Layers of Distinct Mobility in Densely Grafted Dendrimer Arborescent Polymer Hybrids

Melts of multiarm stars of 1,4-polybutadiene (dendrimer arborescent hybrids) with very high branching functionality (f) and small arm molar mass behave as jammed colloids and show distinct layers of segmental mobility. Three mobility layers were identified, comprising outer, intermediate, and near-core segments, all displaying a Vogel-Fulcher-Tammann temperature dependence. The respective glass temperatures increase as f(1/2). Our findings pave the way for further progress in this field by reconsidering previous theoretical treatments based on a single friction coefficient in hybrid nanoparticles such as densely grafted stars.

Automated summary

Multiarm stars of 1,4-polybutadiene with very high branching functionality exhibit distinct layers of segmental mobility, with outer, intermediate, and near-core segments displaying a Vogel-Fulcher-Tammann temperature dependence. The corresponding glass temperatures increase with the square root of the branching functionality, suggesting potential implications for theoretical treatments in hybrid nanoparticles.