AbstractAcyclic diene metathesis (ADMET) polymerization/hydrogenation methodology was used to synthesize a family of amphiphilic polyethylenes (PEs) with precisely placed poly(ethylene glycol) branches. Four structural parameters are varied in this report: size of the hydrophilic pendant group, manner in which the pendant group is connected to the backbone, distance between the pendant moieties along the backbone, and saturation of the polyolefin backbone. Varying the branch size with other parameters held constant results in negligible effects on thermal behavior. However, when either the distribution of branches or manner of connection of the branches is altered, changes in the thermal behavior become clear. These slight structural changes allow tunability of the structural morphology from fully amorphous to semicrystalline materials melting over a range of temperatures above 60 °C.magnified image