Poly(butylene succinate/diglycolate) copolymers by reactive blending were subjected to molecular and solid-state characterization to study the effects of transesterification reactions. 13C-nuclear magnetic resonance analysis evidenced the formation of block copolymers. Thermal measurements showed that all the samples were semicrystalline, with a soft amorphous phase and a rigid crystal phase. Wide-angle x-ray diffraction measurements indicated that the copolymers are characterized by cocrystallization. The mechanical properties were found related to crystallinity degree. The random copolymer, characterized by the lowest crystallinity degree, exhibits the lowest elastic modulus and the highest deformation at break. Therefore, solid-state properties of poly(butylene succinate/diglycolate) copolymers can be tailored by acting on the molecular architecture. POLYM. ENG. SCI., 2013. (c) 2012 Society of Plastics Engineers