A study of the ionic liquid mediated microwave heating for the synthesis of new thermally stable and optically active aromatic polyamides under green procedure

Abstract

Ionic liquids (ILs) of the 1,3-dialkylimidazolium-type have great potential for the innovative application of microwaves in synthesis and separation. The use of ILs as reagents in conjunction with microwave heating makes it possible to prepare new organsoluble optically active aromatic polyamides (PAs) by a direct polycondensation reaction of our synthesized dicarboxylic acid: (2S)-4-[(4-methyl-2-phthalimidylpentanoylamino)benzoylamino]-isophthalic acid (9), with several aromatic diamines. The polymerization reactions provided chiral PAs in high yield and inherent viscosities in the range of 0.43-0.85 dLg -1 . The chemical structures of some of these samples as representatives were characterized by 1 H NMR and elemental analysis. All polymers were characterized by FTIR and specific rotation tools. Their thermal properties were determined by differential scanning calorimetry and thermogravimetric analysis. The efficiency of microwave irradiation conjugated with ILs was compared with that of the polycondensation of this monomer in ILs using conventional heating. The results showed that much shorter reaction times, higher yields and inherent viscosities were obtained under microwave assisted conditions. Furthermore, the use of ILs as a media and catalyst for the above polymerization reactions will eliminate the need of volatile and toxic solvents and reagents as condensing agents and provide a environmentally benign process.

Dispersion of surface-modified nano-Fe3O4 with poly(vinyl alcohol) in chiral poly(amide-imide) bearing pyromellitoyl-bis-l-phenylalanine segments

“…Another very interesting feature of PAIs is their unique capability of allowing particularly high mineral loading for the preparation of NC membranes [26]. Among the PAIs, the type of chiral is important because the majority of bioorganic molecules are chiral [27,28].…”

“…As part of our continuing efforts in developing tractable chiral macromolecules including natural amino acid [27][28][29][30][31][32][33][34], in this work for the first time, we reported the synthesis of NC materials based on amino acid containing PAI and modified Fe 3 O 4 NPs. In this way, at first, the Fe 3 O 4 NPs were successfully fabricated by the reaction between Fe2 ?…”

Novel poly(ether-amide)s derived from 1,4-(4-carboxy phenoxy)butane and ethereal diamines: Synthesis and properties

“…It is known that the solubility of polymers is often increased when flexible bonds such as [-O-, -SO 2 -, -CH 2 -, -C(CF 3 -) 2 ], bulky pendent groups (such as t-butyl and adamantyl), large pendent groups or polar constituents are incorporated into the polymer backbone due to the altering crystallinity and intermolecular interactions. [7][8][9][10][11][12][13][14] It has been recognized that the incorporation of aryl-ether linkages generally imparts an enhanced solubility, processability, and toughness of aromatic polyamides and polyimides as well as their copolymers without substantial diminution of thermal properties. [15][16][17][18][19][20] In this article, we describe synthesis and characterization a series of novel poly(ether-amide)s 7a-e containing methylene segments from the direct polycondensation reaction of 1,4-(4-carboxy phenoxy)butane 3 with 1,1-bis[4-aminophenoxy]methane 6a, 1,2-bis[4-aminophenoxy]ethane 6b, 1,3-bis [4-aminophenoxy]propane 6c, 1,4-bis [4-aminophenoxy] butane 6d and 4,4-diamino diphenylether 6e in a medium consisting of N-methyl-2-pyrrolidone, triphenyl phosphite, calcium chloride and pyridine.…”

Synthesis, characterization, and thermal properties of new organosoluble poly(ester-imide)s containing ether group

“…[3][4][5][6] Copolycondensation is one of the possible ways for modification of polymer properties and various copolymers have been developed and reported, such as poly(amide-imide)s, poly(sulfone-imide)s, poly(ether-imide)s, poly(ester-imide)s and other copolymers have been prepared. [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Aromatic polymers that contain aryl ether linkage generally have greater tractability, lower glass transition, and greater chain flexibility than their corresponding polymers without these groups in the repeat units. 22 The improved solubility and lower glass transition temperatures are attributed to the flexible linkages that provide a polymer chain with a lower energy of internal rotation.…”