Synthesis and characterization of poly(amide-imide)s derived from a new ortho-functional unsymmetrical dicarboxylic acidElectronic supplementary information (ESI) available. See DOI: 10.1039/c7ra11710h

• Main Authors: Canto-Acosta, Rodrigo Javier, Loría-Bastarrachea, María Isabel, Carrillo-Escalante, Hugo Joel, Hernández-Núñez, Emanuel, Aguilar-Vega, Manuel, Santiago-García, José Luis
• Format: Journal Article
• Published: 02.01.2018
• ISSN: 2046-2069
• DOI: 10.1039/c7ra11710h

A new diacid monomer containing an imide ring and a methoxy pendant group, 3-trimellitimido-4-methoxybenzoic acid TMBA , was synthesized and characterized. The diacid was used to synthesize six novel poly(amide-imide)s, ( PAI s), through a polycondensation reaction with different diamines in the presence of triphenylphosphite, calcium chloride, and pyridine in N -methyl-2-pyrrolidinone. The chemical structures of the diacid monomer and poly(amide-imide)s were confirmed by FTIR and 1 H NMR spectroscopy. All PAI s were obtained in high yield with inherent viscosities ranging from 0.32 to 0.54 dL g −1 . They were soluble in aprotic solvents, and exhibited film forming ability. The PAI films displayed glass transition temperatures between 281 and 377 °C, as determined by dynamic mechanical analysis, and they show high thermal stability. Gas permeability results for TMBA-6FDA film show that this PAI could be an interesting material for polymeric membranes aimed to CO 2 separation process. Herein, we report a new diacid monomer containing an imide ring and a methoxy pendant group, 3-trimellitimido-4-methoxybenzoic acid TMBA, for the preparation of poly(amide-imide)s.