Extensional deformation of polymer melts

Extensional Response of the Pom-pom Model through Planar Contraction Flows for Branched Polymer Melts -part 2 Extensional Response of the Pom-pom Model through Planar Contraction Flows for Branched Polymer Melts -part 2

One objective of this study is to assess the influence of the number of dangling arms at each end of the pom-pom molecule on flow characteristics in a 4:1 planar rounded-corner contraction, where varying the number of arms affects the level of entanglement in the system. For these complex flows, we evaluate the major influence of extensional viscosity and Trouton ratio when comparing kinetic-ba...

Effect of a controlled pre-deformation history on extensional viscosity of dilute polymer solutions

We use a modified filament stretching rheometer to quantify the influence of a known controlled pre-shear history on the transient extensional viscosity of a dilute polymer solution. Two different types of pre-deformation are explored; both influence the subsequent stretching significantly, albeit in opposite ways. Small-amplitude oscillatory straining parallel to the direction of stretching en...

Properties of Confined Polymer Melts

Properties of simple models of confined linear polymer chains were studied by means of the Monte Carlo method. Model chains were built of united atoms (statistical segments) and embedded to a simple cubic lattice. Then polymers were put into a slit formed by two parallel impenetrable surfaces. Chain lengths were varied up to 800 segments and the density of the polymer melt was changed up to 0.5...

Extensional deformation of non-Newtonian liquid bridges

A numerical method for simulating the extensional dynamics of elongating ®laments of non-Newtonian ̄uids in a ®lament stretching rheometer is presented. The boundary element method, in conjunction with either the Oldroyd-B or the generalized multimode Upper-Convected Maxwell constitutive model, is used to calculate the transient evolution of the liquid interface, the applied force on the station...

Nanoparticle Dynamics in Polymer Melts