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Multiblock copolymers of poly(arylene ether sulfones) (PAESs) and poly(1,4cyclohexylenedimethylene terephthalate) (PCT) were synthesized via melt-phase polymerization. PAES oligomers (M n = 2000 g/mol) were synthesized with hydroxyethoxyl end groups, and then reacted with dimethyl terephthalate (DMT) and 1,4-cyclohexanedimethanol (CHDM) to obtain segmented copolymers with the goal of introducing semi-crystallinity into the PAES segmented block copolymers. Two CHDM (all trans and cis/trans = 30/70) were used for comparison. Weight percentages of PCT segments varied from 20 wt% to 80 wt%. According to the results measured by DSC, DMA and WAXS, the copolymers crystallized when the content of PCT segment was above 50 wt%, and the crystallinity of the copolymers exhibited a proportional dependence on the weight percentage of PCT segments. Segmented copolymers with trans

High Tg amorphous copolyester thermoplastics were synthesized by incorporating 4,4′‐bibenzoate (4,4′BB) and 3,4′‐bibenzoate moieties into the polyester backbone via melt polycondensation. The high levels of crystallinity typically associated with 4,4′BB containing polyesters were suppressed through copolymerization of ethylene glycol, 1,4‐cyclohexane dimethanol, and neopentyl glycol (NPG) diols. NPG was shown to be highly effective in suppressing crystallization and was used to produce amorphous compositions with Tg’s as high as 129 °C. Diol ratios were determined by 1H NMR spectroscopy and molecular weights were assessed with inherent viscosity (ηinh). Thermogravimetric analysis showed single‐step weight losses in the range of 395–419 °C. Differential scanning calorimetry was used to determine melting points and glass transition temperatures over a wide range of copolyester compositions and identified amorphous compositions. Dynamic mechanical analysis confirmed Tg’s and was used to study β‐relaxations below the Tg. Rheological analysis revealed the effect of NPG structures on shear thinning and thermal stability. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 579–587