporting Information Scheme S1, after one phenol reacted with the carbonyl group of 4‐nitroacetophenone, the resulting carbocation was stabilized by the phenolic‐OH. Since the resonance between the phenolic‐OH and the carbocation stabilized the carbocation, the electrophilic substitution of second phenol on the carbocation proceeds.…”

Dendritic aromatic polyamides and polyimides

“…There are a few publications on dendritic aromatic polyimides prepared by stepwise reactions. Shu and coworkers35, 36 reported the preparation of dendritic poly(ether imide)s by a convergent growth approach, using 1‐(4‐aminophenyl)‐1,1‐bis(4‐hydroxyphenyl)ethane as a building block (Scheme ). The aromatic nucleophilic substitution of the building block with 3‐nitro‐ N ‐phenylphthalimide led to the first‐generation dendron ( 18 ) with an aminophenyl group at the focal point.…”

Synthesis and Characterization of Hyperbranched Aromatic Poly(ether imide)s

“…Dendritic poly(ether imide)s can be prepared from 2B and 3-nitro-N-phenylphthalimide having high reactivity at room temperature. 28 Preliminary experiments, however, suggested that hyperbranched poly(ether imide)s cannot be obtained under the same condition from corresponding monomers, 3A-D, due to low reactivity. Poly(ether imide)s, 4A-D, were prepared by selfcondensation of corresponding monomers, 3A-D, at high temperature and in the presence of potassium carbonate, as shown in Scheme 2.…”

“…25,26 Recently, Kakimoto's group 27 prepared new aromatic hyperbranched polyimides from 1,4-phenylenediamine (A 2 ) and tri(phthalic acid methyl ester) (B 3 ) in the presence of condensation agent. Shu et al [28][29][30] reported the synthesis of dendritic poly(ether imide)s from the building block 1-(4-aminophenyl)-1,1-bis(4-hydroxyphenyl)ethane and hyperbranched poly(ether imide)s from AB 2 monomer containing a fluoro-substituted phthalimide. In this paper, we report synthesis and characterization of various aromatic hyperbranched poly(ether imide)s with hydroxy, cyanophenyl, aromatic imide, aryl ester, and alkyl ester end groups from AB 2 monomers containing a chloro-substituted phthalimide.…”