Optically active and organosoluble poly(amide-imide)s derived fromN,N′-(Pyromellitoyl)bis-l-histidine and various diamines: Synthesis and characterization

Abstract

An optically active diacid containing the L-histidine moiety was prepared by reacting pyromellitic dianhydride (1,2,4,5-benzenetetracarboxylic acid 1,2,4,5-dianhydride) 1 with L-histidine 2 in acetic acid, and was polymerized with several aromatic diamines 5a-g to obtain a new series of optically active poly(amide-imide)s (PAIs) using two different methods, such as direct polycondensation in a medium consisting of N-methyl-2-pyrrolidone (NMP)/triphenyl phosphite (TPP)/calcium chloride (CaCl 2 )/pyridine (Py) and direct polycondensation in a tosyl chloride (TsCl)/pyridine (Py)/N,N-dimethylformamide (DMF) system as a condensation agent. The resulting new polymers 6a-g with inherent viscosity was obtained in good yield. The polymers were readily soluble in polar organic solvents, such as N,N-dimethyacetamide (DMAc), N,N-dimethyformamide (DMF), and dimethyl sulfoxide (DMSO). The obtained polymers were characterized by FTIR, specific rotation, elemental analysis as well as 1 H-NMR spectroscopy and gel permeation chromatography (GPC). The thermal stability of the resulting PAIs was evaluated with thermogravimetric analysis techniques under a nitrogen atmosphere.

A simple method to generate spontaneous chemisorption of metallic particles mediated by carboxylate groups from silylated oligomeric poly(amide‐imide)s

“…Oligomeric matrices, poly(amide‐imides)s (PAIs), were prepared from the monomers using standard methods . Briefly, a 1:1 (mol/mol) mixture of the respective diimidocarboxylic acid (DICA) with different radical groups (R), such as —CH 3 ( l ‐alanine), —CH 2 CH(CH 3 ) 2 ( l ‐leucine), —CH(CH 3 ) 2 ( l ‐valine), —CH 2 Ph ( l ‐phenylalanine), and the aromatic diamine (DA) – both of symmetric structure containing a silicon atom as central element – was reacted with anhydrous calcium dichloride, TPP, pyridine and NMP (Scheme ).…”

Eco-friendly flame retardant poly(butylene terephthalate) copolymers with thermal stability and hydrolytic resistance

“…13 Organic phosphorus compounds are good flame retardants in combustion conditions because they form carbonaceous char which acts as a physical barrier for heat transfer from the flame to the polymer. [14][15][16][17] Nevertheless, when low molecular weight phosphorous compound was incorporated into polymer, the compound may slowly diffuse out, resulting in gradual loss of flame retardance. Therefore, copolymers containing phosphorous moiety as comonomer unit have been investigated.…”

New Poly(amide-imide)/Nanocomposites Reinforced Silicate Nanoparticles Based on N-pyromellitimido-L-phenyl Alanine Containing Ether Moieties

“…Several approaches such as introduction of flexible bridging linkages into the polymer backbone such as -NHCO-, -O-, and -SO 2 - [16][17][18], are incorporated into the polymer backbone due to the altering crystallinity and intermolecular interactions [19,20]. Among them, polyamide-imide (PAI) is the most successful material, which combines the advantages of high-temperature stability and processability [21][22][23][24]. Performance of polymer-clay nanocomposites (PCNs) depends on dispersion and spacing between clay layers.…”