Some physical properties of the polyester-polyeher multiblock copolymers with Si-containing hard segment were further examined by a series of physical methods. Thehydrophobicity of the copolymers was improved with the incorporation of increasing amountof organosilicone

XPS test proved that silicon element was enriched at the surface of theSi-containing polyeser-polyether copolymers. It was also found that their heat resistanceand gas permeability for O2 and N2 were greatly improved.The study on semipermeability of films made of the Si-containing copolymers was also followed with interest.