New polyamides based on 1,3-bis(4-carboxy phenoxy) propane and hydantoin derivatives: synthesis and properties

Six new polyamides 5a-f containing flexible trimethylene segments in the main chain were synthesized through the direct polycondensation reaction of 1,3-bis(4-carboxy phenoxy) propane 3 with six derivatives of hydantoins 4a-f in a medium consisting of N-methyl-2-pyrrolidone, triphenyl phosphite, calcium chloride and pyridine. The polycondensation reaction produced a series of novel polyamides in high yield with inherent viscosities between 0.30-0.47 dL/g. The resulted polymers were fully characterized by means of FT-IR, 1H-NMR spectroscopy, elemental analyses, inherent viscosity, solubility tests and gel permeation chromatography (GPC). Thermal properties of these polymers were investigated by using thermal gravimetric analysis (TGA) and differential thermal gravimetry (DTG). The glass-transition temperatures of these polyamides were recorded between 130 and 155 oC by differential scanning calorimetry (DSC), and the 5% weight loss temperatures were ranging from 325 to 415 oC under nitrogen. 1,3-bis(4-Carboxy phenoxy) propane 3 was prepared from the reaction of 4-hydroxy benzoic acid 1 with 1,3-dibromo propane 2 in the presence of NaOH solution. KEY WORDS: Polyamides, 1,3-bis(4-Carboxy phenoxy) propane, Hydantoin derivatives, Inherent viscosity Bull. Chem. Soc. Ethiop. 2010, 24(1), 77-83.