Polyethylene glycol (PEG) has proven to be a versatile soluble-polymer support for organic synthesis, though the use of PEG has been limited by its relatively low loading (0.5 mmol/g or less). We have developed a new high-loading (1 mmol/g) soluble-star polymer based on a cyclotriphosphazene core with PEG arms that exhibit superior precipitation properties compared with those of linear PEG. Additionally, the heterocyclic core does not add interfering signals to the H-1 or C-13 NMR.