A polymeric method was explored for the preparation of polyester-polyether multiblock copolymers using polyesters and polyethers as starting materials. The mechanism of the reaction and the effect of the segment structure on it

the segment sequence of the block copolymers prepared have been studied. It has been shown that to the polymeric method the degree of compatibility between starting polyester and poly ethers is of paramount importance which determines not only the compositional homogeneity of the block copolymers formed but also the success of the polymeric method to get the block copolymers of the expected structure.