(174f) Thermo-Mechanical and Flow Properties of Polymer Nanocomposites

The enhancement of structural and thermo-mechanical properties of polymer nanocomposites (PNCs) that has been observed is not only due to the addition of nanoparticles but also due to the role of the interface between polymer chains and nanoparticles. The thermo-mechanical and flow properties are investigated as a function of type and size distribution of nanoparticles and compared with the pure polymer melt. Firstly, the diffusivity of PGNPs in a homopolymer matrix is investigated as a function of graft length and grafting density, and is compared to that of bare nanoparticles with comparable effective size. Our results indicate that, in addition to the increase in the effective size of PGNPs due to grafting, the interpenetration of matrix polymers into the grafted layer plays an important role in the mobility of PGNPs. In systems consisting of both PGNPs and bare particles, the spatial arrangement of the bare particles was found to be having a significant influence on the mobility of PGNPs. The viscoelastic properties of PNCs as a function of binary size distribution of nanoparticles and nature of interactions between polymer-nanoparticles have been investigated. The local chain dynamics and the behavior of monomer segments at the polymer-particle interface have a strong influence on the viscoelastic behavior of polymer nanocomposites.