Poster Presentation 30
Structure, Dynamics, Rheology and Thermal Properties of Polymer
Grafted Nanoparticles Diluted with Free Polymer Chains
G. C. Louis,1,2 S. Ramakrishnan,1,2 S. Shanbhag3 and J. Che4
1
FAMU-FSU College of Chemical & Biomedical Engineering, 2525 Pottsdamer St, Tallahassee, FL 32310
2
National High Magnetic Field Laboratory, 1800 E Paul Dirac Dr., Tallahassee, FL 32310
3
Department of Scientific Computing, Florida State University, 488 Dirac Science Laboratory, Tallahassee, FL 32317
4
Air Force Research Laboratory, 2941 Hobson Way, Wright-Patterson AFB, Ohio 45433
Studies on the mechanical reinforcement of polymer composites with polymer grafted nanoparticles achieves
much scientific attention. Addition of polymer grafted nanoparticles can improve the dispersion and mechanical
properties of composites by tailoring the parameters like graft density (σ), graft chain length (Ng), graft (Mg) and
matrix (Mm) molecular weight. Unlike the previous reported studies, the present research work is dedicated to
explore the influence of dilution after the addition of free polymer chains on the structure, dynamics and
thermal properties of polymer grafted nanoparticles. In the present scenario, polystyrene (PS) grafted silica
nanoparticles were synthesized through surface initiated atom transfer radical polymerization (SI-ATRP). For
the studies, we varied the graft densities (0.33 chains/nm2 and 0.06 chains/nm2), graft molecular weight (28 kDa
and 55 kDa) of graft PS chains and free PS (10 kDa and 100 kDa) for a volume fraction, = 0.05. The graft
particle-free polymer blend was characterized by rheology, structure and morphology through grazing incidence
small angle x-ray scattering (GISAXS) and transmission electron microscopy (TEM), dynamics through x-ray
photon correlation spectroscopy (XPCS) and thermal properties through thermogravimetric analysis (TGA) and
differential scanning calorimetry (DSC).
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