Preparation and properties of poly(amide-imide)s derived from trimellitic anhydride, α-amino acids, and aromatic diamines

✍ Scribed by Sheng-Huei Hsiao; Chin-Ping Yang; Feng-Yueh Wu

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 611 KB
• Volume: 195
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.1994.021950721

✦ Synopsis

Abstract

Four dicarboxylic acids containing one preformed imide ring were prepared by condensation of trimellitic anhydride with α‐amino acids such as glycine, DL‐alanine, DL‐valine, and DL‐lcucinc. These diacids were subsequently directly polycondensated with various aromatic diamines using triphenyl phosphite (TPP) and pyridine as condensing agents in N‐methyl‐2‐pyrrolidone (NMP) containing calcium chloride, producing various aliphatic‐aromatic poly(amide‐imide)s with pendant alkyl groups. The resultant polymers have inherent viscosities in the range of 0,58–2,15 dL/g and were amorphous, as revealed by wide‐angle X‐ray diffractograms. All polymers were readily soluble in a variety of solvents such as N,N‐dimethylacetamide (DMAc), N,N‐dimethylformamide (DMF), and NMP, and could be cast from their DMAc solutions into transparent, flexible, and tough films. All poly(amide‐imide)s showed clear glass transition temperatures in the range of 181–313°C on the heating traces of differential scanning calorimetry (DSC). Almost all the poly(amide‐imide)s exhibited no appreciable decomposition below 370°C, with 10% weight loss being recorded above 400°C in nitrogen and air. The polymers with larger side chain attached exhibited higher solubility, but lower glass transition temperature and initial decomposition temperature.