Segmental dynamics of poly(tetrahydrofuran) cross-linked by click-chemistry: Single-chain nanoparticles vs cross-linked networks

Cross-linked poly(tetrahydrofuran) (PTHF) networks are useful as organic solvent/oil sorbents with high swelling capacity and mechanically robust solid polymer electrolyte membranes for lithium-ion batteries, as well as solid-state calcium ion batteries. Recently, the control of intra-vs intermolecular interactions has attracted significant interest to modulate the properties of dynamic networks involving non-covalent and dynamic covalent bonds. However, to the best of our knowledge, a comparison of the segmental dynamics in polymeric materials prepared exactly from the same precursor polymer through intra-vs intermolecular covalent bonds is still lacking. In this work, we report the dissimilar dynamic properties of PTHF-based materials prepared through intra-vs intermolecular click chemistry (i.e., films of PTHF-based single-chain nanoparticles (SCNPs) vs cross-linked networks). Particularly we observed remarkable similarities in the segmental relaxation time and glass transition temperature value but evident differences in the dynamic heterogeneities. These differences are attributed to the peculiar morphology of the intra-chain collapsed polymer chains (i.e., SCNPs).