Dynamic Differences in Loop-Grafted and Linear Polymer-Grafted Nanoparticles and their Interphases

The performance of polymer nanocomposites depends on polymer-nanoparticle compatibility and dispersion quality, as interfacial dynamics often deviate from bulk properties. We prepare loop-grafts on silica nanoparticles and characterize the success of looping and fractional loop formation in these complex hybrid systems. In this talk, I will present the synthesis of poly(methyl methacrylate) (PMMA) loop-grafted nanoparticles and how loop constrains influence the glass-transition temperature compared to that of linear-grafted ones. Next, I will discuss the all-PMMA composite results, where PMMA grafted particles are dispersed in PMMA matrix. The particle dispersion, rheological and thermal properties of samples with different molecular weights will be examined. Comparative studies with linear- and loop-grafted particle composites aim to uncover molecular dynamics via differential scanning calorimetry and broadband dielectric spectroscopy. These insights could inspire new strategies to design network forming interphases with tunable mechanical properties.