Solution properties of linear poly(glycerol): quantitative comparison with PEGs

초록

Linear poly(glycerol) (linPG) is an attractive hydrophilic polymer for biomedical coronas because its hydroxyl-rich backbone can provide strong hydration and offers versatile sites for functionalization. Previous studies have reported good biocompatibility and reduced accelerated blood clearance (ABC) in PG-grafted systems. However, quantitative benchmarks describing linPG chain dimensions and solvent quality in water remain limited. Here, we synthesize linPG by anionic ring-opening polymerization and quantify its structural and thermodynamic properties in water using small-angle neutron scattering (SANS). Zimm analysis yields the radius of gyration at infinite dilution (Rg,0) and second virial coefficient (A2) for linPG between 25 and 60 °C across a range of molecular weights, enabling direct comparison with poly(ethylene glycol) (PEG). The A2 values of linPG are positive throughout this temperature window, which is consistent with good solvent conditions, whereas A2 and Rg,0 decrease slightly with increasing temperature, indicating reduced polymer–solvent affinity. Compared with PEG at comparable degrees of polymerization, linPG has smaller Rg,0 values while maintaining similar A2 magnitudes, which is consistent with a less expanded yet still swollen coil conformation. These results establish quantitative benchmarks for linPG in aqueous solution and provide design-relevant parameters for PG-based hydrophilic coronas. © The Author(s), under exclusive licence to The Society of Polymer Science, Japan 2026.