Synthesis and Properties of Aromatic Polyamides Containing 5-(4-Acetoxybenzoylamino) Side Groups

Abstract

New aromatic polyamides containing 5-(4-acetoxybenzoylamino) side groups have been synthesized by low-temperature solution polycondensation reaction of equimolar amounts of aromatic diamines having ether bridges with 5-(4-acetoxybenzoylamino)isophthaloyl chloride, in N -methylpyrrolidinone (NMP) as a solvent and in the presence of pyridine as acid acceptor. These polyamides were characterized by IR spectra, viscometry, differential scanning calorimetry (DSC), thermogravimetric analyses and dielectric measurements. These polymers show improved solubility in polar aprotic solvents such as NMP and dimethylacetamide (DMA) and good thermal stability comparable with traditional aromatic polyisophthalamides, with initial decomposition temperature being between 270 and 320 • C and glass transition temperature in the range of 230-270 • C.

Insights into the Chain and Local Mobility of Some Aromatic Polyamides and Their Influence on the Physicochemical Properties

“…The introduction of flexible aryl‐ether linkages in the polymer backbone is a frequently used approach, which imparts characteristics such as better solubility, melt processing, and improved toughness as compared with polymers without these flexible linkages . Also, it was found that the introduction of hexafluoroisopropylidene groups into the polymeric structure resulted in overall benefits for the polymer solubility, thermal, and environmental stability and electrical and dielectric performances, mainly attributed to the increase in free volume, small dipole, and low polarizability of the C–F bond .…”

The Influence of Conformational Parameters on Some Physical Properties of Polyamides Containing Pendant Acetoxybenzamide Groups

“…The polyamides containing acetoxybenzamide groups in the side chain were obtained by low temperature solution polycondensation reaction of equimolar amounts of 5-(4-acetoxybenzamido) isophthaloyl chloride, 4) with various aromatic diamines containing ether linkages, 44) in N-methylpyrrolidinone (NMP) as a solvent and in the presence of pyridine as acid acceptor, as previously reported [8,9]. These polymers have the structure 444, as shown in scheme 1.…”

Conformational Parameters and Some Physical Properties of Polyamides Containing Pendant Acetoxybenzamide Groups

“…The polyamides containing acetoxybenzamide groups in the side chain were obtained by low temperature solution polycondensation reaction of equimolar amounts of 5-(4-acetoxybenzamido) isophthaloyl chloride, I, with various aromatic diamines containing ether linkages, preformed 1,3,4-oxadiazole ring or hexafluoroisopropylidene units II, in N-methylpyrrolidinone (NMP) as a solvent and in the presence of pyridine as acid acceptor, as previously reported [4][5][6]. These polymers have the structure III, as shown in Scheme 1.…”

“…In this away it is possible to obtain good solubility without sacrifying the thermal and mechanical properties to a great extent [2,3]. The introduction of pendent acetoxybenzamide units in the macromolecular chain of polyamides improves the solubility while maintaining a fairly good thermal stability [4][5][6]. We took into account that the study of physical properties of such polymers in connection with conformational parameters of the macromolecular chain is of interest for future advanced applications.…”