Microwave-induced synthesis of aromatic polyamides by the phosphorylation reaction
Résumé
This paper reports an optimization of the Yamazaki-Higashi method of direct polyamidation from arom. diacids and arom. diamines. As a model reaction, the polycondensation between 4,4'-oxydianiline and isophthalic acid was studied in the presence of a phosphorylation agent and under microwave irradn. This exptl. study revealed that optimal results can be attained by using a great excess of pyridine as catalyst (pyridine-to-monomer ratio of 7), at moderate radiation intensity (200 W), and up to 25% (w/v) monomer concn. Although the inherent viscosity achieved by microwave and by conventional heating was comparable, an exceptional reaction rate under microwave irradn. yielded a polyamide inherent viscosity of around 1 dLg-1 in only a few minutes