Synthesis of polyamides by energy-efficient ultrasonic-assisted direct polycondensation

Abstract

Four polyamides were synthesized by novel ultrasonic irradiation at 50 °C. Direct polymerization of 2-(morpholino)-4,6-bis(phenoxy-3-carboxy)-s-triazine with different diamines was conducted using a condensing agent. Synthesized polyamides were characterized by particle size distribution, solubility, density, viscosity, Fourier transform infrared spectra, ¹H-nuclear magnetic resonance, thermogravimetric analysis and accelerated degradation of polyamides. All polyamides were readily soluble in polar organic solvents like N-methylpyrrolidone, N,N-dimethylacetamide and N,N-dimethylformamide at room temperature. The polyamides had inherent viscosities in the range 0.532–0.643 dL g⁻¹ in dimethyl formamide at room temperature (30 °C) and density 1.137–1.198 g cm⁻³. All the polyamides showed good thermal stability under N₂ atmosphere. Under accelerated condition degradation of polyamide was not observed without altering the surface morphology.