Injection-moldable copolyesters of terephthalate units, ethylene units and a high proportion (e.g. 82-87) mole %) of oxybenzoate units, and cookware made of such copolyesters. Process for making such copolyesters by reacting polyethylene terephthalate with p-acetoxybenzoic acid in a solvent, first at a temperature below 240.degree. C. to product a fragmented polyester, raising the temperature to split off acetic acid, then adding more acetoxybenzoic acid to raise the oxybenzoate content to more than 80 mole %.