Research conducted in the 1990s has demonstrated that one can design compounds which are "CO2-philic", that is, they exhibit miscibility with CO2 at pressures significantly below that of conventional alkyl-functional analogues. The use of such CO2-philic functional groups in the design of surfactants and chelating agents has allowed successful implementation of CO2 in processes such as emulsion polymerization, heavy metal extraction, and others. However, the high cost of widely used fluorinated CO2-philes can render the economics of a CO2 process unfavorable. Consequently, we have investigated the design of CO2-philes composed of only carbon, hydrogen, and oxygen. Using fundamental data on the thermophysical behavior of CO2, as a guide, we focused on the design and synthesis of functionalized polyethers and copolymers of cyclic ethers and carbon dioxide that were found to be soluble in liquid and supercritical carbon dioxide. By choosing the proper amount of incorporated carbon dioxide, we can generate propylene oxide-CO2 copolymers that exhibit lower miscibility pressures than fluoroethers with the same number of repeat units.