Synthesis and properties of polyamides and polyesters containing 2,2-Di-2'-thienyl-propane links

Abstract

Polyamides and polyesters containing 2,2-di-2`-thienylpropane links were synthesized by the interfacial polycondensation of 2,2-bis-(5-chlorocarbonyl-2- thienyl)propane with various diamines and diols in water-dichloromethane solvents at $25\,^\circ\!C$ in the presence of sodium hydroxide as an acid acceptor. The structures of these polymers were identified by IR spectroscopy. Characteristic absorption bands of polyamides appeared at $3380-3240 cm^{-1}$ (NH stretching), $1670-1640 cm^{-1}$ (amide I band), and $1560-1540 cm^{-1}$ (amide II band) and those of polyesters were observed at $1750-1720 cm^{-1}$ (carbonyl stretching of ester group). The properties of these polyamides and polyesters were also investigated. The resulting polyamides had inherent viscosities in the range of 0.25-0.69 dl/g and those of polyesters were 0.12-0.33 dl/g. And polyamides were obtained in higher yields than polyesters. Although most of the polyamides were soluble in polar solvents, polyesters were quite insoluble in common organic solvents. These polymers revealed relatively good thermal stability. The TGA data showed 5\% weight losses of polyamides at $257-383\,^\circ\!C$ and those of polyesters at $244-308\,^\circ\!C$.