POLYESTER COPOLYMER AND METHOD FOR PRODUCING SAME

The present invention addresses the problem of providing a biodegradable and bioabsorbable polymer having a low Young's modulus and high tensile strength. To solve the problem, the present invention provides a polyester copolymer having two kinds of ester bond-forming monomer residues as main constituent units, wherein, when the two kinds of ester bond-forming monomers are respectively monomer A and monomer B, the polyester copolymer satisfies (1) and (2) below. (1) The R value represented by R=[AB]/(2[A][B])*100 is 0.45-0.99, where [A]: the mole fraction of the monomer A residue in the polyester copolymer, [B]: the mole fraction of the monomer B residue in the polyester copolymer, and [AB]: the mole fraction of a structure (A-B and B-A) in which the monomer A residue and the monomer B residue in the polyester copolymer are adjacent to each other. (2) The degree of crystallization of at least one among the monomer A residue and the monomer B residue is less than 14%. 本发明的课题在于，提供杨氏模量低、并且拉伸强度高的生物降解性·生物可吸收性聚合物。用