There is a need for continuing development of CO2-soluble polymers to be used as suitable surfactants, ligands, or phase transfer agents in CO2 solvent processes Identifying CO2/polymer solubility trends will help to enhance the search for CO2-soluble polymers The synthesis and characterization of structurally diverse polyester libraries using high-throughput techniques combined with the use of a high-throughput gravimetric extraction (HTGE) technique for the measurement of polymer solubility in super-critical carbon dioxide has enabled the study of structure/CO2 solubility relationships Small structural changes in polyesters have significant effects on their CO2 solubility Branching in either the diacid moiety or diol moiety Imparts a significant increase in solubility, and in particular, branching with acyl chains enhances solubility by as much as 20 times The length of the acyl chain is significant with the solubility of the polymer increasing in a systematic way as the acyl chain length increases to 10 carbon atoms There are odd/even effects on solubility relating to the number of carbon atoms in the diacid moiety of the polyester The results provide pointers for the development of more soluble alkyl polymers useful as ligands for synthesis and polymerization in CO2 The use of HTGE to examine the effect of small structural changes on the solubility of polymers in CO2 suggests that a quantitative study of structure property relationships of polymers is possible, leading to the understanding and ability to predict solubility properties