Effect of clay modifier on morphology, thermal properties and flammability of newly synthesized poly(sulfide–sulfone–amide)

Abstract

A novel polyamide bearing sulfide and sulfone units was synthesized through a direct polycondensation reaction between 2,2′-(phenylmethylene)bis(sulfanediyl)diacetic acid and 4,4′-diaminodiphenylsulfone. The resulting poly(sulfide–sulfone–amide) (PSA) exhibited high solubility in organic solvents such as tetrahydrofuran. A series of nanocomposites based on the synthesized functional polyamide loaded with a reactive organoclay containing triazine ring (Mt-Traz) and also with Cloisite 15A (Mt-15A) as reinforcing agents were prepared through a solution technique. Flammability and thermal stability of the neat PSA and corresponding nanocomposites were studied by microscale combustion calorimetry (MCC) and thermogravimetric analysis (TGA) techniques. Thermal properties of the nanocomposites were strongly influenced by the nature of the modifiers. Use of Mt-Traz led to a more improved flame retardancy and higher thermal stability as compared to Mt-15A. According to the MCC data, by introducing 5 mass% of Mt-Traz into PSA matrix a reduction of about 25% in the peak heat release rate and 47% in total heat release values was observed, while incorporation of Mt-15A led to a reduction of about 13% and 27% in those values.