Synthesis and rheological study of some maleic acid and fumaric acid stereoregular polyesters, 5. Structural study by 1H and 13C NMR of random, multi‐block and alternating unsaturated copolyesters from fumaric, maleic and phthalic acid potassium salts and 1,4‐dibromobutane

The sequence distribution in random, multi‐block and alternating copolyesters based on the reaction of fumaric, maleic and phthalic acid potassium salts with 1,4‐dibromobutane were examined by 1H and 13C NMR spectra. Quantitative sequence distibution results were obtained from the analysis of 13C NMR spectra. The different structures of synthesized copolyesters, expected from the experimental procedures used, were confirmed. In addition, it can be concluded that the esterification route used is irreversible and that no appreciable transesterification reaction between two different ester groups occurs in the course of the synthesis.