In this study, new chiral poly(amide-imide)s (PAIs) were synthesized from polycondensation reaction of 3,5-diamino-N-(thiazole-2-yl)benzamide with various N-trimellitylimido-L-amino acids in a green medium consisting of molten tetra-n-butylammonium bromide and triphenyl phosphite. The polymerization reactions produced new PAIs with high yields and inherent viscosities ranging from 0.28 to 0.38 dL/g. The obtained materials were characterized by means of Fourier transform infrared, 1H NMR spectroscopy, specific rotation measurements, thermogravimetric analysis, X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and elemental analysis techniques. The FE-SEM micrographs and XRD results showed that the polymers have nanostructure morphology and they are amorphous in nature.

Efficient Preparation of New Nanostructured Poly(Amide-Imide)s Condensed From 3,5-Diamino-N-(Thiazole-2-yl)Benzamide and Various N-Trimellitylimido-L-Amino Acids

Two kinds of imide dicarboxylic acid monomers, 4,4'-bis(trimellitimido) diphenyl ether Ⅰ and p-trimellitimido-benzoic acid Ⅱ were successfully synthesized from 4,4'-diaminodiphenyl ether and p-aminobenzoic acid with trimellitic anhydride respectively.and used to synthesize a series of new aromatic poly(amide-imide)s (PAIs) by the tri-phenyl phosphite-activated polycondensation method. The preparation of PAIs was carried out using triphenyl phosphate and pyridine symtem. The PAIs had inherent viscosities of 0.55–1.46 dL g-1. PAI films were obtained by casting their N-Methyl-2-pyrrolidone (NMP) solution. Their cast films had tensile strengths ranging from 37.4 to 83.9 MPa. The glass-transition temperatures (measured by differential scanning calorimetry) were in the range of 265-310°C. According to thermogravimetric analysis, the polymers were fairly stable up to temperature around 420°C, and 10% weight losses in the temperature range of 474-550°C in nitrogen, that showed good thermal stabilities of these polymers.

Zhen Bao Li

Papers

Synthesis and Properties of New Poly( Amide-Imide)s Based on Imide Dicarboxylic Acid