N-Trimellitylimido-l-isoleucine (3) was prepared from the reaction of trimellitic anhydride with lisoleucine [l-2-amino-3-methylvalerianic acid or (2S,3S)-2-amino-3-methyl-n-valerinic acid] in an N,N-dimethylformamide solution at the refluxing temperature. The direct polycondensation reaction of the monomer imide diacid (3) with 1,4-phenylenediamine, 4,4Ј-diaminodiphenylmethane, 4,4Ј-diaminodiphenylsulfone, diaminodiphenylether, 1,5-naphthalendiamine, 2,4-diaminotoluene, and 1,3-phenylenediamine was performed in a medium consisting of triphenyl phosphite, N-methyl-2-pyrolidone (NMP), pyridine, and calcium chloride. The polycondensation was performed under two different conditions: in one method, the reaction mixture was heated in an NMP solution at 60, 90, and then 130°C for different periods of time, and in the other method, the reaction mixture was refluxed only for 1 min in the same solvent. The resulting poly(amide imide)s (PAIs), with inherent viscosities of 0.21-0.37 dL/g, were obtained in high yields. All of these compounds were fully characterized by IR spectra, elemental analyses, and specific rotation measurements. Some structural characterizations and physical properties of these new optically active PAIs were examined.

N,N′‐(Pyromellitoyl)‐bis‐(L‐leucine) diacid was reacted with ethyl chloroformate in the presence of triethylamine followed by reaction with activated sodium azide and gave N,N′‐(pyromellitoyl)‐bis‐(L‐leucine) diacylazide in high yield. This diacylazide was heated in dry benzene and gave the unstable N,N′‐(pyromellitoyl)‐bis‐(L‐leucine) diisocyanate (5) in quantitative yield. Thus, diisocyanate 5 was generated in situ and polycondensation reaction of this monomer with several aromatic diols, such as 4,4′‐dihydroxybiphenyl, 1,4‐hydroquinone, bisphenol A, phenolphthalein and 1,4‐dihydroxyanthraquinone, was performed in dry toluene under refluxing in the presence of 1,4‐diazabicyclo[2.2.2]octane (triethylenediamine) as a catalyst. The polymerization reactions proceeded within 48 h, producing a series of optically active poly(imide–urethane)s with good yield and moderate inherent viscosity in the range 0.18–0.28 dl g−1. All of the above polymers were fully characterized by infrared spectra, elemental analyses and specific rotation. Some structural characterization and physical properties of these optically active poly(imide–urethane)s are reported Copyright © 2003 Society of Chemical Industry

ABSTRACT:A pyromellitic dianhydride (benzene-1,2,4,5-tetracarboxylic dianhydride) was reacted with l-isoleucine in acetic acid, and the resulting imide acid [N,NЈ-(pyromellitoyl)-bis-l-isoleucine] (4) was obtained in a high yield. 4 was converted into N,NЈ-(pyromellitoyl)-bis-l-isoleucine diacid chloride by a reaction with thionyl chloride. The polycondensation reaction of this diacid chloride with several aromatic diamines, including 1,4-phenylenediamine, 4,4Ј-diaminodiphenyl methane, 4,4Ј-diaminodiphenylsulfone (4,4Ј-sulfonyldianiline), 4,4Ј-diaminodiphenylether, 2,4-diaminotoluene, and 1,3-phenylenediamine, was developed with two methods. The first method was polymerization under microwave irradiation, and the second method was low-temperature solution polymerization, with trimethylsilyl chloride used as an activating agent for the diamines. The polymerization reactions proceeded quickly and produced a series of optically active poly(amide imide)s with good yields and moderate inherent viscosities of 0.17-0.25 dL/g. All of the aforementioned polymers were fully characterized by IR, elemental analyses, and specific rotation. Some structural characterization and physical properties of these optically active poly(amide imide)s are reported.