Synthesis and characterization of cardo poly(ether-ester)s containing 1,1-bis (4-hydroxyphenyl) cyclohexane in the main chain

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

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.

Photoisomerization and thermal degradation kinetics of poly(ether–ester)s containing azomethine moiety in the main chain

Poly(ether–ester)s containing azomethine group in the main chain were synthesized by solution polycondensation of 4,4′-bis(3-hydroxypropyloxy)- N-benzylidene aniline with adipoyl and terephthaloyl diacid chlorides. The synthesized poly(ether–ester)s were characterized by Fourier transform infrared and proton, and carbon-13 nuclear magnetic resonance spectroscopic techniques. Thermal properties were studied using thermogravimetric analysis (TGA) and differential scanning calorimetry. Thermal degradation kinetics of poly(ether–ester)s were characterized by TGA at various heating rates (5°C min−1, 10°C min−1, and 20°C min−1). The apparent activation energy for the degradation of both the polymers was determined by three different non-isothermal model-free kinetics methods (Friedmann, Flynn–Wall Ozawa, and Kissinger–Akahira–Sunose). The photoisomerization property was examined with ultraviolet (UV) spectroscopy, and the polymer PEE1 showed a rate of trans to cis isomerization ranging 10–20 s, whereas reverse process took around 100 min in solution. UV studies suggested that this material may be used in the field of rewritable applications.