Novel thermally stable and chiral poly(amide-imide)s bearing from N,N′-(4,4′-diphthaloyl)-bis-l-isoleucine diacid: Synthesis and characterization

New optically active poly(amide-imide)s based on N,N′-(pyromellitoyl)-bis-L-amino acid and methylene diphenyl-4,4′-diisocyanate: synthesis and characterization

“…One common approach is to introduce asymmetric units or bulky substituents into the polymer backbones [19,21,22] that possess various copolyimides such as poly(amide-imide)s (PAIs). [16,17,20,23] There is a growing interest in optically active poly(amide-imide)s (OAPAIs) in enantiomeric molecular recognition in chromatography, [24,25] ferroelectrics and nonlinear optical devices, [26] and separation membranes. [27] Here, we report five novel OAPAIs synthesized by the direct polycondensation reactions between chiral N,N′-(pyromellitoyl)-bis-L-amino acids derivatives (L-alanine, L-phenyl alanine, L-leucine, L-isoleucine, and L-valine) and methylene diphenyl-4,4′-diisocyanate.…”

Preparation of New Optically Active and Thermally Stable Poly(amide-Imide) Containing Bicyclo Segment and Ether Group in the Main Chain by Direct Polycondensation in Two Different Media

“…[15][16][17] Optically active polymers can be obtained by polymerization of optically active monomers or by stereo selective polymerization of racemic or prochiral monomers using optically active catalysts. 18,19 In this article, a series of new optically active and thermally stable organosoluble PAIs 8a-g containing bicycle and ether moiety were synthesized by the direct polycondensation reactions of seven chiral N,N΄-(bicyclo [2,2,2]oct-7-ene-tetracarboxylic)-bis-l-amino acids 3a-g with 1,2-Bis[4-aminophenoxy] ethane 7 by two different media 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.…”

Synthesis and characterization of new optically active and organosoluble poly(ester-imide)s based on bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic diimide by direct polycondensation

“…However, these polymers are generally intractable and lack the properties essential for successful fabrication into useful forms because of their high melting or glass-transition temperatures and limited solubility in organic solvents [3]. One of the successful approaches to improving solubility is the incorporation of other functional groups, such as amide, ether, ester and siloxane linkages, along the polymer skeleton and, consequently, the preparation of the appropriate copolyimides [4][5][6][7][8][9][10][11][12].…”