US Patent 11970573 Bifuran-modified polyesters

Bifuran-modified polyester, polyethylene-terephthalate-co (2,2′-bifuran-5,5′-dicarboxylate), prepared by esterifying or transesterifying a diacid component comprising from 2 to 10 mole percent 2,2′-bifuran-5,5′-dicarboxylate and a diol component with a catalyst compound comprising metal present in an amount of from about 10 to about 450 ppm and polycondensation to form the polyester wherein the polyester has an inherent viscosity of at least 0.5 g/dL, a glass transition temperature (Tg) of 82° C. or more, a semicrystalline melting peak (Tm) with ΔHf equal to or greater than 5 J/g on the second heating ramp, and melting temperature (T