From nano to the macro: tuning hierarchical aggregation of thermoresponsive PEG/PCL-based polyurethanes via molar mass/composition control

Abstract Amphiphilic hyperbranched polyurethanes (HPUs) based on PEG and PCL are promising for several biomedical applications. However, the lack of control over molar mass composition hinders a deep understanding aqueous self-assembly HPUs. In this paper, HPU was provided by dynamic urea bond-mediated polymerization (DUBMP), enabling careful evaluation their 1 H NMR, DLS, Cryo-TEM. HPUs containing single block per chain self-assemble into nanoaggregates ( R h ≈ 10 nm) in water up to its cloud-point temperature T cp ) 34 °C. On other hand, with more than one clusters below . case, solution behavior can be tuned mass. Increasing $$\overline{{\mathrm{M} }_{\mathrm{w}}}$$ M w ¯ from 4 19 kDa, similar form colloidally stable cluster suspensions = kDa) phase separate denser liquid aggregate–cluster 7 or highly viscous aggregate-network kDa). This type hierarchical aggregation reported first time is interesting Graphical abstract