Aromatic Polyesters Containing Ether and a Kinked Aromatic Amide Structure in the Main Chain: Synthesis and Characterisation

Satish S Deokar,Noormahamad N Maldar,Asiya M Tamboli,Nguyen Tam Nguyen Truong,Mohaseen S Tamboli,Sultan Alshehri,Makarand D Joshi,Mohammed M Ghoneim

doi:10.3390/coatings12020181

Satish S Deokar, Noormahamad N Maldar + Show 6 more

Open Access

https://doi.org/10.3390/coatings12020181

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Abstract

A novel bisphenol containing preformed multiple ether and amide linkages, N, N′-Bis (4-hydroxyphenoxyphenylene) isophthalamide (IPCD), was prepared and analysed by spectroscopic methods. New aromatic polyesters were prepared by polycondensation of IPCD with 1, 3-benzene diacidchloride and/or 1, 4-benzene diacidchloride. These obtained polyesters were structurally analysed by infra-red spectroscopy, measurements of inherent viscosity, wide-angle X-ray diffraction patterns, and thermal techniques such as differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and solubility tests in organic solvents. The synthesised polyesters had high molecular weights, as indicated by their inherent viscosities from 0.67 to 0.78 dL/g in N-methyl-2-pyrrolidone. The incorporation of ether and kinked aromatic amide moieties in the main polyester chains greatly affected the properties of these aromatic polyesters. The prepared polyesters readily dissolved in amide-type polar aprotic solvents and pyridine, indicating their solution processability. The DSC curves above the polyesters showed glass transition temperatures of 194 to 269 °C. TGA indicated that these newly obtained polyesters were stable up to 301 °C and retained a 39 to 48% weight at 900 °C. W-XRD analyses showed that the newly synthesised polyesters were amorphous, which is reflected in their solubility behaviour.

Highlights

Aromatic polyesters have good thermal stability and other physico-mechanical properties, leading to their wide applications in various important state-of-the-art industries [1,2,3].wholly polyarylates are insoluble and have high glass transition or melting temperatures and are difficult to process
[11] Pendant biphenyl [3], naphthyl [10], or phenothiazine moiety [12] in aromatic polyesters improved the solubility of resulting polyesters, and there was no significant loss in their thermal stability
-Hydroxyphenoxy)phenylene]isophthalamide action with p-chloronitrobenzene gave 4(4′-nitrophenoxy)phenol (NPP) which, on reducThe bisphenol IPCD was synthesised in three steps, including hydroquinone on reaction, gave 4(4′-aminophenoxy)phenol (APP)

Summary

Introduction

Aromatic polyesters have good thermal stability and other physico-mechanical properties, leading to their wide applications in various important state-of-the-art industries [1,2,3]. [11] Pendant biphenyl [3], naphthyl [10], or phenothiazine moiety [12] in aromatic polyesters improved the solubility of resulting polyesters, and there was no significant loss in their thermal stability Linkages such as ether and sulphone in polymers increased the solubility and solution processability without any comprise in the polymer thermal stability [13,14,15,16]. Aromatic polymers containing the ether and amide side groups showed improved solubility and thermal stability [17] To achieve these properties in high-performance polymers, various flexible ether linkages were incorporates to yield poly(ether ester)s and poly(ether amide)s [18,19]. The thermal and structural characterisation of these polyesters is reported

Materials

Synthesis of Bisphenol

Result and Discussion

Polymerisation

Characterisation of Polyesters

Conclusions