Solid polyethylene glycols (PEGs) are used in many pharmaceutical preparations as water soluble/absorbable excipients. However, because of their relatively lower molecular weight as compared to absorbable thermoplastic polyesters, commercially available PEGs, having a molecular weight of 10,000 or less are not suitable for use in preparing molded, or extruded, biomedical devices with high mechanical integrity, including high fracture resistance and flexural strength. Similarly, the commercially available PEGs cannot be used to form medical device coatings with sufficient flexibility and resistance to fracture to be clinically acceptable. On the other hand, exceptionally high molecular analogs of PEG, namely, polyethylene oxides having a molecular weight of 100,000 Da or more, can be used as tough coating, extrusion, or molding materials. Unfortunately, if such polyethylene oxides are used as soluble/absorbable implants, they are not fully excreted since their molecular weights exceed the cut-off molecular weight of 45,000 Da for passing through the kidneys. Other applications of polyethylene oxides having molecular weights exceeding 100,000 Da include their use (1) as highly water absorbent, swellable implants; and (2) in preparing highly viscous aqueous solutions at relatively low concentration. Once again, these applications cannot be associated with the use of these polymers as an absorbable/soluble implantable device, part of an absorbable implant, or a vehicle for a parenteral pharmaceutical formulation that are expected to absorb/biodegrade to extractable by-products. This situation evoked the need for a new approach to preparing derivatives of PEG, and allied polyalkylene glycols, that can be used effectively as coating or molded articles while allowing the release of molecular species having molecular weights that can be easily excreted through the kidneys. Accordingly, this invention deals with high to ultrahigh molecular weight derivatives of solid PEGs and allied polyalkylene glycols that can be readily absorbed and excreted.