Synthesis and characterization of novel optically active poly(imide–urethane)s derived from N,N′‐(pyromellitoyl)‐bis‐(L‐leucine) diisocyanate and aromatic diols

Abstract

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

Synthesis and properties of optically active nanostructured polymers bearing amino acid moieties by direct polycondensation of 4,4′-thiobis(2-tert-butyl-5-methylphenol) with chiral diacids

“…To overcome these disadvantages many attempts have been made by incorporating different moieties into polyimide chain (Raju and Alam 2008;Guo et al 2007b;Edlund and Albertsson 2003). Thus, many copolyimides, such as poly(amide-imide)s, poly(ester-imide)s (PEI)s and other copolymers have been prepared (Saxena et al 2003;Mallakpour and Kowsari 2006a, b;Mallakpour and Shahmohammadi 2004). PEIs which combine many useful properties of polyimides and polyesters are well known for their thermal resistance coupled with easy processability.…”

Synthesis and characterization of new poly(ester-imide)s based on 1,3-bis[4,4′-bis(trimellitimido) phenyl]-2-propenone and aromatic diols

“…Among these polymers poly(ester-imide)s (PEIs) are well known for their thermal resistance coupled with easy processability. [17][18][19][20][21][22][23][24][25][26][27] In this article, we describe synthesis and characterization of a new series of PEIs 9a-f containing chalcone segments between imide rings in the main chain by using microwave assisted polycondensation reaction of 1,3-bis [4,4'-bis(trimellitimidoyl chloride) phenyl]-2-propenone 7 with several aromatic diols 8a-f using a domestic microwave. In our pervious papers we reported synthesis and characterization of different polyamides, poly(amide-imide)s, polyesters and poly(ester-imide)s with improved solubility and thermal stability by using microwave assisted polycondensation.…”

Synthesis and characterization of novel optically active, poly(ester-imide)s bearing calix[4]arene and amino acid moieties: ionophoric properties and extraction abilities towards alkali-metal cations

“…Poly(ester-imide)s (PEI)s posses desirable characteristics with the moieties of both polyimides and polyesters such as high thermal stability and good mechanical properties as well as easy processability [22][23][24][25][26][27].…”